Marine biologists have warned of the high invasion rate seen among poisonous sea urchins off the coast of southern Turkey's Mersin.
During a two-month-long controlled research over two 9 square meter areas, they found that the invasive species resettlement rate in that part of the Mediterranean has reached 108%.
The study, led by professor Deniz Ayas from Mersin University Fisheries department, made its first dive earlier in May. It found and cleared 34 sea urchins from the designated area.
However, when the divers returned in July there were as many as 37 poisonous sea urchins in each location, putting the return rate at 108%. The sea urchins were collected at depths of 10 to 20 meters at two locations between Kızkalesi and Narlıkuyu.
"It poses a serious risk in every area it settles in," said Ayas about the long-spined sea urchins (Diadema setosum) that settle on rocks, corals near the shore and feed on plant species.
He explained that the species also harms the population of other living things that feed on it.
"The species tends to shrink its populations by sharing the nutrients of other creatures in the Mediterranean. It has a very successful competitive relationship with other species, but we have not observed any living thing that will balance this in nature and put pressure on this species. Long-spined sea urchins pose a serious risk in every area they settle, especially on the Mersin coastline." he said.
"Today we found a total of 37 sea urchins from the two locations we are studying. This means about two creatures per square meter, putting the remigration rate at 108%, meaning this is a serious risk. Even if you clear all the sea urchins, you see that more species have settled in the area in a short period of 2 months."
Ezgi Biçer Uçar, a spokesperson for the local community organization, Slow Fish Mersin, said they are trying to promote human consumption of sea urchins as a possible way of fighting the invasive species.
