jellyfish on the move!

A blood-orange blob the size of a small refrigerator emerged from the dark waters, its venomous tentacles trapped in a fishing net.

Within minutes, hundreds more were being hauled up, a pulsating mass crowding out the catch of mackerel and sea bass.

The fishermen leaned into the nets, grunting and grumbling as they tossed the translucent jellyfish back into the bay, giants weighing up to 200 kilograms (450 pounds), marine invaders that are putting the men’s livelihoods at risk.

The venom of the Nomura, the world’s largest jellyfish, a creature up to 2 meters (6 feet) in diameter, can ruin a whole day’s catch by tainting or killing fish stung when ensnared with them in the maze of nets here in northwest Japan’s Wakasa Bay.

Scientists believe climate change — the warming of oceans — has allowed some of the almost 2,000 jellyfish species to expand their ranges, appear earlier in the year and increase overall numbers, much as warming has helped ticks, bark beetles and other pests to spread to new latitudes.

These increases in jellyfish should be a warning sign that our oceans are stressed and unhealthy, said Lucas Brotz, a University of British Columbia researcher.

Heat Is Online – The Associated Press, 16 Nov 2009