Journal articles on the topic 'Macroalgae'
To see the other types of publications on this topic, follow the link: Macroalgae.
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 journal articles for your research on the topic 'Macroalgae.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.
1
Diansyah, Sufal, Ika Kusumawati, and Fandi Hardinata. "INVENTARISASI JENIS-JENIS MAKROALGA DI PANTAI LHOK BUBON KECAMATAN SAMATIGA KABUPATEN ACEH BARAT." JURNAL PERIKANAN TROPIS 5, no. 1 (April 1, 2018): 93. http://dx.doi.org/10.35308/jpt.v5i1.1029.
Full textAbstract:
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.
2
Siqueiros Beltrones, D. A., and O. U. Hernández Almeida. "FLORÍSTICA DE DIATOMEAS EPIFITAS EN UN MANCHÓN DE MACROALGAS SUBTROPICALES." CICIMAR Oceánides 21, no. 1-2 (December 31, 2006): 11. http://dx.doi.org/10.37543/oceanides.v21i1-2.25.
Full textAbstract:
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.
3
Siqueiros Beltrones, D. A., and O. U. Hernández Almeida. "FLORÍSTICA DE DIATOMEAS EPIFITAS EN UN MANCHÓN DE MACROALGAS SUBTROPICALES." CICIMAR Oceánides 21, no. 1-2 (December 31, 2006): 11. http://dx.doi.org/10.37543/oceanides.v21i1-2.25.
Full textAbstract:
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.
4
Cordova, Muhammad Reza, and 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, no. 3 (December 28, 2017): 25. http://dx.doi.org/10.14203/oldi.2017.v2i3.93.
Full textAbstract:
<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.
5
Dziergowska, Katarzyna, Maja Wełna, Anna Szymczycha-Madeja, Jacek Chęcmanowski, and Izabela Michalak. "Valorization of Cladophora glomerata Biomass and Obtained Bioproducts into Biostimulants of Plant Growth and as Sorbents (Biosorbents) of Metal Ions." Molecules 26, no. 22 (November 16, 2021): 6917. http://dx.doi.org/10.3390/molecules26226917.
Full textAbstract:
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.
6
Martins, Nuno Tavares, Maria Alves Napolitani, João Pedro Guimarães Machado, Yocie Yoneshigue-Valentin, and Vinícius Peruzzi Oliveira. "Competitive interactions in marine macroalgae: an analysis of the literature by boolean operators." OBSERVATÓRIO DE LA ECONOMÍA LATINOAMERICANA 21, no. 8 (August 23, 2023): 9675–700. http://dx.doi.org/10.55905/oelv21n8-099.
Full textAbstract:
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.
7
Kamal, Marwa, Neveen Abdel-Raouf, Khairiah Alwutayd, Hamada AbdElgawad, Mohamed Sayed Abdelhameed, Ola Hammouda, and Khaled N. M. Elsayed. "Seasonal Changes in the Biochemical Composition of Dominant Macroalgal Species along the Egyptian Red Sea Shore." Biology 12, no. 3 (March 7, 2023): 411. http://dx.doi.org/10.3390/biology12030411.
Full textAbstract:
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.
8
Farobie, Obie, Novi Syaftika, Edy Hartulistiyoso, Apip Amrullah, Asep Bayu, Navid R. Moheimani, Yukihiko Matsumura, and Surachai Karnjanakom. "The Potential of Sustainable Biogas Production from Macroalgae in Indonesia." IOP Conference Series: Earth and Environmental Science 1038, no. 1 (June 1, 2022): 012020. http://dx.doi.org/10.1088/1755-1315/1038/1/012020.
Full textAbstract:
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.
9
Hagar Kamal Ahmed, Samia Heneidak, Abdel-Hamied Mohammed Rasmey, and Gihan Ahmed El Shoubaky. "Fatty acids composition and profiling of nine abundant marine Macroalgae, Egypt." GSC Biological and Pharmaceutical Sciences 24, no. 2 (August 30, 2023): 099–109. http://dx.doi.org/10.30574/gscbps.2023.24.2.0311.
Full textAbstract:
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.
10
Bambaranda, B. V. A. S. Manori, Takuji W. Tsusaka, Anong Chirapart, Krishna R. Salin, and Nophea Sasaki. "Capacity of Caulerpa lentillifera in the Removal of Fish Culture Effluent in a Recirculating Aquaculture System." Processes 7, no. 7 (July 10, 2019): 440. http://dx.doi.org/10.3390/pr7070440.
Full textAbstract:
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.
11
Strong, James A., Christine A. Maggs, and 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, no. 2 (March 2009): 303–14. http://dx.doi.org/10.1017/s0025315408003226.
Full textAbstract:
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.
12
Clements, Cody S., and Mark E. Hay. "Competitors as accomplices: seaweed competitors hide corals from predatory sea stars." Proceedings of the Royal Society B: Biological Sciences 282, no. 1814 (September 7, 2015): 20150714. http://dx.doi.org/10.1098/rspb.2015.0714.
Full textAbstract:
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.
13
Damare, Varada S., Estha T. Fernandes, Anjita A. Naik, Svetlana P. Cardozo, Vilda Borges, and Pramod Phuge. "Occurrence of thraustochytrids: the fungoid protists vis-a-vis marine macroalgae (seaweeds) along the coast of Goa, India." Botanica Marina 64, no. 6 (November 15, 2021): 461–75. http://dx.doi.org/10.1515/bot-2021-0052.
Full textAbstract:
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.
14
Raven, John. "Blue carbon: past, present and future, with emphasis on macroalgae." Biology Letters 14, no. 10 (October 2018): 20180336. http://dx.doi.org/10.1098/rsbl.2018.0336.
Full textAbstract:
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.
15
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, no. 2 (September 2, 2022): 153–59. http://dx.doi.org/10.21107/jk.v15i2.14374.
Full textAbstract:
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
16
Budzałek, Gracjana, Sylwia Śliwińska-Wilczewska, Kinga Wiśniewska, Agnieszka Wochna, Iwona Bubak, Adam Latała, and Józef Maria Wiktor. "Macroalgal Defense against Competitors and Herbivores." International Journal of Molecular Sciences 22, no. 15 (July 23, 2021): 7865. http://dx.doi.org/10.3390/ijms22157865.
Full textAbstract:
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.
17
Lenzo, Denise, Marina Antonia Colangelo, Andrea Pasteris, Fabio Rindi, Rossella Pistocchi, and 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, no. 9 (April 27, 2023): 1697. http://dx.doi.org/10.3390/w15091697.
Full textAbstract:
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.
18
Li, Xunmeng, Jianqu Chen, Jun Li, Kai Wang, Zhenhua Wang, and Shouyu Zhang. "Determination of intertidal macroalgae community patterns using the power law model." PLOS ONE 17, no. 11 (November 7, 2022): e0277281. http://dx.doi.org/10.1371/journal.pone.0277281.
Full textAbstract:
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.
19
Tukai, R., W. A. Maher, I. J. McNaught, M. J. Ellwood, and M. Coleman. "Occurrence and chemical form of arsenic in marine macroalgae from the east coast of Australia." Marine and Freshwater Research 53, no. 6 (2002): 971. http://dx.doi.org/10.1071/mf01230.
Full textAbstract:
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.
20
Pederson, Hugh G., and 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, no. 1 (November 20, 2007): 1–11. http://dx.doi.org/10.1093/icesjms/fsm168.
Full textAbstract:
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.
21
Hadisusanto, Suwarno, Shinta Candra Dewi, Afra Meilianda, Riswi Haryatfrehni, and Ihda Zuyina Ratna Sari. "MACROALGAL ABUNDANCE IN INTERTIDAL ZONE OF SARANGAN BEACH, GUNUNGKIDUL, DIY." KnE Life Sciences 2, no. 1 (September 20, 2015): 518. http://dx.doi.org/10.18502/kls.v2i1.207.
Full textAbstract:
<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>
22
Gadhi, Alaa Aref, Mohsen M. El-Sherbiny, Abdul Mohsin Al-Sofynai, Mohammad Abdulaziz Ba-Akdah, and Sathianeson Satheesh. "Antimicrofouling activities of marine macroalga Dictyota dichotoma from the Red Sea." Journal of Agricultural and Marine Sciences [JAMS] 23 (January 10, 2019): 58. http://dx.doi.org/10.24200/jams.vol23iss0pp58-67.
Full textAbstract:
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.
23
Gadhi, Alaa Aref, Mohsen M. El-Sherbiny, Abdul Mohsin Al-Sofynai, Mohammad Abdulaziz Ba-Akdah, and Sathianeson Satheesh. "Antimicrofouling activities of marine macroalga Dictyota dichotoma from the Red Sea." Journal of Agricultural and Marine Sciences [JAMS] 23, no. 1 (January 10, 2019): 58. http://dx.doi.org/10.24200/jams.vol23iss1pp58-67.
Full textAbstract:
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.
24
Garcia-Vaquero, Marco, Gaurav Rajauria, Marta Miranda, Torres Sweeney, Marta Lopez-Alonso, and 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, no. 4 (April 4, 2021): 204. http://dx.doi.org/10.3390/md19040204.
Full textAbstract:
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.
25
Schram, Julie B., Margaret O. Amsler, Aaron W. E. Galloway, Charles D. Amsler, and James B. McClintock. "Fatty acid trophic transfer of Antarctic algae to a sympatric amphipod consumer." Antarctic Science 31, no. 6 (October 22, 2019): 315–16. http://dx.doi.org/10.1017/s0954102019000397.
Full textAbstract:
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).
26
Krause-Jensen, Dorte, Paul Lavery, Oscar Serrano, Núria Marbà, Pere Masque, and Carlos M. Duarte. "Sequestration of macroalgal carbon: the elephant in the Blue Carbon room." Biology Letters 14, no. 6 (June 2018): 20180236. http://dx.doi.org/10.1098/rsbl.2018.0236.
Full textAbstract:
Macroalgae form the most extensive and productive benthic marine vegetated habitats globally but their inclusion in Blue Carbon (BC) strategies remains controversial. We review the arguments offered to reject or include macroalgae in the BC framework, and identify the challenges that have precluded macroalgae from being incorporated so far. Evidence that macroalgae support significant carbon burial is compelling. The carbon they supply to sediment stocks in angiosperm BC habitats is already included in current assessments, so that macroalgae are de facto recognized as important donors of BC. The key challenges are (i) documenting macroalgal carbon sequestered beyond BC habitat, (ii) tracing it back to source habitats, and (iii) showing that management actions at the habitat lead to increased sequestration at the sink site. These challenges apply equally to carbon exported from BC coastal habitats. Because of the large carbon sink they support, incorporation of macroalgae into BC accounting and actions is an imperative. This requires a paradigm shift in accounting procedures as well as developing methods to enable the capacity to trace carbon from donor to sink habitats in the ocean.
27
Hermanto, B., D. G. Bourne, and 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, no. 1 (January 1, 2023): 012052. http://dx.doi.org/10.1088/1755-1315/1137/1/012052.
Full textAbstract:
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).
28
Fabricius, Katharina E., Kerryn Crossman, Michelle Jonker, Mathieu Mongin, and Angus Thompson. "Macroalgal cover on coral reefs: Spatial and environmental predictors, and decadal trends in the Great Barrier Reef." PLOS ONE 18, no. 1 (January 20, 2023): e0279699. http://dx.doi.org/10.1371/journal.pone.0279699.
Full textAbstract:
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.
29
Bauman, Andrew G., Jovena C. L. Seah, Fraser A. Januchowski-Hartley, Andrew S. Hoey, Jenny Fong, and Peter A. Todd. "Fear effects associated with predator presence and habitat structure interact to alter herbivory on coral reefs." Biology Letters 15, no. 10 (October 2019): 20190409. http://dx.doi.org/10.1098/rsbl.2019.0409.
Full textAbstract:
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.
30
Velázquez-Ochoa, Roberto, María Julia Ochoa-Izaguirre, and 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, no. 1 (January 3, 2022): 1–27. http://dx.doi.org/10.5194/bg-19-1-2022.
Full textAbstract:
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.
31
Senga, Yukiko, Tsubasa Sato, Kanae Shibaki, Megumi Kuroiwa, Seiichi Nohara, and Yuichi Suwa. "Alteration of Dissimilatory Nitrate Reduction Pathways in the Intertidal Sediment during Macroalgae Blooms." Water 14, no. 19 (September 26, 2022): 3022. http://dx.doi.org/10.3390/w14193022.
Full textAbstract:
To elucidate the effect of macroalgae blooms on dissimilatory nitrate reduction pathways (denitrification, anammox, and DNRA) in sediments of the hypereutrophic Yatsu tidal flat, eastern Japan, sediment denitrification, anammox, and DNRA rates were measured using a 15N tracer technique at two sites affected and unaffected by macroalgae (Ulva) blooms and in incubation experiments with and without Ulva. Anammox was insignificant at both sites and in both experiments. The denitrification rate was consistently higher than the DNRA rate, and its contributions to the total dissimilatory nitrate reduction were 82% and 85% at sites affected and unaffected by Ulva, respectively. In a sediment incubation experiment with Ulva, the contribution of DNRA had increased to approximately 30% on day 7, which is when the sulfide concentration was the highest. Sulfide produced by sulfate reduction during macroalgae blooms inhibited denitrification and did not change the DNRA, and consequently increased the DNRA contribution. On day 21, after reaching the peak sulfide concentration during the late macroalgae collapse, the DNRA contribution decreased to 15%. These results indicated that the DNRA contribution was greater during the macroalgae blooms than at the collapse, although denitrification dominated DNRA regardless of the macroalgal status. Therefore, vigorous macroalgae cover and sulfide production under the macroalgae cover had an important impact on the nitrogen dynamics.
32
Handayani, Tri, Firman Zulpikar, and Agus Kusnadi. "The roles of macroalgae in climate change mitigation: opportunities and challenges for marine-based carbon donor." IOP Conference Series: Earth and Environmental Science 1119, no. 1 (December 1, 2022): 012014. http://dx.doi.org/10.1088/1755-1315/1119/1/012014.
Full textAbstract:
Abstract Anthropogenic activities will lead to an exponential increase in CO2 emissions in the future. Increased CO2 emissions have an impact on global climate patterns, ocean acidification, and ecosystem function. Marine vegetation has the potential to absorb CO2 through photosynthesis and store carbon in its biomass and sediments. This is known as blue carbon. Research on blue carbon in the world, including Indonesia, is more focused on seagrass and mangroves because including macroalgae carbon in the blue carbon strategy is still controversial. Currently, there are many considerations for including macroalgal carbon in the blue carbon strategy. Macroalgae have a shorter life cycle than seagrass and mangroves. In addition, macroalgae generally grow on hard substrates, resulting in lower levels of carbon storage than seagrass and mangroves. However, macroalgae can serve as carbon donors and contribute to the effort to mitigate climate change. In this review, we present the potential and challenges of macroalgae as carbon donors. Macroalgae will be significant as carbon donors if they have the following three criteria: high production of biomass; effective biomass moved to recipient habitat; and carbon donors that can be buried in recipient habitat. The fate of macroalgae carbon in recipient habitats still needs to be studied.
33
Jung, Somi, Than Van Chau, Minju Kim, and 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, no. 9 (August 24, 2022): 1184. http://dx.doi.org/10.3390/jmse10091184.
Full textAbstract:
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.
34
Harun-Al-Rashid, Ahmed, and Chan-Su Yang. "Improved Detection of Tiny Macroalgae Patches in Korea Bay and Gyeonggi Bay by Modification of Floating Algae Index." Remote Sensing 10, no. 9 (September 16, 2018): 1478. http://dx.doi.org/10.3390/rs10091478.
Full textAbstract:
This work focuses on the detection of tiny macroalgae patches in the eastern parts of the Yellow Sea (YS) using high-resolution Landsat-8 images from 2014 to 2017. In the comparison between floating algae index (FAI) and normalized difference vegetation index (NDVI) better detection by FAI was observed, but many tiny patches still remained undetected. By applying a modification on the FAI around 12% to 27% increased and correct detection of macroalgae is achieved from 35 images compared to the original. Through this method many scattered tiny patches were detected in June or July in Korea Bay and Gyeonggi Bay. Though it was a small-scale phenomenon they occurred in the similar period of macroalgal bloom occurrence in the YS. Thus, by using this modified method we could detect macroalgae in the study areas around one month earlier than the previously used Geostationary Ocean Color Imager NDVI-based detection. Later, more macroalgae patches including smaller ones occupying increased areas were detected. Thus, it seems that those macroalgae started growing locally from tiny patches rather than being transported from the western parts of the YS. Therefore, this modified FAI could be used for the precise detection of macroalgae.
35
Amsler, Charles D., Margaret O. Amsler, Michelle D. Curtis, James B. McClintock, and Bill J. Baker. "Impacts of gastropods on epiphytic microalgae on the brown macroalga Himantothallus grandifolius." Antarctic Science 31, no. 2 (March 15, 2019): 89–97. http://dx.doi.org/10.1017/s0954102019000014.
Full textAbstract:
AbstractChemically defended benthic macroalgae that dominate shallow, hard bottom communities along the western Antarctic Peninsula support very high densities of mesograzers, particularly amphipods but also small gastropods. Previous studies have demonstrated that the macroalgae and amphipods form a mutualistic relationship. The chemically defended macroalgae provide the amphipods with a refuge from predation while the macroalgae benefit from the amphipods greatly reducing surface fouling by smaller algae. One of the three most important macroalgae in terms of overstory cover, Himantothallus grandifolius, forms huge blades that can carpet the benthos. Field observations suggest that gastropods may be higher in relative abundance in proportion to amphipods on H. grandifolius than on other overstory macroalgae. The present study documents the finding that natural abundances of gastropods on H. grandifolius maintained in mesocosms reduce fouling by microscopic algae, primarily diatoms. However, amphipods are probably also important in keeping the macroalga clean of diatoms in nature. In a smaller scale experiment, three gastropod species were differentially effective at reducing diatom coverage on H. grandifolius. The hypothesis that gastropods benefit from associating with H. grandifolius in potentially gaining a refuge from sea-star predation was also tested but not supported by the experimental results.
36
He, Quan, Linqing Liu, Yujie Qin, Qiang Lin, Guangyan Ni, Binbin Chen, Zengling Ma, Dinghui Zou, and 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, no. 7 (July 13, 2023): 1409. http://dx.doi.org/10.3390/jmse11071409.
Full textAbstract:
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.
37
Kumagai, Naoki H., Jorge García Molinos, Hiroya Yamano, Shintaro Takao, Masahiko Fujii, and Yasuhiro Yamanaka. "Ocean currents and herbivory drive macroalgae-to-coral community shift under climate warming." Proceedings of the National Academy of Sciences 115, no. 36 (August 20, 2018): 8990–95. http://dx.doi.org/10.1073/pnas.1716826115.
Full textAbstract:
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.
38
Cardoso, Susana, Olívia Pereira, Ana Seca, Diana Pinto, and Artur Silva. "Seaweeds as Preventive Agents for Cardiovascular Diseases: From Nutrients to Functional Foods." Marine Drugs 13, no. 11 (November 12, 2015): 6838–65. http://dx.doi.org/10.3390/md13116838.
Full textAbstract:
Being naturally enriched in key nutrients and in various health-promoting compounds, seaweeds represent promising candidates for the design of functional foods. Soluble dietary fibers, peptides, phlorotannins, lipids and minerals are macroalgae’s major compounds that can hold potential in high-value food products derived from macroalgae, including those directed to the cardiovascular-health promotion. This manuscript revises available reported data focusing the role of diet supplementation of macroalgae, or extracts enriched in bioactive compounds from macroalgae origin, in targeting modifiable markers of cardiovascular diseases (CVDs), like dyslipidemia, oxidative stress, vascular inflammation, hypertension, hypercoagulability and activation of the sympathetic and renin-angiotensin systems, among others. At last, the review also describes several products that have been formulated with the use of whole macroalgae or extracts, along with their claimed cardiovascular-associated benefits.
39
Miao, Xiaoxiang, Jie Xiao, Qinzeng Xu, Shiliang Fan, Zongling Wang, Xiao Wang, and Xuelei Zhang. "Distribution and species diversity of the floating green macroalgae and micro-propagules in the Subei Shoal, southwestern Yellow Sea." PeerJ 8 (December 17, 2020): e10538. http://dx.doi.org/10.7717/peerj.10538.
Full textAbstract:
Massive floating green macroalgae have formed harmful green tides in the Yellow Sea since 2007. To study the early development and the associated environmental factors for the green tide, a field survey was carried out in the Subei Shoal, southwestern Yellow Sea. Multiple species were identified in both floating green macroalgae and micro-propagules , while their abundances showed distinct spatial variations. The floating macroalgal biomass was widespread in the northern Subei Shoal and most abundant at 34°N. Ulva prolifera dominated (91.2% in average) the floating macroalgae, and the majority (88.5%) of U. prolifera was the ‘floating type’. In comparison, the micro-propagules were most abundant around the aquaculture rafts, and decreased significantly with the distance to the rafts. The dominant species of micro-propagules was U. linza (48.5%), followed by U. prolifera (35.1%). Their distinct distribution patterns and species diversity suggested little direct contribution of micro-propagules for the floating macroalgae. The spatial variation of the floating macroalgae was probably a combined result from the biomass source and environmental factors, while the abundance of micro-propagules was closely associated with the rafts. A positive correlation between the floating macroalgae and DO was observed and suggested active photosynthesis of the initial biomass in Subei Shoal. This study revealed specific distributional pattern and relationships among the floating macroalgae, micro-propagules and the environmental factors in the source region, which helps understanding the early blooming dynamics of the green tides in Yellow Sea.
40
Meinita, Maria Dyah Nur, Amron Amron, Agus Trianto, Dicky Harwanto, Wahyu Caesarendra, Gwi-Taek Jeong, and Jae-Suk Choi. "Levulinic Acid Production from Macroalgae: Production and Promising Potential in Industry." Sustainability 13, no. 24 (December 16, 2021): 13919. http://dx.doi.org/10.3390/su132413919.
Full textAbstract:
The development of macroalgal biorefinery products as an alternative source of renewable fuels is an opportunity to solve the dependence on fossil fuels. Macroalgae is a potential biomass that can be developed as a raw material for producing platform chemicals such as levulinic acid (LA). In the industrial sector, LA is among the top 12 biomass-derived feedstocks designated by the U.S. Department of Energy as a high-value chemical. Several studies have been conducted on the production of LA from terrestrial-based biomass, however, there is still limited information on its production from macroalgae. The advantages of macroalgae over terrestrial and other biomasses include high carbohydrate and biomass production, less cultivation cost, and low lignin content. Therefore, this study aims to investigate the potential and challenge of producing LA from macroalgae in the industrial sector and determine its advantages and disadvantages compared with terrestrial biomass in LA production. In this study, various literature sources were examined using the preferred reporting items for systematic reviews and meta-analyses (PRISMA) method to identify, screen, and analyze the data of the published paper. Despite its advantages, there are some challenges in making the production of levulinic acid from macroalgae feasible for development at the industrial scale. Some challenges such as sustainability of macroalgae, the efficiency of pretreatment, and hydrolysis technology are often encountered during the production of levulinic acid from macroalgae on an industrial scale.
41
Lee, Hojun, Stephen Depuydt, Kisik Shin, Jonas De Saeger, Taejun Han, and Jihae Park. "Interactive Effects of Blue Light and Water Turbulence on the Growth of the Green Macroalga Ulva australis (Chlorophyta)." Plants 13, no. 2 (January 17, 2024): 266. http://dx.doi.org/10.3390/plants13020266.
Full textAbstract:
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.
42
Zainee, N. F. A., N. Ibrahim, N. Hidayah, and M. Rozaimi. "Variation in antibacterial properties of endophytic fungi isolated from Phaeophytes and Rhodophytes of Johor, Malaysia." Journal of Environmental Biology 42, no. 3(SI) (May 31, 2021): 840–48. http://dx.doi.org/10.22438/jeb/42/3(si)/jeb-16.
Full textAbstract:
Aim: To identify endophytic fungi of tropical macroalgae and analyse variation in antibacterial activity. Methodology: Endophytic fungi were aseptically isolated from macroalgae tissue, identified by macroscopic and microscopic observations, screened for the presence of antibacterial activity using cross streak and disc diffusion methods against six human pathogenic bacteria. Results: A total of 27 endophytic fungi were isolated and identified from 7 species of macroalgae collected from the Johor coast, Malaysia. Twenty-three fungal isolates belonged to Ascomycota, while two belonged to Zygomycota and Oomycota, respectively. Aspergillus niger was the most common and abundant endophyte found in macroalgal samples. Preliminary screening determined 13 species (48.15%) having positive antibacterial activity. Quantitative analysis of antibacterial activity showed significant differences (p< 0.01) against six human pathogenic bacteria. Two fungal isolates indicated strong and broad-spectrum antibacterial activity namely, Pythium sp. and Trichoderma viride. Interpretation: The findings demonstrate that certain macroalgae-derived endophytic fungi from Johor possess antibacterial properties and can be potentially new antibiotic sources, which are hitherto under-reported.
43
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, and Covadonga Rodríguez. "Lipid characterization of 14 macroalgal species from Madeira Archipelago: implications for animal and human nutrition." Botanica Marina 65, no. 1 (December 10, 2021): 51–67. http://dx.doi.org/10.1515/bot-2021-0024.
Full textAbstract:
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.
44
Doi, Hideyuki, Masatoshi Matsumasa, Mamoru Fujikawa, Keiichi Kanou, Takao Suzuki, and Eisuke Kikuchi. "Macroalgae and seagrass contribution to gastropods in sub-tropical and temperate tidal flats." Journal of the Marine Biological Association of the United Kingdom 89, no. 2 (October 16, 2008): 399–404. http://dx.doi.org/10.1017/s0025315408002683.
Full textAbstract:
Macroalgal and seagrass communities are widely distributed in marine and brackish shallow water and have high productivity. The primary production in marine costal areas is often transported to intertidal flats by waves and currents and beached on the flats. Thus, we hypothesized that the macroalgae and seagrasses are food sources for benthic communities on intertidal flats where some gastropod species often dominate. We performed comparisons of food sources among different gastropod species on sub-tropical and temperate tidal flats (26° and 38°N, respectively), and used isotope mixing models using carbon and nitrogen stable isotopes. A mixing model for stable isotopes, IsoSource, revealed that main food sources for three snails were macroalgae (50–56%) and seagrass (39–45%) at the temperate site. The contributions of terrestrial plants, sediment organic matter and benthic microalgae were weaker than those of macroalgae and seagrasses. At the sub-tropical site, snails fed mainly on macroalgae. The differences in food sources between snail species were not remarkable, although the nitrogen values were slightly different. It would thus appear that macroalgae and seagrass play an important role in the food webs not only in their own habitats but also on the adjacent tidal flats.
45
Quezada-Perez, Fabio, Sebastián Mena, Cindy Fernández-García, and Juan José Alvarado. "Status of Coral Reef Communities on the Caribbean Coast of Costa Rica: Are We Talking about Corals or Macroalgae Reefs?" Oceans 4, no. 3 (September 20, 2023): 315–30. http://dx.doi.org/10.3390/oceans4030022.
Full textAbstract:
In the past decades, one of the most widely reported phenomena on Caribbean reefs is the general fall in coral cover and rise in macroalgae. Reefs with low coral cover and high macroalgal abundances are often presumed to provide poorer ecosystem functions and services. In this study, we assessed the condition of coral reefs on the Caribbean Coast of Costa Rica and determined how eight key ecosystem metrics varied in response to different coral and fleshy macroalgae covers. Most reefs surveyed had high fleshy macroalgae and low live coral covers, with an average (±SD) of 31 ± 28% and 14 ± 13% per site. The value of many of the ecosystem metrics estimated for coral reefs of the region appears to be lower than what has been reported for other areas in the Caribbean. We found that the rugosity, urchin density, fish richness, total fish biomass, large fish density, and the potential fishery value of the reef were higher in sites with low fleshy macroalgae covers (<10%). Our results concur with the prevailing paradigm that an increase in macroalgae abundance could reduce the ecosystem services provided by coral reefs.
46
Beaulieu, Lucie. "Insights into the Regulation of Algal Proteins and Bioactive Peptides Using Proteomic and Transcriptomic Approaches." Molecules 24, no. 9 (May 2, 2019): 1708. http://dx.doi.org/10.3390/molecules24091708.
Full textAbstract:
Oceans abound in resources of various kinds for R&D and for commercial applications. Monitoring and bioprospecting allow the identification of an increasing number of key natural resources. Macroalgae are essential elements of marine ecosystems as well as a natural resource influenced by dynamic environmental factors. They are not only nutritionally attractive but have also demonstrated potential health benefits such as antioxidant, antihypertensive, and anti-inflammatory activities. Several bioactive peptides have been observed following enzymatic hydrolysis of macroalgal proteins. In addition, significant differences in protein bioactivities and peptide extracts of wild and cultivated macroalgae have been highlighted, but the metabolic pathways giving rise to these bioactive molecules remain largely elusive. Surprisingly, the biochemistry that underlies the environmental stress tolerance of macroalgae has not been well investigated and remains poorly understood. Proteomic and functional genomic approaches based on identifying precursor proteins and bioactive peptides of macroalgae through integrated multi-omics analysis can give insights into their regulation as influenced by abiotic factors. These strategies allow evaluating the proteomics profile of regulation of macroalgae in response to different growth conditions as well as establishing a comparative transcriptome profiling targeting structural protein-coding genes. Elucidation of biochemical pathways in macroalgae could provide an innovative means of enhancing the protein quality of edible macroalgae. This could be ultimately viewed as a powerful way to drive the development of a tailored production and extraction of high value molecules. This review provides an overview of algal proteins and bioactive peptide characterization using proteomics and transcriptomic analyses.
47
Duran, Alain, Ligia Collado-Vides, and Deron E. Burkepile. "Seasonal regulation of herbivory and nutrient effects on macroalgal recruitment and succession in a Florida coral reef." PeerJ 4 (November 2, 2016): e2643. http://dx.doi.org/10.7717/peerj.2643.
Full textAbstract:
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.
48
Correia, Kelly M., Scott B. Alford, Benjamin A. Belgrad, Kelly M. Darnell, M. Zachary Darnell, Bradley T. Furman, Margaret O. Hall, et al. "Drift macroalgal distribution in northern Gulf of Mexico seagrass meadows." PeerJ 10 (August 23, 2022): e13855. http://dx.doi.org/10.7717/peerj.13855.
Full textAbstract:
Drift macroalgae, often found in clumps or mats adjacent to or within seagrass beds, can increase the value of seagrass beds as habitat for nekton via added food resources and structural complexity. But, as algal biomass increases, it can also decrease light availability, inhibit faunal movements, smother benthic communities, and contribute to hypoxia, all of which can reduce nekton abundance. We quantified the abundance and distribution of drift macroalgae within seagrass meadows dominated by turtle grass Thalassia testudinum across the northern Gulf of Mexico and compared seagrass characteristics to macroalgal biomass and distribution. Drift macroalgae were most abundant in areas with higher seagrass shoot densities and intermediate canopy heights. We did not find significant relationships between algal biomass and point measures of salinity, temperature, or depth. The macroalgal genera Laurencia and Gracilaria were present across the study region, Agardhiella and Digenia were collected in the western Gulf of Mexico, and Acanthophora was collected in the eastern Gulf of Mexico. Our survey revealed drift algae to be abundant and widespread throughout seagrass meadows in the northern Gulf of Mexico, which likely influences the habitat value of seagrass ecosystems.
49
Tonetto, AF, CK Peres, MA Khnayfes, and CCZ Branco. "Effects of crevice size on the establishment of macroalgae in subtropical streams." Brazilian Journal of Biology 74, no. 4 (November 2014): 803–9. http://dx.doi.org/10.1590/1519-6984.03813.
Full textAbstract:
Considering that in previous studies, the surface roughness (micrometric dimension) showed a weak effect on the colonization of stream macroalgae, we investigated the effects of different crevice sizes (milimetric dimension, a scale slightly higher than previous investigations) on the macroalgal abundance in three streams exposed to full sunlight in southern Brazil. We used smooth sterile glass plates with different shapes: P – plane surface without crevices; S – sinuous surface (depth of crevices with 0.159 mm ± 0.03); N – non-unifom surface (0.498 mm ± 0.09); C – surfaces with convex structures (1.190 mm ± 0.12); and three additional surface types with different patterns of heterogeneity with combinations of glass pieces: P + S (H1); P + S + N (H2) and P + S + N + C (H3). The plates were placed into the streams and after 105 days the percent cover of macroalgal community was measured. No significant differences among treatments were recorded. However, we observed a trend of macroalgae occurs within the crevices in all treatments and this suggests that, for stream macroalgae, the crevice sizes used in this study was still not enough to provide an expressive algal growth, even in the treatment with bigger crevices.
50
Gubelit, Yulia I. "Opportunistic Macroalgae as a Component in Assessment of Eutrophication." Diversity 14, no. 12 (December 14, 2022): 1112. http://dx.doi.org/10.3390/d14121112.
Full textAbstract:
For the last few decades, coastal eutrophication with the associated mass development of opportunistic macroalgae has increased on a global scale. Since the end of the 2000’s, the number of studies of macroalgal blooms also increased many times. Mass occurrences of such species as Cladophora spp., Ulva spp., and Spirogyra spp. caused a necessity to improve existing methods of ecological assessment and develop new ones. There are many indices based on macroalgae and developed for marine and estuarine ecosystems. However, for correct evaluation, they demand a presence of a number of species, including perennial species from the order Fucales. This requirement cannot be satisfied in fresh or brackish waters, including some estuaries, because often, the freshwater communities are dominated by only one or two opportunistic species. The present paper defines the most relevant topics in studies of macroalgal blooms and reviews indices and metrics which can be recommended for the ecological assessment in diverse habitats influenced or dominated by opportunistic macroalgae species. For ecological assessment of opportunistic communities, according to their seasonal peculiarities, the author recommends, besides biomass, involving evaluation of algal mats (thickness, coverage) and signs of hypoxia.