Abstract:
This study investigates the fish assemblage in a temporarily-closed sandbar estuary along India\'s west coast, across different zones and seasons. Moderate species diversity (54 species), low species abundance, varying fish diversity from lower to upper estuarine gradient (higher counts in lower zones, and decreasing from middle to upper zones), and higher prevalence of marine migrants (estuarine use) and piscivorous species (feeding mode) were the significant characteristics of the estuary. Distinct spatial, seasonal, and estuarine mouth state-based variations were recorded in the estuary, based on diversity indices and count of taxa. Peak diversity and abundance were noted during the pre-monsoon, and during the open mouth state of the estuary. The entire estuarine gradient is anthropogenically impacted by a multitude of stressors, except at the estuarine mouth region, which is favored by marine connectivity. The fish assemblage structure in Poonthura estuary (PE) has thus far remained unaffected by anthropogenic disturbances. Nevertheless, growth and nursery function of the estuary have been significantly compromised. The predominance of juvenile fish in the ecosystem, and prevailing anthropogenic stressors from point and non-point sources underscore the necessity for long-term maintenance of the population of coastal species, as well as a need for developing and implementing urgent management strategies for this fragile ecosystem.
摘要:
这项研究调查了印度西海岸暂时封闭的沙洲河口的鱼类聚集,跨越不同的区域和季节。中等物种多样性(54种),低物种丰度,从较低到较高河口梯度的鱼类多样性变化(较低区域的计数较高,并从中部到上部区域减少),河口的显着特征是海洋移民(河口使用)和食肉物种(摄食方式)的患病率较高。独特的空间,季节性,在河口记录了基于河口状态的变化,基于多样性指数和分类单元的数量。在季风前发现了峰值多样性和丰度,在河口张开的状态下。整个河口梯度受到多种压力源的人为影响,除了河口地区,这受到海洋连通性的青睐。迄今为止,Poonthura河口(PE)的鱼类组合结构尚未受到人为干扰的影响。然而,河口的生长和苗圃功能受到了严重损害。幼鱼在生态系统中占主导地位,以及来自点源和非点源的普遍人为压力强调了长期维持沿海物种种群的必要性,以及需要为这个脆弱的生态系统制定和实施紧急管理战略。