Dr. J A Johnson (Wildlife Institute of India)
Dr. Anuradha Bhat (Indian Institutes of Science Education and Research)
Dr. K. Sivakumar (Wildlife Institute of India)
Dr. Prasanta Nanda (Dera Natung Government College)
Dr. Vidyadhar Atkore (World Wildlife Fund)
Many fish are sensitive to environmental change and can serve as excellent indicators of aquatic ecosystem health. Given the importance of, and the rapidly declining health, of freshwater ecosystems, it is necessary to monitor these habitats. Freshwater fish are characterised by a high degree of endemism/ highly specialized to particular watershed, and the presence and abundance of these unique fishes can be quantified to measure responses to various impacts. Flow obstructions, Industrial and agricultural effluents into freshwaters, introduction of invasive species are some of the primary disturbances to freshwater habitats and their assemblages. Fish can play an important role as indicators of such disturbances to freshwater habitats. For example, habitat quality studies can help detect changes in population dynamics of sensitive species. In addition to providing basic information on ecological factors that structure biotic communities, long-term collection (that includes seasonal and spatial monitoring) can provide baselines for testing effects of natural and anthropogenic disturbances. These will help in making informed decisions for freshwater conservation and management.
Fish can be monitored by observing by conducting periodic fish sampling using standard nets and effort in a permanent monitoring stations. Parameters such as presence/absence of indicator species, abundance of select species, and body size can be used to monitor trends in fish populations. The environmental and anthropogenic variables collected along with fish population can help in finding the role of these factors on fish population dynamics. In addition to providing basic information on ecological factors that structure biotic communities, long term collection (that includes seasonal and spatial monitoring) can provide baselines for testing effects of natural and anthropogenic disturbances.