ICAR-Central Coastal Agricultural Research Institute, Old Goa, Goa, India.
ICAR-Central Institute of Fisheries Education, Mumbai, Maharashtra, India.
Environ Monit Assess. 2019 Apr 25;191(5):305. doi: 10.1007/s10661-019-7436-x.
This study analyzes the trophic structure of fish assemblages in a well-mixed tropical estuary, Zuari, located in southwest coast of India. A total of 224 fish species were collected between September 2013 and August 2016 from 324 sampling events from 9 sampling stations using surface and bottom set gillnets. The sampling events were designed to cover three major seasons such as the pre-monsoon, monsoon, and post-monsoon. For each sampling event, abiotic variables such as temperature, salinity, dissolved oxygen, and transparency of the water were recorded. The data obtained for abundance of fish species was subjected to cluster analysis and non-metric multidimensional scaling. The results defined six spatio-temporally varying groups (clusters) within Zuari estuary. Canonical correspondence analysis demonstrated that temperature, salinity, dissolved oxygen, and transparency were important in determining the fish assemblages in Zuari. The estuarine resident species were abundant in the inner zone (riverine side) of the estuary, where the salinity and temperature recorded lower dimensions compared to middle and outer zones (marine side). However, the inner shallow zone of the estuary was not a preferred habitat for the migrating marine species. Majority of the fish species preferred middle and outer zones and post-monsoon and pre-monsoon seasons for inhabiting the estuary. The present study furnishes a reference data for the spatio-temporal dynamics of fish assemblages in tropical monsoonal estuaries.
本研究分析了位于印度西南海岸的祖阿里（Zuari）混合良好的热带河口鱼类群落的营养结构。2013 年 9 月至 2016 年 8 月期间，从 9 个采样站的 324 次采样中，使用表面和底部刺网共采集了 224 种鱼类。采样设计旨在涵盖三个主要季节，如前季风期、季风期和后季风期。对于每个采样事件，记录了温度、盐度、溶解氧和水的透明度等非生物变量。对鱼类物种丰度的数据进行了聚类分析和非度量多维标度分析。结果在祖阿里河口内定义了六个时空变化的组（聚类）。典范对应分析表明，温度、盐度、溶解氧和透明度对祖阿里的鱼类群落有重要影响。河口定居物种在河口的内区（河流侧）丰富，与中区和外区（海洋侧）相比，盐度和温度记录的维度较低。然而，河口的内浅区并不是洄游性海洋物种的首选栖息地。大多数鱼类物种更喜欢中区和外区以及后季风期和前季风期来栖息在河口。本研究为热带季风河口鱼类群落的时空动态提供了参考数据。
