From warming seas to algal blooms, climate risks pose growing threat to ocean ecosystems

Kochi: Warming seas, marine heatwaves, shifting fish populations, coral bleaching, algal blooms and increasingly unpredictable ocean conditions are posing mounting challenges to fisheries and coastal livelihoods, marine scientists have warned.

Speaking at the opening day of the international TREVOR SAFARI (Societal Applications in Fisheries and Aquaculture using Remote Sensing Imagery) symposium, they suggested integrating diverse expertise to monitor rapidly changing ocean conditions.

The three-day symposium, hosted by the ICAR-Central Marine Fisheries Research Institute (CMFRI), brings together over 300 participants from 30 countries including fishery scientists, climate and remote sensing experts and oceanographers. They underscored the growing need to integrate satellite remote sensing, oceanographic observations, climate models, artificial intelligence and in-situ data to better understand the physical and biological change in marine ecosystems and provide timely advisories and early warnings.

Inaugurating the symposium, Dr Sophie Seeyavae, CEO of Partnership for Observation of the Global Ocean (POGO), U K said technological innovation is required to develop accurate potential fishing zone advisories, detect harmful algal blooms, forecast marine heatwaves, and provide reliable weather and sea-condition alerts to fishing communities. Emphasising the need to expand ocean observation capacity, she said building expertise in this area would help improve climate resilience, water-quality monitoring and fisheries management.  “POGO has trained nearly 1500 early career ocean scientists from 102 countries aimed at strengthening ocean observation globally”, Dr Seeyavae added.

On climate impact, John A Gittings of the National and Kapodistrian University of Athens, Greece, presented research showing that extreme climate events such as marine heatwaves are driving unusual changes in marine productivity across the global oceans. “Frequency of extreme events including storms, droughts, wildfires and heatwaves has increased in recent decades, leading to the alterations to the physiology, abundance, geographic distribution and community structure of marine organisms”, he said, adding that continuous monitoring is required to detect significant changes in ocean conditions.

Experts suggested that integrating ocean observations with weather forecasts, wave conditions and current patterns could strengthen safety advisories.

The symposium is jointly organised by the Department of Chemical Oceanography of the Cochin University of Science and Technology (CUSAT), Trevor Platt Science Foundation, CMFRI and Marine Biological Association of India.

CUSAT Vice Chancellor Dr Prof (Dr) M Junaid Bushiri presided over the inaugural function. Prof. Shubha Sathyendranath, Principal Scientist at Plymouth Marine Laboratory, UK, Dr Grinson George, Director of CMFRI, Dr N Aparna, Deputy Director of National Remote Sensing Centre under Indian Space Research Organisation (ISRO) and Dr Shaju S S, Convenor of the symposium spoke on the occasion.

India’s ocean satellites advance monitoring of El Nino, algal blooms

India’s advanced ocean-observation satellites are strengthening the monitoring of marine ecosystems, with satellite imagery helping scientists monitor El Nino, detect algal blooms and access ocean productivity, said Dr N Aparna, Deputy Director of National Remote Sensing Centre under Indian Space Research Organisation (ISRO) in her keynote address at the international TREVOR SAFARI symposium.  

The emerging application of India’s Ocean Colour Monitor-3 (OCM-3) onboard EOS-06 (Oceansat-3) helps for identification of potential fishing zones. The application can help track changes in cholorophyll-a concentration, an important indicator of ocean productivity, Dr Aparna said.

“OCM-3 observations, combined with ocean-surface wind measurements from the EOS-06 scatterometer are also being used to study changes in ocean productivity associated with El Nino. This will help scientists understand the relationship between changing wind patterns, ocean upwelling, nutrient availability and phytoplankton abundance”, she added.

Dr Aparna further said that following advisories on potential fishing zones generated through the application, fish catches in the recommended zones were found to be 1.5 to 4 times higher than those in areas outside them.

Experts gathered at CMFRI to participate in the international symposium after the inaugural ceremony.