From production seascapes to biological systems: Redefining coastal waters

Vardhan Patankar

Team members : Mayuresh Gangal, Rohan Arthur, Uma Ramakrishanan

We consider coastal waters to be essentially “Production seascapes” – where fish are ours for the taking. This is so ingrained in our cultural mindset that rarely do we think of coastal waters as complex biological systems. In fact, we do not even have a “name” for these coastal habitats. Our ignorance of the basic biology, ecology and life history of the animals and plants in this “production seascape” is certainly one of the most important contributing factors to the overfishing crisis. My doctoral aims to contribute in efforts bridging this gap between fish ecology and fisheries management so we can work towards reducing our human impact on coastal marine ecosystems. The project does this by examining coastal fisheries in India through two lenses. The first uses genetics to determine boundaries between fish populations along the coast. The second takes a detailed look at coastal fisheries policy, to determine how coastal ecosystems are imagined by regional and national governments.

Identifying genetic structure in fish populations

In India, we manage our fisheries according to state boundaries. Neighbouring states have different rules when it comes to fishing. What this means, is that certain methods of fishing might be allowed in one state and not allowed in the neighbouring state. This form of management makes sense only if fish are also bound by state boundaries.

Yet it is hardly a surprise that fish populations do not respect political divisions. The geographic spread of their population is bound by their ability to swim, reproduce, by ocean currents, bathymetry etc and have nothing to do with how we have divided the coastline. This mismatch may be a huge problem for the sustainable management of fish. Neighbouring states may share the same population of fish while having very different rules regarding the catching of that fish. This might contribute to the overexploitation of certain fish populations and also lead to conflict between fisheries from neighbouring states.

We believe that the first step to solving this issue is knowing how fish populations are distributed across the coastline. My doctoral research uses genetic techniques to answer these questions. For a start I am currently working on 9 species which are ecologically important as well as commercially valuable. My work focuses on the entire west coast of India, and on species that are typically caught in mid-sized trawlers. Using a technique called Single Nucleotide Polymorphism or SNPs, I look for differences between individuals of the species sampled along the coast. This helps identify if they come from the same population, or represent completely different populations. These results will help determine which species and populations are most at risk from a differential management along the coast.

How do we understand fish “officially”?

In India the government has a huge influence on fisheries activities. Who can fish? Where to fish? How to fish? When to fish? The answer to these questions is linked either to schemes provided by the government or rules made by the government. It is important to know what fish represent to the “official” imagination, since this translates to very real consequences on the ground in terms of money spent, infrastructure provided and rules formulated. What is more, this image can change from state to state. My doctoral project is dedicated to unpacking how the fish has been viewed through the decades by the central government and states along the west coast. This work involves a detailed analysis of policies and government regulations from the early 1900s, through independence and to the present. This analysis examines the relationship between the states and the central government, and the role that science has played in influencing fisheries policy and the way fish have been understood and managed.

Shoal of fish in its natural habitat