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Dziergowska, Katarzyna, Maja Wełna, Anna Szymczycha-Madeja, Jacek Chęcmanowski und Izabela Michalak. „Valorization of Cladophora glomerata Biomass and Obtained Bioproducts into Biostimulants of Plant Growth and as Sorbents (Biosorbents) of Metal Ions“. Molecules 26, Nr. 22 (16.11.2021): 6917. http://dx.doi.org/10.3390/molecules26226917.
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The aim of this study was to propose a complete approach for macroalgae biomass valorization into products useful for sustainable agriculture and environmental protection. In the first stage, the effects of macroalgal extracts and ZnO NPs (zinc oxide nanoparticles) on the germination and growth of radish were examined. Macroalgal extract was produced from freshwater macroalga, i.e., Cladophora glomerata by ultrasound assisted extraction (UAE). The extract was used to biosynthesize zinc oxide nanoparticles. In germination tests, extracts and solutions of ZnO NPs were applied on paper substrate before sowing. In the second stage, sorption properties of macroalga, post-extraction residue, and ZnO NPs to absorb Cr(III) ions were examined. In the germination tests, the highest values of hypocotyl length (the edible part of radish), i.e., 3.3 and 2.6 cm were obtained for 60 and 80% extract (among the tested concentrations 20, 40, 60, 80, and 100%) and 10 and 50 mg/L NPs, respectively. The highest sorption capacity of Cr(III) ions (344.8 mg/g) was obtained by both macroalga and post-extraction residue at a pH of 5 and initial Cr(III) ions concentration of 200 mg/L. This study proves that macroalgae and products based on them can be applied in both sustainable agriculture and wastewater treatment.
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Diansyah, Sufal, Ika Kusumawati und Fandi Hardinata. „INVENTARISASI JENIS-JENIS MAKROALGA DI PANTAI LHOK BUBON KECAMATAN SAMATIGA KABUPATEN ACEH BARAT“. JURNAL PERIKANAN TROPIS 5, Nr. 1 (01.04.2018): 93. http://dx.doi.org/10.35308/jpt.v5i1.1029.
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Indonesia has tropical marine waters rich in biodiversity. One of the organisms living in Indonesian coastal waters is macroalgae. Algae is one of the marine natural resources of economic value and has an ecological role as a high producer in the food chain and spawning place of marine biota. types of macroalgae have many benefits, ecologically and economically for the community. The ecological benefits of macroalgae are to provide habitat for several types of marine life such as species of crustaceans, mollusca, echinoderms, fish or other small algae. The economic value of macroalgae can be used as food, industrial raw materials, and materials for laboratories such as wet preserved materials, media materials for bacterial and fungal breeding to produce antibiotics, and there are also macroalgal types used as medicines. This study aims to identify and inventory the types of macroalgae in Lhok Bubon waters. The research method used is survey method, by identifying macroalga and inventory of macroalga contained in research location. The results of identification of macroalgae in Lhok Bubon waters are Caulerpa racemosa, Chaetomorpha anteninna, Halimeda micronesica, Boegesenia forbesi, Cladhopora hespetica, Halimeda discoidea, Chaetomorpha sp, Sargasum sp., Sargasum natans, Padina australis, Turbinaria ornata, Canistrocaptus crispatus, Asparagopsis taxiformis, Galaxaura filamentosa, dan Halymenia durvillei.
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Siqueiros Beltrones, D. A., und O. U. Hernández Almeida. „FLORÍSTICA DE DIATOMEAS EPIFITAS EN UN MANCHÓN DE MACROALGAS SUBTROPICALES“. CICIMAR Oceánides 21, Nr. 1-2 (31.12.2006): 11. http://dx.doi.org/10.37543/oceanides.v21i1-2.25.
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Se determinó la composición de especies de diatomeas epifitas en macroalgas de distintos taxa en una zona subtropical. Para ello, en un manchón ubicado en la playa Punta Roca Caimancito, B. C. S., se tomaron muestras de las macroalgas sobresalientes, en junio y diciembre de 2001, y abril, mayo y julio del 2002. Se identificaron 13 especies de macroalgas, de las cuales: Hydroclathrus clathrathus, Laurencia pacifica, L. johnstonii, Padina mexicana, P. caulescens y Codium spp. fueron las más conspicuas. El examen de la flora epifítica redituó 278 taxa de diatomeas, que es la máxima riqueza registrada para este tipo de sustrato, y de los cuales 44 son nuevos registros para la región. De los 75 géneros reconocidos de diatomeas, los mejor representados fueron: Mastogloia (25 especies), Amphora (23), Navicula (23), Nitzschia (22), Cocconeis (22), Lyrella (12) y Achnanthes (11). Los taxa más abundantes fueron Cocconeis disculus y C. dirupta. El número de taxa de diatomeas por especie hospedera también fue alto y varió entre 89 ( Codium spp.) y 143 ( L. pacifica), aunque las diferencias podrían deberse al número de especímenes procesados por especie de macroalga. Floristics of epiphytic diatoms in a patch of subtropical macroalgae The species composition of epiphytic diatom assemblages found on different taxa of subtropical macroalgae was determined. Samplings were carried out in a macroalgae bed located in Punta Roca Caimancito beach, B. C. S. in june and december 2001, and on april, may and july 2002, collecting the most frequent macroalgae taxa. The most conspicuous out of twelve macroalgae taxa were: Hydroclathrus clathrathus, Laurencia pacifica, L. johnstonii, Padina mexicana and P. caulescens. A total of 278 diatom taxa were recorded. This is the largest species richness recorded for this type of substrate, and out of which 44 are new records for the region. Out of 75 genera recognized the best represented were: Mastogloia (25 species), Amphora (23), Navicula (23), Nitzschia (22), Cocconeis (22), Lyrella (12) and Achnanthes (11). The most abundant taxa were Cocconeis disculus and C. dirupta. The number of diatom taxa per macroalgae species was also high, ranging from 89 (Codium spp.) to 143 (L. pacifica). Albeit, this difference could be attributed to the number of specimens collected per macroalga species.
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Siqueiros Beltrones, D. A., und O. U. Hernández Almeida. „FLORÍSTICA DE DIATOMEAS EPIFITAS EN UN MANCHÓN DE MACROALGAS SUBTROPICALES“. CICIMAR Oceánides 21, Nr. 1-2 (31.12.2006): 11. http://dx.doi.org/10.37543/oceanides.v21i1-2.25.
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Se determinó la composición de especies de diatomeas epifitas en macroalgas de distintos taxa en una zona subtropical. Para ello, en un manchón ubicado en la playa Punta Roca Caimancito, B. C. S., se tomaron muestras de las macroalgas sobresalientes, en junio y diciembre de 2001, y abril, mayo y julio del 2002. Se identificaron 13 especies de macroalgas, de las cuales: Hydroclathrus clathrathus, Laurencia pacifica, L. johnstonii, Padina mexicana, P. caulescens y Codium spp. fueron las más conspicuas. El examen de la flora epifítica redituó 278 taxa de diatomeas, que es la máxima riqueza registrada para este tipo de sustrato, y de los cuales 44 son nuevos registros para la región. De los 75 géneros reconocidos de diatomeas, los mejor representados fueron: Mastogloia (25 especies), Amphora (23), Navicula (23), Nitzschia (22), Cocconeis (22), Lyrella (12) y Achnanthes (11). Los taxa más abundantes fueron Cocconeis disculus y C. dirupta. El número de taxa de diatomeas por especie hospedera también fue alto y varió entre 89 ( Codium spp.) y 143 ( L. pacifica), aunque las diferencias podrían deberse al número de especímenes procesados por especie de macroalga. Floristics of epiphytic diatoms in a patch of subtropical macroalgae The species composition of epiphytic diatom assemblages found on different taxa of subtropical macroalgae was determined. Samplings were carried out in a macroalgae bed located in Punta Roca Caimancito beach, B. C. S. in june and december 2001, and on april, may and july 2002, collecting the most frequent macroalgae taxa. The most conspicuous out of twelve macroalgae taxa were: Hydroclathrus clathrathus, Laurencia pacifica, L. johnstonii, Padina mexicana and P. caulescens. A total of 278 diatom taxa were recorded. This is the largest species richness recorded for this type of substrate, and out of which 44 are new records for the region. Out of 75 genera recognized the best represented were: Mastogloia (25 species), Amphora (23), Navicula (23), Nitzschia (22), Cocconeis (22), Lyrella (12) and Achnanthes (11). The most abundant taxa were Cocconeis disculus and C. dirupta. The number of diatom taxa per macroalgae species was also high, ranging from 89 (Codium spp.) to 143 (L. pacifica). Albeit, this difference could be attributed to the number of specimens collected per macroalga species.
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Bauman, Andrew G., Jovena C. L. Seah, Fraser A. Januchowski-Hartley, Andrew S. Hoey, Jenny Fong und Peter A. Todd. „Fear effects associated with predator presence and habitat structure interact to alter herbivory on coral reefs“. Biology Letters 15, Nr. 10 (Oktober 2019): 20190409. http://dx.doi.org/10.1098/rsbl.2019.0409.
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Non-consumptive fear effects are an important determinant of foraging decisions by consumers across a range of ecosystems. However, how fear effects associated with the presence of predators interact with those associated with habitat structure remain unclear. Here, we used predator fish models ( Plectropomus leopardus ) and experimental patches of the macroalga Sargassum ilicifolium of varying densities to investigate how predator- and habitat-associated fear effects influence herbivory on coral reefs. We found the removal of macroalgal biomass (i.e. herbivory) was shaped by the interaction between predator- and habitat-associated fear effects. Rates of macroalgal removal declined with increasing macroalgal density, likely due to increased visual occlusion by denser macroalgae patches and reduced ability of herbivorous fishes to detect the predators. The presence of the predator model reduced herbivory within low macroalgal density plots, but not within medium- and high-density macroalgal plots. Our results suggest that fear effects due to predator presence were greatest at low macroalgal density, yet these effects were lost at higher densities possibly due to greater predation risk associated with habitat structure and/or the inability of herbivorous fishes to detect the predator model.
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Strong, James A., Christine A. Maggs und Mark P. Johnson. „The extent of grazing release from epiphytism forSargassum muticum(Phaeophyceae) within the invaded range“. Journal of the Marine Biological Association of the United Kingdom 89, Nr. 2 (März 2009): 303–14. http://dx.doi.org/10.1017/s0025315408003226.
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The overall biotic pressure on a newly introduced species may be less than that experienced within its native range, facilitating invasion. The brown algaSargassum muticum(Yendo) Fensholt is a conspicuous and successful invasive species originally from Japan and China. We comparedS. muticumand native macroalgae with respect to the biotic pressures of mesoherbivore grazing and ectocarpoid fouling. In Strangford Lough, Northern Ireland,S. muticumthalli were as heavily overgrown with seasonal blooms of epiphytic algae as native macroalgal species were. The herbivorous amphipodDexamine spinosawas much more abundant onS. muticumthan on any native macroalga. When cultured with this amphipod,S. muticumlost more tissue than three native macroalgae,Saccharina latissima(Linnaeus) Laneet al.,Halidrys siliquosa(Linnaeus) Lyngbye andFucus serratusLinnaeus.Sargassum muticumcultured with both ectocarpoid fouling and amphipods showed a severe impact, consistent with our previous findings of large declines in the density ofS. muticumobserved in the field during the peak of fouling. Despite being a recent introduction into the macroalgal community in Strangford Lough,S. muticumappears to be under biotic pressure at least equal to that on native species, suggesting that release from grazing and epiphytism does not contribute to the invasiveness of this species in Strangford Lough.
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Hagar Kamal Ahmed, Samia Heneidak, Abdel-Hamied Mohammed Rasmey und Gihan Ahmed El Shoubaky. „Fatty acids composition and profiling of nine abundant marine Macroalgae, Egypt“. GSC Biological and Pharmaceutical Sciences 24, Nr. 2 (30.08.2023): 099–109. http://dx.doi.org/10.30574/gscbps.2023.24.2.0311.
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This study analyzed the fatty acids composition and their profile qualitatively and quantitatively of the nine abundant macroalgal specimens collecting from Egyptian coasts. GC mass analysis identified 23 types, including 13 of saturated fatty acids (SFA) and 10 of monounsaturated fatty acids (MUSFA). SFA dominated with 78%, while MUFAs had 22%, and UFAs were negligible at 0.01%. MUSFA oleic acid (omega-9) was present in all species except green macroalgae Galaxura rugosa and Ulva fasciata, replaced by MUSFA linoleic acid (omega-6). Oleic acid methyl ester (omega-9) was registered in all the studied species, except red Hypnea cornuta & Jania rubens, and brown Hormophysa cuneiformis. Chlorophyta registered 35% of the fatty acid composition, followed by Rhodophyta (33%) and Phaeophyta (32%). Major SFAs were palmitic acid glycidyl ester, oleic acid glycidyl ester and palmitic methyl ester, comprising over half of total fatty acids. Red and brown macroalgae were richer in palmitic and oleic glycidyl esters, while green macroalgae had more palmitic methyl ester. Linoleic acid, nonadecylic acid, elaidic acid methyl ester, linoleic acid methyl, behenic acid, pentacosylic acid, palmitic acid, and trans-palmitoleic acid were exclusively identified in Chlorophyta. Lacceroic acid was distinguished in Rhodophyta, whereas pelargonic acid just appeared in brown alga Turbinaria turbinata. The maximum values of fatty acids were recorded in the green macroalga Caulerpa racemosa while reed macroalga Hypnea cornuta.was the minimum one. The research sheds light on the fatty acid composition and its potential implications for human health and nutrition.
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Pederson, Hugh G., und Craig R. Johnson. „Growth and age structure of sea urchins (Heliocidaris erythrogramma) in complex barrens and native macroalgal beds in eastern Tasmania“. ICES Journal of Marine Science 65, Nr. 1 (20.11.2007): 1–11. http://dx.doi.org/10.1093/icesjms/fsm168.
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Abstract Pederson, H. G., and Johnson, C. R. 2008. Growth and age structure of sea urchins (Heliocidaris erythrogramma) in complex barrens and native macroalgal beds in eastern Tasmania. – ICES Journal of Marine Science, 65: 1–11. The formation of small-scale barrens of sea urchins on the east coast of Tasmania allows for direct comparison of the growth rates and age structures of sea urchin populations in barrens and habitats dominated by native macroalgae. However, such barrens are atypical of any previously described in temperate regions worldwide mainly because of the establishment and seasonal colonization by the introduced macroalga Undaria pinnatifida. Growth models were fitted to sea urchin (Heliocidaris erythrogramma) data, based on tag-recapture information from two distinct community types, a native macroalgal bed and a sea urchin barren colonized by U. pinnatifida. Despite the distinct contrast in habitats, size-at-age relationships and age frequency distributions were not significantly different between the two populations. However, the relationship between jaw length and test diameters was significantly different between populations, sea urchins in barrens possessing larger jaws relative to conspecifics of similar test diameter in native macroalgal habitats. It is proposed that the growth of sea urchins on barrens is not adversely affected by the loss of native macroalgae in the presence of U. pinnatifida. However, sea urchins display a level of resource limitation in barrens because of differences in the relationships of sea urchin morphometrics.
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Martins, Nuno Tavares, Maria Alves Napolitani, João Pedro Guimarães Machado, Yocie Yoneshigue-Valentin und Vinícius Peruzzi Oliveira. „Competitive interactions in marine macroalgae: an analysis of the literature by boolean operators“. OBSERVATÓRIO DE LA ECONOMÍA LATINOAMERICANA 21, Nr. 8 (23.08.2023): 9675–700. http://dx.doi.org/10.55905/oelv21n8-099.
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Marine macroalgae are the ecological basis in most of the marine environments. Light and space, added to nutrients rank among the most important elements influencing their distribution in the marine environment. Thus, this work aimed to identify and quantify the current and past literature on marine macroalgae competitive interactions and to address the main questions on the competitive patterns and their consequences for community structure, as well as to compare the competitive capacity among different macroalgal taxa. To do so, a quantitative literature search was performed based on papers published from 1934 to 2022, using the following combination of Boolean operators and keywords: “Seaweed OR macroalgae OR macroalga, AND ecolog *, AND competiti *”. A total of 173 articles were then compiled and selected. Our results compiled 124 different macroalgae genera with 546 studied taxa on competition processes. Among them, 38% of the compiled taxa belonged to Ochrophyta; 31% Rhodophyta and 18% Chlorophyta. The most-studied genera were Dictyota (6.8%), Sargassum (6.8%), Ulva (4.9%) and Lobophora (4.2%). Space was the most analyzed limiting factor (40.9%), followed by papers related to herbivory (26.1%), and lastly by competition over nutrients (15.1%). Our results, while attesting to the overarching complexity of competitive interactions, nevertheless allowed us to summarize the current knowledge regarding the patterns of competitive interactions on macroalgae, thus providing a useful synthesis for new perspectives on marine systems and research.
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Cordova, Muhammad Reza, und Ahmad Muhtadi. „Skrining Kemampuan Absorpsi Merkuri pada Makroalga Cokelat Hormophysa triquetra dan Makroalga Merah Gracilaria salicornia dari Pulau Pari“. Oseanologi dan Limnologi di Indonesia 2, Nr. 3 (28.12.2017): 25. http://dx.doi.org/10.14203/oldi.2017.v2i3.93.
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<strong>Screening of Mercury Absorption in Brown Macroalgae Hormophysa triquetra and Red Macroalgae Gracilaria salicornia from Pari Island.</strong> Macroalgae or seaweed has good absorptive capacity against all substances present in the aquatic environment, including mercury (Hg). The purpose of this study was to determine mercury content in brown macroalga <em>Hormophysa triquetra</em> and red macroalga <em>Gracilaria salicornia</em> and also on sediment and then assess the potential of both types of macroalgae as mercury bioaccumulator. Samples of macroalgae and sediment were taken from the northern, eastern, southern, and western regions of Pari Island, Seribu Archipelago in April 2016, analyzed by Mercury Analyzer NIC MA-3000. The results of this study indicated the mercury content in red macroalgae was higher than brown macroalgae. Mercury content in macroalgae from Pari Island waters was in the range of 21.50 ± 9.59 μg/kg (brown macroalga) and 41.45 ± 14.00 μg/kg (macroalgae red). The complexity of the functional groups makes the mercury content higher in the red macroalgae than in the brown macroalgae. The ability of mercury accumulation makes these macroalgae species potential to become bioaccumulator.
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Bambaranda, B. V. A. S. Manori, Takuji W. Tsusaka, Anong Chirapart, Krishna R. Salin und Nophea Sasaki. „Capacity of Caulerpa lentillifera in the Removal of Fish Culture Effluent in a Recirculating Aquaculture System“. Processes 7, Nr. 7 (10.07.2019): 440. http://dx.doi.org/10.3390/pr7070440.
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Aquaculture is one of the fastest growing food producing industries in the world. Aquaculture effluent contains high concentrations of inorganic nutrients. Reduction of these inorganic nutrients in aquaculture effluent is crucial for fulfilling the effluent standards or reuse of aquaculture effluent. This study investigated the effective use of green macroalga Caulerpa lentillifera as a bioremediatory species for nutrient removal from aquaculture effluent by conducting an on-station experiment and measurements. The effluent of a fish culture unit was circulated through a macroalgal culture unit every four days for a total of 60 days, allowing 15 circulations. Concentrations of inorganic nutrients (NO2−-N, NO3−-N, NH3-N, and PO43−) were measured in the integrated system consisting of a fish unit, settling unit, macroalgal unit and extra tank for water circulation in triplicates. Multiple linear regression analysis revealed that the application of the bioremediation system led to a significant reduction in nutrient concentrations within one day, and slightly further in the following two days. On average over the 15 circulations, the first one day of application decreased the concentrations of NO2−-N, NO3−-N, NH3-N, and PO43− by 0.247 mg/L, 81.6 mg/L, 0.682 mg/L, and 0.352 mg/L, respectively. Furthermore, the C:N ratio of macroalgae decreased during the 60-day application period, providing evidence of the nutrient uptake by macroalgae. Based on the European Union (EU) standard and quality criteria of France and the Joint FAO/WHO Expert Committee (JFWEC), the macroalgae grown in the integrated system were at the safe level for human consumption in terms of contents of Cd, Pb, and As. The results of our study imply that recirculating aquaculture systems utilizing C. lentillifera for biofiltration have the potential for effective treatment of aquaculture effluent integrating fish and macroalgae production.
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Lee, Hojun, Stephen Depuydt, Kisik Shin, Jonas De Saeger, Taejun Han und Jihae Park. „Interactive Effects of Blue Light and Water Turbulence on the Growth of the Green Macroalga Ulva australis (Chlorophyta)“. Plants 13, Nr. 2 (17.01.2024): 266. http://dx.doi.org/10.3390/plants13020266.
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Macroalgal growth and yield are key to sustainable aquaculture. Although light and water turbulence are two important factors that affect algal productivity, research on their interaction is limited. Therefore, in this study, we investigated the effects of different wavelengths of light and the presence or absence of water turbulence on the growth of the green macroalga Ulva australis. Water turbulence was found to enhance the growth of U. australis irrespective of photosynthetic performance, but only in blue light cultures. The quantum dose of blue light required to induce 50% growth promotion was 1.02 mol m−2, which is comparable to the reported values for cryptochrome-mediated effects in other macroalgae. The combined effect of blue light and water turbulence led to the accumulation of photosynthesis-related proteins that support plastid differentiation and facilitate efficient photosynthesis and growth. Our findings thus highlight the potential of harnessing blue light and water turbulence to maximise macroalgal cultivation for sustainable and profitable algal aquaculture.
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Gadhi, Alaa Aref, Mohsen M. El-Sherbiny, Abdul Mohsin Al-Sofynai, Mohammad Abdulaziz Ba-Akdah und Sathianeson Satheesh. „Antimicrofouling activities of marine macroalga Dictyota dichotoma from the Red Sea“. Journal of Agricultural and Marine Sciences [JAMS] 23 (10.01.2019): 58. http://dx.doi.org/10.24200/jams.vol23iss0pp58-67.
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Introduction. Marine organisms produce a variety of secondary metabolites mainly for achieving the defence against the competitors and predators. These compounds could be used as natural product antifoulants for the management of biofouling growth on marine structures. Objectives. To understand the antifouling defence strategies of marine macroalgae collected from the Red Sea. Methodology. The macroalga Dictyota dichotoma was collected from the Obhur Creek of Red Sea, Saudi Arabia and extracted using methanol. Surface and total extraction methods were performed and tested against a bacterial strain isolated from the microfouling assemblage. Results. The extracts obtained from the macroalgal samples have strong antibacterial and antibiofilm activities against the bacterial strain isolated from the marine microfouling assemblage. The total extracts showed strong bacterial growth inhibitory activities in culture plate method. In microtitre plate assay, surface extract showed strong biofilm inhibitory activity. GC-MS analysis indicated considerable variations in the metabolic profile of the surface and total extracts. Conclusion. This study revealed the importance of surface-associated compounds in antifouling defence mechanism of the marine macroalgae.
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Gadhi, Alaa Aref, Mohsen M. El-Sherbiny, Abdul Mohsin Al-Sofynai, Mohammad Abdulaziz Ba-Akdah und Sathianeson Satheesh. „Antimicrofouling activities of marine macroalga Dictyota dichotoma from the Red Sea“. Journal of Agricultural and Marine Sciences [JAMS] 23, Nr. 1 (10.01.2019): 58. http://dx.doi.org/10.24200/jams.vol23iss1pp58-67.
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Introduction. Marine organisms produce a variety of secondary metabolites mainly for achieving the defence against the competitors and predators. These compounds could be used as natural product antifoulants for the management of biofouling growth on marine structures. Objectives. To understand the antifouling defence strategies of marine macroalgae collected from the Red Sea. Methodology. The macroalga Dictyota dichotoma was collected from the Obhur Creek of Red Sea, Saudi Arabia and extracted using methanol. Surface and total extraction methods were performed and tested against a bacterial strain isolated from the microfouling assemblage. Results. The extracts obtained from the macroalgal samples have strong antibacterial and antibiofilm activities against the bacterial strain isolated from the marine microfouling assemblage. The total extracts showed strong bacterial growth inhibitory activities in culture plate method. In microtitre plate assay, surface extract showed strong biofilm inhibitory activity. GC-MS analysis indicated considerable variations in the metabolic profile of the surface and total extracts. Conclusion. This study revealed the importance of surface-associated compounds in antifouling defence mechanism of the marine macroalgae.
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Tukai, R., W. A. Maher, I. J. McNaught, M. J. Ellwood und M. Coleman. „Occurrence and chemical form of arsenic in marine macroalgae from the east coast of Australia“. Marine and Freshwater Research 53, Nr. 6 (2002): 971. http://dx.doi.org/10.1071/mf01230.
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Arsenic concentrations were measured in thirteen macroalgal species from Sydney, Australia. Brown macroalgae contained, on average, more arsenic (range, mean ± s.e.: 5–173 μg g–1, 39 ± 4 μg g–1) than either green (0.12–30.2 μg g–1, 10.7 ± 0.7 μg g–1) or red macroalgae (0.11–16.9 μg g–1, 4.3 ± 0.3 μg g–1). Despite the overlap in arsenic concentrations between different macroalgal species, inter-species arsenic variation was apparent with arsenic concentrations following the order brown > green > red macroalgal species. It was concluded that the main contribution to the variation in arsenic concentration was from natural variability expected to occur between individuals of any species as a result of physiological differences.Most of the arsenic compounds in macroalgae (70–108%) could be extracted using methanol/water mixtures, with 38–95% of the arsenic compounds present in characterizable forms. All macroalgal species contained arsenoribosides (9–99%). The distribution of arsenoribosides followed a general pattern; glycerol-arsenoriboside and phosphate-arsenoriboside were common to all macroalgal species. Sulfonate-arsenoriboside and sulfate-arsenoriboside were found in brown macroalgal species and one red macroalgal species. Six macroalgal species contained high concentrations of inorganic arsenic (14.2–62.9%) and four species contained high concentrations of dimethylarsinic acid (13.3–41.1%). The variation in the distribution of arsenic compounds in marine macroalgal species appears to be related to taxonomic differences in storage and structural polysaccharides.
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Clements, Cody S., und Mark E. Hay. „Competitors as accomplices: seaweed competitors hide corals from predatory sea stars“. Proceedings of the Royal Society B: Biological Sciences 282, Nr. 1814 (07.09.2015): 20150714. http://dx.doi.org/10.1098/rspb.2015.0714.
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Indirect biotic effects arising from multispecies interactions can alter the structure and function of ecological communities—often in surprising ways that can vary in direction and magnitude. On Pacific coral reefs, predation by the crown-of-thorns sea star, Acanthaster planci , is associated with broad-scale losses of coral cover and increases of macroalgal cover. Macroalgal blooms increase coral–macroalgal competition and can generate further coral decline. However, using a combination of manipulative field experiments and observations, we demonstrate that macroalgae, such as Sargassum polycystum , produce associational refuges for corals and dramatically reduce their consumption by Acanthaster . Thus, as Acanthaster densities increase, macroalgae can become coral mutualists, despite being competitors that significantly suppress coral growth. Field feeding experiments revealed that the protective effects of macroalgae were strong enough to cause Acanthaster to consume low-preference corals instead of high-preference corals surrounded by macroalgae. This highlights the context-dependent nature of coral–algal interactions when consumers are common. Macroalgal creation of associational refuges from Acanthaster predation may have important implications for the structure, function and resilience of reef communities subject to an increasing number of biotic disturbances.
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Farobie, Obie, Novi Syaftika, Edy Hartulistiyoso, Apip Amrullah, Asep Bayu, Navid R. Moheimani, Yukihiko Matsumura und Surachai Karnjanakom. „The Potential of Sustainable Biogas Production from Macroalgae in Indonesia“. IOP Conference Series: Earth and Environmental Science 1038, Nr. 1 (01.06.2022): 012020. http://dx.doi.org/10.1088/1755-1315/1038/1/012020.
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Abstract Indonesia is the second world’s major macroalgae producer after China, contributing to 28% of the global macroalgae production. Indonesia increased its macroalgae farming output from less than 4 million tons in 2010 to over 9.9 million tons in 2019. It is expected to continue rising to 13 million tons by 2024. The contribution of macroalgal products is quite significant, 60.7% of the total national aquaculture production. To achieve sustainable energy development goals in many developing countries, including Indonesia, biomass to energy technology such as the production of biogas form macroalgae has been considered one of the best options. Therefore, we aim to investigate the potential application of biomass to energy technology via the production of biogas from macroalgae as an alternative source of local power generation. Indonesia’s energy mix and several issues regarding macroalgae production are comprehensively reviewed. Additionally, we also discussed the process of macroalgal biogas production.
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Turupadang, Welem. „A Comparison of Morphological Features Between Freshly Collected and Silica Beads-Dehydrated Macroalgal Samples in The Central Great Barrier Reef, Australia“. Jurnal Kelautan: Indonesian Journal of Marine Science and Technology 15, Nr. 2 (02.09.2022): 153–59. http://dx.doi.org/10.21107/jk.v15i2.14374.
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ABSTRACTAccurate and reliable identification of macroalgae has a crucial role in a range of research relating to the interaction and function of macroalgae in reef ecosystems. The dependency on identifying macroalgae on fresh samples places severe constraints on conducting this research leading to potential biases due to the selection of sites either close to shore or in the vicinity of fully equipped research stations. Therefore, this study aimed to determine if could reliably be used silica bead-dehydrated samples to identify genera characteristics that are only visible in sectioned material. Fresh macroalgal samples were collected at Nelly Bay, compared to Magnetic Island. Materials and sections were to previously collect macroalgal samples and sections dehydrated in silica beads while in the field and reconstituted in filtered seawater for identification. Each sample was identified using histological sections supported with visual tools (photograph, herbaria). In this study, macroalgal identified samples from all species to genus with characteristic features recognizable within both fresh and reconstituted samples. No artifacts were present in reconstituted macroalgal samples compared to freshly collected samples. Therefore, it is suggested that using silica beads as a preservation field method for collecting and identifying macroalgal samples is a suitable and accurate alternative method to the use of fresh samples, which eliminates the time and distance constraints associated with fresh samples.Keywords: Great Barrier Reef, Histological sectioning, Macroalgae identification, Silica-beads preservation, Reconstituted
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Raven, John. „Blue carbon: past, present and future, with emphasis on macroalgae“. Biology Letters 14, Nr. 10 (Oktober 2018): 20180336. http://dx.doi.org/10.1098/rsbl.2018.0336.
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Blue carbon did not originally include macroalgal ecosystems; however evidence is mounting that macroalgal ecosystems function in marine carbon sequestration. The great majority of present day marine macroalgal net primary productivity (NPP) involves haptophytic algae on eroding shores. For these organisms the long-term storage of particulate organic carbon involves export from the site of production of biomass that has evaded parasites and grazers, and that some of the exported biomass is sedimented and stored rather than being mineralized en route by detritivores (microbes and fauna). Export from eroding shores, and subsequent storage, of haptophytic marine macroalgal particulate organic carbon could have started by 1.6 Ga. Storage on depositing shores close to the site of NPP by rhizophytic macroalgae and then by rhizophytic coastal seagrasses, tidal marshes and mangroves began not less than 209 Ma ago. Future increases in surface ocean temperatures may bring tropical marine macroalgae to their upper temperature limit, while temperate marine macroalgae will migrate poleward, in both cases assuming that temperature increases faster than genetic adaptation to higher temperature. Increased CO 2 in the surface ocean will generally favour uncalcified over calcified marine macroalgae. This results in decreased CO 2 release from decreased calcification, as well as decreased ballasting by CaCO 3 of exported particulate organic carbon resulting in decreasing sedimentation. While much more work is needed, the available information suggests that macroalgae play a significant role in marine organic carbon storage.
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Kamal, Marwa, Neveen Abdel-Raouf, Khairiah Alwutayd, Hamada AbdElgawad, Mohamed Sayed Abdelhameed, Ola Hammouda und Khaled N. M. Elsayed. „Seasonal Changes in the Biochemical Composition of Dominant Macroalgal Species along the Egyptian Red Sea Shore“. Biology 12, Nr. 3 (07.03.2023): 411. http://dx.doi.org/10.3390/biology12030411.
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Macroalgae are significant biological resources in coastal marine ecosystems. Seasonality influences macroalgae biochemical characteristics, which consequentially affect their ecological and economic values. Here, macroalgae were surveyed from summer 2017 to spring 2018 at three sites at 7 km (south) from El Qusier, 52 km (north) from Marsa Alam and 70 km (south) from Safaga along the Red Sea coast, Egypt. Across all the macroalgae collected, Caulerpa prolifera (green macroalgae), Acanthophora spicifera (red macroalgae) and Cystoseira myrica, Cystoseira trinodis and Turbinaria ornata (brown macroalgae) were the most dominant macroalgal species. These macroalgae were identified at morphological and molecular (18s rRNA) levels. Then, the seasonal variations in macroalgal minerals and biochemical composition were quantified to determine the apt period for harvesting based on the nutritional requirements for commercial utilizations. The chemical composition of macroalgae proved the species and seasonal variation. For instance, minerals were more accumulated in macroalgae C. prolifera, A. spicifera and T. ornata in the winter season, but they were accumulated in both C. myrica and C. trinodis in the summer season. Total sugars, amino acids, fatty acids and phenolic contents were higher in the summer season. Accordingly, macroalgae collected during the summer can be used as food and animal feed. Overall, we suggest the harvesting of macroalgae for different nutrients and metabolites in the respective seasons.
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Damare, Varada S., Estha T. Fernandes, Anjita A. Naik, Svetlana P. Cardozo, Vilda Borges und Pramod Phuge. „Occurrence of thraustochytrids: the fungoid protists vis-a-vis marine macroalgae (seaweeds) along the coast of Goa, India“. Botanica Marina 64, Nr. 6 (15.11.2021): 461–75. http://dx.doi.org/10.1515/bot-2021-0052.
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Abstract Thraustochytrids are fungoid protists ubiquitous in the marine environment and found to be associated with decaying macroalgae. Not much is known about their association with living macroalgae. Hence in the present study, different macroalgal samples were collected from various beaches of Goa to examine the presence of thraustochytrids during a four-year-long study. Brown, red and green algae were found to be substrata of thraustochytrids. Thraustochytrids were isolated on pine pollen baiting from 17 to 58% of the specimens. Thraustochytrids isolated from various macroalgae belonged to the genera Oblongichytrium, Schizochytrium, Ulkenia, and Thraustochytrium. Labyrinthula sp. was also found once on the green alga Bryopsis hypnoides. These were generally found during dry seasons rather than in monsoons. The seasonal occurrence of thraustochytrids was found to be associated with temporal variation in macroalgal diversity. The statistical analysis supported individual or interactive effects of both factors viz, seasons and macroalgal diversity, on the occurrence of thraustochytrids. Thraustochytrids were also isolated from seawater adjoining macroalgae and from estuarine water at all times of the year. Oblongichytrium sp. was isolated from the green alga Ulva compressa and Anjuna seawater samples at the same time, thus indicating that thraustochytrids from seawater could inhabit the macroalgae.
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Al-Khaldi, Wejdan Ahmed, Lafi Al Solami und Sathianeson Satheesh. „Effects of copper and cadmium on physiology and antifouling defense of the marine macroalga Ulva reticulata“. Oceanological and Hydrobiological Studies 50, Nr. 2 (01.06.2021): 184–97. http://dx.doi.org/10.2478/oandhs-2021-0017.
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Abstract Heavy metals are major stressors for benthic macroalgal communities in marine ecosystems. In this study, the effects of copper and cadmium on some physiological parameters along with antifouling defense of the marine macroalga Ulva reticulata were assessed under laboratory conditions. Macroalgal samples were treated with three concentrations (1 mg l−1, 3 mg l−1 and 5 mg l−1) of copper and cadmium for 2 and 7 days. After treatment, algal samples were analyzed for chlorophyll-a, carotenoid, total polyphenol and total antioxidant capacity. Also, algal extracts were tested against biofilm-forming bacteria strains to understand differences in antifouling activity. The results indicated that exposure of U. reticulata to copper and cadmium, on the one hand, induced protective mechanisms such as total phenol production and antioxidant capacity against metal stress and, on the other hand, reduced photosynthesis. While the extract obtained from control algal samples showed a strong inhibitory effect on the growth of biofilm-forming bacteria, treatment with heavy metals resulted in reduced antibiofilm activity. In general, the results revealed that exposure of macroalgae to heavy metals can affect antifouling defense traits in addition to changes in photosynthetic pigment content.
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Garcia-Vaquero, Marco, Gaurav Rajauria, Marta Miranda, Torres Sweeney, Marta Lopez-Alonso und John O’Doherty. „Seasonal Variation of the Proximate Composition, Mineral Content, Fatty Acid Profiles and Other Phytochemical Constituents of Selected Brown Macroalgae“. Marine Drugs 19, Nr. 4 (04.04.2021): 204. http://dx.doi.org/10.3390/md19040204.
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The main objective was to determine the chemical, phytochemical, fatty acid and mineral profiles of three commercially relevant brown macroalgae (Laminaria digitata, Laminaria hyperborea and Ascophyllum nodosum) collected each season for two years off the west coast of Ireland. All the chemical, phytochemical, fatty acid and minerals analysed varied significantly depending on the macroalgal species, season and year of collection. Overall, the protein contents of macroalgae were negatively correlated with carbohydrate content. Protein (2–11%) was at its highest during winter and/or spring, decreasing to a minimum during summer and/or autumn. The three macroalgal species analysed in this study had clearly differentiated fatty acid profiles. The concentration of fatty acids was higher in A. nodosum compared with both Laminaria species. The mineral profile of the three macroalgal species was rich in essential metals, particularly Ca, Mg and P, while the levels of I were approximately 9- to 10-fold higher in both Laminaria spp. compared with A. nodosum. The levels of toxic metals (Cd, Hg and Pb) in all the macroalgal species studied were low in the current study; while the levels of total As were high (49–64 mg/kg DW macroalgae) compared with previous reports.
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Galindo, Ana, Diana B. Reis, Inés Rodríguez, José A. Pérez, Beatriz Abdul-Jalbar, Rafael Zárate, Nuno Nunes, Miguel A. A. Pinheiro de Carvalho, Nieves G. Acosta und Covadonga Rodríguez. „Lipid characterization of 14 macroalgal species from Madeira Archipelago: implications for animal and human nutrition“. Botanica Marina 65, Nr. 1 (10.12.2021): 51–67. http://dx.doi.org/10.1515/bot-2021-0024.
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Abstract The lipid and fatty acid profiles of 14 marine macroalgal species from the Madeira Archipelago, including two green (Ulvales and Dasycladales), three red (Corallinales, Bonnemaisoniales, and Ceramiales) and nine brown (Fucales, Dictyotales, and Sphacelariales) species were characterised in order to determine their potential use for animal and human nutrition. The total lipid content of species analysed was generally low, varying from 0.2 to 5.2% of dry weight. All species presented an omega 6/omega 3 (n-6/n-3) ratio lower than 10, as recommended by the World Health Organization for proper human health. Polyunsaturated fatty acids (PUFA), including linoleic acid and alpha-linolenic acid were exceptionally high in the green macroalga Ulva sp. Red macroalgae were rich in n-3 long-chain PUFA, particularly Asparagopsis taxiformis, which contained 6.6% of docosahexaenoic acid, and Halopithys incurva with 9.3% of eicosapentaenoic acid. Within Ochrophyta, Dictyota dichotoma is an interesting source of n-3 PUFA due to its high stearidonic acid proportion (8.0%). In addition, H. incurva contained a high proportion of both mono- and digalactosyldiacylglycerols. According to their lipid profiles, most macroalgae analysed might be considered of particular interest for their potential exploitation for human nutrition and livestock and aquaculture production.
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Fabricius, Katharina E., Kerryn Crossman, Michelle Jonker, Mathieu Mongin und Angus Thompson. „Macroalgal cover on coral reefs: Spatial and environmental predictors, and decadal trends in the Great Barrier Reef“. PLOS ONE 18, Nr. 1 (20.01.2023): e0279699. http://dx.doi.org/10.1371/journal.pone.0279699.
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Macroalgae are an important component of coral reef ecosystems. We identified spatial patterns, environmental drivers and long-term trends of total cover of upright fleshy and calcareous coral reef inhabiting macroalgae in the Great Barrier Reef. The spatial study comprised of one-off surveys of 1257 sites (latitude 11–24°S, coastal to offshore, 0–18 m depth), while the temporal trends analysis was based on 26 years of long-term monitoring data from 93 reefs. Environmental predictors were obtained from in situ data and from the coupled hydrodynamic-biochemical model eReefs. Macroalgae dominated the benthos (≥50% cover) on at least one site of 40.4% of surveyed inshore reefs. Spatially, macroalgal cover increased steeply towards the coast, with latitude away from the equator, and towards shallow (≤3 m) depth. Environmental conditions associated with macroalgal dominance were: high tidal range, wave exposure and irradiance, and low aragonite saturation state, Secchi depth, total alkalinity and temperature. Evidence of space competition between macroalgal cover and hard coral cover was restricted to shallow inshore sites. Temporally, macroalgal cover on inshore and mid-shelf reefs showed some fluctuations, but unlike hard corals they showed no systematic trends. Our extensive empirical data may serve to parameterize ecosystem models, and to refine reef condition indices based on macroalgal data for Pacific coral reefs.
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Schram, Julie B., Margaret O. Amsler, Aaron W. E. Galloway, Charles D. Amsler und James B. McClintock. „Fatty acid trophic transfer of Antarctic algae to a sympatric amphipod consumer“. Antarctic Science 31, Nr. 6 (22.10.2019): 315–16. http://dx.doi.org/10.1017/s0954102019000397.
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The shallow benthos along the western Antarctic Peninsula supports brown macroalgal forests with dense amphipod assemblages, commonly including Gondogeneia antarctica (Amsler et al. 2014). Gondogeneia antarctica and most other amphipods are chemically deterred from consuming the macroalgae (Amsler et al. 2014). They primarily consume diatoms, other microalgae, filamentous macroalgae and a few undefended macroalgal species, including Palmaria decipiens (Aumack et al. 2017). Although unpalatable when alive, G. antarctica and other amphipods will consume the chemically defended brown algae Himantothallus grandifolius and Desmarestia anceps within a few weeks of death (Amsler et al. 2014).
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Hadisusanto, Suwarno, Shinta Candra Dewi, Afra Meilianda, Riswi Haryatfrehni und Ihda Zuyina Ratna Sari. „MACROALGAL ABUNDANCE IN INTERTIDAL ZONE OF SARANGAN BEACH, GUNUNGKIDUL, DIY“. KnE Life Sciences 2, Nr. 1 (20.09.2015): 518. http://dx.doi.org/10.18502/kls.v2i1.207.
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<p>Sarangan beach has high biodiversity of macroalgae. Macroalgae has an important role as primary producer for herbivorous marine animals, potentially as biomonitoring, and pollutant bioremediation. As benthic organisms, macroalgae grows attached rocky or reef substrate in intertidal zone. These research aimed to study the macroalgal abundance in Sarangan Beach and influence factors of it. This study is important for local government as a reference to manage and develop the coastal areas of Gunungkidul. Sampling was conducted in 2012-2013 start from determination of the sampling point with line transect then collect data using quadrat plots 100 x 100 cm2 size, seawater nutrient analysis, species identification, and data calculation. The results showed that there were 14 species of Chlorophyta, 4 species of Phaeophyta, and 17 species of Rhodophyta. Enteromorpha intestinalis has a highest abundance, then Ulva fasciata, and Cladophora catenata. Analysis of correlation and regression showed that nutrient levels doesn’t affect the macroalgal abundance in Sarangan Beach. Based on result, the limiting factor of macroalgal abundance in Sarangan Beach is substrate. <br /><strong></strong></p><p><strong>Keywords</strong>: Abundance, Macroalgae, Sarangan Beach, Substrate</p>
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Müller, Malika, Constanze F. K. Staab, Laura D. Puk, Eike M. Schoenig, Sebastian C. A. Ferse und Christian Wild. „The Rabbitfish Siganus virgatus as Key Macroalgae Browser in Coral Reefs of the Gulf of Thailand“. Diversity 13, Nr. 3 (13.03.2021): 123. http://dx.doi.org/10.3390/d13030123.
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Coral reef resilience is greatly influenced by herbivory. There is a need to identify key fish species fulfilling this critical function in biogeographically distinct regions. This experimental in situ study investigated fish herbivory in coral reefs of the lower Gulf of Thailand characterized by a considerably low herbivorous fish biomass and diversity, but high live coral and low macroalgal cover. This provided an intriguing situation for macroalgal browsing research. Visual census techniques assessed the abundance of local herbivorous fish species, and filmed single-choice assays using the macroalga Turbinaria evaluated mass-standardized bites (ms-bites) and biomass removal. Multiple-choice assays offering four locally abundant macroalgae identified specific biomass removal and ms-bites to uncover selection and avoidance patterns of observed fish species. The rabbitfish Siganusvirgatus constituted only 39% of herbivore biomass but accounted for 90% of ms-bites. In multiple-choice assays, fishes took most (61%) bites on Sargassum, followed by Padina (28%) and Turbinaria (11%), while Lobophora was avoided. S. virgatus exhibited the most generalized browsing pattern of all species observed. Coinciding with recent studies, our findings suggest that S. virgatus plays a key functional role in reefs characterized by low diversity of herbivores and low functional redundancy.
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He, Quan, Linqing Liu, Yujie Qin, Qiang Lin, Guangyan Ni, Binbin Chen, Zengling Ma, Dinghui Zou und Gang Li. „Taxonomic and Morpho-Functional Photosynthetic Patterns of 18 Intertidal Macroalgal Species in the Guangdong–Hong Kong–Macao Greater Bay Area, China“. Journal of Marine Science and Engineering 11, Nr. 7 (13.07.2023): 1409. http://dx.doi.org/10.3390/jmse11071409.
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Macroalgae provide food for microbial, meio- and macro-faunal communities in coastal ecosystems, thus mediating nutrient dynamics and functions in these ecosystems. Because of this vital role, it is important to clarify physiological information about macroalgae as it reflects their growth potential in the field. In this study, we examined the biomass, pigment content, and photosynthetic O2 evolution rate versus irradiance curves of 18 macroalgal species from the intertidal zone of the Guangdong–Hong Kong–Macao Greater Bay Area, China, and investigated their photosynthetic patterns in relation to phyla characteristics, morphology, and growth locations. The results showed that green algae had the highest maximum photosynthetic O2 evolution rate (Pmax), light utilization efficiency (α), and dark respiration (Rd) among the three macroalgal phyla; the sheet-like macroalgal species had the highest Pmax, α, and Rd among the four morphological categories. The macroalgal species in the upper intertidal zone showed higher Pmax and α and lower saturation irradiance (EK) and compensation irradiance (EC) than those species in the lower intertidal location. The PCA results showed that the biomass of sheet-like macroalgal species was positively correlated with factor PC1 (50.34%), and that of finely branched species was negatively correlated with factor PC2 (25.17%). In addition, our results indicate that the light absorption and utilization capabilities of macroalgae could determine whether they could dominate the intertidal zone and that their photosynthetic characteristics could be used as a potential indicator of their biomass distribution in the Greater Bay Area.
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Budzałek, Gracjana, Sylwia Śliwińska-Wilczewska, Kinga Wiśniewska, Agnieszka Wochna, Iwona Bubak, Adam Latała und Józef Maria Wiktor. „Macroalgal Defense against Competitors and Herbivores“. International Journal of Molecular Sciences 22, Nr. 15 (23.07.2021): 7865. http://dx.doi.org/10.3390/ijms22157865.
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Macroalgae are the source of many harmful allelopathic compounds, which are synthesized as a defense strategy against competitors and herbivores. Therefore, it can be predicted that certain species reduce aquaculture performance. Herein, the allelopathic ability of 123 different taxa of green, red, and brown algae have been summarized based on literature reports. Research on macroalgae and their allelopathic effects on other animal organisms was conducted primarily in Australia, Mexico, and the United States. Nevertheless, there are also several scientific reports in this field from South America and Asia; the study areas in the latter continents coincide with areas where aquaculture is highly developed and widely practiced. Therefore, the allelopathic activity of macroalgae on coexisting animals is an issue that is worth careful investigation. In this work, we characterize the distribution of allelopathic macroalgae and compare them with aquaculture locations, describe the methods for the study of macroalgal allelopathy, present the taxonomic position of allelopathic macroalgae and their impact on coexisting aquatic competitors (Cnidaria) and herbivores (Annelida, Echinodermata, Arthropoda, Mollusca, and Chordata), and compile information on allelopathic compounds produced by different macroalgae species. This work gathers the current knowledge on the phenomenon of macroalgal allelopathy and their allelochemicals affecting aquatic animal (competitors and predators) worldwide and it provides future research directions for this topic.
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Riadi, Hassane, Ghizlane Salhi, Younes Saoud, Mohamed Kadiri und Mohamed Kazzaz. „Nuevas aportaciones a la flora algal de las costas marroquíes“. Acta Botanica Malacitana 36 (01.12.2011): 161–63. http://dx.doi.org/10.24310/abm.v36i1.2831.
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Lenzo, Denise, Marina Antonia Colangelo, Andrea Pasteris, Fabio Rindi, Rossella Pistocchi und Laura Pezzolesi. „Understanding the Role of Macroalgal Complexity and Allelochemicals Production in Invasive and Non-Invasive Macroalgae in the North-Western Adriatic Sea: Effect on the Associated Communities“. Water 15, Nr. 9 (27.04.2023): 1697. http://dx.doi.org/10.3390/w15091697.
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Highly diverse microphyto and meiobenthic communities are associated with large-sized marine macroalgae. Both morphological traits and allelochemical responses of macroalgae affect the composition of these communities, but the relative importance of these factors remains incompletely understood. In this study we investigated the microphytobenthic and meiobenthic communities associated with some native macroalgae and a non-indigenous species (Sargassum muticum) of the north-western Adriatic Sea. These seaweeds were sampled in two coastal sites subjected to different impacts. The possible effects of the structural complexity of the macroalgae and the potential role of allelochemicals (specifically polyunsaturated aldehydes, PUAs) on the associated communities were examined using univariate and multivariate analyses. The results indicate that distinct assemblages were associated with the macroalgae collected at the two different sites. Differences in microphytobenthic communities could be ascribed to differences in the macroalgal morphological traits and in their PUAs production. Conversely, variation of the meiobenthic community seemed to be related mainly to differences in the macroalgal communities at the two sites. This apparent inconsistency between the two analyzed communities suggests that microphytobenthos and meiofauna were differently shaped by the environmental habitat provided by macroalgae in the two sites, that are subjected to different environmental conditions and human activities. Overall, these results indicate that interactions between organisms belonging to different trophic groups (e.g., microphytobenthos and meiofauna) should be investigated in detail to better understand the global role of macroalgae as habitat formers on coastal ecosystems, especially in the case of large-sized introduced species.
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Fong, Jenny, Peggy P. Y. Tang, Lindsey K. Deignan, Jovena C. L. Seah, Diane McDougald, Scott A. Rice und Peter A. Todd. „Chemically Mediated Interactions with Macroalgae Negatively Affect Coral Health but Induce Limited Changes in Coral Microbiomes“. Microorganisms 11, Nr. 9 (09.09.2023): 2261. http://dx.doi.org/10.3390/microorganisms11092261.
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Allelopathic chemicals facilitated by the direct contact of macroalgae with corals are potentially an important mechanism mediating coral–macroalgal interactions, but only a few studies have explored their impacts on coral health and microbiomes and the coral’s ability to recover. We conducted a field experiment on an equatorial urbanized reef to assess the allelopathic effects of four macroalgal species (Bryopsis sp., Endosiphonia horrida, Hypnea pannosa and Lobophora challengeriae) on the health and microbiomes of three coral species (Merulina ampliata, Montipora stellata and Pocillopora acuta). Following 24 h of exposure, crude extracts of all four macroalgal species caused significant coral tissue bleaching and reduction in effective quantum yield. The corals were able to recover within 72 h of the removal of extracts, except those that were exposed to L. challengeriae. While some macroalgal extracts caused an increase in the alpha diversity of coral microbiomes, there were no significant differences in the composition and variability of coral microbiomes between controls and macroalgal extracts at each sampling time point. Nevertheless, DESeq2 differential abundance analyses showed species-specific responses of coral microbiomes. Overall, our findings provide insights on the limited effect of chemically mediated interactions with macroalgae on coral microbiomes and the capacity of corals to recover quickly from the macroalgal chemicals.
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Duran, Alain, Ligia Collado-Vides und Deron E. Burkepile. „Seasonal regulation of herbivory and nutrient effects on macroalgal recruitment and succession in a Florida coral reef“. PeerJ 4 (02.11.2016): e2643. http://dx.doi.org/10.7717/peerj.2643.
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Herbivory and nutrient enrichment are drivers of benthic dynamics of coral reef macroalgae; however, their impact may vary seasonally. In this study we evaluated the effects of herbivore pressure, nutrient availability and potential propagule supply on seasonal recruitment and succession of macroalgal communities on a Florida coral reef. Recruitment tiles, replaced every three months, and succession tiles, kept in the field for nine months, were established in an ongoing factorial nutrient enrichment-herbivore exclusion experiment. The ongoing experiment had already created very different algal communities across the different herbivory and nutrient treatments. We tracked algal recruitment, species richness, and species abundance through time. Our results show seasonal variation in the effect of herbivory and nutrient availability on recruitment of coral reef macroalgae. In the spring, when there was higher macroalgal species richness and abundance of recruits, herbivory appeared to have more control on macroalgal community structure than did nutrients. In contrast, there was no effect of either herbivory or nutrient enrichment on macroalgal communities on recruitment tiles in cooler seasons. The abundance of recruits on tiles was positively correlated with the abundance of algal in the ongoing, established experiment, suggesting that propagule abundance is likely a strong influence on algal recruitment and early succession. Results of the present study suggest that abundant herbivorous fishes control recruitment and succession of macroalgae, particularly in the warm season when macroalgal growth is higher. However, herbivory appears less impactful on algal recruitment and community dynamics in cooler seasons. Ultimately, our data suggest that the timing of coral mortality (e.g., summer vs. winter mortality) and freeing of benthic space may strongly influence the dynamics of algae that colonize open space.
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Jung, Somi, Than Van Chau, Minju Kim und Won-Bae Na. „Artificial Seaweed Reefs That Support the Establishment of Submerged Aquatic Vegetation Beds and Facilitate Ocean Macroalgal Afforestation: A Review“. Journal of Marine Science and Engineering 10, Nr. 9 (24.08.2022): 1184. http://dx.doi.org/10.3390/jmse10091184.
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Macroalgae are invaluable constituents of marine forest environments and important sources of material for human needs. However, they are currently at risk of severe decline due to global warming and negative anthropogenic factors. Restoration efforts focus on beds where macroalgae previously existed, as well as the creation of new marine forests. Some artificial seaweed reefs (ASRs) have succeeded but others have failed; the contributions of ASRs to marine forest formation have been not fully determined. Here, we review ASRs, the benefits of macroalgal forests, threats to macroalgae, restoration, and marine forest formation to explore the current status of ASRs. The published literature indicates that ASRs have played critical roles in marine forest formation; notably, they support the establishment of submerged aquatic vegetation beds that allow ocean macroalgal afforestation. ASRs have evolved in terms of complexity and the materials used; they can sustainably mitigate marine deforestation. However, continuous reviews of ASR performance are essential, and performance improvements are always possible.
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Hermanto, B., D. G. Bourne und H. Smith. „Comparative image analysis approaches to assess ecological effects of macroalgal removal on inshore reefs of Magnetic Island, Australia“. IOP Conference Series: Earth and Environmental Science 1137, Nr. 1 (01.01.2023): 012052. http://dx.doi.org/10.1088/1755-1315/1137/1/012052.
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Abstract Macroalgae removal is a proposed management option in the GBR to reverse declines in inshore coral reef health. Automated image analysis (AIA) is a valuable tool to assess benthic community assemblages. This study compared the accuracy of benthic community assemblages assessed through the AIA program CoralNet to manual image analysis. The ecological effect of macroalgae removal on benthic community composition was also investigated on established permanent quadrats (5x5 m) for reefs at Florence and Arthur Bay, Magnetic Island. Control and treatment quadrats (n=3 respectively) were photographed before and after macroalgae removal over 6 months. The results obtained by AIA and manual approaches were consistent, with macroalgae cover is approximately 77%-87% in all quadrats before macroalgal removal. Through the monitoring period, a small increase in coral cover in the macroalgal removal quadrats was observed in Florence and Arthur Bay (an increase of 1.8% and 0.1%, respectively). CoralNet was demonstrated to be robust for assessing reef benthic cover with no significant difference in recorded benthic categories when compared to the manual approach. CoralNet was accurate for identifying broad benthic categories, but less effective than manual image analyses for lower taxonomic categories (i.e., genus or species level).
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Argumedo Hernández, U. „HÁBITOS ALIMENTARIOS DE Haliotis spp. Y BASES NUTRICIONALES PARA SU MANEJO“. CICIMAR Oceánides 22, Nr. 1-2 (31.12.2007): 13. http://dx.doi.org/10.37543/oceanides.v22i1-2.34.
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La mayor parte del conocimiento sobre la dieta de abulón emana de bases empíricas bajo condiciones de cultivo, sobre todo en las primeras etapas de vida. Así mismo la mayoría de estos estudios se hacen con adultos y enfocados sobre macroalgas, las cuales albergan un gran número de especies de diatomeas epifitas que podrían estar enriqueciendo la dieta del abulón. Sin embargo, al segregarse de los estudios de contenido intestinal éstas podrían estar subestimadas. El suministro empírico de pocos taxa de diatomeas en la dieta de juveniles de abulón en cultivo no corresponde con el gran número de diatomeas encontradas en contenidos intestinales de organismos del medio natural. De tal forma, su uso como alimento en cultivo requiere de mayor base científica; observaciones hechas con dietas combinadas a base de macroalga y diatomeas parecen ser mejor opción. Por otro lado, una dieta artificial para abulones adultos que busque sustituir el uso de macroalgas disminuyendo costos de producción, dependerá de la información de los requerimientos nutricionales y del aprovechamiento de la fuente de alimento por las distintas especies de abulón, lo cual se desconoce, sobre todo en relación con su dieta natural. Las dietas mixtas proveen más nutrientes esenciales, a diferencia de dietas monoespecíficas en las cuales se puede presentar deficiencia en uno o más nutrientes. Finalmente el sabor del músculo de abulón al ser alimentado con dietas artificiales puede ser diferente al que se obtiene con dietas naturales, reflejándose en una menor aceptación del producto en el mercado. Feeding habits of Haliotis spp. And nutritional basis for its Management Most of the knowledge on abalone diet rises from empirical bases under cultured conditions,especially during its early life stages. Likewise, most of these studies have been made on adults and are focused on macroalgae, which harbor a large number of epiphytic diatom species that could enrich the abalone diet. Nevertheless, when these are segregated its diet contribution could be underestimated. The empiric supply of few diatom taxa on juvenile cultured abalone do not correspond to the large number of diatoms observed in intestinal contents of wild specimens. Likewise, their use as food for cultured abalone needs a larger scientific base; meanwhile combined diets using macroalgae and diatoms seems to be a better alternative. On the other hand, an artificial diet for adult abalones as an alternative for the macroalgal diet with lower production costs, will depend on the information about nutrimental requirements and the use of food sources by different abalone species, which is unknown, especially in relation with their natural diet. On the plus side, mixed diets provide more essential nutrients than the mono-specific diets which can be lacking in one or more nutrients. Also, it has to be taken into account that the flavor of abalone meat fed with artificial diets could be different than that obtained with natural diets and could result in less acceptance of the product in the market
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Argumedo Hernández, U. „HÁBITOS ALIMENTARIOS DE Haliotis spp. Y BASES NUTRICIONALES PARA SU MANEJO“. CICIMAR Oceánides 22, Nr. 1-2 (31.12.2007): 13. http://dx.doi.org/10.37543/oceanides.v22i1-2.34.
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La mayor parte del conocimiento sobre la dieta de abulón emana de bases empíricas bajo condiciones de cultivo, sobre todo en las primeras etapas de vida. Así mismo la mayoría de estos estudios se hacen con adultos y enfocados sobre macroalgas, las cuales albergan un gran número de especies de diatomeas epifitas que podrían estar enriqueciendo la dieta del abulón. Sin embargo, al segregarse de los estudios de contenido intestinal éstas podrían estar subestimadas. El suministro empírico de pocos taxa de diatomeas en la dieta de juveniles de abulón en cultivo no corresponde con el gran número de diatomeas encontradas en contenidos intestinales de organismos del medio natural. De tal forma, su uso como alimento en cultivo requiere de mayor base científica; observaciones hechas con dietas combinadas a base de macroalga y diatomeas parecen ser mejor opción. Por otro lado, una dieta artificial para abulones adultos que busque sustituir el uso de macroalgas disminuyendo costos de producción, dependerá de la información de los requerimientos nutricionales y del aprovechamiento de la fuente de alimento por las distintas especies de abulón, lo cual se desconoce, sobre todo en relación con su dieta natural. Las dietas mixtas proveen más nutrientes esenciales, a diferencia de dietas monoespecíficas en las cuales se puede presentar deficiencia en uno o más nutrientes. Finalmente el sabor del músculo de abulón al ser alimentado con dietas artificiales puede ser diferente al que se obtiene con dietas naturales, reflejándose en una menor aceptación del producto en el mercado. Feeding habits of Haliotis spp. And nutritional basis for its Management Most of the knowledge on abalone diet rises from empirical bases under cultured conditions,especially during its early life stages. Likewise, most of these studies have been made on adults and are focused on macroalgae, which harbor a large number of epiphytic diatom species that could enrich the abalone diet. Nevertheless, when these are segregated its diet contribution could be underestimated. The empiric supply of few diatom taxa on juvenile cultured abalone do not correspond to the large number of diatoms observed in intestinal contents of wild specimens. Likewise, their use as food for cultured abalone needs a larger scientific base; meanwhile combined diets using macroalgae and diatoms seems to be a better alternative. On the other hand, an artificial diet for adult abalones as an alternative for the macroalgal diet with lower production costs, will depend on the information about nutrimental requirements and the use of food sources by different abalone species, which is unknown, especially in relation with their natural diet. On the plus side, mixed diets provide more essential nutrients than the mono-specific diets which can be lacking in one or more nutrients. Also, it has to be taken into account that the flavor of abalone meat fed with artificial diets could be different than that obtained with natural diets and could result in less acceptance of the product in the market
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Burnett, Nicholas P., und Brian Gaylord. „Flow, form, and force: methods and frameworks for field studies of macroalgal biomechanics“. Journal of Experimental Botany 73, Nr. 4 (17.11.2021): 1122–38. http://dx.doi.org/10.1093/jxb/erab498.
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Abstract Macroalgae are ecologically important organisms that often inhabit locations with physically challenging water motion. The biomechanical traits that permit their survival in these conditions have been of interest to biologists and engineers alike, but logistical and technical challenges of conducting investigations in macroalgal habitats have often prevented optimal study of these traits. Here, we review field methods for quantifying three major components of macroalgal biomechanics in moving water: fluid flow, macroalgal form, and hydrodynamic force. The implementation of some methodologies is limited due to the current state and accessibility of technology, but many of these limitations can be remedied by custom-built devices, borrowing techniques from other systems, or shifting lab-based approaches to the field. We also describe several frameworks for integrating flow, form, and force data that can facilitate comparisons of macroalgal biomechanics in field settings with predictions from theory and lab-based experiments, or comparisons between flow conditions, habitats, and species. These methods and frameworks, when used on scales that are relevant to the examined processes, can reveal mechanistic information about the functional traits that permit macroalgae to withstand physically challenging water motion in their habitats, using the actual fluid flows, macroalgal forms, and physical forces that occur in nature.
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Vieira, Christophe, Claude Payri und Olivier De Clerck. „A fresh look at macroalgal-coral interactions: are macroalgae a threat to corals?“ Perspectives in Phycology 3, Nr. 3 (01.12.2016): 129–40. http://dx.doi.org/10.1127/pip/2016/0068.
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Kinley, Robert D., Rocky de Nys, Matthew J. Vucko, Lorenna Machado und Nigel W. Tomkins. „The red macroalgae Asparagopsis taxiformis is a potent natural antimethanogenic that reduces methane production during in vitro fermentation with rumen fluid“. Animal Production Science 56, Nr. 3 (2016): 282. http://dx.doi.org/10.1071/an15576.
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Livestock feed modification is a viable method for reducing methane emissions from ruminant livestock. Ruminant enteric methane is responsible approximately to 10% of greenhouse gas emissions in Australia. Some species of macroalgae have antimethanogenic activity on in vitro fermentation. This study used in vitro fermentation with rumen inoculum to characterise increasing inclusion rates of the red macroalga Asparagopsis taxiformis on enteric methane production and digestive efficiency throughout 72-h fermentations. At dose levels ≤1% of substrate organic matter there was minimal effect on gas and methane production. However, inclusion ≥2% reduced gas and eliminated methane production in the fermentations indicating a minimum inhibitory dose level. There was no negative impact on substrate digestibility for macroalgae inclusion ≤5%, however, a significant reduction was observed with 10% inclusion. Total volatile fatty acids were not significantly affected with 2% inclusion and the acetate levels were reduced in favour of increased propionate and, to a lesser extent, butyrate which increased linearly with increasing dose levels. A barrier to commercialisation of Asparagopsis is the mass production of this specific macroalgal biomass at a scale to provide supplementation to livestock. Another area requiring characterisation is the most appropriate method for processing (dehydration) and feeding to livestock in systems with variable feed quality and content. The in vitro assessment method used here clearly demonstrated that Asparagopsis can inhibit methanogenesis at very low inclusion levels whereas the effect in vivo has yet to be confirmed.
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Necchi-Júnior, O., L. H. Z. Branco und C. C. Z. Branco. „Ecological distribution of stream macroalgal communities from a drainage basin in the Serra da Canastra National Park, Minas Gerais, Southeastern Brazil“. Brazilian Journal of Biology 63, Nr. 4 (November 2003): 635–46. http://dx.doi.org/10.1590/s1519-69842003000400010.
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Twelve stream segments were sampled four times in 1998-1999 (one sampling per season) in the drainage basin of the upper São Francisco River (19º45'-21º25'S, 49º05'-51º30'W), situated in Serra da Canastra National Park, at altitudes ranging from 1,175 to 1,400 m. The macroalgae survey resulted in 30 species, with a predominance of Cyanophyta (12 species = 40%) and Chlorophyta (11 species = 36.5%) and a lower proportion of Rhodophyta (seven species = 23.5%). Two species, Klebsormidium rivulare (Chlorophyta) and Kyliniella latvica (Rhodophyta), were new records for Brazil. Capsosira sp. and Stigonema sp. (Cyanophyta) and the "Chantransia" stage of Batrachospermum (Rhodophyta) were the most widespread macroalgae, occurring in six sampling sites, whereas 11 species were found at only one site. The proportion of macroalgal morphological types were as follows: mats (33%), free filaments (27%), gelatinous filaments (27%), crusts (7%), tufts (3%), and gelatinous colonies (3%). The flora revealed few species in common (4%-8%) with stream macroalgae from other Brazilian regions. The macroalgal communities proved to have species richness values close to the highest values reported in previous studies. The patterns typical for stream macroalgal communities (patchy distribution and dominance of few species) were also found in this basin. However, the stream variables most influential in macroalgal distribution in this study (rocky substratum, low pH, high COD, water color, and current velocity) were essentially the same that best describe the limnological characteristics of this lotic ecosystem. In addition, this combination of variables differed sharply from results of previous studies in other Brazilian stream ecosystems.
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Li, Xunmeng, Jianqu Chen, Jun Li, Kai Wang, Zhenhua Wang und Shouyu Zhang. „Determination of intertidal macroalgae community patterns using the power law model“. PLOS ONE 17, Nr. 11 (07.11.2022): e0277281. http://dx.doi.org/10.1371/journal.pone.0277281.
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The spatial heterogeneity of macroalgae in intertidal zones affects the stability of marine ecosystem communities, contributes to the maintenance of coastal biodiversity, and has an essential role in ecosystem and habitat maintenance. We explored the feasibility of applying the power law model to analyze the spatial distribution of macroalgae on Lvhua Island (Zhejiang Province, China) and characterized the intertidal spatial heterogeneity of the macroalgae present. The results showed a strong association between the spatial distribution of macroalgae in the intertidal zone and the power law model (R2 = 0.98). There was a positive association between species occurrence frequency and the spatial heterogeneity index of macroalgae species. The model also indicated there was macroalgal habitat structure at the site as the spatial heterogeneity within the community was greater than that of random distribution. The power law model reported here provides a new method for macroalgae community ecology research and could be broadly utilized to analyze the spatial pattern of macroalgae in intertidal zones.
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Velázquez-Ochoa, Roberto, María Julia Ochoa-Izaguirre und Martín Federico Soto-Jiménez. „An analysis of the variability in <i>δ</i><sup>13</sup>C in macroalgae from the Gulf of California: indicative of carbon concentration mechanisms and isotope discrimination during carbon assimilation“. Biogeosciences 19, Nr. 1 (03.01.2022): 1–27. http://dx.doi.org/10.5194/bg-19-1-2022.
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Abstract. The isotopic composition of carbon in macroalgae (δ13C) is highly variable, and its prediction is complex concerning terrestrial plants. The determinants of δ13C macroalgal variations were analyzed in a large stock of specimens that vary in taxa and morphology and were collected in shallow marine habitats in the Gulf of California (GC) with distinctive environmental conditions. A large δ13C variability (−34.6 ‰ to −2.2 ‰) was observed. Life-forms (taxonomy 57 %, morphology and structural organization 34 %) explain the variability related to carbon use physiology. Environmental conditions influenced the δ13C macroalgal values but did not change the physiology, which is most likely inherently species-specific. Values of δ13C were used as indicators of the presence or absence of carbon concentrating mechanisms (CCMs) and as integrative values of the isotope discrimination during carbon assimilation in the life cycle macroalgae. Based on δ13C signals, macroalgae were classified in three strategies relative to the capacity of CCM: (1) HCO3- uptake (δ13C > −10 ‰), (2) using a mix of CO2 and HCO3- uptake (-10<δ13C > −30 ‰), and (3) CO2 diffusive entry (δ13C < −30 ‰). Most species showed a δ13C that indicates a CCM using a mix of CO2 and HCO3- uptake. HCO3- uptake is also widespread among GC macroalgae, with many Ochrophyta species. Few species belonging to Rhodophyta relied on CO2 diffusive entry exclusively, while calcifying macroalgae species using HCO3- included only Amphiroa and Jania. The isotopic signature evidenced the activity of CCM, but it was inconclusive about the preferential uptake of HCO3- and CO2 in photosynthesis and the CCM type expressed in macroalgae. In the study of carbon use strategies, diverse, species-specific, and complementary techniques to the isotopic tools are required.
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Lõugas, Laura, Tiit Kutser, Jonne Kotta und Ele Vahtmäe. „Detecting Long Time Changes in Benthic Macroalgal Cover Using Landsat Image Archive“. Remote Sensing 12, Nr. 11 (11.06.2020): 1901. http://dx.doi.org/10.3390/rs12111901.
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Coastal macroalgae worldwide provide multiple ecological functions and support vital ecosystem services. Thereby, it is important to monitor changes in the extent of benthic macroalgal cover. However, as in situ sampling is costly and time-consuming, areal estimates of macroalgal species cover are often based only on a limited number of samples. This low sampling effort likely yields very biased estimates, as macroalgal communities are often characterized by large spatial variability at multiple spatial scales. Moreover, ecological time series are often short-term, making it impossible to assess changes in algal communities over decades and relate this to different human pressures and/or climate change. The Landsat series satellites have operated for 40 years. In the current study, we tested if the Landsat sensors could be used for mapping the cover of shallow water benthic macroalgae. This study was carried out at two sites in the West Estonian Archipelago, in the northeastern Baltic Sea. Our results show that the Landsat imagery accurately reflected both spatial and temporal variability in benthic algal cover. To conclude, the current methodology can be used to improve the existing assessments of areal macroalgal cover, or to estimate the cover values, in areas and times lacking ecological observations.
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Whiting, Jonathan M., Taiping Wang, Zhaoqing Yang, Michael H. Huesemann, Phillip J. Wolfram, Thomas F. Mumford und Dylan Righi. „Simulating the Trajectory and Biomass Growth of Free-Floating Macroalgal Cultivation Platforms along the U.S. West Coast“. Journal of Marine Science and Engineering 8, Nr. 11 (18.11.2020): 938. http://dx.doi.org/10.3390/jmse8110938.
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Trajectory tracking and macroalgal growth models were coupled to support a novel macroalgae-harvesting concept known as the Nautical Off-shore Macroalgal Autonomous Device (NOMAD). The NOMAD consists of 5 km long carbon-fiber longlines that are seeded and free float southward along the U.S. West Coast for approximately 3 months before harvesting off the California coast, taking advantage of favorable environmental conditions. The trajectory and macroalgal growth models were applied to answer planning questions pertinent to the techno-economic analysis such as identifying the preferred release location, approximate pathway, timing until harvest, and estimated growth. Trajectories were determined with the General NOAA Operational Modeling Environment (GNOME) model, using 11 years of current and wind data, determining probabilities by running nearly 40,000 Monte Carlo simulations varying the start time and location. An accompanying macroalgal growth model was used to estimate the growth of macroalgae based on the trajectory tracks and environmental forcing products, including light, temperature and nutrients. Model results show that NOMAD lines transit south in the months of April to September due to seasonal currents, taking approximately 3 months to reach Southern California. During transit, NOMAD lines are dispersed but typically avoid beaching or passing through marine sanctuaries. NOMAD lines can yield up to 30 kg wet weight per meter of cultivation line.
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Briggs, Amy A., Anya L. Brown und Craig W. Osenberg. „Local versus site-level effects of algae on coral microbial communities“. Royal Society Open Science 8, Nr. 9 (September 2021): 210035. http://dx.doi.org/10.1098/rsos.210035.
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Microbes influence ecological processes, including the dynamics and health of macro-organisms and their interactions with other species. In coral reefs, microbes mediate negative effects of algae on corals when corals are in contact with algae. However, it is unknown whether these effects extend to larger spatial scales, such as at sites with high algal densities. We investigated how local algal contact and site-level macroalgal cover influenced coral microbial communities in a field study at two islands in French Polynesia, Mo'orea and Mangareva. At 5 sites at each island, we sampled prokaryotic microbial communities (microbiomes) associated with corals, macroalgae, turf algae and water, with coral samples taken from individuals that were isolated from or in contact with turf or macroalgae. Algal contact and macroalgal cover had antagonistic effects on coral microbiome alpha and beta diversity. Additionally, coral microbiomes shifted and became more similar to macroalgal microbiomes at sites with high macroalgal cover and with algal contact, although the microbial taxa that changed varied by island. Our results indicate that coral microbiomes can be affected by algae outside of the coral's immediate vicinity, and local- and site-level effects of algae can obscure each other's effects when both scales are not considered.
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Cheutin, Marie-Charlotte, Sébastien Villéger, Christina C. Hicks, James P. W. Robinson, Nicholas A. J. Graham, Clémence Marconnet, Claudia Ximena Ortiz Restrepo, Yvan Bettarel, Thierry Bouvier und Jean-Christophe Auguet. „Microbial Shift in the Enteric Bacteriome of Coral Reef Fish Following Climate-Driven Regime Shifts“. Microorganisms 9, Nr. 8 (11.08.2021): 1711. http://dx.doi.org/10.3390/microorganisms9081711.
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Replacement of coral by macroalgae in post-disturbance reefs, also called a “coral-macroalgal regime shift”, is increasing in response to climate-driven ocean warming. Such ecosystem change is known to impact planktonic and benthic reef microbial communities but few studies have examined the effect on animal microbiota. In order to understand the consequence of coral-macroalgal shifts on the coral reef fish enteric bacteriome, we used a metabarcoding approach to examine the gut bacteriomes of 99 individual fish representing 36 species collected on reefs of the Inner Seychelles islands that, following bleaching, had either recovered to coral domination, or shifted to macroalgae. While the coral-macroalgal shift did not influence the diversity, richness or variability of fish gut bacteriomes, we observed a significant effect on the composition (R2 = 0.02; p = 0.001), especially in herbivorous fishes (R2 = 0.07; p = 0.001). This change is accompanied by a significant increase in the proportion of fermentative bacteria (Rikenella, Akkermensia, Desulfovibrio, Brachyspira) and associated metabolisms (carbohydrates metabolism, DNA replication, and nitrogen metabolism) in relation to the strong turnover of Scarinae and Siganidae fishes. Predominance of fermentative metabolisms in fish found on macroalgal dominated reefs indicates that regime shifts not only affect the taxonomic composition of fish bacteriomes, but also have the potential to affect ecosystem functioning through microbial functions.
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Kumagai, Naoki H., Jorge García Molinos, Hiroya Yamano, Shintaro Takao, Masahiko Fujii und Yasuhiro Yamanaka. „Ocean currents and herbivory drive macroalgae-to-coral community shift under climate warming“. Proceedings of the National Academy of Sciences 115, Nr. 36 (20.08.2018): 8990–95. http://dx.doi.org/10.1073/pnas.1716826115.
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Coral and macroalgal communities are threatened by global stressors. However, recently reported community shifts from temperate macroalgae to tropical corals offer conservation potential for corals at the expense of macroalgae under climate warming. Although such community shifts are expanding geographically, our understanding of the driving processes is still limited. Here, we reconstruct long-term climate-driven range shifts in 45 species of macroalgae, corals, and herbivorous fishes from over 60 years of records (mainly 1950–2015), stretching across 3,000 km of the Japanese archipelago from tropical to subarctic zones. Based on a revised coastal version of climate velocity trajectories, we found that prediction models combining the effects of climate and ocean currents consistently explained observed community shifts significantly better than those relying on climate alone. Corals and herbivorous fishes performed better at exploiting opportunities offered by this interaction. The contrasting range dynamics for these taxa suggest that ocean warming is promoting macroalgal-to-coral shifts both directly by increased competition from the expansion of tropical corals into the contracting temperate macroalgae, and indirectly via deforestation by the expansion of tropical herbivorous fish. Beyond individual species’ effects, our results provide evidence on the important role that the interaction between climate warming and external forces conditioning the dispersal of organisms, such as ocean currents, can have in shaping community-level responses, with concomitant changes to ecosystem structure and functioning. Furthermore, we found that community shifts from macroalgae to corals might accelerate with future climate warming, highlighting the complexity of managing these evolving communities under future climate change.
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Cikoš, Ana-Marija, Mladenka Jurin, Rozelindra Čož-Rakovac, Stela Jokić und Igor Jerković. „Update on Monoterpenes from Red Macroalgae: Isolation, Analysis, and Bioactivity“. Marine Drugs 17, Nr. 9 (16.09.2019): 537. http://dx.doi.org/10.3390/md17090537.
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Macroalgae produce a wide range of monoterpenes as secondary metabolites of mevalonate (MVA) and/or methylerythritol phosphate (MEP) pathway (often including haloperoxidase action). Great biodiversity of macroalgal monoterpenes was reported including acyclic, monocyclic, and bicyclic structures. Halogenated monoterpenes exhibited significant biological activity (e.g., anticancer, antiplasmodial, and insecticidal) that is influenced by the number of present halogens (higher halogen content is preferable, especially bromine) and their position within the monoterpene skeleton. In distinction from the existing reviews, the present review provides novelty with respect to: (a) exclusively monoterpenes from red macroalgae are targeted; (b) biosynthesis, isolation, and analysis, as well as bioactivity of monoterpenes are represented; (c) the methods of their isolation, analysis, and structure elucidation are summarized; (d) the bioactivity of macroalgal monoterpenes is systematically presented with emphasis on anticancer activity; (e) the literature references were updated.