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Ponmani, M.; Manimekalai, D.; Padmavathy, P.; Parthiban, F., and Manickavasagam, S., 2023. Spatial variations of hydrocarbon-degrading bacteria in relation to physicochemical parameters along the coastal waters of Thoothukudi (India). Journal of Coastal Research, 39(5), 869–879. Charlotte (North Carolina), ISSN 0749-0208. The present study involves collecting seawater and sediment samples from two different locations along the Thoothukudi coast, namely the fishing harbour and the dry-docking yard, to analyse physicochemical parameters and bacterial abundance. Total heterotrophic bacteria, total hydrocarbon utilizer, total naphthalene utilizer, total phenanthrene utilizer, organic carbon, and physicochemical parameters were all analysed from the collected water and sediment samples to determine the condition and quality of the waters and sediments. Maximum counts of total hydrocarbon utilizers (15.5 × 104 cfu/mL), total naphthalene utilizers (8.5 × 104 cfu/mL), and total phenanthrene utilizers (11.8 × 104 cfu/mL) were observed in fishing harbour waters. The highest total heterotrophic bacteria counts were found in fishing harbour sediments (15.5 × 105cfu/g). Maximum counts of total heterotrophic bacteria and minimum counts of total phenanthrene utilizers were observed in dry-docking yard water and sediments. Higher bacterial counts were found in the fishing harbour with a high concentration of oil and grease, as well as other environmental parameters. A significant positive correlation (P < 0.05) was found between the bacterial population of oil and grease and organic carbon. This investigation revealed that the water column contains oil and grease, which promotes the growth of hydrocarbon-utilizing bacteria, as well as organic matter, which promotes the growth of heterotrophic bacteria. The current study found that bacterial populations had a positive correlation (P < 0.05) with the suspended matter, indicating that anthropogenic activities dominated the coastal areas of the Thoothukudi coast. [ABSTRACT FROM AUTHOR]

Ravikumar, T.; Neethirajan, N.; Chandran, S.; Sangaralingam, M.; Natarajan, J.; Umamaheswar, T., and Padmavathy, P., 2024. Ichthyofaunal diversity from longline catches in the Gulf of Mannar (GoM), southeast coast of India. Journal of Coastal Research, 40(1), 115–128. Charlotte (North Carolina), ISSN 0749-0208. The present study aimed to document the spatial and temporal ichthyofaunal diversity of reef associated fishes caught with experimental longlines fitted with different "J" hook sizes (no. 12, no. 9, and no. 6) and shapes (Straight, Kirbed, and Reversed) from the Therespuram and Mundhal fish landing centres of Gulf of Mannar (GoM), Southeast Coast of India. Sampling was done at a fortnightly interval from February 2020 to January 2022. The total of 21,322 fish diversity includes 37 species of fish belonging to 15 genera, 10 families, and seven orders have been recorded during the study period. Order wise and species wise landing revealed the dominance of Perciformes with five families (Haemulidae, Lethrinidae, Lutjanidae, Nemipteridae, and Serranidae) and 28 species while in the case of order Centrarchiformes it represented with only one species. Fish diversity of GoM was assessed by calculating the various diversity indices such as Shannon–Weiner biodiversity index (H′) ranged from 2.31 to 3.29, Simpson's Dominance Index (1-λ′) ranged from 1.80 to 4.73, Pielou's Species Evenness index (J′) ranged from 0.90 to 0.99, and Margalef index (d) of species richness ranged from 2.03 to 4.73. The results of the present study revealed that the experimental longlines caught one endangered (3%), four vulnerable (11%), two not evaluated (5%), one data deficient (3%), and 29 species (78%) of least concern as per the International Union for Conservation of Nature status. The assessment is a prerequisite for understanding the biodiversity and to help fishery managers to evolve new strategies for the sustainable exploitation and conservation of coral reef associated fishes in this region. [ABSTRACT FROM AUTHOR]

Naganandhini, V.; Muthupandi, K.; Vasanth, K.; Neethiselvan, N.; Padmavathy, P., and Radhakrishnan, K., 2023. Influence of hook number on species composition, catch rate, and size of needlefishes in the Gulf of Mannar, India. Journal of Coastal Research, 39(3), 502–508. Charlotte (North Carolina), ISSN 0749-0208. The contribution of needlefishes from the Gulf of Mannar coast has been remarkable and is presently exploited by pelagic longlines. The J hook is extensively used in longline fishing in the Indian region to capture carnivore fishes, including needlefish. Catch rate significantly differed between the hook numbers. In this context, three hook numbers of 10 J, 11 J, and 12 J were studied from January to May 2022. Results showed that the Ablennes hians was the dominant fish caught (47.9%), followed by Tylosurus crocodiles (22.2%), T. choram (16.6%), and Strongylura strongylura (13.3%); weight-based catches of T. crocodiles (39.7%) were dominantly higher, followed by A. hians (35.9%), T. choram (13.8%), and S. strongylura (10.6%). The two-way ANOVA results revealed that a significant (p <0.05) difference occurred between the hook number and the number of species caught. The largest number of fish were caught with hook number 12 (3769), followed by hook number 11 (2745) and hook number 10 (1445). However, the highest weight of 2749.74 kg was recorded with hook number 11 and the lowest of 1602.65 kg in hook number 10 (p <0.05). This is related to fewer fish caught with hook number 10 and heavy fishing pressure on subadults (<50 cm) due to the use of hook number 12. Considering the maximum total length and weight, the optimum hook number for the commercial exploitation of needlefishes was hook number 11. The catch per unit effort disproportionately increased with the increasing of the hook number; the significant higher contribution of 48.25 individuals/1000 hooks was from hook number 12, whereas hook numbers 11 and 10 were 35.13 individuals/1000 hooks and 18.51 individuals/1000 hooks, respectively. [ABSTRACT FROM AUTHOR]

The length‐weight relationships were estimated for three reef fish species caught in the Gulf of Mannar, India using experimental longlines. The longline fishing took place from December, 2019 to September, 2021 in fortnightly intervals, using longlines (2400 m, 2700 m and 3360 m each), equipped with each 600 various "J" type fishing hooks (straight, reversed, kirbed). The hook sizes used were standard size numbers 6, 9, and 12. The longlines fabricated with polyamide monofilament line were operated from 20 to 50 m depth for 3–5 hours each time. Overall, 81,000 hooks were deployed in 45 fishing trials. The total length and total weight of the combined sex group was recorded nearest to 0.1 cm and 0.01 g, respectively. By using the logarithmic transformed data, linear regression analysis was performed to calculate a and b values for three fish species to establish length‐weight relationships. The parameters for the length‐weight equations for three species are provided along with respective coefficient of correlation and the 95% confidence intervals. A new maximum total length was recorded for two grouper species, viz., Epinephelus faveatus (36.5 cm) and Cephalopholis urodeta (46.0 cm). [ABSTRACT FROM AUTHOR]

This study compared the heavy metal concentration in water, sediment, and shrimp at different growth stages of culture and subsequently evaluated the ecotoxicological and human health risk status. Total trace element concentration in the water, sediment and shrimp ranged from not detected (ND) (Hg) to 91.05 (Fe) μg/L, 0.01 (Hg) to 19, 246.33 (Fe) mg/kg, and ND (Hg) to 13.98 (Fe) mg/kg, respectively. Toxic metals such as, Cd, Hg, and Pb in shrimps ranged from ND to 2.11 mg/kg, ND to 0.158 mg/kg, ND to 0.088 mg/kg, and ND to 0.469 mg/kg, respectively. Toxic heavy metals at all the growth stages of shrimps (days of culture (DOC)-01 to DOC-90) were found below the maximum residual limit (MRL) of 0.5 mg/kg set by the European Commission (EC). Similarly, Cu, Zn, and As concentrations in shrimp were also far below the MRLs of 30 mg/kg, 100 mg/kg, and 76 mg/kg set by the World Health Organization and Food Safety and Standard Authority of India, respectively. The concentration of heavy metals increased from DOC-01 to DOC-90 and was positively correlated with the length and weight of the shrimps (p < 0.05). The risk assessment was estimated for both Indians and Americans and found no carcinogenic (lifetime cancer risk (LCR) < 10−4) and non-carcinogenic (THQ and TTHQ<1) health risks through consumption of shrimp cultured in this region. The hazard quotient (HQ dermal < 1), hazard index (HI < 1), and LCR (<10−4) values of the heavy metals indicated that the dermal absorption might not be a concern for the local fishermen and marine fish/shrimp farmworkers. Water and sediment quality indices were applied to assess the surface water and sediment quality, and their results were found nil to low levels of heavy metal contamination at all the sampling sites. All heavy metals studied in sediments were < effect range low (ERL) and < threshold effect level (TEL), indicating no adverse biological effects on aquatic organisms. Therefore, regular monitoring of the shrimp aquaculture system throughout the crop will provide evidence of heavy metals bioaccumulation in shrimps. This research will provide baseline data to help farmers establish the optimal aquaculture practices and regulatory authorities to formulate legislation and strategies to reduce heavy metal biomagnification in shrimps from farm to fork. • Heavy metals concentrations in shrimps were below the maximum residual limit •Total heavy metal concentration in shrimps increased from day 1 to 90 (p<0.05) •Heavy metals in shrimps positively correlated with their length and weight (p<0.05) •Target hazard quotient (THQ) and total THQ (<1) revealed shrimp consumption is safe •Shrimps cultured in India and exported worldwide are safe for consumption [ABSTRACT FROM AUTHOR]

Food safety is crucial in today's competitive trading market, as it directly affects human health and promotes seafood exports. The effects of thermal processing (boiling, frying, grilling, and microwave cooking) on pesticide residues (PR) in P. vannamei were assessed. The PR in raw and processed shrimp ranged from 0.007 to 0.703 μg/kg for uncooked/raw, not detected (ND) to 0.917 μg/kg for boiled, ND to 0.506 μg/kg for fried, ND to 0.573 μg/kg for grilled and ND to 0.514 μg/kg for microwave cooked shrimps. The Endrin, endosulfan sulfate, and heptachlor were predominant PR found in the raw and processed shrimp. The PR content in raw and cooked shrimps were below the maximum residue limits (MRL) set by the Codex Alimentarius Commission (2021) and the European Commission (86/363/1986 and 57/2007). The estimated daily intake (EDI) of PR from raw and processed shrimps were below the ADI prescribed by CAC. The hazard quotient (HQ) and hazard ratio (HR) values were <1, indicating no non-carcinogenic or carcinogenic health implications through shrimp consumption. The estimated maximum allowable shrimp consumption rate (CRlim) suggests an adult can eat >100 shrimp meals/month, which is over the USEPA's (2000)recommendation of >16 meals/month without health issues. The Effect of thermal processing was detected in the following order: boiling < grilling < frying < microwave cooking. The processing factor (PF < 0.7), paired t -test (t < 0.05), Tukey post hoc (p < 0.05) test, Bray-Curtis similarity index, and matrix plot exhibited that all the four thermal processing methods have a considerable impact on pesticides in the processed shrimps. But frying (59.4%) and microwave cooking (60.3%) reduced PR far beyond boiling (48.8%) and grilling (51.3%). Hence, we recommend frying and microwave processing are better methods for minimizing PR in seafood than boiling or grilling. [Display omitted] • Pesticide residues were found below the maximum residual limits (MRL). • Frying and microwave cooking showed a significant impact on pesticides. • Endosulfan, endrin and aldrin were predominant pesticides in raw and cooked shrimps. • Pesticides reduced significantly in the order of boiling < grilling < frying < microwave. • Consumption limit confirms that an adult can safely consume >100 shrimp meals/month. [ABSTRACT FROM AUTHOR]