( where they congregate because of food...)Long-lived deep-sea fishes imperiled by technology, overfishing

Technological advances have made targeting these fish easier, the panelists pointed out, because powerful ships can drag huge nets hundreds of feet below the surface. New refrigeration techniques, including "flash freezing," allow ships to range far out into the ocean for days at a time. And sophisticated global positioning systems (GPS) and fish finders can target schools of fish or seamounts with ease.

"One reason that many of these fish species were fished sustainably in the past is that we couldn't fish all of the places all of the time," Heppell said. "That isn't necessarily true anymore."

Heppell is a faculty member in the Department of Fisheries and Wildlife at Oregon State, where she studies fish dynamics, populations and life cycles. The deep-sea fishes are among the hardest to study for obvious reasons, she said, and additional research is critical to protect these species.

Long-lived fish usually have low reproductive rates, either because of low breeding success or high mortality. In the case of deep-sea fishes, both scenarios often play out.

In some species, such as sharks, the fish may only produce a handful of offspring and the chances of survival by an individual are low. In other species, including orange roughy and oreos, an individual fish produces thousands of eggs ?most of which die through predation or starvation.

"One of the things we need to know more about is how the fish larvae get transported," Heppell said. "We don't know whether fish from different seamounts are genetically distinct or whether larvae from one seamount end up populating another. The odds against these fish are so high that, in a reproductive sense, they have to wait for the stars to align before they successfully produce offspring that will survive until maturity."

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Source:Oregon State University