Twenty to 30 new jellyfish species have been detected within the Marmara Sea within the final 20 years, posing threats to fish shares and marine livelihoods.
Speaking to Anadolu Agency (AA), professor Melek Işibili Okyar, dean of Istanbul University’s Faculty of Aquatic Sciences, said that jellyfish, which have survived on the planet for 550 million years with out present process any morphological modifications, are extraordinarily sturdy organisms.
Emphasizing that jellyfish have a excessive tolerance for modifications equivalent to temperature and seawater salinity, Okyar stated, “As they feed on plankton and zooplankton, they have an intense food supply.”
“There are also creatures that feed on jellyfish, the most well-known are sea turtles. Apart from that, over 120 fish species in the ecosystem feed on jellyfish, which includes sardines, swordfish and sprats. While dolphins feed on jellyfish to train their young, the numbers of these fish species and sea turtles have dwindled significantly,” she defined.
Stressing on the influence of local weather change, Okyar stated: “On one hand, with dams built on rivers, seas are losing their regeneration abilities with rivers; and the input of domestic, industrial and agricultural wastes such as nitrogen and phosphorus into the sea has increased. Due to global warming, the marine temperature has been expanding to the north as creatures accustomed to warmer temperatures begin migrating north. On the other hand, overfishing has been a factor. We have industrial fisheries with very strong equipment and they hunt fish that feed on jellyfish during the fishing season. Man-made structures made of wood and concrete on shores prevent water circulation and allow jellyfish larvae to affix to the hard surfaces, thereby boosting their numbers.”
Effect of plastic
Okyar identified that plastic air pollution at sea is among the causes for a rise in jellyfish numbers. Stating that plastics create a tough space the place jellyfish repair themselves and play an energetic function of their migration to locations the place they aren’t usually discovered, Okyar stated: “You normally do not see an increase in jellyfish in the heart of the Marmara Sea, but a large increase has been seen in coastal areas. The ecosystem on the coast is more suitable for the species to attach themselves to plastic and spread to deeper areas as well.”
The improve in jellyfish impacts different fish species by way of replica, as they feed on the eggs and larvae of a number of species. Their dominance over plankton, fish eggs and feeding on their larvae prevents future fish shares from forming. Predicting that many fish species could disappear sooner or later, Okyar stated, “You will order your child, ‘Eat the jellyfish on your plate’ instead of nutritional fish.”
Okyar famous that jellyfish are usually not solely rising in Türkiye however globally as properly. This contains areas such because the seas of Japan, China, Israel, France, Spain and the Mediterranean a part of Italy which have witnessed these issues.
“It is not just the result of the past few years, but decades of how we have mercilessly utilized the Marmara. Local governments and ministries must work together and establish treatment facilities to protect the fish that will form the future stock at sea,” Okyar added.
Source: www.dailysabah.com
