Coastal Conservation Association (CCA)

Haunted by Ghost Nets

Lost and discarded gillnets are taking a terrible toll on marine life in the Pacific Northwest.

By Angela Hult

TIDE

May/June 2008

The Pacific Northwest is a microcosm of the problems plaguing the world’s fisheries: over-harvest, habitat, predators…these are tangible problems that have reached the public’s consciousness to some degree, thanks to equal parts activism (from both sides of the fray) and media interest (which likes to cover the conflict between both sides of the fray). It’s a day-to-day cause and effect that keeps the issues alive in the public’s mind, and therefore the possibility of progress.

There is another issue that is just as dire, yet for the most part is unknown to the public – and therefore largely ignored – because it can’t be seen. If the old adage what you don’t know can hurt you is any indication, we are in serious pain. That’s because the waters of the Puget Sound and the Columbia River are haunted by a menace that is invisible at the surface yet prolific in its indiscriminant destruction of fish, marine mammals and their habitat: The ghost net.

EQUAL OPPORTUNITY KILLERS

Ghost nets are primarily gill nets that are lost or discarded while fishing and continue to trap fish, marine mammals and birds. In fact, when not trapping and killing sturgeon, the ghost nets found in the lower part of the Columbia River sometimes provide a source for seabird samples for National Marine Fisheries Service biologists.

The nets are equal opportunity killers, catching threatened species and undersized and protected fish with the same vigor and certainty: death to all. The submerged nets create a vicious circle of destruction as fish, crabs and marine mammals get caught, die, and attract predators, which also get caught and die. Ghost nets sometimes entangle boats and have even trapped and killed recreational divers.

As if the death toll weren’t enough, the nets also wreak havoc on marine habitat. Carried by currents and tides, the nets and the attached lead lines methodically scrape the floor of rivers and bays, relentlessly scouring the fragile ecosystem.

Since these nets are virtually invisible to the public, the adverse impacts of ghost nets are not widely known or understood. However, it’s estimated that thousands of discarded nets – adding up to tens of thousands of miles of devastation – litter the waters of the Puget Sound and the Columbia River.

Compounding the problem is the longevity of the lost and discarded nets. Modern nets made of synthetic materials have been in use since the 1940s and take decades, even hundreds of years, to decompose in water.

Many of the nets are believed to have been lost during the peak of the Pacific Northwest’s gill net fishery in the 1970s and the 1980s, and some nets are a mile long and hundreds of feet wide. When you start compounding the annual mortality rate, it quickly adds up to a frightening amount.

The cycle of death and decay that happens beneath the water’s surface remains out of sight, out of mind, in part because we don’t see it each day. It’s worth noting that more research has been done regarding the impact of ghost nets on seabirds than on fish and marine mammals, most likely because the majority of birds remain visible at the surface. While floating feathers might be effective, I’m willing to bet that rattling a net woven and weighted with the bones of hundreds of fish and mammals would also catch some attention.

3,000 “HIGH-PRIORITY” GHOST NETS

To be fair, some studies are underway to better determine the annual mortality rates of ghost nets, but here is a recent example of their destruction. In October 2007, The Northwest Straights Commission, based in Washington, organized the removal of two large gill nets from the Puget Sound’s Hood Canal. According to an account provided by the Commission, both nets had caused extensive habitat damage, smothering the reef and killing crabs, rockfish, shellfish and other marine species.

Each net, when fully stretched, could be as long as 1,800 feet and as wide as 100 feet. Combined, the two nets covered over 40,000 square feet or nearly one acre of rocky reef seabed habitat. More than 100 dead and dying marine organisms were removed from the nets, combined with numerous other species that were freed and returned to the canal. Given the rapid decomposition rates of most marine life, this likely represented only one or two weeks’ worth of the nets’ “catch.”

One of the nets removed dated to the early 1960s, and provides an opportunity for some unfortunate math. If 100 marine organisms were trapped and killed every other week, and you multiplied that by 40 years, it quickly becomes a sickening and incomprehensible number. And that’s only one net.

Several organizations – including The Northwest Straights Commission – are working hard to remove the ghost nets, but progress is slow and removal efforts are woefully under-funded. Recovery can also be dangerous. Divers can get caught in the nets or debris while trying to untangle a net from rocks or other objects. And, the depth of the nets sometimes means that only a portion of the problem can be removed. Divers might have to go 100 feet down to find the net –and often the net goes much deeper – but the divers cannot.

Compounding the problem is the Pacific Northwest’s commitment to recycling, which can have unintended consequences. In a misguided attempt to take a “green” approach to net removal, some organizations that are recovering nets are recycling the silent killers for future use.

As a matter of fact, we might be putting them back into the water as fast as we’re taking them out./derelict/

To determine the extent of the problem in the Puget Sound, The Northwest Straits Commission has conducted net surveys of about 10 percent of the Puget Sound and Juan de Fuca Straits historical fishing grounds and estimates there are nearly 3,000 “high priority” derelict gill nets remaining that need to be removed. Most of these nets are located along important returning adult salmon migration routes, in orca feeding areas, nearby marine refuge areas and on habitat critical for a variety of declining species such as rockfish. It’s a good starting point, and the same kind of research is needed on the Columbia River.

Until removed, ghost nets will continue to negatively impact the ecosystems of the Puget Sound and the Columbia River. While the impact of some habitat-focused projects can take years to realize, the benefits of removing the nets are immediate and large. Countless fish, marine mammals, seabirds and invertebrates will be saved each year and valuable marine habitat will be restored.

The removal of the ghost nets is an important step toward the creation of sustainable fisheries in the Pacific Northwest.

A lifelong resident of the Pacific Northwest and an angler since the age of three, Angela Hult is chairman of the Pacific Northwest Regional Government Relations Committee. In her spare time she heads up media relations for the region's largest health insurance carrier.Removing derelict gear