Salah satu spesies ubur-ubur memiliki tentakel yang beracun dan dapat mematikan (antigravitas.com)
VIVAnews – Ubur-ubur merupakan makhluk laut yang jelek, cukup berbahaya, dan tidak seperti pembunuh lainnya di samudera yakni hiu. Ubur-ubur tidak terlalu enak untuk disantap. Sayangnya, hewan itu kini siap menguasai dua pertiga bagian planet Bumi.
Pada tahun 2006 sampai 2010, sekelompok kawanan besar ubur-ubur menginvasi pantai-pantai di Spanyol. Menyengat puluhan ribu perenang. Di sejumlah tempat, ubur-ubur ini hadir dengan konsentrasi hingga 10 ekor per meter persegi.
Kelompok ubur-ubur ini juga muncul di kawasan lain di seluruh dunia. Tahun 2007, Hawaii dan Irlandia mengalami hama ubur-ubur. Perairan Israel dan Prancis di tahun 2008. Tunisia dan Italia diserbu pada 2009. Di Jepang, ubur-ubur berukuran hingga 1,8 meter makin banyak bermunculan.
Di perairan kawasan utara Australia, populasi ubur-ubur dengan tentakel hingga 2,5 meter juga meledak. Padahal, ubur-ubur ini punya racun yang bisa membunuh manusia dalam tiga menit.
Menurut María Luz Fernández de Puelles, peneliti asal Spanish Institute of Oceanography’s Balearic Oceanography Center, ada tiga penyebabnya. Seperti dikutip dari Mother Nature Network, 28 Desember 2010, ubur-ubur hidup subur sebagai efek samping dari polusi, kenaikan temperatur air dan penangkapan ikan yang berlebih.
Manusia terlalu banyak membuang limbah, termasuk limbah pertanian ke sungai yang akhirnya mengalir ke laut. Seperti diketahui, pupuk didesain untuk meningkatkan pertumbuhan tanaman. Ternyata, pupuk juga berfungsi sama di laut dengan meningkatkan pertumbuhan ganggang.
Yang jadi masalah, ganggang merupakan makanan bagi mikro organisme di laut, yang merupakan makanan utama para ubur-ubur. Semakin melimpahnya ganggang dan mikro organisme, semakin terjamin pula hidup ubur-ubur.
Kedua, pemanasan global membuat suhu air laut makin hangat. Dari penelitian, ini memicu ubur-ubur makin subur dalam bereproduksi dan membuat mereka berenang semakin mendekati pantai. Demikian pula dengan ubur-ubur tropis yang memiliki tentakel beracun.
Ketiga, penangkapan ikan yang berlebihan, khususnya tuna, hiu, dan juga penyu laut membuat ubur-ubur semakin bebas berkeliaran. Padahal, hewan-hewan pemangsa itu biasanya memakan ubur-ubur dan telur-telurnya.
“Ubur-ubur adalah pemangsa yang sangat rakus dan bersaing dengan organisme dan plankton lain untuk berebut makanan,” kata de Puelles. “Dengan melejitnya pertumbuhan ubur-ubur, maka mereka akan mengubah struktur ekosistem di laut secara drastis.”
Jellyfish Threatens Marine Life
One species of jellyfish have tentacles that are toxic and can be deadly (antigravitas.com)
VIVAnews - Jellyfish are sea creatures are ugly, dangerous enough, and unlike the other killers in the ocean the sharks. Jellyfish are not too tasty to eat. Unfortunately, the animal is now ready to master the two-thirds of planet Earth.
In 2006 to 2010, a group of large swarm of jellyfish invade Spanish beaches. Sting tens of thousands of swimmers. In some places, jellyfish are present in concentrations up to 10 per square meter.
These jellyfish group also appeared in other regions around the world. In 2007, Hawaii and Ireland experienced pest jellyfish. Israeli and French waters in 2008. Tunisia and Italy was invaded in 2009. In Japan, a jellyfish measuring up to 1.8 meters more and more popping up.
In the waters of northern Australia, populations of jellyfish with tentacles up to 2.5 meters also explode. In fact, this jellyfish has toxins that can kill humans within three minutes.
According to María Luz Fernández de Puelles, researchers from the Spanish Institute of Oceanography's Balearic Oceanography Center, there are three causes. As quoted from Mother Nature Network, December 28, 2010, jellyfish fertile life as a side effect of pollution, rising water temperatures and excessive fishing.
According to María Luz Fernández de Puelles, researchers from the Spanish Institute of Oceanography's Balearic Oceanography Center, there are three causes. As quoted from Mother Nature Network, December 28, 2010, jellyfish fertile life as a side effect of pollution, rising water temperatures and excessive fishing.
Man is too much waste, including agricultural waste into rivers that eventually flow into the sea. As is known, fertilizer designed to enhance plant growth. Apparently, fertilizer also works the same in the sea by increasing algae growth.
The problem, algae are food for micro-organisms in the sea, which is the main food of jellyfish. The more abundant algae and micro-organisms, the more secure also live jellyfish.
Second, global warming causes the temperature of the warm sea water. From research, it triggers a jellyfish in the more fertile reproduce and make them swim closer to shore. Similarly, the tropical jellyfish that have poisonous tentacles.
Second, global warming causes the temperature of the warm sea water. From research, it triggers a jellyfish in the more fertile reproduce and make them swim closer to shore. Similarly, the tropical jellyfish that have poisonous tentacles.
Third, excessive fishing, especially tuna, sharks, and sea turtles also make a jellyfish increasingly free to roam. In fact, predatory animals that normally eat the jellyfish and its eggs.
"Jellyfish are a very voracious predators and compete with other planktonic organisms and to fight for food," said de Puelles. "With the skyrocketing growth of the jellyfish, then they will change in the marine ecosystem structure drastically."
