12/28/2023 0 Comments Who made crab game![]() ![]() In the French West Indies, the cost of this invasion is estimated at more than €10m ($10.2m/£8.4m) a year through damage to the fishing and tourism industries. The lionfish eats large quantities of small native fish and crustaceans, and its stomach can expand up to 30 times its original volume to accommodate them.Įxperiences from other parts of the world show how much damage it can do: in the Bahamas, it was responsible for a 65% reduction in its prey biomass in just two years. Well established in southern and eastern areas of the Mediterranean Sea, it is now heading west and north towards the Aegean and Ionian seas. Sometimes considered the single most damaging invasive species known to science, the lionfish ( Pterois miles) is a highly aggressive fish sporting fierce venomous spines. "In our study, we found that large populations of rabbitfish are confined to the warmer eastern parts of the Mediterranean."Īnother new entrant to the Mediterranean is of even greater concern. "Given that rabbitfish are a tropical species generally confined to warm waters, we think that their expansion is linked to warming," says Adrianna Verges, a researcher on the ecological impacts of climate change at the University of New South Wales in Sydney and an author of the Greek and Turkish survey. These fish devour the vegetation that provides habitat to native species, decreasing native vegetation cover – mostly canopy algae – by as much as 65% in Greece and Turkey. The rabbitfish ( Siganus rivulatus and Siganus luridus), is another particularly successful new entrant. Indeed, the blue crab is far from alone in making the journey to the Mediterranean. "As for many invasive species, the proliferation of the blue crab has intensified with the warming of surface waters due to climate change, and with the increase of maritime traffic," says Jamila Ben Souissi, a researcher on biodiversity and climate change in the Mediterranean and member of the Mediterranean Science Commission. Since then, the crustacean has been recorded in various areas in the Mediterranean, from the Levantine basin up through Sicily, spreading according to environmental conditions, its migration capacity and shipping activities. The blue crab originates in Indo-Pacific waters and reached the Mediterranean Sea in 1898, around a decade after the Suez Canal opened. But after the initial shock, it has now become one of the region's most sought-after seafoods. The blue crab has upended Tunisia's fishing industry in more ways than one. "They remained piled up in the port, or they were thrown back into the sea," says Naloufi. Even disposing of the crab bycatch became a challenge. "We were clueless," says Fethi Naloufi, a fishing engineer and head of the Interprofessional Group of Fishery Products in Zarzis, a public organisation responsible for promoting fisheries and aquaculture in Tunisia. The terror the crabs caused was such that they became known locally as "Daesh", the Arabic acronym for the group calling itself Islamic State.Īt first, the fisherfolk's livelihoods were overturned. This crustacean is "very aggressive", says Gribaa – it destroys nets, and nips fishermen and other fish. The blue crabs were prolific, reproducing up to four times a year with litters of 100,000 per female. How India's sacred groves protect nature.The promise and danger of Scotland's bog."The crab represented almost 70% of my fishing catches and I did not know what to do with it." Hakim Gribaa, a fisherman on the island of Djerba, remembers it as if it were yesterday. Soon after, the blue crab population exploded. Little did he know, however, that a year later this non-native, or alien species would become a national curse. Rabaoui, at the time researcher at the Faculty of Science of Tunis at the University of Tunis El Manar, noted the discovery with interest. More remarkable still, was that the fishermen didn't find just one blue crab – their nets had captured 24 of them. Tangled in their net was a species of crab, Portunus segnis or blue crab, that wasn't native to the region. Traversing the beds of seagrass and algae, the fishermen made an unusual catch. In October 2014, Lotfi Rabaoui was travelling the shallow sandy waters near Ghannouch, a small coastal town in the Gabes Gulf in Tunisia, with a group of local fishermen.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |