G. B. Sreekanth

Temporal Patterns in Fish Community Structure: Environmental Perturbations from a Well-Mixed Tropical Estuary

Abstract The composition of fish communities in tropical coastal ecosystems is regulated by seasonal patterns in the oceanographic environment. In the present study, the authors have studied the temporal variation of fish assemblages and environmental variables in a tropical coastal ecosystem, Zuari estuary in Goa located along the west coast of India. The species abundance and environmental data were subjected to multivariate analysis (canonical correspondence analysis and non-metric multidimensional scaling) and showed seasonal differences in fish communities. The second canonical axis was loaded with salinity, temperature, dissolved oxygen, transparency and depth separating the seasons into discrete groupings. The authors also found that the species diversity is significantly less during the monsoon season in comparison to pre- and post-monsoon seasons. Moreover, season-specific diagnostic species were identified using SIMPER analysis. The seasonal migration of species mediated by environmental factors seems to be an important element which determines the temporal pattern in fish communities. The results of the study have implications on fish diversity, conservation and coastal fisheries management.

Can Artificial Reefs Really Enhance the Inshore Fishery Resources Along Indian Coast? A Critical Review

The depletion of fishery resources and their habitats on account of fishing, pollution and other anthropogenic activities necessitates their replenishment by some strategic management approaches. Artificial reef (AR) is a kind of artificial fish habitat which provides living, hiding and breeding places for aquatic organisms and thereby augmenting the biodiversity and abundance of fishery resources. In particular, the installation of ARs along coastal regions could bring down the fishing pressure from mechanized sectors and thus support the small scale traditional fisheries. Since the management based on AR is not species specific but effective for all aquatic organisms in the ecosystem, it allows fishery managers to move from a single species framework to ecosystem based fisheries management in the long run. Being a tropical coastal nation, India has also initiated trials on AR deployment. However, these studies so far are limited to the design, construction and performance of AR. In this review paper, the historical AR initiatives in India are critically analyzed and potential areas for research and development that the country can focus on are discussed particularly in the perspective of supplementing the inshore fisheries.