Journal articles: 'Microphytobentho'

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Sylwestrzak, Zuzanna, Aleksandra Zgrundo, and Filip Pniewski. "Ecotoxicological Studies on the Effect of Roundup® (Glyphosate Formulation) on Marine Benthic Microalgae." International Journal of Environmental Research and Public Health 18, no. 3 (January 20, 2021): 884. http://dx.doi.org/10.3390/ijerph18030884.

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Glyphosate is a very effective herbicide and the main active ingredient in Roundup®—the most extensively used herbicide in the world. Since glyphosate is highly water soluble it reaches water bodies easily in surface water runoff. This prompted us to undertake an experiment to evaluate the effects of glyphosate in Roundup® on natural communities of marine microphytobenthos. Microphytobenthos communities were obtained from the environment, and after transporting them to the laboratory and acclimatizing them, they were tested under controlled conditions. Changes in microphytobenthos composition and structure and the deteriorating condition of the cells of community-forming organisms (assessed by analyzing changes in chloroplast shape) were used to assess the impact of Roundup® on endpoints. The tests indicated that microphytobenthic communities were relatively resistant to herbicide. The species richness of the communities probably enabled them to rebuild effectively. Sensitive species were replaced by those more tolerant of glyphosate. Only at the highest glyphosate concentration (8.5 g·dm−3) tested was a strong negative effect noted that limited community abundance and eliminated some of the organisms. The dominant diatoms in the communities were replaced by intensively developing cyanobacteria, which ultimately comprised nearly 60% of all the cells observed in the communities.

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Böer, S. I., C. Arnosti, J. E. E. van Beusekom, and A. Boetius. "Temporal variations in microbial activities and carbon turnover in subtidal sandy sediments." Biogeosciences Discussions 5, no. 6 (November 6, 2008): 4271–313. http://dx.doi.org/10.5194/bgd-5-4271-2008.

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Abstract. Temporal dynamics and vertical patterns in bacterial abundances and activities were studied in a shallow subtidal sand flat in the Sylt-Rømø Basin (North Frisian Wadden Sea, Germany.) Extracellular enzymatic activities, bacterial carbon production and community respiration showed strong (factor of 4–5) temporal variations that were mostly related to seasonal temperature change, but also to changes in substrate availability. These temporal patterns in activity were barely reflected in bacterial (200–400 mmol C m−2) and microphytobenthic biomass (800–1500 mmol C m−2) or the sedimentary carbohydrate inventory (1300–2900 mmol C m−2), suggesting that grazing controls the standing stocks of the microphytobenthic and bacterial assemblages. Despite their exposure to strong hydrodynamic forces such as tidal currents and wind-induced wave surge, the subtidal sandy sediments showed persistent vertical gradients in bacterial abundances, bacterial carbon production and extracellular enzymatic activities at all times. The vertical distribution of these parameters was tightly coupled to that of the microphytobenthos, dominated by diatoms. Despite the low organic carbon content typical for surge-exposed sandy sediments, high extracellular enzymatic activities and bacterial carbon production rates indicate a very active heterotrophic bacterial community, with a gross secondary productivity of 30–180 mmol C m−2, and a biomass turnover time of 2–18 days. Our data suggest that this high activity is supported by the rapid flux of carbohydrates from microphytobenthic primary productivity. Accordingly, the potential activities of enzymes hydrolyzing carbohydrates cover most of the total bacterial carbon demand during all seasons.

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Böer, S. I., C. Arnosti, J. E. E. van Beusekom, and A. Boetius. "Temporal variations in microbial activities and carbon turnover in subtidal sandy sediments." Biogeosciences 6, no. 7 (July 10, 2009): 1149–65. http://dx.doi.org/10.5194/bg-6-1149-2009.

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Abstract. Temporal dynamics and vertical patterns in bacterial abundances and activities were studied in a shallow subtidal sand flat in the Sylt-Rømø Basin (North Frisian Wadden Sea, Germany). Extracellular enzymatic activities, bacterial carbon production and community respiration showed strong (factor of 4–5) temporal variations that were mostly related to seasonal temperature change and to changes in substrate availability. These temporal patterns in enzymatic activity were barely reflected in bacterial (200–400 mmol C m−2) and microphytobenthic biomass (800–1500 mmol C m−2) or the sedimentary carbohydrate inventory (1300–2900 mmol C m−2), suggesting that grazing controls the standing stocks of the microphytobenthic and bacterial assemblages. Despite their exposure to strong hydrodynamic forces such as tidal currents and wind-induced wave surge, the subtidal sandy sediments showed persistent vertical gradients in bacterial abundances, carbon production and extracellular enzymatic activities at all times. The vertical distribution of these parameters was tightly coupled to that of the microphytobenthos, dominated by diatoms. Despite the low organic carbon content typical for surge-exposed sandy sediments, high extracellular enzymatic activities and bacterial carbon production rates indicate a very active heterotrophic bacterial community, with a gross secondary productivity of 30–180 mmol C m−2, and a biomass turnover time of 2–18 days. Our data suggest that this high activity is supported by the rapid flux of carbohydrates from microphytobenthic primary productivity. Accordingly, the potential activities of enzymes hydrolyzing carbohydrates cover most of the total bacterial carbon demand during all seasons.

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Defew, E. C., T. J. Tolhurst, and D. M. Paterson. "Site-specific features influence sediment stability of intertidal flats." Hydrology and Earth System Sciences 6, no. 6 (December 31, 2002): 971–82. http://dx.doi.org/10.5194/hess-6-971-2002.

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Abstract. The factors that influence the sediment stability and the transport of estuarine mudflats are not yet fully understood but knowledge of them is essential in coastal engineering applications and pollution ecology studies. The suggestion that variation in predictive models of sediment stability might be due to site-specific characteristics is investigated using data from four estuarine mudflats (Eden Estuary, Scotland, the Biezelingsche Ham, Zandkreek, and Molenplaat mudflats in The Netherlands). These estuaries differ in their environmental conditions, macrofaunal species composition and local features (e.g. Enteromorpha mats, migratory biofilms). Stable and unstable sediments were compared, and mean chlorophyll-a concentrations and granulometry of the sediments were significantly different between the two groups. Step-wise multiple linear regressions were applied to the sediment stability data of all sites to establish the influences on erosion threshold of microphytobenthic biomass, water content, granulometry, organic carbon content and the abundance of dominant macrofaunal species. The stability of each site was influenced by different factors. Sediment stability of the Eden Estuary was affected by the Enteromorpha bloom; Biezelingsche Ham was influenced by the highly migratory nature of the diatom biofilms and the abundance of Corophium volutator; the polychaete worm Arenicola marina had a net negative effect on sediment stability of the Zandkreek; and the Molenplaat was influenced by microphytobenthic biomass. This research highlights the need for site-specific calibration of models and suggests that a universal proxy parameter for sediment stability is unlikely to be obtained. Keywords: sediment stability; erosion threshold; cohesive strength meter; microphytobenthos; Enteromorpha spp.

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Sylwestrzak, Zuzanna, Aleksandra Zgrundo, and Filip Pniewski. "Effects of the Ionic Liquid [BMIM]Cl on the Baltic Microphytobenthic Communities." Journal of Marine Science and Engineering 10, no. 9 (September 1, 2022): 1223. http://dx.doi.org/10.3390/jmse10091223.

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Ionic liquids (IL) are regarded as the solution to the modern world’s need to create and use compounds that exhibit a range of desirable properties while having a low environmental impact. However, recent reports are shattering the image of ionic liquids as environmentally friendly substances, especially in relation to the aquatic environment, revealing their potentially toxic effects. To assess the potential environmental impact of ILs, we conducted an experiment involving 1-butyl-3-methylimidazolium chloride ([BMIM]Cl), a substance considered to be the least hazardous among the imidazolium chloride ILs, on Baltic microphytobenthic communities. Microphytobenthos collected from the environment was tested under controlled laboratory conditions, and both the cell counts and the chloroplast condition were used as endpoints. It was shown that [BMIM]Cl at concentrations of 10−3 and 10−2, considered safe based on a cumulative impact assessment, has a negative effect on the condition of the microalgal cells and causes a reduction in population size. Although, under the influence of [BMIM]Cl, only a small proportion of the species was eliminated from the communities, only two species among those important to the communities showed resistance to this compound and eventually began to dominate the communities.

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SANILKUMAR, M. G., A. V. SARAMMA, K. J. JOSEPH, and L. B. CAHOON. "Monsoon Effects on Biomass and Composition of Microphytobenthic Diatoms in the Cochin Estuary, Southwest India." Journal of North Carolina Academy of Science 127, no. 1 (March 1, 2011): 1–12. http://dx.doi.org/10.7572/2167-5880-127.1.1.

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Abstract Microphytobenthos are important primary producers in shallow aquatic ecosystems, but processes regulating this group are poorly understood in comparison to phytoplankton. We examined microphytobenthos at a station in Cochin Estuary for 13 months (February 2005–February 2006) to evaluate effects of the annual southwest monsoon on total biomass, depth distribution and species composition of the microphytobenthos. Significant declines in microphytobenthos and phytoplankton biomass occurred with onset of the southwest monsoon in June 2005. Phytoplankton biomass began to recover before the monsoon rains ended in September 2005, but microphytobenthos biomass recovered only after the rains ended. Microphytobenthos biomass declined throughout the top 5 cm of the sediment column concurrently with declines in abundance of most pennate diatom taxa, particularly larger forms, as well as some macrobenthos taxa. Changes in the microphytobenthos were not consistent with direct effects of the monsoon (changes in salinity, temperature, pH, physical disturbance, and turbidity), but were consistent with the effects of mud deposition by land runoff caused by heavy monsoon rains. These results suggest the hypothesis that sediment loading into estuaries from storm water runoff may have significant negative effects on microphytobenthos and the communities they support.

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Kelly, Julie A., Claire Honeywill, and David M. Paterson. "Microscale analysis of chlorophyll-a in cohesive, intertidal sediments: the implications of microphytobenthos distribution." Journal of the Marine Biological Association of the United Kingdom 81, no. 1 (February 2001): 151–62. http://dx.doi.org/10.1017/s0025315401003496.

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Microphytobenthos are significant primary producers in many coastal systems. It is therefore important to quantify their biomass and productivity. Chlorophyll-a is often used as an index for microphytobenthic biomass. However, complications arise as most studies of sediment properties have been on a millimetre scale, whilst chemical and biological gradients in the surface layers of sediment occur over a microscale. The development of a new technique, the Cryolander (Wiltshire et al., 1997; Wiltshire, 2000), now allows microscale analysis of the sediment surface. Areas of high and low diatom biomass were compared using two coring techniques of different vertical resolution; the Cryolander method, with a vertical resolution of 0·2 mm and plastic core tubes (coarse coring), with a vertical resolution of 5 mm. Results indicated that, except at extreme biomass levels, coarse coring does not detect statistically significant differences in chlorophyll-a between obviously diverse sample sites. This may lead to misinterpretation of seasonal and spatial data when coarse coring is used. Furthermore microscale sectioning allows distinctions to be made between chlorophyll-a measured in the photic zone (photosynthetically active biomass (PAB)) and chlorophyll-a measured below the photic zone (photosynthetically inactive biomass (PIB)), allowing accurate determination of biomass specific primary production.

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Davydov, O. A., and O. V. Kravtsova. "ЕКОЛОГО-МОРФОЛОГІЧНА СТРУКТУРА МІКРОФІТОБЕНТОСУ ОЗЕРА ТЕЛЬБІН." Scientific Issue Ternopil Volodymyr Hnatiuk National Pedagogical University. Series: Biology 80, no. 3-4 (December 1, 2020): 79–84. http://dx.doi.org/10.25128/2078-2357.20.3-4.10.

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The paper considers the findings of studies on ecological-morphological structure of microphytobenthos in Telbin Lake located in the residential community of Kyiv city. The research study aimed to distinguish ecological-morphological groups of algae in microphytobenthos of the human-impacted waterbody within the urban area and to evaluate the role of microphytobenthos structural components in forming a certain type of algal community. Microphytobenthos was sampled with the MB-TE microbenthometer within the littoral area at aquatic-vegetation-free sites and within the deep-water area of the lake. Algae sampling and laboratory processing of samples were performed in accordance with the methods generally accepted in hydrobiology. For diatoms identification permanent slides were made with special high-resolution mounting media. Ecological-morphological groups of benthic algae were distinguished considering the habitats of algae. The relative share in the microphytobenthos species richness was calculated for each group. The degree of human impact on the lake ecosystem was evaluated according to the proven method, consisting in distinguishing the total number of factors, which most frequently affect the lake ecosystem. The findings of studies on the ecological-morphological structure of microphytobenthos in Telbin Lake have made it possible to distinguish 7 ecological-morphological groups of algae. The species richness is mainly formed by periphytont and plankton, and benthonts are for the most part represented by the ecological-morphological group of eurytopic littoral diatoms. In the high-degree human impact waterbody (8 points) the share of benthonts’ major ecological-morphological groups in the species richness decreases in 1.6–2 times, and the shares of periphyton and plankton increase 1.3–2-fold respectively, as compared with low-degree human impact waterbody (3 points). The resulting unstable algal community consisting mainly of species getting to the lake bottom from other habitats is defined as algal aggregation, which is indicative of unfavorable conditions for residential algal flora development. Various waterbodies of Ukraine can differ significantly in the environmental variables playing a determining role in microphytobenthos structure and abundance. Microphytobenthos may act as a reliable biological indicator of aquatic ecosystem’s disturbance caused by human pressure upon waterbodies, responding to such pressure with the transformation of its structural elements. For several waterbodies of Ukraine detailed analysis of microphytobenthos ecological-morphological structure made it possible to characterize bottom algal communities and to distinguish algal cenoses, which allowed to assess ecological state deterioration in different areas of the waterbodies under study. The information on the microphytobenthos structural components of urban lakes is scarce. Therefore, studying the ecological-morphological structure of microphytobenthos in various waterbodies within Kyiv city is of high importance.

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Davydov, O. A., and D. P. Larionova. "САНІТАРНО-ГІДРОБІОЛОГІЧНА ХАРАКТЕРИСТИКА ОЗЕРА ВЕРБНЕ ЗА МІКРОФІТОБЕНТОСОМ." Scientific Issue Ternopil Volodymyr Hnatiuk National Pedagogical University. Series: Biology 77, no. 3 (September 24, 2019): 46–51. http://dx.doi.org/10.25128/2078-2357.19.3.6.

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Assessing ecological and sanitary state of aquatic ecosystems, including their trophic and saprobiological status and impact of human factors, is among key objectives in modern hydrobiology. Apart from common hydrobiological methods (identifying species compositions, calculating algae number and biomass etc), there are specific methods for the assessment of aquatic ecosystems. Bioindication, which is based on aquatic organisms’ response to environmental factors, including human factors, is the most important. Microphytobenthos is highly sensitive to changes in natural and human factors. Its bioindication capabilities are widely known, therefore studying them as part of sanitary and hydrobiological characteristics of various water bodies is of great interest. Water basins across the City of Kyiv are under diversified human impact including various factors and effects, which differ in pressure degree. Thus, using microphytobenthos for sanitary and hydrobiological assessment, even within one type of water basins, has certain aspects, which depend on the bottom algal communities’ stability or degree of transformation. It is often caused by trophic and topic competition between microphytobenthos, phytoplankton and higher aquatic plants, as the latter two can inhibit growth of bottom algae. In the view of the above, special attention should be paid to quantitative characteristics of benthonts, which may act as cenose-forming organisms. The paper examines the findings of the studies on microphytobenthos in Verbne Lake, which is affected by negative human factor – contamination by surface and ground flow from Kyiv City area and is intensively used for recreation. The objective is to study the sanitary and hydrobiological characteristics and ecological quality of Verbne Lake according to microphytobenthos’ biondication indices. Benthic algae were sampled with the MB-TE microbenthometer within the littoral zone in triplicate from the total area of 40 cm2. Algae number was calculated on a counting plate in a 0.1 cm3 drop, their biomass was calculated according to geometric similarity method. Trophic and saprobiological values were assessed in accordance with the scale, proven for microphytobenthos. Saprobity index was calculated according to the Pantle-Buck method in Sladecek modification on the grounds of traditional and modern data on saprobity indicator algae. Benthonts, planktonts and periphytonts were distinguished with consideration taken of their association with particular habitats. Ecological classification of water quality was performed on the grounds of saprobity bioindication (saprobity indices) according to microphytobenthos. For microphytobenthos’ structural components their role in species richness, number and biomass were analyzed. Proceeding from the obtained findings, sanitary and hydrobiological characteristics of Verbne Lake were presented according to microphytobenthos. On the whole, the lake can be classified as mesotrophic, β-mesosaprobic water body. Benthonts proved to play an essential part in forming microphytobenthos’ indicatory characteristics. Intensive phytoplankton growth in the water column and its sedimentation upon the lake bottom inhibit development of benthic algal forms. In accordance with the ecological water quality classification based on microphytobenthos saprobity bioindication results (saprobity indices), the water of Verbne Lake relates to Water Quality Class II, Water Quality Category 3. The most unfavorable situation within the lake’s littoral area was registered in summer, which signals that self-purification processes are becoming less intensive and the aquatic ecosystem state is getting worse.

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Polsenaere, P., E. Lamaud, V. Lafon, J. M. Bonnefond, P. Bretel, B. Delille, J. Deborde, D. Loustau, and G. Abril. "Spatial and temporal CO<sub>2</sub> exchanges measured by Eddy Correlation over a temperate intertidal flat and their relationships to net ecosystem production." Biogeosciences Discussions 8, no. 3 (June 6, 2011): 5451–503. http://dx.doi.org/10.5194/bgd-8-5451-2011.

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Abstract. Measurements of carbon dioxide fluxes were performed over a temperate intertidal mudflat in southwestern France using the micrometeorological Eddy Correlation (EC) technique. EC measurements were carried out in two contrasting sites of the Arcachon lagoon during four periods and in three different seasons (autumn 2007, summer 2008, autumn 2008 and spring 2009). In this paper, spatial and temporal variations in vertical CO2 exchanges at the diurnal, tidal and seasonal scales are presented and discussed. In addition, satellite images of the tidal flat at low tide were used to link the net ecosystem exchange (NEE) with the occupation of the mudflat by primary producers, particularly by Zostera noltii meadows. CO2 fluxes during the four deployments showed important spatial and temporal variations, with the lagoon rapidly shifting from a sink to a source of CO2. CO2 fluxes showed generally low negative (influx) and positive (efflux) values and ranged from −13 to 19 μmol m−2 s−1 at maximum. Low tide and daytime conditions were always characterised by an uptake of atmospheric CO2. In contrast, during immersion and during low tide at night, CO2 fluxes where positive, negative or close to zero, depending on the season and the site. During the autumn of 2007, at the innermost station with a patchy Zostera noltii bed (cover of 22 ± 14 % in the wind direction of measurements), CO2 influx was −1.7 ± 1.7 μmol m−2 s−1 at low tide during the day, and the efflux was 2.7 ± 3.7 μmol m−2 s−1 at low tide during the night. A gross primary production (GPP) of 4.4 μmol m−2 s−1 during emersion could be attributed mostly to microphytobenthic communities. During immersion, the water was a source of CO2 to the atmosphere, suggesting strong heterotrophy or resuspension of microphytobenthic cells. During the summer and autumn of 2008, at the central station with a dense eelgrass bed (92 ± 10 %), CO2 uptakes at low tide during the day were −1.5 ± 1.2 and −0.9 ± 1.7 μmol m−2 s−1, respectively. Nighttime effluxes of CO2 were 1.0 ± 0.9 and 0.2 ± 1.1 μmol m−2 s−1 in summer and autumn, respectively, resulting in a GPP during emersion of 2.5 and 1.1 μmol m−2 s−1, respectively, attributed primarily to the seagrass community. At the same station in April 2009, before Zostera noltii started to grow, the CO2 uptake at low tide during the day was the highest (−2.7 ± 2.0 μmol m−2 s−1) and could be attributed to microphytobenthos dominance on NEP in this case. NEE versus PAR relationships for data ranked by wind directions were generally negative where and when Zostera noltii was dominant and positive when this community was minor. The latter relationship suggests important processes of photo-acclimatisation by the microphytobenthos, such as migration through the sediment. Influxes of CO2 were also observed during immersion at the central station in spring and early autumn and were apparently related to phytoplankton blooms occurring at the mouth of the lagoon, followed by the advection of CO2-depleted water with the tide. Although winter data would be necessary to determine a precise CO2 budget for the lagoon, our results suggest that tidal flat ecosystems are a modest contributor to the CO2 budget of the coastal ocean.

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Jordan, Leonie, Andrew McMinn, and Peter Thompson. "Diurnal changes of photoadaptive pigments in microphytobenthos." Journal of the Marine Biological Association of the United Kingdom 90, no. 5 (October 21, 2009): 1025–32. http://dx.doi.org/10.1017/s0025315409990816.

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Microphytobenthos need photoadaptive strategies to survive the highly dynamic light environment in which they reside. Xanthophyll pigments can provide photoprotection by cycling electrons between epoxide and de-epoxide forms, dissipating excess light energy as heat. This study examined the xanthophyll cycle in microphytobenthos on a tidally exposed substrate at Browns River, Tasmania. Fv/Fm decreased from 0.52±0.01 to 0.47±0.01 at noon in surface samples and a decrease in the diadinoxanthin:chlorophyll-a ratio from 0.022±0.003 to 0.015±0.005 also suggests that the microphytobenthos was under physiological stress at noon. The results indicate that the cells exposed to light at the surface migrated deeper into the sediments and replenished the epoxide form of their xanthophylls. The results suggest that micrphytobenthos utilizes both behavioural and physiological strategies to survive in the dynamic intertidal environment.

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Cintra, Allsay K. A., Selvia Oktaviyani, Tyani Fitrian, and Nurul D. M. Sjafrie. "Pengaruh Liang Boleophthalmus pectinirostris (Linnaeus, 1758) (Actinopterygii:Gobiidae) terhadap Biomassa Mikrofitobenthos di Ekosistem Mangrove Pandansari Brebes Jawa Tengah." Jurnal Kelautan Tropis 23, no. 2 (April 24, 2020): 183–90. http://dx.doi.org/10.14710/jkt.v23i2.6977.

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Mudskippers (Boleophthalmus pectinirostris) in temperate climates make burrows and shallow ponds surrounded by mud walls as a provider of microhabitats for microphytobenthos. In the mangrove ecosystem of Pandansari Brebes there are also Boleophthalmus pectinirostris which make burrows. The purpose of this study is to determine the effect of the Boleophthalmus pectinirostris burrow as a microhabitat for microphytobenthos in the mangrove ecosystem of Pandansari, Kaliwlingi village, Brebes. This research was conducted in mangrove and mudflat beach areas with three transects and three replications each. Samples were taken were burrow structures, temperature, and microphytobenthos biomass in the inner and outer area of the burrow. The results showed a total area of burrows in mudflat beach areas 71.93 ± 24.9cm2/m2 was greater than in mangrove areas 50.51 ± 46.9cm2/m2 because the beach has more mud than in mangrove. Microphytobenthos biomass was fewer in mudflat beach areas than mangrove areas because the density of Boleophthalmus pectinirostris was more on the mudflat. There was no difference in microphytobenthos biomass inside the burrow (mangrove: 1623 ± 1108µg/mm2; mudflat beach: 94.5 ± 67.5µg/mm2) from outside the burrow (mangrove: 2484 ± 3161µg/mm2; mudflat beach: 145 ± 151µg/mm2). This shows that the Boleophthalmus pectinirostris burrow in Pandansari Brebes does not provide microhabitats for microphytobenthos. This is because in the tropics the temperature is almost the same every year so that microphytobenthos can always live every year. Ikan gelodok (Boleophthalmus pectinirostris) di daerah beriklim temperate membuat liang dan juga kolam dangkal yang di kelilingi oleh dinding lumpur sebagai penyedia mikrohabitat bagi mikrofitobenthos. Di ekosistem mangrove Pandansari Brebes juga terdapat B. pectinirostris yang membuat liang. Tujuan penelitian ini mengetahui pengaruh liang ikan gelodok jenis B. pectinirostris sebagai mikrohabitat bagi mikrofitobenthos di ekosistem mangrove daerah Pandansari desa Kaliwlingi Brebes. Penelitian ini dilakukan di daerah mangrove dan daerah pantai berlumpur dengan masing tiga transek dan tiga ulangan. Sampel yang diambil berupa struktur liang, suhu dan biomassa mikrofitobenthos di area dalam dan luar liang. Hasil menunjukan luas liang total lebih besar di daerah pantai 71,93±24,9 cm2/m2 karena pantai memiliki lumpur yang banyak daripada di daerah mangrove 50,51±46,9cm2/m2. Biomassa mikrofitobenthos lebih sedikit di daerah pantai daripada daerah mangrove karena kepadatan B. pectinirostris lebih banyak di pantai. Tidak ada perbedaan biomassa mikrofitobenthos secara signifikan di dalam liang (mangrove: 1623±1108µg/mm2; pantai: 94,5±67,5µg/mm2) dengan di luar liang (mangrove: 2484±3161µg/mm2; pantai:145±151µg/mm2) hal ini menunjukan liang B. pectinirostris di Pandansari Brebes tidak menyediakan mikrohabitat bagi mikrofitobenthos. Hal ini disebabkan di daerah tropis suhu tiap tahun yang hampir sama sehingga mikrofitobenthos dapat selalu hidup tiap tahun

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Jacobs, Pascalle, Jaime Pitarch, Jacco C. Kromkamp, and Catharina J. M. Philippart. "Assessing biomass and primary production of microphytobenthos in depositional coastal systems using spectral information." PLOS ONE 16, no. 7 (July 6, 2021): e0246012. http://dx.doi.org/10.1371/journal.pone.0246012.

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In depositional intertidal coastal systems, primary production is dominated by benthic microalgae (microphytobenthos) inhabiting the mudflats. This benthic productivity is supporting secondary production and supplying important services to humans including food provisioning. Increased frequencies of extreme events in weather (such as heatwaves, storm surges and cloudbursts) are expected to strongly impact the spatiotemporal dynamics of the microphytobenthos and subsequently their contribution to coastal food webs. Within north-western Europe, the years 2018 and 2019 were characterized by record-breaking summer temperatures and accompanying droughts. Field-calibrated satellite data (Sentinel 2) were used to quantify the seasonal dynamics of microphytobenthos biomass and production at an unprecedented spatial and temporal resolution during these years. We demonstrate that the Normalized Difference Vegetation Index (NDVI) should be used with caution in depositional coastal intertidal systems, because it may reflect import of remains of allochthonous pelagic productivity rather than local benthic biomass. We show that the reduction in summer biomass of the benthic microalgae cannot be explained by grazing but was most probably due to the high temperatures. The fivefold increase in salinity from January to September 2018, resulting from reduced river run-off during this exceptionally dry year, cannot have been without consequences for the vitality of the microphytobenthos community and its resistance to wind stress and cloud bursts. Comparison to historical information revealed that primary productivity of microphytobenthos may vary at least fivefold due to variations in environmental conditions. Therefore, ongoing changes in environmental conditions and especially extreme events because of climate change will not only lead to changes in spatiotemporal patterns of benthic primary production but also to changes in biodiversity of life under water and ecosystem services including food supply. Satellite MPB data allows for adequate choices in selecting coastal biodiversity conservation and coastal food supply.

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Gerasimiuk, Valerii, Natalia Gerasimiuk, and Yana Litovchak. "Microphytobenthos of Kuchurgan estuary." Chornomorski Botanical Journal 9, no. 2 (June 1, 2013): 226–37. http://dx.doi.org/10.14255/2308-9628/13.92/8.

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Hardison, A. K., E. A. Canuel, I. C. Anderson, C. R. Tobias, B. Veuger, and M. N. Waters. "Microphytobenthos and benthic macroalgae determine sediment organic matter composition in shallow photic sediments." Biogeosciences 10, no. 8 (August 20, 2013): 5571–88. http://dx.doi.org/10.5194/bg-10-5571-2013.

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Abstract. Microphytobenthos and benthic macroalgae play an important role in system metabolism within shallow coastal bays. However, their independent and interactive influences on sediment organic matter (SOM) are not well understood. We investigated the influence of macroalgae and microphytobenthos on SOM quantity and quality in an experimental mesocosm system using bulk and molecular level (total hydrolyzable amino acids, THAA; phospholipid linked fatty acids, PLFA; pigment) analyses. Our experiment used an incomplete factorial design made up of two factors, each with two levels: (1) light (ambient vs. dark) and (2) macroalgae (presence vs. absence of live macroalgae). Over the course of the 42-day experiment, total organic carbon (TOC) and total nitrogen (TN) increased under ambient light by 173 ± 14 and 141 ± 7%, respectively, compared to in the dark (78 ± 29 and 39 ± 22%). THAA comprised a substantial fraction of SOM (~ 16% of TOC, 35% of TN) and followed TOC and TN accumulation patterns. Mole percent composition of the THAA pool indicated that SOM was composed of more labile organic material (e.g., L-glutamic acid, phenylalanine) under ambient light conditions while SOM in dark treatments was more degraded, with higher proportions of glycine and D-alanine. PLFA content, which represents viable biomass, made up ~ 1% of TOC and contained high levels of algal fatty acids in the light, particularly PLFA derived from diatoms. In the presence of microphytobenthos (i.e., light and macroalgae treatments), SOM lability increased, resulting in the observed increases in bacterial PLFA concentrations. Macroalgae, which were added to half of the light treatments, decreased SOM accumulation compared to light treatments without macroalgae, with TOC and TN increasing by only 130 ± 32 and 94 ± 24%, respectively. This decrease likely resulted from shading by macroalgae, which reduced production of microphytobenthos. The presence of macroalgae decreased SOM lability as well, which resulted in diminished buildup of bacterial biomass. By the final day of the experiment, principal component analysis revealed that sediment composition in treatments with macroalgae was more similar to dark treatments and less similar to light treatments without macroalgae. Overall, microphytobenthos and benthic macroalgae fundamentally altered SOM quality and quantity, which may have notable ecological consequences for shallow-water systems such as increased hypoxia/anoxia, sulfide accumulation, enhanced mineralization and/or stimulated denitrification.

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Vander Grinten, E., W. Admiraal, and M. H. S. Kraak. "Periodic flooding restrains local succession of microphytobenthos in floodplain lakes." Fundamental and Applied Limnology 173, no. 3 (January 21, 2009): 227–36. http://dx.doi.org/10.1127/1863-9135/2008/0173-0227.

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Aberle, N., and K. H. Wiltshire. "Seasonality and diversity patterns of microphytobenthos in a mesotrophic lake." Archiv für Hydrobiologie 167, no. 1-4 (October 5, 2006): 447–65. http://dx.doi.org/10.1127/0003-9136/2006/0167-0447.

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Gorska, Natalia, Ewa Kowalska-Duda, Jacek Marszal, Jan Schmidt, and Zygmunt Klusek. "Impact of Microphytobenthos Photosynthesis on the Characteristics of the Echo Signal from Baltic Sandy Sediments." Archives of Acoustics 40, no. 3 (September 1, 2015): 395–405. http://dx.doi.org/10.1515/aoa-2015-0041.

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Abstract The understanding the influence of biological processes on the characteristics of the signals backscattered by the sea floor is crucial in the development of the hydroacoustical benthic habitat classification techniques. The impact of the microphytobenthos photosynthesis on the acoustical backscattering properties of the Atlantic sandy sediments was previously demonstrated by Holliday et al. (2004) and Wildman and Huettel (2012). To account for the sensitivity of the hydroacoustical classification techniques to the backscattering properties of local marine sediments, it is important to understand the microphytobenthos photosynthesis impact for the Baltic Sea where the techniques are being actively developed now. This is the main motivation of the paper. In the paper the influence of the microphytobenthos photosynthesis on the characteristics of the echo signals reflected by sandy sediments in the typical Baltic temperature and the salinity conditions is discussed. The interdisciplinary multiday laboratory experiment was conducted to study the impact of benthic microalgal photosynthesis on the characteristics of the echo signal reflected by sandy sediments. Hydroacoustical data were collected under controlled constant light, temperature and salinity conditions. The oxygen content at different levels of the water column was simultaneously monitored.

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Pomazkina, G. V., Ye V. Rodionova, and O. M. Mushnikova. "Microphytobenthos of Southern Baikal (Russia)." International Journal on Algae 10, no. 2 (2008): 117–30. http://dx.doi.org/10.1615/interjalgae.v10.i2.20.

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Dyson, Kirstie E., Mark T. Bulling, Martin Solan, Gema Hernandez-Milian, David G. Raffaelli, Piran C. L. White, and David M. Paterson. "Influence of macrofaunal assemblages and environmental heterogeneity on microphytobenthic production in experimental systems." Proceedings of the Royal Society B: Biological Sciences 274, no. 1625 (August 14, 2007): 2547–54. http://dx.doi.org/10.1098/rspb.2007.0922.

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Despite the complexity of natural systems, heterogeneity caused by the fragmentation of habitats has seldom been considered when investigating ecosystem processes. Empirical approaches that have included the influence of heterogeneity tend to be biased towards terrestrial habitats; yet marine systems offer opportunities by virtue of their relative ease of manipulation, rapid response times and the well-understood effects of macrofauna on sediment processes. Here, the influence of heterogeneity on microphytobenthic production in synthetic estuarine assemblages is examined. Heterogeneity was created by enriching patches of sediment with detrital algae ( Enteromorpha intestinalis ) to provide a source of allochthonous organic matter. A gradient of species density for four numerically dominant intertidal macrofauna ( Hediste diversicolor , Hydrobia ulvae , Corophium volutator , Macoma balthica ) was constructed, and microphytobenthic biomass at the sediment surface was measured. Statistical analysis using generalized least squares regression indicated that heterogeneity within our system was a significant driving factor that interacted with macrofaunal density and species identity. Microphytobenthic biomass was highest in enriched patches, suggesting that nutrients were obtained locally from the sediment–water interface and not from the water column. Our findings demonstrate that organic enrichment can cause the development of heterogeneity which influences infaunal bioturbation and consequent nutrient generation, a driver of microphytobenthic production.

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Fonseca, Alessandra Larissa D'Oliveira, Eunice da Costa Machado, Frederico Pereira Brandini, and Nilva Brandini. "Microphytobenthic biomass on a subtropical intertidal flat of Paranaguá bay (Southern Brazil): spatio-temporal distribution and the influence of environmental conditions." Brazilian Journal of Oceanography 61, no. 2 (June 2013): 83–92. http://dx.doi.org/10.1590/s1679-87592013000200001.

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Seasonal and spatial dynamics of the microphytobenthic biomass on a subtropical intertidal sand flat (25°32'S; 48°24'W) was investigated monthly from September 1995 to July 1996. Chlorophyll-a and Phaeophytin-a contents, temperature, salinity, inorganic nitrogen and phosphate pore water concentrations and sediment characteristics were assessed in the upper (HW), middle (MW) and lower (LW) sections of the flat. Microphytobenthic biomass content showed a conspicuous seasonal and spatial gradient. Higher chlorophyll-a contents were registered in the HW section of the tidal flat (from 11.78 µg.gsed-1 to 38.18 µg.gsed-1) decreasing towards the LW section (from 6.23 µg.gsed-1 to 18.23 µg.gsed-1). Microphytobenthic seasonality was determined mainly by turbulence of the water column, which was influenced by atmospheric events. The sediment properties and nutrient concentrations had a significant effect on the spatial and seasonal distribution of pigments on the intertidal flat.

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Oksiyuk, O. P., O. A. Davydov, and Yu I. Karpezo. "Ecological and Morphological Structure of Microphytobenthos." Hydrobiological Journal 45, no. 2 (2009): 13–23. http://dx.doi.org/10.1615/hydrobj.v45.i2.20.

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Davydov, O. A., and D. P. Larionova. "МІКРОФІТОБЕНТОС ЯК БІОІНДИКАТОР ЗМІНИ ГІДРОМОРФОМЕТРИЧНИХ ПАРАМЕТРІВ ВОДНОГО ОБ’ЄКТУ МІСТА КИЄВА." Scientific Issue Ternopil Volodymyr Hnatiuk National Pedagogical University. Series: Biology 78, no. 4 (June 4, 2020): 30–35. http://dx.doi.org/10.25128/2078-2357.19.4.5.

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A great number of water bodies within urban areas of Kyiv City are exposed to human impact. Hydrotechnical construction operations alter their morphometric and hydrological parameters, water bodies are contaminated with various inorganic and organic substances etc. Since human impact upon water bodies has diversified, bioindication is a well-established and effective method of assessing water bodies’ ecological status and measuring the rate of their ecosystems’ disturbance. Microphytobenthos is an important element of aquatic ecosystems and is widely used as a reliable biological indicator. While using microphytobenthos as an ecological community, it is required to evaluate the bioindication efficiency of its indicative structural elements, which respond distinctly to changes in anthropogenic factors on the whole and in the degree of human impact upon water bodies of different types. This paper considers the findings of studying microphytobenthos indicative structural element bioindication characteristics – ecological-morphological group of benthic filamentous blue-green algae and their role in forming the respective parameters among benthonts in the littoral area of Opechen Lower Lake, located within Kyiv City residential community. Large-scale hydrotechnical construction operations conducted in the lake in 2019 greatly affected its hydromorphometric parameters by reducing the shallow-water area and disturbing the bottom sediments stability, which resulted in increase of the human load. The objective of the study was to identify key characteristics of the microphytobenthos indicative structural element under conditions of the lake’s hydromorphometric parameters alteration. Benthic algae were sampled with the MB-TE microbenthometer within the littoral area at aquatic-vegetation-free sites located in the lake’s upper and lower sections. Algae sampling and laboratory processing of samples were performed in accordance with the methods generally accepted in hydrobiology. For diatoms identification permanent slides were made with using special high-resolution mounting media. Autochthonous components in microphytobenthos, the indicative ecological-morphological group of benthic filamentous blue-green algae were distinguished proceeding from algae’s association with particular biotopes. In addition to separate characteristics (species richness, number, biomass), a multimetric index was calculated for the benthonts’ indicative group as an arithmetic average of several characteristics. The degree of human impact upon the lake ecosystem was calculated according to the proven method, consisting in distinguishing the total number of the most obvious human factors with consideration taken of their different intensity. The findings of studying the key characteristics of phytomicrobenthos indicative structural element – benthic filamentous blue-green algae in 2018–2019 confirm their high bioindication efficiency and distinct response to hydromorphometric parameters alteration in Opechen Lower Lake. As a consequence of hydromorphometric alterations the share of these algae in the benthonts’ species richness, number and biomass has decreased by half, and the vegetation-period-average multimetric index has lowered by 1.7. This gives the evidence that the conditions for bottom algae vegetation have worsened.

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Blanchard, G. F., B. Simon-Bouhet, and J. M. Guarini. "Properties of the dynamics of intertidal microphytobenthic biomass." Journal of the Marine Biological Association of the United Kingdom 82, no. 6 (November 21, 2002): 1027–28. http://dx.doi.org/10.1017/s0025315402006574.

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The short-term variability of intertidal microphytobenthic biomass was characterized by analysing a 30-day time series encompassing two spring–neap tide cycles. Chlorophyll-a concentration was measured every day at the beginning and at the end of every diurnal exposure periods. Microalgal biomass exhibited predictible net increases during diurnal exposures due to a positive production-loss balance. In addition, our data series shows that after an environmental disturbance, even though biomass decreased strongly, it converged quickly back to its initial steady-state oscillation pattern. This study supports some fundamental properties of the dynamics of microphytobenthic biomass, as previously predicted in our mathematical model of primary production.

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Герасимюк, В. П., and Х. О. Чемерська. "MICROPHYTOBENTOS OF THE RIVER MERTVOVID." Odesa National University Herald. Biology 19, no. 1(34) (March 27, 2015): 57. http://dx.doi.org/10.18524/2077-1746.2014.1(34).39989.

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Denis, Lionel, and Pierre-Emmanuel Desreumaux. "Short-term variability of intertidal microphytobenthic production using an oxygen microprofiling system." Marine and Freshwater Research 60, no. 7 (2009): 712. http://dx.doi.org/10.1071/mf08070.

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Despite their high productivity and their key role in coastal processes, intertidal areas remain poorly documented because alternating conditions of sediment-water and sediment-air interfaces result in inaccurate temporal estimations of interfacial carbon exchanges. This study describes the short-term variability of microphytobenthic production in an estuarine mudflat (the Canche estuary of the English Channel) by using an autonomous acquisition system for oxygen microprofiles. More than 240 profiles were measured at low and high tide during three deployments performed within a 3-week period (April–May 2007). Additional measurements characterised the surficial sediments (granulometry, porosity, chlorophyll a, temperature, salinity) and incident light. Depth-integrated gross production values were correlated with light intensity and reached up to 146 mg C m–2 h–1, while the turbidity of the overlying water prevented any primary production during immersion. Photosynthesis–irradiance curves were highly variable between field campaigns. Indeed, we have recorded a drastic reduction in microphytobenthic production, which might result from a pulse input of polychaete juveniles (Lanice conchilega). Ephemeral structures, such as invertebrate tubes, are seldom considered as factors that may influence the variability of benthic primary production. Monitoring oxygen microprofiles may be a useful tool for understanding and quantifying the impact of short-term temporal changes on the budgets of microphytobenthic production.

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Ryabushko, L. I., and A. V. Bondarenko. "The microphytobenthos of the Sea of Azov." Russian Journal of Marine Biology 43, no. 4 (July 2017): 249–54. http://dx.doi.org/10.1134/s1063074017040095.

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Méléder, Vona, Bruno Jesus, Alexandre Barnett, Laurent Barillé, and Johann Lavaud. "Microphytobenthos primary production estimated by hyperspectral reflectance." PLOS ONE 13, no. 5 (May 14, 2018): e0197093. http://dx.doi.org/10.1371/journal.pone.0197093.

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Delgado, M., V. N. de Jonge, and H. Peletier. "Experiments on resuspension of natural microphytobenthos populations." Marine Biology 108, no. 2 (June 1991): 321–28. http://dx.doi.org/10.1007/bf01344347.

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Masuda, L. S. M., and A. Enrich-Prast. "Benthic microalgae community response to flooding in a tropical salt flat." Brazilian Journal of Biology 76, no. 3 (April 19, 2016): 577–82. http://dx.doi.org/10.1590/1519-6984.18314.

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Abstract This research evaluated the effect of flooding on the microphytobenthos community structure in a microbial mat from a tropical salt flat. Field samples were collected during four consecutive days: on the first three days the salt flat was dry, on the fourth day it was flooded by rain. In order to evaluate the community maintained in flood conditions, samples from this area were collected and kept in the laboratory for 10 days with sea water. The results of total abundance of microphytobenthos varied from 4.2 × 108 to 2.9 × 109 organisms L–1, total density increased one order of magnitude under the effect of water for both situations of precipitation in the salt flat and in experimental conditions, an increase due to the high abundance of Microcoleus spp. Shannon index (H’) was higher during the desiccation period. Our data suggest that changes in the abundance of organisms were due to the effect of water. The dominance of the most abundant taxa remained the same under conditions of desiccation and influence of water, and there is probably a consortium of microorganisms in the microbial mat that helps to maintain these dominances.

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31

de Jonge, VN, and F. Colijn. "Dynamics of microphytobenthos biomass in the Ems estuary." Marine Ecology Progress Series 104 (1994): 185–96. http://dx.doi.org/10.3354/meps104185.

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Gerasimiuk, V. P. "Species diversity of microphytobenthos of the Red sea." Algologia 23, no. 4 (December 20, 2013): 450–60. http://dx.doi.org/10.15407/alg23.04.450.

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Maggi, E., L. Rindi, M. Dal Bello, D. Fontanini, A. Capocchi, L. Bongiorni, and L. Benedetti-Cecchi. "Spatio-temporal variability in Mediterranean rocky shore microphytobenthos." Marine Ecology Progress Series 575 (July 20, 2017): 17–29. http://dx.doi.org/10.3354/meps12216.

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Longphuirt, SN, A. Leynaert, JM Guarini, L. Chauvaud, P. Claquin, O. Herlory, E. Amice, P. Huonnic, and O. Ragueneau. "Discovery of microphytobenthos migration in the subtidal zone." Marine Ecology Progress Series 328 (December 20, 2006): 143–54. http://dx.doi.org/10.3354/meps328143.

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Giorgi, Adonis, and Leonardo Malacalza. "Biomass variation of microphytobenthos in a plain stream." SIL Proceedings, 1922-2010 25, no. 3 (January 1994): 1883–87. http://dx.doi.org/10.1080/03680770.1992.11900515.

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Blanchard, GF. "Overlapping microscale dispersion patterns of meiofauna and microphytobenthos." Marine Ecology Progress Series 68 (1990): 101–11. http://dx.doi.org/10.3354/meps068101.

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Seuront, Laurent, and Nicolas Spilmont. "Self-organized criticality in intertidal microphytobenthos patch patterns." Physica A: Statistical Mechanics and its Applications 313, no. 3-4 (October 2002): 513–39. http://dx.doi.org/10.1016/s0378-4371(02)00989-5.

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Janousek, Christopher N., Carolyn A. Currin, and Lisa A. Levin. "Succession of microphytobenthos in a restored coastal wetland." Estuaries and Coasts 30, no. 2 (April 2007): 265–76. http://dx.doi.org/10.1007/bf02700169.

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Jesus, B., V. Brotas, M. Marani, and D. M. Paterson. "Spatial dynamics of microphytobenthos determined by PAM fluorescence." Estuarine, Coastal and Shelf Science 65, no. 1-2 (October 2005): 30–42. http://dx.doi.org/10.1016/j.ecss.2005.05.005.

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Masini, R. J., and Arthur J. McComb. "Production by microphytobenthos in the Swan-Canning Estuary." Hydrological Processes 15, no. 13 (2001): 2519–35. http://dx.doi.org/10.1002/hyp.290.

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Lee, Shi Hong, and Andrew McMinn. "Physiological response of temperate microphytobenthos to freezing temperatures." Journal of the Marine Biological Association of the United Kingdom 93, no. 8 (July 2, 2013): 2039–47. http://dx.doi.org/10.1017/s0025315413000593.

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Microphytobenthos (MPB) contributes up to half the primary production of estuaries. These microorganisms are sensitive to changes in sediment temperatures, particularly the extreme temperatures during exposure periods. This study investigates the physiological responses of MPB to freezing temperatures at two locations near Hobart, Tasmania during winter. Photosynthetic parameters were measured at 2 mm intervals to a depth of 10 mm. FV/FM values at three different distances from the shoreline at Kings Beach and Browns River in winter were between 0.584 and 0.617. rETRmax values were between 24.696 and 20.773. Maximum α values peaked in the subsurface rather than at the sediment surface. In vitro laboratory experiments (down to −5°C) showed little difference in response between the control and treatment groups, indicating no apparent effects of short term freezing on the MPB. Little change in photosynthetic parameters in response to freezing was probably associated with the resistance of light-harvesting reactions to freezing temperatures, recovery of the plasmalemma integrity or cryoprotection. Sediment composition and species composition were similar at both sampling sites. Therefore, responses of MPB were not due to species and grain size composition.

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Shadrin, Nickolai, Daria Balycheva, and Elena Anufriieva. "Microphytobenthos in the Hypersaline Water Bodies, the Case of Bay Sivash (Crimea): Is Salinity the Main Determinant of Species Composition?" Water 13, no. 11 (May 30, 2021): 1542. http://dx.doi.org/10.3390/w13111542.

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In hypersaline water bodies, the microphytobenthos plays a very important ecosystem role and demonstrates variability along with a salinity change. Due to anthropogenic activity, the sharp salinity increase in Bay Sivash occurred after 2014. To assess the changes in the microalgae community during the bay ecosystem transformation, the study was conducted four times in 2018 and 2019. At every sampling period, the samples were taken in a salinity gradient (from 7 to 10 sites). A total of 40 species of microalgae were identified during all research, including Cyanobacteria (Cyanophyceae, 2 species), Ochrophyta (Bacillariophyceae, 35 species), Haptophyta (Prymnesiophyceae, 2 species), and Miozoa (Dinophyceae, 1 species). According to the calculated similarity indices of Jaccard and Czekanowski–Sørensen–Dice, the species composition significantly differed during sampling periods. A total of 15 species were recorded at salinities of 80–90 psu, and 10 species at higher salinities, which contribute 64% of all species found in this study. The microalgae abundance was two times more in the floating green algae mat than on the bottom. There was no significant correlation between the number of species and salinity in all sampling periods. In November 2018, a significant positive correlation between the number of species in the sample and total suspended solids (TSS) and dissolved organic matter (DOM) was revealed. A significant correlation between the cell length in different species and salinity and DOM concentration was noted. Before the onset of the salinity increase, 61 species of microalgae were found in Eastern Sivash, of which only 12 have now been recorded, 31% of the currently found species. The characteristics of the total microphytobenthos abundance also significantly changed during all studies. Many characteristics have changed in the bay: the concentration of total suspended matter and dissolved organic matter, the temperature regime, composition of zoobenthos and plankton, and oxygen concentration. Due to this, it is unlikely that only the salinity increase caused the microphytobenthos changes in the lagoon.

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Murolo, Priscila Porchat de Assis, Paulo Vladmir Vandenberg da Costa Carvalho, Monica Lucia Botter Carvalho, Lilia Pereira de Souza-Santos, and Paulo Jorge Parreira dos Santos. "Spatio-Temporal Variations of Microphytobenthos in the Botafogo and Siri estuaries (norteast - Brazil)." Brazilian Journal of Oceanography 54, no. 1 (March 2006): 19–30. http://dx.doi.org/10.1590/s1679-87592006000100002.

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Spatio-temporal variations of microphytobenthic biomass were investigated in the Botafogo and Siri estuaries, Pernambuco - Brazil. Samples were taken during low water (bi-monthly) from February to December, 2003. Three sampling stations were located in each estuary, in both midlittoral and sublittoral areas. Clear spatial and temporal variations were found for both chlorophyll-a and phaeopigment concentrations. In Botafogo, chlorophyll-a had 34% of total variation explained by MRA from nitrogen and phosphorus concentrations, while only 16% of total variation was thus explained from nitrogen concentration in the Siri estuary. Phaeopigments had 39% of total variation explained by MRA from nitrogen concentration and salinity in the Botafogo estuary and 58% of total variation was similarly explained from nitrogen concentration in the Siri estuary. Nitrogen was discriminated by the b coefficients as the most important factor in the explanation of the microphytobenthic pigments variations in the Botafogo estuary. The data of this study emphasize the role of nutrients and suggest that both estuaries show evidence of eutrophication.

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SOUZA, M. F. L. de, and E. C. G. COUTO. "Short-term changes and longitudinal distribution of carbon metabolism in the Piauí River estuary (Sergipe, Brazil)." Revista Brasileira de Biologia 59, no. 2 (May 1999): 195–202. http://dx.doi.org/10.1590/s0034-71081999000200003.

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Net pelagic metabolism (NPM) and net ecosystem metabolism (NEM) were assessed by sigmaCO2 changes in three sampling stations along Piauí River estuary. At the upper estuary station, sampling was carried out over 48 h. Samples exhibited high DIN:DIP ratios. Chlorophyll-a ranged from 0.2 to 2.5 mug.l-1, being higher at the upper estuarine station than marine ones. Net pelagic metabolic rates ranged from -13.2 to 61.2 mgC.m7-2.d-1. Presence of mucilaginous algal material can explain the net mineralization. In the photic period, NPM ranged from-0.05 to 3.04 mgC.m-2h-1. NEM ranged from -7.77 to 6.65 mgC.m-2.d-1. Bottom ressuspension due to microphytobenthic flotation and a high turbidity plume inside de estuary reflected in negative metabolic rates (mineralization). Benthic metabolism was inferred by net system minus pelagic metabolism. Microphytobenthic community seems to be the main responsible for system metabolism, specially in the upper estuary, although the anthropogenic inputs exert strong long term influence.

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Prasad, B. S. R. V., P. D. N. Srinivasu, P. Sarada Varma, A. V. Raman, and Santanu Ray. "Dynamics of Dissolved Oxygen in Relation to Saturation and Health of an Aquatic Body: A Case for Chilka Lagoon, India." Journal of Ecosystems 2014 (February 20, 2014): 1–17. http://dx.doi.org/10.1155/2014/526245.

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Dissolved oxygen (DO) is essential for an aquatic ecosystem since it controls the biological productivity. Here, we propose a unidimensional dynamic model for DO by incorporating biological (photosynthesis, respiration, and mineralization), physical (atmospheric reaeration) and chemical (nitrification) processes so characteristic of shallow coastal water bodies. The analytical study of the proposed model is focussed on supersaturation and undersaturation of oxygen in the water body. The controllability of the ecosystem health has also been investigated. Model results indicate that, while undersaturation of oxygen is largely governed by nitrification and Net Ecosystem Metabolism (NEM), the supersaturation is controlled by photosynthetic activity. The model results are corroborated with observed data collected from Chilka lagoon, India. Subsequently, a biogeochemical model to study the DO variations in Chilka lagoon has been constructed. The model is properly calibrated and validated with observed data. Two independent sets of data (2004-2005 and 2005-2006) were used for model calibration and validation and Chi-square tests supported its robustness (R2=0.982 and 0.987; P<0.05). The model was used to evaluate independently the influence of individual taxa (diatoms, microphytobenthos, and cyanophyceans) on DO variations. Simulations indicate the vital role of microphytobenthos in lagoon DO dynamics and the overall wellbeing.

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Blanchard, Gérard F., Jean-Marc Guarini, Christian Dang, and Pierre Richard. "CHARACTERIZING AND QUANTIFYING PHOTOINHIBITION IN INTERTIDAL MICROPHYTOBENTHOS1." Journal of Phycology 40, no. 4 (June 24, 2004): 692–96. http://dx.doi.org/10.1111/j.1529-8817.2004.03063.x.

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Larson, F., and K. Sundbäck. "Recovery of microphytobenthos and benthic functions after sediment deposition." Marine Ecology Progress Series 446 (February 2, 2012): 31–44. http://dx.doi.org/10.3354/meps09488.

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Oksiyuk, O. P., O. A. Davydov, and Yu I. Karpezo. "Microphytobenthos as Bioindicator of the State of Aquatic Ecosystems." Hydrobiological Journal 47, no. 1 (2011): 72–85. http://dx.doi.org/10.1615/hydrobj.v47.i1.70.

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Gerasimyuk, V. P., and O. A. Kovtun. "Species Diversity of Microphytobenthos of the Red Sea (Egypt)." International Journal on Algae 16, no. 1 (2014): 57–67. http://dx.doi.org/10.1615/interjalgae.v16.i1.40.

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Pomazkina, G. V., E. V. Rodionova, T. A. Scherbakova, and I. V. Khanayev. "Changes of Microphytobenthos in Listvennichnyi Bay, Lake Baikal (Russia)." International Journal on Algae 19, no. 1 (2017): 71–78. http://dx.doi.org/10.1615/interjalgae.v19.i1.60.

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Journal articles on the topic 'Microphytobentho'

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