Brackish Water Ecosystem Research Articles

Pelatihan Pembuatan Stik Ikan Berbasis Bahan Dasar Lokal di Ekosistem Gambut Desa Bahaur Hulu Permai, Kabupaten Pulang Pisau

The aim of training activities in Bahaur Hulu Permai Village is an effort to improve the abilities and skills of people living in peat ecosystems, especially in coastal areas. Coastal areas not only have potential as fisheries resources, but also agriculture in a broad sense. The main income of coastal communities is marine fisheries and brackish water fisheries, if they are in a brackish water ecosystem. The potential for marine and river fisheries and land fisheries in Indonesia is very large. The problem is that people in coastal areas are still unable to manage natural potential into goods or products that have high economic benefits. The importance of increasing the abilities and skills of communities in coastal areas by conducting outreach, counseling and training in making fish-based food. One of the activities that can be improved is making fish sticks, in order to increase income for fishing families in particular, and coastal communities in general.

Embryonic and Pre-Larval Developmental Patterns in Cryptocentroides arabicus (Teleostei, Gobiidae).

The Arabian goby, Cryptocentroides arabicus (Gobiidae: Gobiinae), is a significant species in marine and brackish water ecosystems. However, limited information is available about the reproductive biology and the early life history of this species. This study aimed to understand the embryonic and pre-larval development of C. arabicus under controlled laboratory conditions using light microscopy. Ten fish pairs were placed in five 70-L glass aquaria, and environmental parameters were carefully monitored. After 4 months, spawning began, with each event yielding between 700 and 1500 eggs, totaling 10 spawning events. The elliptical-shaped eggs, measuring 3.9 ± 0.1 mm in length and 1.6 mm in maximum width, hatched after 7 days and 4 h at a water temperature of 28°C. This process resulted in the identification of eight distinct larval developmental stages. Parental care by both the male and female was observed during the incubation period. Documenting the morphological changes during incubation contributes to a better understanding of the reproductive behaviour and early life history of C. arabicus. This is essential for the conservation management of marine and brackish water environments.

A systematic review on analytical methods of the neurotoxin β-N-methylamino-L-alanine (BMAA), and its causative microalgae and distribution in the environment

β-N-Methylamino-L-alanine (BMAA), a neurotoxin produced by various microalgal groups, is associated with neurodegenerative diseases and is considered a major environmental factor potentially linked to sporadic amyotrophic lateral sclerosis. This study systematically reviews the analytical methods used to study BMAA in publications from 2019 to the present. It also investigates the causative microalgae of BMAA and its geographical distributions in aquatic ecosystems based on studies conducted since 2003. A comprehensive search using the Web of Science database revealed that hydrolysis for extraction (67%), followed by quantification using LC-MS/MS (LC: 84%; MS/MS: 88%), is the most commonly employed method in BMAA analysis. Among analytical methods, RPLC-MS/MS had the highest percentage (88%) of BMAA-positive results and included a high number of quality control (QC) assessments. Various genera of cyanobacteria and diatoms have been reported to produce BMAA. The widespread geographical distribution of BMAA across diverse ecosystems highlights significant environmental and public health concerns. Notably, BMAA accumulation and biomagnification are likely more potent in marine or brackish water ecosystems than in freshwater ecosystems, potentially amplifying its ecological impacts. Future research should prioritize advanced, sensitive methods, particularly LC-MS/MS with as many QC assessments as possible, and should expand investigations to identify novel microalgal producers and previously uncharted geographical areas, with a special focus on marine or brackish water ecosystems. This effort will enhance our understanding of the environmental distribution and impacts of BMAA.

Electrolyzed Water Treatment for the Control of the Zoonotic Pathogen Vibrio vulnificus in Aquaculture: A One Health Perspective.

Vibrio vulnificus (Vv) is a bacterial pathogen native to warm and brackish water ecosystems that can cause fatal septicemia (Vv-vibriosis) in humans and various farmed fish species. From a One Health perspective, controlling Vv-vibriosis outbreaks on farms is essential not only for animal but also for human health, as it reduces the risk of Vv transmission to humans. Electrolyzed water (EW) is a sustainable control method, exhibiting transient disinfectant properties due to the formation of hypochlorous acid (HOCl). We hypothesized that EW could effectively reduce Vv populations in aquaculture facilities, preventing outbreak emergence. To test this hypothesis, survival assays in EW were conducted under varying conditions of salinity, pH, and free available chlorine (FAC). The results indicated that an intermediate concentration of FAC had a significant bactericidal effect on Vv populations regardless of the condition and tested strain. Consequently, the strategic use of EW could serve as an eco-friendly preventive and control measure against Vv-vibriosis by significantly decreasing the bacterial load in farm water.

Comparison of the Proximate Composition of Liver and Muscle Tissue Contents in Freshwater and Brackishwater Tilapia, Oreochromis mossambicus

The purpose of the study was to examine the closely related composition of freshwater and brackish fish Oreochromis mossambicus. The fish was brought to the lab and sacrificed for further research. The muscle and liver tissues were processed for moisture, ash, protein, carbohydrate and lipids estimations. The outcomes of the current study showed that the moisture (77.09%), ash (0.78%), protein (195.72mg/gm), lipids (23.07mg/gm) and carbohydrate (15.84mg/gm) content were higher in freshwater fish when compared to brackish water fish. Protein (205.19mg/gm), lipids (3.25mg/gm) and carbohydrate (0.42mg/gm) content were higher in freshwater fish when compared to the liver of brackish water fish. Brackish water fish’s proximate composition in muscle and liver was protein, lipids and carbohydrates are significantly (P<0.05) decreased as compared with freshwater fish. As a result, the chemical composition of fish from brackish water sources has been affected by brackish water ecosystems and, at the same time, the dry matter content, in protein and protein as well as the declared carbohydrate and fat content have been reduced.

Watershed Development-Present Status and Fisheries Perspectives in Indian Context

India encompasses a rich aquatic biodiversity, hosting vast arrays of freshwater, brackish water, and marine ecosystems. These unique landscapes harbor abundant fisheries resources, constituting primary protein sources and income channels for millions. Fisheries are an essential source of food security, livelihoods, employment generation, recreation, trade, and foreign exchange earnings worldwide. However, over exploitation, pollution, habitat destruction, climate change, invasive species, and other anthropogenic activities threaten fisheries resources’ sustainability. Therefore, integrated approaches like watershed management can help restore and maintain aquatic ecosystem health, ensuring sustainable fish production while enhancing social welfare. This article explores the significance of watershed development in conserving fisheries resources and promoting their long-term viability.Watershed development plays a pivotal role in nurturing sustainable aquatic ecosystems and enhancing fisheries production in India. Amid intensified exploitative pressures coupled with changing climatic scenarios, watershed development emerges as an integral intervention toward sustainable fisheries conservation and management. Despite considerable progress made, certain constraints persist, necessitating targeted strategies for optimal outcomes. This article evaluates the current scenario, future possibilities, and viewpoints concerning watershed development vis-a-vis fisheries in India.

A comprehensive study on ecological insights of Ulva lactuca seaweed bloom in a lagoon along the southeast coast of India

Ulva lactuca, commonly known as sea lettuce is a green macroalgae (chlorophyta) and its uncontrolled proliferation forms a bloom, which causes ecological imbalances and adversely impacts brackishwater ecosystems. Algal bloom can harm the environment and aquatic organisms, but it can also be beneficial if harvested and utilized for industrial purposes. A massive bloom of green macroalgae was observed in the Muttukadu lagoon, located along the southeast coast of India in the Bay of Bengal. A comprehensive study was taken up to assess the spatial distribution, proximate, nutrients, minerals, heavy metals, and factors inducing the bloom. For this study, high-resolution satellite images (Sentinel 2) were used. The spatial distribution of seaweed was mapped using Floating Algae Index (FAI), Modified Floating Algae Index (MFAI), Normalized Difference Red Edge (NDRE) Index and Seaweed Index (SI) models. Results were validated using the MAVIC 3 pro drone and field survey. The SI model was found to be more accurate compared to other models. The bloom exhibited notable temporal dynamics, with peak coverage observed in the last week of May 2023 with a spread area of about 100.05 ha, the bloom intensity was found to be high till the last week of June 2023, after which it gradually declined. The proximate composition (%) of Ulva lactuca showed the moisture content is about 80.00 ± 2.98, crude protein 24.17 ± 1.80, crude lipid 0.81 ± 0.05, Total Ash 37.45 ± 1.44, Fiber (8.92 ± 0.41), and Acid Insoluble Ash (16.18 ± 1.16). The mineral concentration was in the order Ca > Na > Mg > K > P. Iron (Fe) was observed to be high compared to other micronutrients, with a concentration of 1164.40 mg/kg. Rich nutrients and low heavy metal concentration significantly can boost the selling cost of Ulva lactuca providing livelihood support for the coastal fisherfolk.

Assessing Impacts of Flood Diversion on the Ecosystem of Brackish-Water Lakes through Simulation-Optimization Model

This study develops and evaluates a simulation-optimization approach to mitigate the environmental impacts of freshwater pulses in brackish-water lakes whilst maximizing flood diversion benefits. Lake Pontchartrain, located downstream of the Mississippi River, Mississippi, United States, is a brackish-water ecosystem threatened by reducing salinity concentrations due to freshwater pulses from the flood diversion project on the Mississippi River. An adaptive neuro-fuzzy-inference-system-based model was developed as a data-driven model for simulating salinity distribution at a representative station of Lake Pontchartrain. Then, the data-driven model was used as the simulator in the optimization system. Both single-objective and multi-objective particle swarm optimizations were used to find the optimal solutions. Results show that the data-driven model is robust at simulating the salinity time series in the brackish-water ecosystem of Lake Pontchartrain. The Nash–Sutcliffe efficiency index of the data-driven model between measured and modelled salinity is 0.85, which means the model is reliable for applying in further simulations. The proposed optimal solutions for the environmental management of the lake indicate that because of the magnitude of the volume of freshwater released, environmental impacts at this location cannot be optimized through varying the timing and volume of the releases. This work presents a novel contribution to science through developing an optimization framework for mitigating the impacts of flood management on changes in salinity in brackish-water systems.

The ecology and fishery of the vendace (Coregonus albula) in the Baltic Sea.

Brackish water ecosystems often have high primary production, intermediate salinities, and fluctuating physical conditions and therefore provide challenging environments for many of their inhabitants. This is especially true of the Baltic Sea, which is a large body of brackish water under strong anthropogenic influence. One freshwater species that is able to cope under these conditions in the northern Baltic Sea is the vendace (Coregonus albula), a small salmonid fish. Here, we review the current knowledge of its ecology and fishery in this brackish water environment. The literature shows that, by competing for resources with other planktivores and being an important prey for a range of larger species, C. albula plays a notable role in the northern Baltic Sea ecosystem. It also sustains significant fisheries in the coastal waters of Sweden and Finland. We identify the need to better understand these C. albula populations in terms of the predator-prey interactions, distributions of anadromous and sea spawning populations and other putative (eco)morphs, extent of gene exchange between the populations, and effects of climate change on their future. In this regard, we recommend strengthening C. albula-related research and management efforts by improved collaboration and coordination between research institutions, other governmental agencies, and fishers, as well as by harmonization of fishery policies across national borders.

Comparative Eco-toxicological Effect of Corrosion Inhibitors on Aquatic Nitrogen Fixing Bacterium in Fresh and Brackish Water Ecosystem

Aquatic nitrogen-fixing bacteria play a crucial role in maintaining the nitrogen cycle and supporting primary productivity in freshwater and brackish water ecosystems. The activities of oil and gas industries operating within the coastal region of PortHarcourt releases effluents that contain various chemicals including corrosion inhibitors into the aquatic environment which can significantly affect the aquatic organisms including the nitrogen-fixing bacteria. Hence, this study was aimed to determine the comparative eco-toxicological effect of corrosion inhibitors on aquatic nitrogen fixing bacterium (Nitrosomonas sp.) in Fresh and Brackish water ecosystem. Fresh water and brackish water samples were collected from Chokocho stream in Etche Local Government Area and Eagle Island Port Harcourt, all in Rivers State, Nigeria. Standard toxicity procedure was applied on rectangular cut-out crude oil pipeline metal (ME) coated with corrosion inhibitors: Ambercil (AMB) and X-PRO 99 inhibitor (XPRO) immersed in freshwater (FW) prepared at concentrations of 25%, 50%, 75% and 100% for Nitrosomons sp. These inhibitors were tested with Nitrosomonas sp. at 0, 4, 8, 12 and 24hrs separately for each toxicant. The median lethal concentration (LC50) was employed to compare the toxicities of the different toxicants on the test organisms. The result for percentage survival of Nitrosomonas sp decreased when exposed to various concentrations listed above for 24. The LC50 (%) result (noting, that the lower the LC50, the more toxic the toxicant): of Nitrosomonas sp decreased in the following order: FW + ME (85.5) > BW + ME (86.7) > Both FW + AMB & FW + XPRO (86.8) > BW + XPRO (87.9) > BW + ME + XPRO (89.1) > BW + AMB (89.7) > FW + ME + XPRO (94.9). The above results revealed that Nitrosomonas sp decreased in percentage survival with an increase in concentration. The result showed that the effluents of metals coated with corrosion inhibitors (ME + AMB & ME + XPRO) were more toxic to Nitrosomonas sp in brackish water than freshwater while the effluents of XPRO & AMB not coated on metals were more toxic in freshwater than in brackish water. In conclusion, corrosion inhibitors when coated on metals, AMB corrosion inhibitor was more toxic than XPRO corrosion inhibitors in brackish and freshwater. Based on the findings, the use of XPRO corrosion inhibitor should be a best option for coating crude oil pipeline due to its relative low toxicity in upstream sector of the Nigeria petroleum industry.

Cyanotoxins, biosynthetic gene clusters, and factors modulating cyanotoxin biosynthesis.

Cyanobacterial harmful algal blooms (CHABs) are a global environmental concern that encompasses public health issues, water availability, and water quality owing to the production of various secondary metabolites (SMs), including cyanotoxins in freshwater, brackish water, and marine ecosystems. The frequency, extent, magnitude, and duration of CHABs are increasing globally. Cyanobacterial species traits and changing environmental conditions, including anthropogenic pressure, eutrophication, and global climate change, together allow cyanobacteria to thrive. The cyanotoxins include a diverse range of low molecular weight compounds with varying biochemical properties and modes of action. With the application of modern molecular biology techniques, many important aspects of cyanobacteria are being elucidated, including aspects of their diversity, gene-environment interactions, and genes that express cyanotoxins. The toxicological, environmental, and economic impacts of CHABs strongly advocate the need for continuing, extensive efforts to monitor cyanobacterial growth and to understand the mechanisms regulating species composition and cyanotoxin biosynthesis. In this review, we critically examined the genomic organization of some cyanobacterial species that lead to the production of cyanotoxins and their characteristic properties discovered to date.

Species Diversity and Assemblage of Mangroves at Setiu Wetland, Terengganu, Malaysia

Mangroves in wetland ecosystems are diverse and play significant role in the adjacent communities on which they are dependent for their livelihoods. It is also important for fishery resources and nutrient inputs in marine and brackish water ecosystems. However, little is known about the tropical wetland lagoon ecosystems, particularly mangrove diversity and assemblages. Therefore, this present study was initiated to observe the mangrove species diversity and assemblages together with the conservation status in an important tropical wetland ecosystem in Setiu, Terengganu, Malaysia. In a variety of landward and small fringe island areas, three zones of square plots were selected (zones 1, 2 and 3) to address the objectives of this study. As a result, a total of 20 true mangrove species belonging to 11 genera from nine families were documented, of which, Avicennia rumphiana was listed as vulnerable (VU) by the IUCN. Twelve species of mangrove associates from 11 genera and nine families were also found in the investigated zones at Setiu. One of the mangrove associates, Intsia bijuga, was designated as vulnerable (VU) by the IUCN. The Shannon diversity index (H') of mangroves was found to be 1.08 at Setiu Wetland. Rhizophora mucronata was found to be well-expanded (H' = 1.05) followed by A. rumphiana, A. officinalis, Heritiera littoralis, A. corniculatum. Excoecaria agallocha, Lumnitzera racemosa, and A. ebracteatus (H' = 0.0) as the lowest. The findings of the present study revealed that mangroves in the Setiu Wetland are diverse and healthy compared to other mangrove ecosystems in the region. To maintain the health and function of the mangrove ecosystem in Setiu Wetland, proper monitoring is required.

Blooming of a microbial community in an Ediacaran extreme volcanic lake system

Ancient aquatic sediments are critical archives for studying early microbial life and the types of environments in which they thrived. The recently characterized Amane Tazgart microbialites in the Anti-Atlas, Morocco, are a rare and well-preserved non-marine deposit that evolved in an alkaline volcanic lake setting during the Ediacaran Period. A multiproxy geochemical toolbox reveals evidence pointing to spatio-temporal ecosystem organization and succession related to changing lake water chemistry. This is marked by secular transition from a cold/dry climate, hypersaline alkaline thermophilic and anoxic–oxic community, to a stable state warm/wet climate fully oxygenated fresh to brackish water ecosystem, predominated by oxygenic stromatolites. Extreme dissolved Arsenic concentrations suggest that these polyextremophiles required robust detoxification mechanisms to circumvent arsenic toxicity and phosphate deficiency. We propose that self-sustaining and versatile anoxic to oxic microbial ecosystems thrived in aquatic continental settings during the Ediacaran Period, when complex life co-evolved with a rise in atmospheric oxygen content.

Range Extension of Barnea Candida (Linnaeus, 1758) and Habitat Loss in a Tropical Mangrove Estuarine System, Bay of Bengal, India

The most specified wood borer Barnea candida’s has been recorded during three consecutive years from 2015 to 2018 as live form in the river belt of Brahmani and Baitarani mangrove dominated areas of Dhamra estuary. The carcasses of the observed wood borer were found in huge number in and around of Dhamra Port. Present study further declared that the range extension of Barnea candida occurred from Subarnarekha estuary to Dhamra estuary by showing a southward migration. During the survey, other molluscan dead shells were also observed along with the wood borer which could be the consequences of port and harbour related activities. It is well known that Barnea candida is an efficient substrate destructor of wooden boats, shipwrecks, jetty pillars and also cemented structures of fishing harbours in the marine and brackish water ecosystem. Therefore, the observed species might be a threat for the Dhamra ecosystem in future which needs long-term integrated research in future.

Zooplankton studies in Colombian fresh and brackish water ecosystems: A review and future perspectives

Colombia is a global biodiversity hotspot, yet its zooplankton fauna remains poorly explored. In Colombian inland waters, 253 species of rotifers, 119 cladocerans and 82 copepods (not included benthic species) have been reported, in contrast with only 14 genera of protozoa. Most publications report on the Magdalena-Cauca basin, with the highest number of records for lowland areas (< 1000 m.a.s.l.). The least explored regions are the Chocó, Orinoco and Amazon basins. Colombian zooplankton checklists often include several taxa recognized as groups of cryptic species or ones described as cosmopolitan. Integrative taxonomic approaches are scarce, and diversity data need to be validated by molecular analyses and detailed morphological descriptions using optical and scanning electron microscopy. Historical, regional, and local environmental factors that explain the richness, distribution, and the abundance of zooplankton include: water bodies size, hydrological connectivity, trophic status; physical stability and, hydro-climatic patterns of variation. The analysis of ecosystem processes related to patterns in zooplankton communities highlights the importance of detritus as an alternative energy flow path in aquatic ecosystems at all altitude ranges. We propose to strengthen regional studies on functional groups, ecological redundancy, and adaptive traits to evaluate zooplankton responses to climatic, global and local stressors. Due to the great diversity of aquatic ecosystems in the extensive altitudinal gradient of Colombia, it is necessary to expand the coverage of ecological and taxonomic studies to understand zooplankton biodiversity and its role in ecosystem functioning.

Spatial and temporal dynamics of coastal benthic microbial communities along a salinity gradient

The Baltic Sea is a unique brackish water ecosystem that has been studied for decades; however, knowledge about the diversity of the benthic communities of bacteria and microbial eukaryotes within this system is sparse. Using an amplicon sequencing approach, we evaluated alpha and beta diversity of shallow-water coastal microbial sediment communities and their relationship to several environmental factors, on both a large spatial scale in the Baltic Sea and the adjacent North Sea, as well as on a temporal scale at selected sites along the salinity gradient in the Baltic Sea. We found salinity to be among the drivers of alpha diversity for bacteria but not for eukaryotes; however, community network structure appeared to change between sites of different salinity. Furthermore, beta diversity analyses revealed that communities in the poly- to mesohaline sections of the study area were affected to a higher degree by temperature, nutrient and sediment characteristics. This study shows that the structure of coastal microbial communities is to some degree related to salinity, but other factors also play a role.

The role of genomic signatures of directional selection and demographic history in the population structure of a marine teleost with high gene flow

Recent studies have uncovered patterns of genomic divergence in marine teleosts where panmixia due to high gene flow has been the general paradigm. These signatures of divergent selection are often impacted by structural variants, acting as "supergenes" facilitating local adaptation. The highly dispersing European plaice (Pleuronectes platessa)-in which putative structural variants (i.e., inversions) have been identified-has successfully colonized the brackish water ecosystem of the Baltic Sea. Thus, the species represents an ideal opportunity to investigate how the interplay of gene flow, structural variants, natural selection, past demographic history, and gene flow impacts on population (sub)structuring in marine systems. Here, we report on the generation of an annotated draft plaice genome assembly in combination with population sequencing data-following the salinity gradient from the Baltic Sea into the North Sea together with samples from Icelandic waters-to illuminate genome-wide patterns of divergence. Neutral markers pointed at large-scale panmixia across the European continental shelf associated with high gene flow and a common postglacial colonization history of shelf populations. However, based on genome-wide outlier loci, we uncovered signatures of population substructuring among the European continental shelf populations, i.e., suggesting signs of ongoing selection. Genome-wide selection analyses (xp-EHH) and the identification of genes within genomic regions of recent selective sweeps-overlapping with the outlier loci-suggest that these represent the signs of divergent selection. Our findings provide support for genomic divergence driven by local adaptation in the face of high gene flow and elucidate the relative importance of demographic history versus adaptive divergence in shaping the contemporary population genetic structure of a marine teleost. The role of the putative inversion(s) in the substructuring-and potentially ongoing adaptation-was seemingly not substantial.

Aksi Restorasi Penanaman Mangrove Dalam Memitigasi Bencana

The restoration of mangrove planting in the coastal area of ​​Gunung Anyar Village was carried out as a mitigation measure. The mangroves here function as a barrier when high tide occurs. With the mangroves, the tidal waves that occur can be muffled by the mangroves so that the impact of damage that occurs on land can be minimized. This is reinforced by the existence of government regulations with the aim of minimizing disaster damage, namely Law no. 24 of 2007 concerning Disaster Management. The action of planting mangrove plants in one area of ​​Surabaya City, especially the Gunung Anyar sub-district, Rungkut District is a series of community service activities for lecturers and students at Merdeka University Surabaya in 2022. This area has the potential for beaches to be used as new land for the development of mangrove plants because it is a coastal area that Of course, it is very vulnerable to seawater abrasion. The purpose of this service activity is to mitigate disasters, especially the risk of seawater abrasion, flash floods as well as to increase the potential of local areas in developing mangrove tourism, as well as improving brackish water ecosystems, especially fisheries development.

Combined effect of salinity and temperature on copepod reproduction and oxidative stress in brackish-water environment

Climate-induced warming and increased river inflows are forcing the Baltic Sea to radical changes in the near future; organisms living in this brackish-water ecosystem are already experiencing osmotic stress, which, together with thermal stress, may have severe consequences on the ecosystem. The aim of this work was to study the combined effect of decreasing salinity and increasing temperature on reproductive success and oxidative stress in zooplankton by using a calanoid copepod Acartia sp. as a model organism. The field study was conducted during summer 2020 in the western Gulf of Finland, using three sampling sites with naturally differing salinity levels. Additionally, the copepods from these sites were experimentally exposed to ambient or 3°C elevated temperature for 72 h. The copepods derived from the deepest and the most saline sampling site suffered less oxidative damage and exhibited relatively high reproduction, while the temperature treatment itself had little effect. On the other hand, the field-based monitoring data showed otherwise; temperature increased lipid peroxidation, glutathione-s-transferase activity, or both in all three sampling sites. Meanwhile, egg production rate was negatively associated with temperature in the area with the lowest salinity. Moreover, egg production rate decreased from June to September along with increasing temperatures in the mid-salinity sampling site, while similar change occurred also in the highest-salinity site between August and September. The combined effect of salinity and sampling date on reproduction indicates the importance of even subtle salinity changes on copepods. Moreover, the data suggest that the unusually strong heatwave was responsible for increased oxidative stress during the sampling season and possibly forced a trade-off between antioxidant activity and reproductive effort.

Heavy metal accumulation in selected fish species from Pulicat Lake, India, and health risk assessment

Heavy metal pollution in aquatic systems has become a major problem worldwide. The present study was designed to assess bioaccumulation of metals, Cu, Zn, Pb, and Cr, in fish species such as Lutjanus fulviflamma, Chanos chanos, Arius sp., and Terapon jarbua, commonly present in the Pulicat Lake, a brackish water ecosystem located in north Chennai coastal region, southeast India. Mean concentration of Cu and Cr in the sediment samples were 123.1μg/g and 90.1μg/g, respectively. The order of metal prevalence in water and sediment samples were Pb>Cr>Zn>Cu and Cu>Cr>Pb>Zn, respectively. However, in fish samples, the order of metal accumulation was Cu>Cr>Zn>Pb. Mean concentration of Cu in L. fulviflamma, C. chanos, Arius sp., and T. jarbua was 10.5μg/g, 25.5μg/g, 19.0μg/g, and 23.6μg/g, respectively. Mean Cr concentration in the animals varied from 1.19μg/g to 23.1μg/g with highest accumulation in the liver of Arius sp. In general, maximum accumulation of metals is mostly observed in the gills of the organisms. Although the concentration of Cu and Cr in the muscles was above World Health Organization’s permissible limit, the Estimated Daily Intake values were below the standard reference dose which means that the muscle tissues of the fishes are safe for human consumption.