A new study on the southwestern Indian coast shows marine weather forecasts can be localised and aid safe traditional fishing by small-craft fishers close to the shore, even when there may be rough weather offshore. Weather information downscaled for grids of 5 km x 5 kilometres (km), with localised forecasts issued for 25 km x 25 km, can complement official forecasts that are usually meant for large ocean areas, the study by Cochin University of Science and Technology (CUSAT), India Meteorological Department (IMD) and University of Sussex, UK, demonstrated.
As the Arabian Sea becomes increasingly prone to intense storms, such local forecasts can help fishers make informed decisions about when and where to fish, stated a paper based on the study and published online on May 8, 2024, in Weather, the flagship journal of the Royal Meteorological Society, UK. “Localised forecasts allow fishers to launch and land boats at secure spots, fish close to the shore, avoid high-wind ocean areas, and quickly return when the weather turns foul,” Abhilash S, director of the CUSAT Advanced Centre for Atmospheric Radar Research (ACARR) and a co-author of the study, told Down To Earth (DTE).
The research
The paper is an outcome of the Sussex-led safe-fishing research initiative, ‘Forecasting with Fishers’, in Kerala’s Thiruvananthapuram district. An interdisciplinary team — supported by UK Research and Innovation, Sussex Sustainability Research Programme and the Royal Geographical Society — looked at ways of ensuring safe and sustainable fishing over the past six years. Atmospheric scientists, geographers, social scientists and information and communication technology experts observed weather trends, studied local risk cultures and co-produced weather information products with fishers.
Their earlier papers showed that the eastern Arabian Sea is getting stormier and fishers demanded localised forecasts, disseminated over multiple platforms — from phone messages and digital displays to radio programmes and online graphics. The new paper’s lead author is Prabhath H Kurup, an ACARR doctoral scholar guided by Abhilash.
IMD senior scientist VK Mini, ACARR researcher M Sarang, Sussex climate researcher Netsanet Alamirew, and Sussex researcher and Christ University Bengaluru life sciences faculty member Max Martin are the other coauthors. The study highlighted the diverse wind conditions prevalent on India’s southwestern coast. Test forecasts were prepared for a 100 km of coast in the study area, a shared fishing space of the local artisan fishers.
The area was divided into three sub-regions with distinct wind characteristics using the following onshore reference points as boundaries: the lighthouses of Thangasseri (in Kollam district); Anjengo and Vizhinjam (Thiruvananthapuram); and Enayam beach (Kanyakumari, Tamil Nadu) in the south. The wind regimes along this coast are diverse, with the speed increasing towards the south.
That would call for localised, sub-regional and cross-state-border wind forecasts that are highly relevant for artisanal fishers, the paper noted. The current official forecasts are usually for Kerala’s 580 km coast, with restrictions based on high wind warnings applicable for the entire stretch. “Further, availability of such forecasts can limit the number of fishing days lost due to blanket warnings that may not be relevant to local areas where the fishers go,” Abhilash told DTE.
Localised forecasts are the holy grail of the local fishers. “They say there will be high wind — but we find the sea (close to the shore) calm and quiet. The forecasters often scare us,” Davidson Anthony Adima, a fisherman in his 40s, a fisherman from Fathimapuram village north of Thiruvananthapuram, told DTE. Fishers found the localised test forecasts issued as part of the Forecasting with Fishers project useful.
“It is very useful to check localised forecasts before going to fish,” said Tieny Gomez, a fisherman from St Andrew’s village near Fathimapuram. Gomez often goes far offshore in search of tuna on his 34-foot fibreglass boat with twin outboard motors. “When there is high wind offshore, it helps us make a decision. That means we can go to a safe area of say 10 km instead of going far offshore,” he said.
On the margins
Of over 180,000 active traditional fishers in Kerala, 50,000 live in Thiruvananthapuram district. It is known for its diverse kinds of traditional fishing. Many fishers deploy 30-34 feet-long fibreglass boats as well as smaller canoes and rafts. There are bigger, rope-tied shore-seine boats, a few mechanised ring-seine boats and fishers who dive for shellfish and clams – but hardly any industry-scale fishing. ‘Seine’ is a net which surrounds fish and other marine animals.
Historically, fishers lived on the margins of Kerala’s political economy and social structure, many of them in poverty. Coastal households traditionally depend on fishing. It is a precarious job, a precarious job that is seasonal and weather-dependent. The southwestern monsoon season, comprising 122 days, lasts from June to September. Fishing can be risky under rough weather. The months of June-September witness frequent accidents and incidents. A total of 145 fishers died between 2016 and 2021 off Thiruvananthapuram, as per media reports based on official figures.
Fish is also a highly perishable product that has very limited local storage facilities. Fisher families spend the bulk of their income from fishing on household expenses, buying and servicing engines and nets, running boats and repaying debts. Without fishing regularly, income becomes uncertain or inadequate, leading to debts, if not poverty. The situation for fishers in Kerala and indeed, globally, has been compounded by climate change.
While the North Indian Ocean is the warmest ocean in the world, the Arabian Sea, hitherto considered calmer than the Bay of Bengal on the eastern side of peninsular India, remains warm even after the monsoon, not cooling off enough as it used to. That means more intense storms. The North Indian Ocean has two storm seasons. The first is just before the start of the southwestern monsoon — March–June. The second is just after it during October–December. The post-monsoon storm season, especially, is increasingly seeing intense storms over the eastern Arabian Sea, an earlier paper by Forecasting with Fishers appearing in Nature Scientific Reports showed. This trend of intensification of storms over the eastern Arabian Sea is caused by several factors.
The paper pointed out that the heat, temperature and energy relationships of the upper ocean and lower atmosphere contribute to spawning and revving up cyclones over the eastern Arabian Sea. While warm, rising air and high humidity in the lower atmosphere lead to more intense cyclones before the monsoon, changes in ocean temperature variation at different depths and the spread of warm ocean water favour the process after the monsoon, the paper noted.
“Ocean basins, especially the eastern Arabian Sea is warming rapidly due to climate change. This warming affects the lives and livelihoods of traditional artisan fishers and the coastal communities,” Abhilash said. Cyclone Ockhi, which occurred in 2017, exemplifies this climate-based rise in risk. Fishers note that there has been a marked increase in high-wind alerts since the time of the cyclone Ockhi.
With inadequate forecasts and forecast dissemination, the very intense cyclonic storm trapped many fishers off the coasts of Thiruvananthapuram and Kanyakumari and in the deep ocean, killing at least 365 of them. More fishers died off the shores of Sri Lanka. So intense was the impact of Ockhi that fishers in Thiruvananthapuram now talk in terms of before and after the event.
Why ‘local’ is necessary
“Weather systems such as cyclones and deep depressions are becoming more intense; so, fishers have to take more risks,” according to Abhilash. Large-area forecasts lead to very frequent fishing restrictions. But fishers often hear “do-not-go-to-fish” warnings for half of the southwestern monsoon. They say such frequent over-forecasting reduces the credibility of forecasts. It also drastically cuts down the number of days they are allowed to fish. If there is a fishing restriction and fishers face an accident, they do not get government compensations.
Fishers often disregard forecasts when local waters are relatively calmer, as an earlier study published in the American Meteorological Society journal Weather, Climate and Society (WCAS) showed. That paper by the Forecasting with Fishers team noted that seagoing fishers actively seek forecasts from multiple sources. They observe the sky and the sea, and share notes on mobile phones and short-range wireless when they can.
The WCAS paper underlined that fishers often take calculated risks when there are prospects of fish. They do not like to lose those windows of opportunity. Fishing is precarious, seasonal and uncertain, with often inadequate income. As a Sussex blog post explained: “It is not bravado that drives the fishers’ risk-taking behaviour. It is often a compulsion to earn enough, pay off high-interest loans, and live a dignified life in a market economy with inadequate safety nets.” “The most effective solution is to include them (fishers) in a localised, community-orientated, impact-based forecasting system and co-produce weather information,” said Abhilash.
The Scientific Reports paper called for “impact-based…and localised reliable weather services”. Impact-based forecasts inform what the weather will do, not just what the weather will be like. Following up, the new Weather paper used a numerical weather prediction system called Weather Research Forecasting model downscaled with 1-3 days’ lead. The model showed the best performance for moderate wind events at 1-day lead.
A shift towards user experience design, impact-based forecasting, and last-mile dissemination through multiple media can make forecasts more relevant and usable, Forecasting with Fishers research shows. Along with IMD, Indian National Centre for Ocean Information Services, people’s tech firm Gram Vaani, Radio Monsoon community weather service collaborated with local fishers in this research. “We hope our work can lead to more localised weather services by the national forecaster,” Abhilash said.