Finfish Species Research Articles

Length‐weight relations for finfish species landed as trawl by‐catch from north‐western Bay of Bengal

Length‐weight relations for finfish species landed as trawl by‐catch from north‐western Bay of Bengal

Profiling Phospholipids within Atlantic Salmon Salmo salar with Regards to a Novel Terrestrial Omega-3 Oil Source.

The development and inclusion of novel oils derived from genetically modified (GM) oilseeds into aquafeeds, to supplement and supplant current terrestrial oilseeds, as well as fish oils, warrants a more thorough investigation into lipid biochemical alterations within finfish species, such as Atlantic salmon. Five tissues were examined across two harvesting timepoints to establish whether lipid isomeric alterations could be detected between a standard commercial diet versus a diet that incorporated the long-chain polyunsaturated fatty acids (LC-PUFA), EPA (eicosapentaenoic acid), and DHA (docosahexaenoic acid), derived from the GM oilseed Camelina sativa. Tissue-dependent trends were detected, indicating that certain organs, such as the brain, have a basal limit to LC-PUFA incorporation, though enrichment of these fatty acids is possible. Lipid acyl alterations, as well as putative stereospecific numbering (sn) isomer alterations, were also detected, providing evidence that GM oils may modify lipid structure, with lipids of interest providing a set of targeted markers by which lipid alterations can be monitored across various novel diets.

Temporal distribution of fishery resources in Payra River: relationship with climatological changes, ecological assessment, and threat assessment

The Payra river is one of the large coastal rivers in Bangladesh which supports incredible fish species and has been affected by extensive human disturbance due to huge fishing pressure. The present study provides information about the temporal diversity of finfish and shellfish concerning climatological variables and ecological pollution along with threat assessment in the Payra river, Bangladesh. During the entire study, a total of 61 species including 56 finfish and 5 shellfish species were recorded under 22 families belonging to 11 orders. The order-wise fish species availability showed that the Perciformes (29.49%) was the dominant order based on species richness. Among them, 4 endangered, 6 vulnerable, 4 near threatened, 42 least concern, and 5 data deficient species were found. During the study period, the average Shannon-Weaver diversity index value was (3.33 ± 0.12) indicating a good spread of fish population in the Payra river. Average Margalef richness index value was found (7.60 ± 0.32), Pielou's evenness index (0.48 ± 0.05), and Simpson dominance index (0.93 ± 0.02) in the Payra river. The dominance and Richness index value indicates a clear water environment with slight pollution in the Payra river. Ten different kinds of fishing gears were identified under 3 major groups including 5 nets, 3 hooks and lines, and 2 traps. Canonical correspondence analysis ordination plot showed that rainfall was the most influencing driving force among the meteorological parameters. The cluster analysis based on the Bray-Curtis similarity matrix showed that the winter season formed a separate cluster. In the recapitulation, the Payra river is a highly productive system that provides a favorable environment for a large variety of finfish and shellfish species assemblages. The findings of the conducted study are expected to be helpful for the respective researchers, policymakers, managers, and conservationists for the sustainable management of this water body and the interconnected surrounding neighboring countries.

Milk thistle (Silybum marianum) extract improves growth, immunity, serum biochemical indices, antioxidant state, hepatic histoarchitecture, and intestinal histomorphometry of striped catfish, Pangasianodon hypophthalmus

In aquaculture, phytobiotics can be used as feed supplements with attractive growth-promoting, immunomodulatory, antioxidant, and several health benefits for a variety of finfish species. Herein, we evaluated of the impacts of milk thistle extract (MTE; Silybum marianum) on the overall performances of Pangasianodon hypophthalmus juveniles. Fish (7.10 ± 0.00 g) were fed on diets containing graded MTE levels as 0.0 (control), 0.1%, 0.2%, and 0.3%. Fish were assigned into 4 triplicate groups and were hand-fed on the prepared corresponding diets thrice daily for 60 days with 3% of their wet body weight. Significant increases in the feed intake, final weight, weight gain, weight gain%, and specific growth rate were noticed in MTE-supplemented groups with regard to the control group. However, survival rate %, feed conversion ratio, body composition analysis, and amino acid content (% of protein) were statistically non-significant among all experimental groups. Liver function enzymes, intestinal histomorphometry (intestinal villus height, width, and crypt depth), and digestive enzymes (protease, lipase, and amylase) were increased in MTE groups compared to controls. Moreover, dose-dependent significant increases in serum lysozyme activities and total immunoglobulin content were remarked in all MTE groups in comparison with the controls. Liver CAT and SOD enzymes were significantly elevated, and malondialdehyde levels were significantly declined in liver homogenates of MTE groups compared with the controls. However, the levels of serum urea, creatinine, and uric acid were not significantly changed by dietary MTE. Of interest, the histological sections of the hepatopancreatic and intestinal tissues showed normal histoarchitecture of the hepatic cords and pancreatic acini as well as normal intestinal villi, crypts, and enterocytes with no lesions recorded among all the experimental groups. Collectively, the findings mentioned above suggest that MTE could improve the growth, enhance digestive enzymes and intestinal morphometry, and boost the immunity and hepatic antioxidant capacity of P. hypophthalmus. Thus, we suggest the possible application of MTE extract in aquafeed as a growth promotor, immunostimulant, and antioxidant.

An overview of the fish diversity and their threats in the Gowthami-Godavari Estuary in Andhra Pradesh, India

The fish diversity of different estuarine habitats of the Gowthami-Godavari River was studied from 2014 to 2017. We recorded 231 species of finfishes belonging to 27 orders, 81 families, and 167 genera. Perciformes was the most speciose order, followed by Carangiformes and Clupeiformes. Of the 231 species, one is an Endangered species (Silonia childreni), three are Vulnerable (Tenualosa toli, Cirrhinus cirrhosis, and Wallago attu), three are Near Threatened, and 11 are Data Deficient species. We also recorded five exotic species from the study area, of which Oreochromis mossambicus was the most dominant. The major threats, including potential impacts of river regulation and climate change on the estuarine habitats of Gowthami-Godavari, are also discussed.

Marine ecosystem restoration and aquaculture-based stock enhancement for fishery resource conservation in Abu Dhabi Emirate, United Arab Emirates

There is a necessity to protect and manage the marine ecosystem towards the conservation of the ecological equilibrium and in turn the sustainability of the fishery resources in Abu Dhabi, UAE. Marine stock enhancement (MSE) proved that releasing hatchery fingerlings of marine animals can improve the abundance of harvest beyond the level supported by natural recruitment. For such programme to be beneficial and economical, considerable investment and scientific efforts are required. Among the concerned entities in the United Arab Emirates, the Aquaculture and Marine Studies (AMSC) in Abu Al Abyad Island successfully released 59 million of juveniles of different finfish species and 96 million juveniles of prawn species in Abu Dhabi waters. In the context of conserving the ecological equilibrium, the AMSC was able to plant an area of 5,026 ha in various areas of Abu Dhabi Emirate with grey mangrove, Avicennia marina; culturing over 21,290 corals of Acropora sp., Porites sp., Cyphastrea sp and Psammocora sp. in an area of 0.5 ha nurseries in Abu Al Abyad and Yasat Islands which will later be transplanted in the degraded reef sites in both islands; and a well-established seagrass coverage of 2500 m2 was achieved in affected areas in Abu Al Abyad Island.

Reproductive sterility in aquaculture: A review of induction methods and an emerging approach with application to Pacific Northwest finfish species

AbstractAquaculture is the fastest‐growing food‐production sector and is striving to become a long‐term sustainable approach to meet the rising global demand for seafood. During the expansion and advancement of aquaculture, minimizing ecological impacts should occur concomitantly with maximizing production. Farmed fish, often genetically distinct from their natural conspecifics, may pose significant risks of genetic contamination and ecological imbalance to wild populations if they escape from aquaculture confinement. Growing reproductively sterile fish is the most effective way to genetically contain farmed fish. Atlantic salmon (Salmo salar) escape events in the ‘Pacific Northwest’ region of the United States and Canada have raised alarms over potential ecological impacts and led to legislation in Washington State phasing out the culture of non‐native finfish species. Farming sterile native species such as coho salmon (Oncorhynchus kisutch) and sablefish (Anoplopoma fimbria) in the Pacific Northwest would ease public concerns and promote environmentally and economically sustainable aquaculture. Sterile fish also can mitigate the challenge of precocious maturation, a prominent issue associated with culture of salmonids and many other species, to improve somatic growth, flesh quality and fish health and welfare. Here, we review methods having potential applications for producing sterile fish and introduce our novel immersion‐based technology that temporarily silences the dead end (dnd) gene using Morpholino oligonucleotides to produce sterile coho salmon and sablefish for the first time. The successful induction of sterility in these two iconic Pacific Northwest species without introducing genetic modifications would promote the use of this immersion‐based sterilization technology for more aquaculture finfish worldwide.

Clinico-pathological findings and expression of inflammatory cytokines, apoptosis, and oxidative stress-related genes draw mechanistic insights in Nile tilapia reared under ammonia-N exposure and Aeromonas hydrophila challenge

Fish diseases have a “stress-related” nature, whereas fish exposure to stressors will increase their susceptibility to infections. It was also noted that fish exposure to biotic and abiotic stressors would exaggerate the disease signs, elicit high mortalities, and cause severe economic losses. Motile aeromonad septicemia (MAS) is a major bacterial disease affecting a variety of finfish species throughout the globe and is caused by Aeromonas hydrophila. Herein, we have evaluated the impacts of ammonia-N stress and/or Nile tilapia challenge with pathogenic A. hydrophila on the clinical picture of MAS disease. Clinical signs, postmortem lesions, histoarchitectural changes, and gene transcription analysis were studied. Fish experimentally infected with A. hydrophila were exophthalmic and showed darkened skin. Moreover, opercular hyperemia, petechial hemorrhages, and gill congestion alongside dermal ulcerations were noticed in ammonia-exposed fish. On the other side, fish exposed to both stressors exhibited exophthalmia, corneal opacity, severe dropsy, and hemorrhagic dermal ulcerations. At the tissue levels, the histopathological lesions were exaggerated in the fish group exposed to ammonia stress and challenged with A. hydrophila than fish group exposed to each one alone. At the molecular levels, the mRNA expression analysis reveals significant upregulation of inflammatory cytokines such as interleukin-1 beta, CXC chemokine, and tumor necrosis factor-alpha in the kidney tissues of Nile tilapia exposed to ammonia and/or challenged with A. hydrophila. In a similar trend, the mRNA expression values of heat shock protein 70 (HSP70), oxidative stress related genes (SOD and CAT) and apoptosis-related genes (caspase 3, BAX, and cytochrome P450) were also increased in the hepatic tissues of fish exposed to singular or dual stressors. Interestingly, the highest expression levels of the above-mentioned genes were found in the fish group exposed to both stressors. Taken together, these findings indicate the occurrence of severe inflammatory and apoptotic changes in fish exposed to ammonia and infected with A. hydrophila more than each one alone. In contrast, there was a significant decrease in the expression values of the antioxidant enzyme glutathione-S-transferase (GST) in stressed fish, suggesting the occurrence of oxidative stress. This study will be helpful to draw mechanistic insights into the exposure of fish to ammonia stress and infection with A. hydrophila.

Using seabird and whale distribution models to estimate spatial consumption of krill to inform fishery management

AbstractEcosystem dynamics at the northwest Antarctic Peninsula are driven by interactions between physical and biological processes. For example, baleen whale populations are recovering from commercial harvesting against the backdrop of rapid climate change, including reduced sea ice extent and changing ecosystem composition. Concurrently, the commercial harvesting of Antarctic krill is increasing, with the potential to increase the likelihood for competition with and between krill predators and the fishery. However, understanding the ecology, abundance, and spatial distribution of krill predators is often limited, outdated, or at spatial scales that do not match those desired for effective fisheries management. We update current knowledge of predator dependence on krill by integrating telemetry‐based data, at‐sea observational surveys, estimates of predator abundance, and physiological data to estimate the spatial distribution of krill consumption during the austral summer by three species ofPygoscelispenguin, 11 species of flying seabirds, one species of pinniped, and two species of baleen whale. Our models show that the majority of important areas for krill predator foraging are close to penguin breeding colonies in nearshore areas where humpback whales also regularly feed, and along the shelf‐break, though we caution that not all known krill predators are included in these analyses. We show that krill consumption is highly variable across the region, and often concentrated at fine spatial scales, emphasizing the need for the management of the local krill fishery at relevant temporal and spatial scales. We also note that krill consumption by recovering populations of krill predators provides further evidence in support of the krill surplus hypothesis, and highlight that despite less than comprehensive data, cetaceans are likely to consume a significant proportion of the krill consumed by natural predators but are not currently considered directly in the management of the krill fishery. If management of the krill fishery is to be precautionary and operate in a way that minimizes the risks to krill predator populations, it will be necessary in future analyses, to include up‐to‐date and precise abundance and consumption estimates for pack‐ice seals, finfish, squid, and other baleen whale species not currently considered.

Genomic Degeneration and Reduction in the Fish Pathogen Mycobacterium shottsii.

ABSTRACTMycobacterium shottsii is a dysgonic, nonpigmented mycobacterium originally isolated from diseased striped bass (Morone saxatilis) in the Chesapeake Bay, USA. Genomic analysis reveals that M. shottsii is a Mycobacterium ulcerans/Mycobacterium marinum clade (MuMC) member, but unlike the superficially similar M. pseudoshottsii, also isolated from striped bass, it is not an M. ulcerans ecovar, instead belonging to a transitional group of strains basal to proposed “Aronson” and “M” lineages. Although phylogenetically distinct from the human pathogen M. ulcerans, the M. shottsii genome shows parallel but nonhomologous genomic degeneration, including massive accumulation of pseudogenes accompanied by proliferation of unique insertion sequences (ISMysh01, ISMysh03), large-scale deletions, and genomic reorganization relative to typical M. marinum strains. Coupled with its observed ecological characteristics and loss of chromogenicity, the genomic structure of M. shottsii is suggestive of evolution toward a state of obligate pathogenicity, as observed for other Mycobacterium spp., including M. ulcerans, M. tuberculosis, and M. leprae.IMPORTANCE Morone saxatilis (striped bass) is an ecologically and economically important finfish species on the United States east coast. Mycobacterium shottsii and Mycobacterium pseudoshottsii were originally described in the early 2000s as novel species from outbreaks of visceral and dermal mycobacteriosis in this species. Biochemical and genetic characterization place these species within the Mycobacterium ulcerans/M. marinum clade (MuMC), and M. pseudoshottsii has been proposed as an ecovar of M. ulcerans. Here, we describe the complete genome of M. shottsii, demonstrating that it is clearly not an M. ulcerans ecovar; however, it has undergone parallel genomic modification suggestive of a transition to obligate pathogenicity. As in M. ulcerans, the M. shottsii genome demonstrates widespread pseudogene formation driven by proliferation of insertion sequences, as well as genomic reorganization. This work clarifies the phylogenetic position of M. shottsii relative to other MuMC members and provides insight into processes shaping its genomic structure.

Human health risk assessment for exposure to heavy metals in finfish and shellfish from a tropical estuary

This investigation measured the extent of heavy metal concentrations (Cr, Pb, Fe, Zn and Ni) in nine finfish and shellfish species from a tropical estuary to determine the degree of pollution and evaluate the human health risk from the exposure to heavy metals through consumption of fish. The hierarchy of mean concentrations (mg/kg) of the heavy metals were: Zn (398.47) > Fe (83.015) > Cr (0.906) > Ni (0.233) > Pb (0.128). The metal concentrations in the edible tissues were ranked in the following sequence: A. bato > C. cirrhosus > A. grammepomus > M. dobsoni > P. paradiseus > O. pama > M. rosenbergii > N. smithi > S. phasa. The results demonstrated that the concentration of Cr and Zn was considerably higher than the guideline values of FAO. Estimated daily intake (EDI), hazard quotient (HQ), hazard index (HI), and cancer risk (CR) values were within the acceptable threshold for both adults and children. However, the EDIs of local consumers in the research area for both adults and children were lower than the recommended daily amount (RDA), following the order of Zn > Fe > Cr > Ni > Pb. The HQs of the elements followed the order of Zn > Cr > Fe > Pb > Ni. The investigated HI was not exceeding the recommended limit.

Effect of Application of Different Activation Media on Fertilization and Embryo Survival of Northern Pike, (Esox lucius) under Hatchery Conditions.

Simple SummaryNorthern pike is one of the most important freshwater species that is produced mainly for restocking. It is economically and ecologically valuable and an important species in recreational fisheries as a top predator in fresh waters. Although the artificial reproduction of this species seems easy, it still poses many difficulties. This is why research is constantly being conducted to improve artificial reproduction, the short-term storage of gametes, and fertilization techniques. The aim of this study was to use various activation media to increase fertilization rates in this species. The results obtained indicate that the use of selected activation media in field hatcheries can significantly increase the reproductive efficiency of northern pike.One of the finfish species that European and North American breeders are most interested in is the northern pike, Esox lucius. Artificial reproduction and the production of viable larvae has a huge impact on further culture. The quality of stripped gametes is highly variable. Therefore, it is important to use gametes with maximum efficiency, which has a direct impact on the amount of stocking material produced and therefore on the economics of production. The aim of this study was to compare northern pike fertilization efficiency, expressed as the survival rate of embryos until hatching. In the first experiment, the highest percentage of hatched embryos was observed in groups of eggs fertilized in a saline diluent prepared with deionized water (after reverse osmosis: group D), at 61.2% and 56.5% in the NaCl5-D and NaCl6-D groups, respectively. The highest percentage of hatched embryos in the second experiment was observed in the egg groups activated with Woynarovich solution (V) at 75.5% and 74.7% for V-D (D—deionized water) and V-T (T—tap water), respectively. In all cases, preparing the activation medium using T versus D water resulted in lower fertilization percentages and lower percentages of hatched larvae. At the same time, two variants (V and B1—Billard solution) were tested during mass spawning in three hatcheries using hatchery water (tap water). The results showed that repeatability was the highest when using activation medium B1.

Exploring the Roles of Dietary Herbal Essential Oils in Aquaculture: A Review.

Simple SummaryEssential oils, also known as aetheroleum, have a variety of therapeutic properties, including analgesic, adaptogen, and astringents, among others. Essential oils have potential growth-promoting, antibacterial, and immunostimulant effects for several fish species. Furthermore, they potentiate the antioxidative capacity and the resistance of aquatic animals against infectious diseases. This article spotlights on the essential oils derived from selected medicinal plants, and their roles in the improvement of the performances of aquatic animals.The aquaculture sector is one of the main activities contributing to food security for humanity around the globe. However, aquatic animals are susceptible to several farming stressors involved in deteriorated growth performance, reduced productivity, and eventually high mortality rates. In some countries still, antibiotics and chemotherapies are comprehensively applied to control biotic stressors. Aside from the apparent benefits, the continuous usage of antibiotics develops bacterial resistance, deteriorates bacterial populations, and accumulates these compounds in the aquatic environment. Alternatively, environmentally friendly additives were used to avoid the direct and indirect impacts on the aquatic ecosystem and human health. In aquaculture, medicinal herbs and extracts are extensively used and approved for their growth-promoting, anti-inflammatory, and antioxidative properties. Herbal essential oils contain many bioactive components with powerful antibacterial, antioxidative, and immunostimulant potentials, suggesting their application for aquatic animals. Essential oils can be provided via diet and can benefit aquatic animals by improving their well-being and health status. The use of essential oils in aquafeed has been studied in a variety of aquatic animals to determine their beneficial roles and optimum doses. The outputs illustrated that herbal essential oils are exciting alternatives to antibiotics with prominent growth promotion, antioxidative, and immunostimulant roles. Herein, we reviewed the beneficial roles of essential oils in aquaculture. This review also aims to describe trends in herbal essential oils use, mainly in commercial fish species, and to analyze different factors that affect essential oils’ efficacy on the growth performance, antioxidative, and immune responses of finfish species.

Estimation of Stock Status Using the LBB and CMSY Methods for the Indian Salmon Leptomelanosoma indicum (Shaw, 1804) in the Bay of Bengal, Bangladesh

As one of the largest and most commercially valuable finfish species, Leptomelanosomaindicum (Indian salmon) significantly contributes to Bangladesh’s marine catches. The length-based Bayesian biomass (LBB) method and catch-based Monte Carlo method (CMSY) are among the most recent and powerful methods for predicting the state of fisheries resources from data-limited fisheries. CMSY requires catch and resilience data, as well as quantitative stock status information. For LBB, only length–frequency (LF) data are required. The stock status of L. indicum was estimated using these two independent methods, utilizing twenty-one years of catch–effort and length–frequency data (978 individuals) from commercial fisheries on the Bangladesh coast. Here, a BSM (Bayesian state-space implementation of the Schaefer surplus production model) was also employed. The current study’s findings showed that the B/B0 ratio of currently exploited biomass to unexploited biomass (0.1) was smaller than BMSY/B0 (0.36) and B/BMSY = 0.28 was smaller than the reference value of 1.0, indicating the grossly overfished and depleted condition of the stock. Similar trends in the results were found for B/BMSY = 0.11 (<1.0) from CMSY. In addition, the exploitation rate (F/FMSY = 5.66), biomass (B < BMSY), and fishing status (F > FMSY) further justify the severely overfished conditions of L. indicum stock in the study area. Furthermore, the Lc_opt (optimal length at first capture) was higher than the Lc (length at first capture), indicating that this species is being overfished, and that mesh sizes should be increased for better management. This study provides information on biological reference points (BRPs), and confirms the severely overfished status of L. indicum in the coastal waters of Bangladesh. More specific and prompt management measures are required to recover and sustainably manage this valuable species, and protect the fish stock from commercial extinction.

Polycyclic aromatic hydrocarbons (PAHs) in fishery resources affected by the 2019 oil spill in Brazil: Short-term environmental health and seafood safety

We present herein a short-term impact on marketed fisheries and human health safety in the first three months following the 2019 oil spill in Brazil. Total PAHs in the edible tissues of 34 finfish and shellfish species ranged from 8.71 to 418 ng g−1 wet weight, with robust evidence supporting crude oil contamination. A prevalence of low molecular weight PAHs was observed, mainly naphthalenes. A decreasing trend in mean total PAHs from mollusks (134 ng g−1) to crustaceans (73.9 ng g−1) and to fishes (45.3 ng g−1) was noted. The spilled oil caused immediate negative impacts on the local seafood market, despite less than 3% of samples exhibited concentrations above levels of concern, revealing a low probability for human health risks. These findings demonstrate that governments must be prepared to provide not only science-based quick responses but also effective science communication for society upon environmental disasters.

Feeding ecology, trophic interaction and resource partitioning among four omnivorous finfish species of a tropical Estuary

A crucial aspect of sustainable resource management is understanding the trophic interactions amongst fish in the estuarine ecosystem. The goal of this study was to look into the food preferences, feeding strategies, trophic partitioning, as well as dietary overlap among four omnivorous species that live in the Cochin Estuary: Mugil cephalus (n = 73), Planiliza parsia (n = 35), Planiliza planiceps (n = 65) and Chanos chanos (n = 55) through the analyses of gut-content. Index of relative importance demonstrated that prey items in Mugil cephalus and Planiliza planiceps guts were dominated by Bacillariophyceae whereas in Planiliza parsia and Chanos chanos guts were dominated by Myxophyceae. The highest diet value (7.5) was recorded in Chanos chanos, while the lowest was recorded in Mugil cephalus (5.69). The highest niche breadth value (0.77) was recorded in Planiliza planiceps while the lowest value was recorded in Planiliza parsia (0.52). Pianka's overlap, evaluated with the help of null models structured by Ecosim 7.0, showed remarkable niche overlap between Mugil cephalus and Planiliza planiceps (0–0.92, P < 0.001), between Planiliza planiceps and Planiliza parsia ( 0–0.77, P < 0.05) and between Mugil cephalus and Planiliza parsia ( 0–0.7, P < 0.05). The fish's trophic niche width, along with prey-specific abundance confirmed that they are generalist feeders. The present results differed from the general hypothesis related to the omnivorous species and concluded that these four omnivorous species live in the same niche zones of the Cochin Estuary with no interspecific conflict.

Finfish Bycatch Diversity of Trawl Fishery of Nagapattinam Coast, Tamil Nadu, South India

Background: The present study was undertaken to analyse the monthly and seasonal finfish bycatch diversity of trawler fishery of Nagapattinam coast situated in the state of Tamil Nadu, South India from January 2017 to August 2019. Methods: Samples of finfish bycatch were collected fortnightly from the commercial shrimp trawlers operating in the coastal waters off Nagapattinam. The collected bycatch of finfish species was identified and month-wise and season-wise trawl finfish bycatch occurrence data collected were subjected to univariate and multivariate analysis using PRIMER Version 6.1.7. software. Result: In this study, the annual average total landing was estimated at 15,414.41 tonnes with an annual average fishing effort of 9327 boat days. Of this total landing, commercial catch constituted 70.75% (10,905.78 tonnes), whereas finfish bycatch formed 21.12% (3,256.14 tonnes) and rest by other groups. The peak fishing effort was observed in every March during the study period. A total of 210 finfish species belonging to 15 orders, 79 families and 153 genera were recorded, in which the order, Perciformes alone shared 53.81% of the total number of species. The monthly univariate analysis revealed that bycatch diversity was the highest in every September and the lowest in every June during the study period, while the season-wise analysis revealed the highest diversity during monsoon seasons. Likewise, the month-wise multivariate analysis performed through cluster analysis divulged the highest similarity between September’17 and September’18, while the season-wise analysis revealed the highest similarity between postmonsoon’17 and postmonsoon’18. Further, the K dominance plot divulged that the highest density of finfish species was in every September and in monsoon seasons during the study period.

​An Annotated Checklist of Finfish and Shellfish Diversity of Pulicat Lake, Southeast Coast of India

Background: Pulicat lake is the second largest brackish water lagoon in the country, lying partly in Andhra Pradesh and Tamil Nadu states along the Coromandel Coast of South India. The present paper gives information on occurrence, habitat preference, trophic level, human utility and fishery status of finfish and shellfish species of the Pulicat Lake. Methods: An extensive survey was conducted on finfish and shellfish diversity of Pulicat Lake from November 2019 to March 2021, selecting four fish landing centres viz, Pazhaverkadu, Arambakkam (fishing villages in Tamil Nadu), Venadu and Vatembedu (fishing villages in Andhra Pradesh) situated along the Lake. Result: In the present study, A total of 145 species including species of finfishes (95), prawns (8), crabs (7) and 35 molluscs (35) were documented from the Lake. Among the four selected landing centres, the highest diversity was observed in Pazhaverkadu, registering 143 species followed by Arambakkam (123), Vatembedu (85) and Venadu (77).

Potential health risk caused by heavy metal associated with seafood consumption around coastal area

The current study investigated seasonal fluctuations in diversity of fish and heavy metal concentrations in coastal areas, as well as the possible human health risks associated by the heavy metals (Mercury, Lead, Chromium, Cadmium, Copper and Zinc). From five different locations across the coastal area, 44 finfish species from 11 orders and 33 families were collected. Four finfish species such as Mugil cephalus, Lates calcarifer, Etroplus suratensis, and Chanos chanos were used to estimate and assess the heavy metal concentrations based on abundance and distribution across coastal area. Results revealed that the metal concentration in these fish species, water, and sediment were all found to be significantly comparable. During the southwest monsoon season, the highest concentrations of metals were found in Chanos chanos, Mugil cephalus, and Lates calcarifer. A hazard index and a target hazard quotient were calculated to determine the human-related health risk. Except for Hg and Cd in children, the anthropological health hazard assessment revealed that most element exposure doses are safe for both children and adults.

Management of trawl by-catch with reference to Visakhapatnam Fishing Harbor: Andhra Pradesh, India

Trawl fishery is a mixed fishery targeting numerous species including consequential huge amounts of non-targeted species, referred to as low value bycatch/trash fish. The aim of the present study is to analyse the composition of trawl bycatch and its management in view of its proper utilization for aqua feed. Random samples of trash fish were collected fortnightly between March 2019 and February 2020 from single day and multi day trawler landings at Visakhapatnam Fishing Harbour (VFH). The preliminary process of utilizing the landed trash fish at VFH is observed. The results of the study revealed the presence of 38 dominant species of finfish and shellfish, representing the families, Leiognathidae, Trichiuridae, Mullidae, Clupeidae and Nemipteridae with 29.73%, 22.5%, 18.69%, 11.96% and 10.59% respectively of 609.991 tons total landing during the study period. The highest landing is 83.362 t reported in the month of Feb, 2019 and lowest landing is 32.2 t reported in the month of Oct, 2020. The study concludes that considerable trash fish composition is being landed at VFH, causing the necessity for Entrepreneurs, to pay immediate attention towards the utilization of total trawl bycatch in terms of converting it into feed and supply to aquaculture and poultry industries. Further research will be beneficial for policy makers to address better trawl bycatch management options.