Dr Mushaiyada Mairaj
CLIMATE risk is emerging as an important dimension of Pakistan’s maritime economy, but the one that is probably the biggest yet least discussed. The warming of the Arabian Sea is an issue that hasn’t gotten the same level of attention as floods, droughts and rising temperatures on land, but it’s a serious problem for the economy. Marine Heat Waves (MHWs) are increasing in frequency and severity, threatening the fisheries sector, seafood trade and coastal livelihoods of Pakistan. The Arabian Sea is one of the fastest-warming tropical seas. Sea temperature increases are changing marine ecosystems, as they are decreasing Dissolved Oxygen (DO) and affecting the distribution of fish stocks. These can also be aggravated by climate patterns like the El Niño Southern Oscillation (ENSO). El Niño’s impact is felt in the Indian Ocean, such as the Arabian Sea, though it is a result of events in the Pacific Ocean. Atmospheric circulation changes during El Niño can help fuel warmer sea surface temperatures, which can lead to more marine heat waves. The combination of these natural cycles of climate and long term global warming makes it even more severe on marine ecosystems.
However, the consequences of this impact go far beyond environmental issues for Pakistan. The 1050 km long coastline of the country has thousands of fishermen in Sindh and Balochistan and fisheries sector provides employment, food security and foreign exchange by exporting sea foods. Nonetheless, the behavior and distribution of commercially valuable species like tuna, pomfret, mackerel, sardines and shrimp are shifting due to warming waters. Many fish species are moving to deeper or cooler waters as the temperature of the sea increases. This not only decreases catches in the traditional fishing ground but also makes fishermen go further offshore, consuming more fuel and fuel costs. The small scale fishermen, who constitute a significant proportion of the total population of fishermen, are the most vulnerable group as their financial capacity is not strong enough to bear these extra costs.
Ocean heat waves not only deplete fish stocks but also adversely affect fish growth, survival and reproduction. As fish resources decreases, the general decline in fish landing may have a direct effect on the fish processors, exporters, transporters and fisheries value chain businesses. There’s another economic worry: elevated likelihood of harmful algal blooms (HABs) that are often referred to as “red tides. These blooms may cause fish mortality and decrease the quality of seafood products, resulting in the difficulties of exporters to comply with international food safety standards. Quality and supply issues may impact Pakistan’s export performance in a growing competitive world market for seafood. Ecosystems are also under threat along the coast of the country. The Indus Delta is a natural spawning ground for numerous commercial fishes. They also help defend coastal structures against erosion and storm surges. Any damage to these systems ultimately leads to a decline in fish productivity, make coastal areas more vulnerable and put up higher adaptation costs in the future.
However, this challenge cannot be overcome unless ocean observation and scientific research are increased to a greater level. Sea surface temperature, dissolved oxygen and fish migration data are continuously monitored and would be useful to fisheries managers and policy makers to better prepare for marine heat waves. Early warning systems would also enable the fishing communities to plan their activities and minimize economic losses. Pakistan needs to consider marine climate risk in its Blue Economy agenda as well. Fisheries management will need to increasingly depend on scientific data and increased investment in climate-resilient aquaculture can help alleviate pressure on wild fish stocks and enhance food security over the long-term. The conservation of mangrove forests and other coastal ecosystems should continue to be a national priority and these natural resources provide livelihoods for the fisheries industry as well as enhancing climate change resilience.
Climate change isn’t just happening on land — it’s changing the oceans as well and they are vital to the economies and livelihoods of the world. Marine heat waves in Arabian Sea are an emerging economic threat which needs immediate policy attention. Awareness of such a risk now and investment in scientific management of the seas will help protect fisheries, boost seafood exports and also help safeguard the coastal economy in the face of future climate shocks. As climate resilience gradually becomes an economic imperative, it’s no longer a question of if, but when, we need to be ready for a warmer Arabian Sea.
—The author is a distinguished Research Fellow and Marine Biologist at the National Institute of Maritime Affairs (NIMA) Karachi.
