Some fishing fleets have switched to deep-sea fisheries following the collapse in more commonly caught species such as cod. Known as bottom trawling, ships often use heavy trawls, which are dragged across the ocean floor, destroying coral and marine ecosystems in the process.
The new research, led by Jennifer Devine of Memorial University in Newfoundland, has produced further evidence that these fishing methods can have serious impact on the marine ecology.
The five species selected for the study are all slow to grow and reproduce, and reach sexual maturity only in their teens. These factors make them especially vulnerable.
They examined records from Canadian Atlantic waters spanning the period 1978-1994 - roughly a single generation and they found that populations of round-nose grenadier, onion-eye grenadier, blue hake, spiny eel and spiny-tail skate all declined spectacularly over the period.
Scientists and conservation groups are pressing for a global moratorium on deep-sea fishing, which they regard as particularly destructive to this undersea environment and the species it supports. The most recent attempt to get a moratorium adopted, at the UN General Assembly last November, failed.
Several deep-sea fish species in the northern Atlantic are on the brink of extinction, according to the findings of a recent study by Canadian scientists.
