May 6, 2009
“˜Ghost Fishing’ Poses Great Ecological Threat
According to a UN report released Wednesday, lost and discarded fishing nets continue to trap fish for years and are becoming a growing threat to the planet's marine ecosystem.
"The report estimates that abandoned, lost or discarded fishing gear in the oceans makes up around 10 percent, (640,000 tons) of all marine litter," the UN Environmental Program said in a statement.
The study, co-authored by the UN's Food and Agriculture Organization (FAO), noted the increasing severity of the problem due to the growing scale of global fishing and the use of fishing gear made of non-biodegradable material.
Fishing gear is usually made from modern synthetic fibers that are non-biodegradable. This means that snagged or lost gear and fragmented nets may continue to catch fish indefinitely. This is termed "ghost fishing".
One of the greatest offenders are bottom set gill nets, which are anchored to the sea floor and attached to floats, making a wall of netting under the sea that that stretches up to several thousand meters.
The UNEP says, "If a gill net is abandoned or lost, it can continue to fish on its own for months -- and sometimes years -- indiscriminately killing fish and other animals."
The report also mentions the case of devices such as crab traps, which are lost by hundreds of thousands with each hurricane season in many regions.
The study lists a variety of ways to mitigate such occurrences such as financial incentives for fishermen to report lost equipment, marking technology, improved disposal methods and the use of biodegradable parts in fishing gear.
The report encouraged leaders gathering in Indonesia on May 11-15 for the World Oceans Conference to address the problem with a sense of urgency.
Ichiro Nomura, a senior FAO official for fisheries and aquaculture warns, "The amount of fishing gear remaining in the marine environment will continue to accumulate and the impacts on marine ecosystems will continue to get worse if the international community doesn't take effective steps to deal with the problem of marine debris as a whole."
"Ghost fishing" can affect other marine species, particularly birds and marine mammals. For example, 99 seabirds were recovered from about a one-mile length of gill net found south of the Aleutian Islands. In Newfoundland, it was estimated that "ghost fishing" killed over 100,000 marine birds and mammals in a four-year period. In the northeast Pacific, it was estimated that 15% of the death of young fur seals could be attributed to net debris, with the average seal expecting to encounter 3 to 25 pieces of net debris every year.
UNEP executive director Achim Steiner says "ghost fishing" is just one of many "ghosts" haunting the marine environment. He insists that there are other serious issues at hand such as acidification linked to greenhouse gases and rising de-oxygenated "dead zones" due to run-off and land-based pollution.
"Abandoned and lost fishing is part of this suite of challenges that must be urgently addressed collectively if the productivity of our oceans and seas is to be maintained for this and future generations," said Steiner.
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