Lagoon Ecosystem Research Articles

Phytoplankton diversity in Gusii wastewater treatment plant in Kisii county, Kenya

Phytoplanktons are free-floating microscopic plants in water and they are the primary producers providing food to aquatic organisms. However, water quality affects the species production and assemblage in terms of diversity, composition, and abundance. This study assessed the spatial and temporal diversity and abundance of phytoplanktons in the Gusii wastewater treatment plant. A total of 124 phytoplankton species were identified and belonged to six families: Euglenophyceae, Bacillariophyceae, Dinophyceae, Cyanophyceae, Chlorophyceae, and Zygnemophyceae. The phytoplankton biovolume was 385.24mm3/L, with the family Euglenophyceae contributing the largest percentage. The species diversity index (H’) was generally low (H’ = 1.759 and 0.7596) in the effluent and influent respectively, indicating a considerable increase in diversity as the wastewater undergoes treatment. The low diversity was attributed to changes in physical, chemical, and biological environmental conditions. The effluent was richer in species, with a value of 5.829, while the influent was the least with 3.409. The low phytoplankton diversity in the wastewater treatment plant was influenced by the physicochemical parameters. It is therefore recommended that the quality of the wastewater during treatment needs to be monitored continuously for quality as baseline information to guide stakeholders and to ensure sustainability for the Gusii wastewater lagoon ecosystem health.

Sequencing of Coastal Lagoon Samples from the Piñones Lagoon, Puerto Rico, Reveals Important Role of Bacterial Sulfur Metabolism in the Lagoon Ecosystem.

This initial microbial analysis of the Piñones Lagoon shows a high representation of sulfur-oxidizing Sulfurimonas and sulfur-reducing Sulfurospirillum bacteria. These species are likely responsible for maintaining sulfur homeostasis and prevent the buildup of toxic sulfur components, but may contribute to nitrogen buildup, in the mangrove ecosystem.

Stakeholders’ use and preservation valuation of lagoon ecosystems

Globally, lagoons are among the most productive and valuable ecosystems. Human pressure on lagoon ecosystems and their exploitation has been rapidly increasing in recent years. Stakeholder awareness of the existence of lagoon resources and their future potential is vital for future sustainability. This paper explores how and in what circumstances stakeholder preferences relating to lagoon resources differ among key users — fishermen, recreational visitors’ and residents who are subjected to flood damage. In particular, we assess stakeholders’ preferences for lagoon conservation and their deterioration. This is achieved by employing a discrete choice experiment involving 432 respondents using two phases of a repeated survey in Sri Lanka. Our findings suggest that various stakeholders’ perceived value of conservation attributes differ based on their own interest rather than holistic conservation benefits. Moreover, we find that fish diversity, the extent of mangrove coverage, flora and fauna and flood control are the most significant resources in the lagoon ecosystem. This study indicates that lagoon users are seeking greater compensation compared to contributions sought for lagoons’ perceived future benefits. These findings contribute to a growing body of empirical work which points to the heterogeneity of lagoon users’ preferences and from its various stakeholders. This study suggests that ecosystem management strategies should be based on how its various users value its potential benefits rather than on holistic conservation beliefs and attitudes.

Random forest-based understanding and predicting of the impacts of anthropogenic nutrient inputs on the water quality of a tropical lagoon

Seawater quality degradation is caused by diverse, non-linearly interacting factors, knowledge of which is essential for understanding and predicting water quality trends. Currently, most water-quality research has been based on certain assumptions to employ linear approaches for solving simplified problems, such as numerical simulations or cumulative impact assessments. To improve the accuracy and ease of prediction, the random forest method has been increasingly employed as a good alternative to traditional prediction methods. In the present study, the random forest method was adopted to construct a model of the water quality response of Xincun Lagoon to anthropogenic nutrient inputs based on a limited amount of sample data, aiming to (a) identify the critical sources of nutrient inputs that affect the meeting of water quality objectives so as to minimize the socioeconomic impact on secondary stakeholders; and (b) predict the impact of a reduction of anthropogenic nutrient inputs on water quality improvement. It can be seen from the results that the intensity of stressors generated by different human activities presents an obvious non-linear superposition pattern, and the random forest method is one of the feasible solutions to this phenomenon; in addition, the impact on the lagoon ecosystem is not directly related to the intensity of the pressure source, for example, coastal aquaculture is more important than shallow sea cage aquaculture. Therefore, the method established in this paper can be used to identify the key pressure sources during the restoration of the lagoon environment, so as to achieve the unity of economy and effectiveness.

Mangrove cluster as adaptation pattern of mangrove ecosystem in Segara Anakan Lagoon

Segara Anakan Lagoon (SAL) as the specific ecosystem is arranged by the mangrove ecosystem and lagoon ecosystem. The mangrove ecosystem in SAL needs high adaptation to reduce the impact of water tide, water inundation, water salinity, and other factors. This research aimed to analyze mangrove clustering in Segara Anakan Lagoon. The method of this research used Hierarchical Clustering Methods based on mangrove density to analyze cluster adaptation of the mangrove ecosystem. The result showed that (1) The mangrove density (diameter > 4 cm) to analysis mangrove clustering showed that East Segara Anakan had density between 900 – 5425 trees ha-1 (low-very high density ) and West Segara Anakan had density between 133 – 3.367 (low – high density). (2) the mangrove clustering showed that West Segara Anakan had three clusters. The first cluster was arranged by clustering of stations {((15.18),(9.17),(3.6)),8)); ((1.2),5)}. The second cluster was arranged by clustering of stations {(((4.10),14,12))}. And the third cluster was arranged by clustering of stations{(((11.20)16));(7.19))}. (b) East Segara Anakan also was formed by three clusters were the first cluster was formed by clustering of stations (2-(((4, 13), 6) ((1.12), ((4.13) ((5.10) (7.11)))) The second cluster was arranged by clustering of stations (9; ((8.15), (19, (20.21)))) The third cluster was formed by clustering of stations (18 (17, (14,16))).

Organic carbon accumulation in oligotrophic coastal lakes in southern Brazil during the last century

We report organic carbon (OC) accumulation rates in three freshwater ecosystems in southern Brazil, along the largest shallow coastal lagoon ecosystem in the world, the Patos-Mirim-Mangueira. After European colonisation in the seventeenth century, regional wetlands started being replaced by agricultural fields (mostly rice). We used excess 210Pb to develop chronologies for lagoon sediment cores and quantify bulk sediment and OC accumulation rates. In the past 120 years, OC accumulation rates in Mirim and Mangueira Lagoons, which are influenced by rice paddies, averaged 14.9 ± 8.5 and 6.4 ± 3.7 g C m−2 year−1, respectively. Greater accumulation rates were estimated for macrophyte-dominated Nicola Lake (69.9 ± 38.5 g C m−2 year−1) located within the protected Taim Wetland with no direct influence of rice plantations. Starting in the early twentieth century, the construction of dams and drainage canals altered regional hydrology. Despite these anthropogenic changes, only a mild increase in OC accumulation was observed in Mirim Lagoon (15% only in site MIR2) after 1970. Mangueira Lagoon experienced the lowest OC burial rates despite increasing sedimentation rate and OC burial after the mid-1970s. This is probably because these large lakes (> 500 km2) have great nutrient-dilution potential, and their well-mixed water columns prevent nutrients from accumulating in the sediments over time.

A Novel Metagenomic Workflow for Biomonitoring across the Tree of Life using PCR-free Ultra-deep Sequencing of Extracellular eDNA

Biodiversity is declining on a planetary scale at an alarming rate due to anthropogenic factors. Classical biodiversity monitoring approaches are time-consuming, resource-intensive, and not scalable to address the current biodiversity crisis. The environmental DNA-based next-generation biomonitoring framework provides an efficient, scalable, and holistic solution for evaluating changes in various ecological entities. However, its scope is currently limited to monitoring targeted groups of organisms using metabarcoding, which suffers from various PCR-induced biases. To utilise the full potential of next-generation biomonitoring, we intended to develop PCR-free genomic technologies that can deliver unbiased biodiversity data across the tree of life in a single assay. Here, we present a novel metagenomic workflow comprising of a lysis-free extracellular DNA enrichment protocol from large-volume filtered water samples, a completely PCR-free library preparation step, an ultra-deep next-generation sequencing, and a pseudo-taxonomic assignment strategy using the dual lowest common ancestor algorithm. We demonstrate the utility of our approach in a pilot-scale spatially-replicated experimental setup in Chilika, a large hyper-diverse brackish lagoon ecosystem in India. Using incidence-based statistics, we show that biodiversity across the tree of life, from microorganisms to the relatively low-abundant macroorganisms such as Arthropods and Fishes, can be effectively detected with about one billion paired-end reads using our reproducible workflow. With decreasing costs of sequencing and the increasing availability of genomic resources from the earth biogenome project, our approach can be tested in different ecosystems and adapted for large-scale rapid assessment of biodiversity across the tree of life. *1

Gap analysis for DNA barcodes of aquatic macroinvertebrate species in the Southeast of Italy

DNA metabarcoding for the identification of species and ecosystem biomonitoring is a promising innovative approach. The applicability of this tool is at first dependent on the coverage of the DNA sequence reference libraries. We performed a gap analysis of available DNA barcodes in the international databases using the aquatic macroinvertebrate species checklist of the Apulia region in southeast Italy. Our analyses show that 42% of the 1546 examined species do not have representative DNA barcodes in the reference libraries, indicating the importance of working toward their completeness and addressing this effort toward specific taxonomic groups in particular at local/regional level. The DNA-barcode coverage also varies among different taxonomic groups and aquatic ecosystem types in which a large number of species are rare. We also analyzed the DNA barcode reference libraries for the primer set used to barcode species. Only for 52% of the examined barcoded species were the primers reported, indicating the importance of uploading this information in the databases for a more extensive use of the DNA metabarcoding. We also highlighted the opportunity to develop combinations of primers useful at the regional level. We tested the application of the DNA barcoding single species to a lagoon ecosystem (the lagoon named “Aquatina di Frigole” in the Apulia region) which are richer in humic substances than other aquatic environments and in which DNA metabarcoding remains under explored.

The emergent fouling population after severe eutrophication in the Mar Menor coastal lagoon

Mar Menor is one of the largest coastal lagoons in the Mediterranean basin. Over the years, Mar Menor has suffered a significant environmental degradation due to multiple factors with anthropogenic origin. The transformation from a rain-fed basin to intensive irrigated agriculture has led to an rise in the water inflow and nutrients in the basin, which has provoked severe eutrophication. The increase in nutrients led to changes in the structure and function of the lagoon ecosystems. The epibenthic and suspension feeder organisms have benefited from this imbalance, proliferating and reaching a high population density. The composition and abundance of the species assemblage found in the sub-coastal bottoms of the coastal lagoon after the environmental crisis occurred in 2016, using artificial settlement structures. The variation in community density and affinity between sampling sites in 2017 and 2018, were determined. A total of 31 species belonging to 27 genera and 7 phyla were observed in 11 samples. The best represented class are polychaeta (Phylum Annelida) with 11 identified species. The genus with the greatest species richness was Hydroides with two species: H. dianthus (Verrill, 1873), and H. elegans (Haswell, 1883), both of them considered potentially invasive and opportunistic species followed by the genus Serpula, with two species: S. vermicularis (Linnaeus, 1767), and S. concharum (Langerhans, 1880) and the genus Branchiomma was represented with another exotic invasive species, B. boholense (Grube, 1878), which is only found in collectors in 2018. These results have allowed to increase the knowledge about the effect of eutrophication in the structure of the fouling community in the assemblage succession in the Mar Menor coastal lagoon.

Niche overlap among anglers, fishers and cormorants and their removals of fish biomass: A case from brackish lagoon ecosystems in the southern Baltic Sea

We used time series, diet studies and angler surveys to examine the potential for conflict in brackish lagoon fisheries of the southern Baltic Sea in Germany, specifically focusing on interactions among commercial and recreational fisheries as well as fisheries and cormorants (Phalacrocorax carbo sinensis). For the time period between 2011 and 2015, commercial fisheries were responsible for the largest total fish biomass extraction (5,300 t per year), followed by cormorants (2,394 t per year) and recreational fishers (966 t per year). Commercial fishing dominated the removals of most marine and diadromous fish, specifically herring (Clupea harengus), while cormorants dominated the biomass extraction of smaller-bodied coastal freshwater fish, specifically perch (Perca fluviatilis) and roach (Rutilus rutilus). Pike (Esox lucius) as large-bodied freshwater fish was the only species where recreational fisheries were responsible for the major fraction of the annual biomass extraction. A strong trophic overlap and hence a similar foraging niche was documented among commercial fishers and recreational anglers and among non-resident and resident anglers, indicating that the aversion expressed by anglers against commercial fisheries in a survey had an objective underpinning related to resource competition. By contrast, the foraging niches of cormorants and of both fishers and anglers differed strongly as evidenced by largely non-overlapping sets of species that were caught and removed by cormorants and by commercial as well as recreational fishers. However, for individual species of commercial and recreational interest, specifically perch, cormorants were responsible for a major fraction of total biomass extraction, suggesting that at the individual fish species level competition with fishers and anglers may still occur. In an angler survey, respondents expressed a preference for cormorant control, indicating the existence of conflict between fisheries and cormorants. We recommend that conflicts in the lagoon fisheries be proactively managed, e.g., through improved communication, zoning, predator control and outreach. Further research should clarify the population-level impacts of cormorants on target species of commercial and recreational fisheries as well as the relative impact of commercial and recreational fisheries on selected species of joint interest.

The seasonal phases of an Arctic lagoon reveal the discontinuities of pH variability and CO<sub>2</sub> flux at the air–sea interface

Abstract. The western Arctic Ocean, including its shelves and coastal habitats, has become a focus in ocean acidification research over the past decade as the colder waters of the region and the reduction of sea ice appear to promote the uptake of excess atmospheric CO2. Due to seasonal sea ice coverage, high-frequency monitoring of pH or other carbonate chemistry parameters is typically limited to infrequent ship-based transects during ice-free summers. This approach has failed to capture year-round nearshore carbonate chemistry dynamics which is modulated by biological metabolism in response to abundant allochthonous organic matter to the narrow shelf of the Beaufort Sea and adjacent regions. The coastline of the Beaufort Sea comprises a series of lagoons that account for > 50 % of the land–sea interface. The lagoon ecosystems are novel features that cycle between “open” and “closed” phases (i.e., ice-free and ice-covered, respectively). In this study, we collected high-frequency pH, salinity, temperature, and photosynthetically active radiation (PAR) measurements in association with the Beaufort Lagoon Ecosystems – Long Term Ecological Research program – for an entire calendar year in Kaktovik Lagoon, Alaska, USA, capturing two open-water phases and one closed phase. Hourly pH variability during the open-water phases are some of the fastest rates reported, exceeding 0.4 units. Baseline pH varied substantially between the open phase in 2018 and open phase in 2019 from ∼ 7.85 to 8.05, respectively, despite similar hourly rates of change. Salinity–pH relationships were mixed during all three phases, displaying no correlation in the 2018 open phase, a negative correlation in the 2018/19 closed phase, and a positive correlation during the 2019 open phase. The high frequency of pH variability could partially be explained by photosynthesis–respiration cycles as correlation coefficients between daily average pH and PAR were 0.46 and 0.64 for 2018 and 2019 open phases, respectively. The estimated annual daily average CO2 efflux (from sea to atmosphere) was 5.9 ± 19.3 mmolm-2d-1, which is converse to the negative influx of CO2 estimated for the coastal Beaufort Sea despite exhibiting extreme variability. Considering the geomorphic differences such as depth and enclosure in Beaufort Sea lagoons, further investigation is needed to assess whether there are periods of the open phase in which lagoons are sources of carbon to the atmosphere, potentially offsetting the predicted sink capacity of the greater Beaufort Sea.

Spatial and seasonal variation of trace elements contamination in the sediments of a tropical lagoon ecosystem: the Lake Togo-Lagoon of Aného complex (southern Togo)

The Lake Togo-Lagoon of Aneho complex is located in the area of the phosphorite mining which produces different types of waste that are dumped directly into the surrounding environment without treatment. In addition, the contributions of its tributaries after leaching agricultural and urban soils need to be considered. This increases the risk of contamination of the hydrosystem, especially the sediments in trace elements. The objective of this study is to evaluate the level of trace elements contamination and their spatial and seasonal variation in the sediments of the Lake Togo-Lagoon of Aneho complex. The sediment physicochemical parameters were determined in line with French standards. The trace elements were determined using an Atomic Absorption Spectrometer coupled to a hydride and cold vapour generator. The spatial and seasonal variation was assessed using Ordinary Kriging Interpolation method. The average content of trace elements in sediments in mg/kg was as follow: Cd: 0.75, Pb: 13.26, Cr: 50.63, Ni: 36.05, Cu: 10.90, Hg: 0.04, As: 3.88, Zn: 47.38 and Mn: 766.74 in the dry season. In rainy season, the average concentration was: Cd: 0.46, Pb: 9.50, Cr: 27.43, Ni: 21.36, Cu: 9.61, Hg: 0.05, As: 5.23, Zn: 39.21 and Mn: 910.08. These concentrations showed a strong spatial variation. Significant seasonal variations were obtained for conductivity, organic matter as well as for Cd, Pb, Cr, Ni, Hg and As. The sediments were found to be weakly to moderately contaminated and enriched by trace elements with a higher contamination for Cd. The sediments may have low to moderate adverse effects on aquatic living organisms. This trace element contamination is of anthropogenic origin through the phosphorite mining and the agricultural and urban effluents. Therefore, this lagoon ecosystem warrants regular monitoring for better understanding to inform protection of the resource.

Blackfordia virginica blooms shift the trophic structure to smaller size plankton in subtropical shallow waters

The hydromedusa Blackfordia virginica is an invasive species that has disrupted coastal marine food webs throughout the world. Here, we report the response of plankton community to B. virginica blooms in a subtropical lagoon in China. Chlorophyll-a concentrations increased after the peak of B. virginica abundance, which was coincident with high concentrations of ammonium. An increase of the biomass and composition of pico- and nano-phytoplankton during the bloom resulted from bottom-up effects due to the nutrients excreted by B. virginica. The average size and grazing rates of microzooplankton concurrently decreased. The negative correlation between the abundances of B. virginica and microzooplankton was accurately simulated by a generalized linear model and redundancy analysis. This study provided empirical evidence of the impacts of the B. virginica bloom on the food web and the mechanisms responsible for those effects. These impacts may lead to serious ecological and environmental consequences for the lagoonal ecosystem.

Monitoring Skeletal Anomalies in Big-Scale Sand Smelt, Atherina boyeri, as a Potential Complementary Tool for Early Detection of Effects of Anthropic Pressure in Coastal Lagoons

Mediterranean coastal lagoons are increasingly affected by several threats, all concurrently leading to habitat degradation and loss. Methods based on fish for the assessment of the ecological status are under implementation for the Water Framework Directive requirements, to assess the overall quality of coastal lagoons. Complementary tools based on the use of single fish species as biological indicators could be useful as early detection methods of anthropogenic impacts. The analysis of skeletal anomalies in the big-scale sand smelt, Atherina boyeri, from nine Mediterranean coastal lagoons in Italy was carried out. Along with the morphological examination of fish, the environmental status of the nine lagoons was evaluated using a method based on expert judgement, by selecting and quantifying several environmental descriptors of direct and indirect human pressures acting on lagoon ecosystems. The average individual anomaly load and the frequency of individuals with severe anomalies allow to discriminate big-scale sand smelt samples on the basis of the site and of its quality status. Furthermore, a relationship between skeletal anomalies and the environmental quality of specific lagoons, driven by the anthropogenic pressures acting on them, was found. These findings support the potentiality of skeletal anomalies monitoring in big-scale sand smelt as a tool for early detection of anthropogenic impacts in coastal lagoons of the Mediterranean region.

An Integrated Environmental Assessment of a coastal lagoon: The Case of the Oualidia lagoon (Morocco)

This paper aims to present a comprehensive socio-economic and environmental analysis of the Oualidia lagoon in Morocco. This lagoon is classified as a RAMSAR site since 2005, providing valuable ecosystem services for the surrounding population. This paper followed the Drivers-Activities-Pressures-State-Change-Impact-Responses (DPSIR) framework to evaluate environmental condition changes within the lagoon to support decision-making. The present research suggests a potential future model for safeguarding the lagoon's ecosystem without risking the well-being of future generations.

The Sedimentation Impact for the Lagoon and Mangrove Stabilization

Sedimentation causes land accretion, silting river water, lagoon, and mangrove degradation. The current study aims to analyze the potential and the impact of sedimentation toward the potential of the lagoon and mangrove ecosystem in Segara Anakan Lagoon. The research methods used mapping analysis, total suspended solid analysis (TSS), sedimentation rate analysis, biodiversity analysis, and mangrove covering. The result showed that (1) the value of TSS between 0.25-1,16 g L-1 (2) sediment flux between 6,8 - 257,7 g m-2s-1 (3) annual rate of sedimentation in West Segara Anakan Lagoon (W-SAL) between 13.82 – 15.49 m yr-1. (4) The effects of sedimentation were (a) the remaining lagoon of West Segara Anakan Lagoon (W-SAL) which was 1.200 ha, (b) land accretion in W-SAL between 27.24 – 160.18 m (1994 – 2003) and 20.91 – 107.55 m (2003 2014), (c) the remaining mangrove of SAL less than 2594 ha (d) the mangrove diversity ranged between 0.48 – 1.71 (low – moderate), (e) the mangrove density of trees were 46 - 205 trees ha-1 (degraded) (5) mangrove landscape was developed to reduce the impact of sedimentation, especially the first zone of mangrove landscaping was dominated by Aegiceras Floridum, Avicennia Alba, Avicennia Marina, Sonneratia Caseolaris, and Sonneratia alba.

Bentho-pelagic mismatches in intertidal sandflats in relation to seasonal upwelling: the role of endobenthic ecosystem engineering

Allochthonous transfers are ubiquitous features of marine ecosystems. While these transfers typically subsidise recipient ecosystems and increase donor control, mismatches in allochthony and biotic recipients can also occur. However, driving processes are not well understood, particularly in the context of biotic determinants in coastal ecosystems. Using a 2 yr dataset, we show that allochthonous inputs related to seasonal offshore upwelling on the west coast of South Africa do not lead to strengthening of bottom-up regulation in intertidal lagoonal sandflat ecosystems. Despite an increase in mean phytoplankton biomass by 46.4% at benthic study sites during summer upwelling seasons, benthic primary producer (microphytobenthos) biomass did not increase proportionally, and neither did consumer (macro- and meiofauna) population metrics. Unexpectedly, levels of these response variables were greater during winter downwelling periods than upwelling phases. Correlation analyses indicated that the bentho-pelagic mismatch documented in relation to upwelling may be related to coincidental increases in densities of endobenthic burrowing sandprawnsKraussillichirus kraussi, which are key ecosystem engineers, principally due to rapid sediment reworking and destabilisation. The predominantly negative correlations recorded between benthic response variables and sandprawn density align with our past experimental work, suggesting that the suppressive effect of sandprawns on benthic primary producers and consumers evident in small-scale experiments also manifests over large temporal scales, thereby overriding potential subsidising effects of upwelling. Our findings indicate that in sandflat ecosystems, endobenthic ecosystem engineers that are rapid benthic destabilisers may be important in determining responses to marine allochthonous inputs and the degree of donor control in recipient ecosystems.

FOOD AND FEEDING HABITS OF MUGIL CEPHALUS (LINNE, 1758) FROM GRAND-LAHOU LAGOON (COTE DIVOIRE)

Mugil cephalus is a permanent and abundant fish species in coastal, estuarine or lagoon ecosystems. This species was sampled in the lagoon of Grand-Lahou (Cote dIvoire) for the study of its diet and its feeding ethology. Stomachs were removed and their contents identified using identification keys to determine the diet. 88 specimens of M. cephalus were examined for food and feeding habits. 42 (47.72%) of the fish had empty stomach. Analysis of stomach contents showed that phytoplankton is the most consumed with a numerical percentage of occurrence of 94.98% (Cyanobacteria, Chlorophytes, Diatoms) and a percentage of occurrence is 64.9%. The proportion of zooplankton is 4.98% (cladocerans, copepods, foraminifera, rotifers and nematodes) according to the numerical percentage and 18.77% according to the frequency of occurrence. Detritus has an occurrence percentage of 8.43 %. Diet is mainly composed of diatom.

Spatial distribution of benthic foraminifera in the Lagos Lagoon (Nigeria): Tracing the impact of environmental perturbations.

Lagos Lagoon is among Africa’s largest estuarine ecosystems, bordered by one of the fastest growing megacities in the world and the ultimate repository of contaminants carried in industrial, municipal and agricultural wastes. The high levels of pollutants have progressively deteriorated the water quality, adversely affected lagoon ecosystems, impacted the livelihood of the coastal population and pose serious risks to human health. Benthic foraminifera are excellent proxies and sensitive bioindicators of environmental disturbances but comprehensive studies on the structure, distribution, diversity and impact of pollution upon foraminiferal communities have not yet been conducted in the Lagos Lagoon. To demonstrate the potential of foraminifera as proxies of environmental perturbations, benthic foraminifera were investigated on a lagoon-wide basis. Lagos Lagoon comprises areas that range from low levels of direct impact to those of severely affected by various forms of anthropogenic disturbance. The goals of this study are to analyze patterns of distribution and species richness, to document foraminiferal community structures, and to identify taxa that track documented records of pollution in Lagos Lagoon sediments. Heat maps were generated from abundance records for selected species to illustrate environmental preferences and relative resistance levels to individual forms of anthropogenic disturbance. Sediments were analyzed for a range of physicochemical properties, via a multi-parameter sensor probe-device, including temperature, pH, depth and total dissolved solids (TDS). Quantitative analysis of 24 sediment samples yielded a total 3872 individuals of benthic foraminifera that belong to 42 species and 25 genera. They comprise 10 porcellaneous, 22 hyaline perforate and 10 agglutinated species. Ammobaculites exiguus, Ammotium salsum, Ammonia aoteana, Ammonia convexa and Trochammina sp. 1 have been found to be the most abundant species. For the first time, the complete present-day foraminifera fauna is illustrated here via scanning electron microscopy. The features recorded allow to assess the spatial effects of pollution upon foraminiferal assemblages on a lagoon-wide basis. The data generated may ultimately form the basis to assess the progressive deterioration of Lagos Lagoon ecosystems from cores by using benthic foraminifera as bioindicators of environmental perturbation.

Species Diversity and Trophic Structure of Macrobenthos Communities in Lagoon Ecosystems (Kandalaksha Bay, White Sea)

The species composition and spatial and trophic structure of the macrobenthos were studied in several lagoon ecosystems (Kandalaksha Bay, White Sea). The main changes in the species diversity and trophic structure were observed with regard to the sea level, from the upper littoral to the middle and lower littoral, and then to the sublittoral. The macrobenthic communities of lagoons more strongly protected from the sea (lagoons of Ermolinskaya Inlet and those in the inner part of Kislaya Inlet located near Ershovskoe Lake) were characterized by the most similar species composition and trophic structure in the tidal zone; in contrast, the most pronounced differences in the sublittoral were observed for the macrobenthic communities of the lagoons more exposed and thus more connected to the sea (lagoon ecosystems in the inner part of Kislaya Inlet). As the connection of the lagoon to the sea decreases, the sedimentation rate, the siltation of sediments, and water desalination grow; the diversity of trophic groups decreases accordingly. The number of detritophagous species increases gradually.