New Zealand officials plan to survey waters for bio invaders

Foreign algae and sea creatures have invaded New Zealand's rivers and harbors where they are threatening the nation's seafood and tourism industries, officials said Friday.

The algae Didymosphenia geminata, commonly called rock snot, has been found in at least a half dozen key trout fishing rivers on South Island and Biosecurity New Zealand officials on Friday began testing rivers in North Island for signs of infestation.

The algae, which covers rocks and reportedly originated in Canada, makes waterways look gray and polluted, smothers the insects that fish eat and can clump on to fishing lines and lures.

North Island fishing guides told local media they were concerned that the algae could devastate trout fisheries, and biosecurity officials plan to survey another 160 river sites on the island next week.

Meanwhile, officials plan to survey the waters in Auckland and Canterbury harbors after finding a small finger-like creature called a sea squirt, also known as the clubbed tunicate or by its Latin name styela clava. The creature, which is native to Korean waters, is believed to have arrived on the hull of a ship.

The sea squirt, which can grow up to 16 centimeters (6.4 inches) long, has caused damage worldwide as it competes for food with shellfish like oysters and mussels and eats their larvae.

Biosecurity New Zealand, charged with protecting the country from biological pests, plans surveys over the next month to determine the sea squirt's spread, and senior marine adviser Brendan Gould said overseas experience suggests the tough, leathery tunicate is difficult to eradicate, reports the AP. I.L.