Abinaya R, Kanishkar A, Sajeevan M K
Department of Fisheries Resource Management, Faculty of Fisheries Science, Kerala University of Fisheries and Ocean Studies, Kochi, Kerala, 682 506, India.
Department of Fisheries Resource Management, Fisheries College and Research Institute, Ponneri, Thiruvallur, Tamil Nadu, 601 204, India.
Environ Monit Assess. 2025 Jun 28;197(7):819. doi: 10.1007/s10661-025-14210-3.
Biodiversity loss is expanding at an unprecedented rate, owing to habitat degradation, overexploitation, pollution, and climate change. Key Biodiversity Areas (KBAs) play an essential role in conservation and spatial planning to reduce the detrimental effects of biodiversity loss. The present study examined the spatio-temporal variations in fish diversity within selected zones of the Point Calimere Wildlife Sanctuary Key Biodiversity Area (PCWSKBA) from January 2023 to December 2024. In this study, 255 species from 39 orders and 85 families were identified. Escualosa thoracata (Valenciennes, 1847) was the most abundant fish species, comprising 7% of the total number of fish collected, followed by Eleutheronema tetradactylum (Shaw, 1804) (4%) and Mugil cephalus Linnaeus, 1758 (3.8%). The diversity indices revealed that Kodiyakarai Wetland (KW) had the highest species richness and abundance. Simultaneously, the SC recorded lower diversity due to anthropogenic pressure and environmental constraints. The post-monsoon season had the greatest seasonal diversity, which corresponded to the input of nutrients from monsoon rain. The K-dominance curve indicated that the samples from 2023 exhibited a higher concentration of dominance than those from 2024. Redundancy analysis (RDA) revealed that dissolved oxygen, salinity, and phosphate nutrient levels significantly influenced fish distribution across various zones. This study suggests that increasing phosphate and organic matter levels may enhance productivity by promoting algal growth and by providing a food source for fishes. However, excessive nutrient enrichment can lead to eutrophication, depletion of oxygen levels, and promotion of opportunistic species that ultimately disrupt the ecosystem balance. Therefore, it is essential to implement measures to reduce nutrient runoff and organic pollution to prevent oxygen depletion and protect the biodiversity and ecological health of the PCWSKBA. Sustainable land-use practices and enhanced water quality monitoring can help mitigate nutrient overload while preserving the productivity and diversity of aquatic ecosystems.
由于栖息地退化、过度开发、污染和气候变化，生物多样性丧失正以前所未有的速度扩大。关键生物多样性地区（KBAs）在保护和空间规划中发挥着重要作用，以减少生物多样性丧失的不利影响。本研究调查了2023年1月至2024年12月期间卡利梅尔角野生动物保护区关键生物多样性地区（PCWSKBA）选定区域内鱼类多样性的时空变化。在本研究中，共鉴定出39目85科的255种鱼类。胸鳍遮目鱼（Escualosa thoracata，瓦朗谢讷，1847年）是最丰富的鱼类物种，占所收集鱼类总数的7%，其次是四指马鲅（Eleutheronema tetradactylum，肖，1804年）（4%）和鲻鱼（Mugil cephalus，林奈，1758年）（3.8%）。多样性指数显示，科迪亚卡赖湿地（KW）的物种丰富度和丰度最高。同时，由于人为压力和环境限制，SC的多样性较低。季风后季节的季节性多样性最大，这与季风降雨带来的营养物质输入相对应。K优势度曲线表明，2023年的样本比2024年的样本具有更高的优势度浓度。冗余分析（RDA）表明，溶解氧、盐度和磷酸盐营养水平显著影响不同区域的鱼类分布。本研究表明，增加磷酸盐和有机物水平可能通过促进藻类生长和为鱼类提供食物来源来提高生产力。然而，过度的营养物质富集可能导致富营养化、氧气水平耗尽，并促进机会主义物种的生长，最终破坏生态系统平衡。因此，必须采取措施减少营养物质径流和有机污染，以防止氧气耗尽，并保护PCWSKBA的生物多样性和生态健康。可持续的土地利用实践和加强水质监测有助于减轻营养物质过载，同时保持水生生态系统的生产力和多样性。
