Shifting Baselines: A Fish Spawning Aggregation in Lakshadweep

On a bright and warm morning in January 2024, our team of four reached Bitra, a tiny, remote atoll in the northern Lakshadweep archipelago. It is unique among all Lakshadweep islands in multiple ways: it is the westernmost island of the archipelago; it has one of the largest lagoons and has been only inhabited since 1948. However, what took us to Bitra is even more special: it is India’s first-ever reported fish spawning aggregation site. Put more simply, each year, squaretail groupers (Plectropomus areolatus) assemble in this part of the archipelago in large numbers (100 per square metres) to look for a perfect mate and reproduce. Excitement was skyrocketing. Three of us were diving here for the first time and were eager to observe this marvellous natural phenomenon.

We jumped into the water at 9.30 am. After a few minutes of swimming, we spotted groupers coming out of their hideouts or roving in the water column. It was unlike anything I had seen before. Squaretail groupers are long-lived, piscivorous (fish-eating) fish that are normally present in reefs in low numbers (about one individual in 100 square metres). But here, they were everywhere. I felt happy and overwhelmed at the same time. Once all of us settled down, we turned to Rucha Karkarey, my advisor and a spawning aggregation veteran, to follow her through the permanently marked fish-counting transects she had been monitoring for the past ten years. Surprisingly, she didn’t look happy at all.

Scales from the past

Rucha has been visiting this site in Bitra since 2011, when they discovered this spawning aggregation serendipitously. According to her, nothing is as it was ten years ago. At its discovery, the site was almost unfished. Post-2013, commercial reef fisheries have risen sharply in the archipelago, and the spawning aggregation became an easy target. Ever since, this once-pristine aggregation in Bitra has become a story of doom and despair.

Rucha seems to have managed to make her peace with observing lower numbers of groupers at the aggregation site. The last census in 2023 showed a drastic drop of 70 per cent from the 2011 count. But 2024 reached a new low.

Since Rucha had previously needed five transects to survey the whole aggregation site, we planned to monitor the same number this time. But after the third transect, we couldn’t see any groupers. The aggregation area had shrunk. Reduced aggregation area, diminished fish counts, small-bodied individuals, fearful fishes, the male-dominated sex ratio of fishes — many such signs of unsustainable fishing pressures were scattered across the aggregation site. I was naive enough not to identify them, but Rucha, with her experienced eyes, spotted these signs even amidst the hurry of collecting data. In the afternoon, we looked at a few photos from the past years, and yes, everything had changed.

Aggregation at the Archipelago

In 2011, Lakshadweep’s commercial fisheries were mostly centred around the pelagic skipjack tuna (Katsuwonus pelamis). Fishing in the reefs was just for sustenance. From 2014 onwards, due to various ecological, social, and market-related changes, commercial fishing shifted to near-shore coral reefs. In this scenario, fish spawning aggregations like this one in Bitra became easy targets.

With the rise of the new moon, squaretail groupers start to aggregate at this site in Bitra, driven by their hardwired biology. Simultaneously, small fishing boats from the islands of the archipelago and mainland India arrive to capture this easy and valuable catch.

The Theory of Everywhere

Globally, aggregation fisheries have contributed to the decline of spawning aggregations, especially of commercially valuable fishes like groupers and snappers. The gathering of such high numbers of fish creates fishing hotspots and leads to unsustainable extraction of resources. Piscivores like groupers and snappers are long-lived species that take substantial time to attain maturity. Disturbances at the early and vulnerable stage of life can have far-reaching consequences on population regeneration. Aggregations in parts of the world have completely collapsed due to the unregulated extraction of fish from aggregation sites.

The Lakshadweep narrative is not unique. Aggregating groupers, snappers, and wrasses are caught by hook and line — which is a sustainable way of fishing. But increasingly, islanders are getting their hands on spearguns. Commercial spearfishing in reefs is growing rapidly (mostly under the influence of big mainland fisheries enterprises). Spearfishing specifically targets larger mature individuals to maximise yield. Such selective extraction of certain kinds of individuals creates an imbalance in the population, leading to catastrophic consequences. The commercialisation of reef fish has dramatically impacted the ecology of this vulnerable island chain. And as a result, nothing is the same anymore.

Shifting Baselines

Though Rucha looked glum, I was still awestruck to witness the aggregation. Our combined introspection made us realise that we obviously had a major difference in our baseline of the aggregation. Rucha was comparing it to a decade ago. I had a clean slate. Our conversations made me realise that our Bitra story is not just a depressing tale of an aggregation. It is also a story of shifting baselines. My lack of a baseline helped me marvel at the sight of 150 groupers, while Rucha was depressed thinking of the old days when the count was 1,500.

Baselines can determine many things for individuals: their emotions, responses, attention, decisions, and even ignorance. The same applies to conservation practices. Over afternoon tea, we wondered: in a world where anthropogenic disturbances have changed the ecological attributes of “wilderness”, whose baseline should we aspire to match? Is a pristine, unfished spawning aggregation what we should aim for? Or is it more pragmatic to try and protect a baseline that had survived almost a decade of extensive fishing pressure?

Fish spawning aggregations have drawn the attention of fishermen, as well as researchers, especially those concerned with sustainable resource extraction and management. Existing knowledge strongly suggests that a bit of management can go a long way in enabling these spawning aggregations to recover and thrive. Is there any possibility of something like this in Lakshadweep? We kept discussing this over lunch, dinner and many cups of steaming black tea at the local canteen.

Looking behind and moving forward

The question we kept asking ourselves is, can we reach a middle ground when conserving declining yet commercially valuable species?

Rucha mentioned that ideas of fisheries sustainability have progressed from ecological-centred views like “maximising yield” or “maximising spawning stock” to people-centred views that support social, economic, and ecological aspects of “leaving enough fish in the sea, protecting habitats and ensuring people who depend on fisheries can maintain livelihoods”. The concept of “functional populations” — keeping enough of a population to keep it going ecologically and socio-economically — specifically caught my attention.

Globally, many different management scenarios exist, ranging from declaring marine protected areas and complete no-catch zones to temporary fishing bans for a few days around spawning time. All show different levels of success and failure. But we don’t know whether any of these will work for Lakshadweep. Will local fishermen, researchers, and other stakeholders have to join hands to construct place-based, tailored, and innovative solutions? The answers to these questions are unknown. But with time, hopefully, we will have solutions. 

But how much time does the aggregation have? How long can it survive through the pervasive fishing pressure? How long does it have before it enters an extinction vortex?

The question of the hour is whether the aggregating population in Bitra is already functionally extinct. Rucha suggests that it is probably not. The aggregation still supports a dense grouper population, definitely supports the local commercial fishery, and is still magnificent. But she knows this population has been severely altered in demography and behaviour since it was first documented. Something needs to be done before it’s too late. But what, how, and to what effect remains the question.

Dark Clouds or Silver Linings

With all these unanswered questions in mind, we sailed our boat from Bitra jetty to the aggregation site the next morning. Again, it was around 9:30 am when we jumped into the water to continue our work at the site: counting grouper numbers, recording their behaviour, following herbivorous fishes, measuring turf algae, etc. Just as we were about to start our work, Rucha spotted a dark cloud moving towards us. It turned out to be a school of about 50 female groupers. They were approaching the site in search of suitable mates to ensure the persistence of their kind. I marvelled at the school, even if Rucha wasn’t impressed. We stopped and watched the shoal for a few minutes. It brought us hope and joy. And then we moved on, wondering if we would get to see this again the next time we’re in Bitra.