29 Oct 2014
Busting Ocean Ghosts
2014 is the
30th anniversary of Ghostbusters.
It seems appropriate that the hugely popular movie was released on June 8,
1984. June 8 is now celebrated as World
Ocean Day and the ocean is full of real ghosts that need busting, because they don't
just haunt, they kill!
referring to abandoned, lost or discarded fishing gear—'ghost nets' and 'ghost
traps'—that keep on entangling, catching and killing fish, sharks, lobsters, crabs,
turtles, birds, seals, whales and others until they disintegrate, a process that can
take centuries. This 'ghost fishing' is a complete loss to marine life and
humans alike, as the animals killed are lost to the population and not
Ghost gear can include longlines, gill nets and other types of nets, traps and pots. Lines and nets are generally made of plastic, whereas traps and pots are typically made of wood slats or metal mesh and weighted to fish on the bottom.
Lost, abandoned or deliberately discarded nets or lines can float for a long time, continually capturing or entangling marine life that slowly drowns or starves. Eventually the accumulating weight of those dead animals sinks the gear to the sea floor where it can still entangle sea life and also smother submarine habitat. In shallow water, waves can wash the tangled mass over a coral reef or seagrass bed, causing further death and destruction. The mass can also be shaken loose by currents to refloat and continue entangling and killing animals until it sinks again someplace else.
pots typically remain on the bottom, but become ‘ghosts’ if the surface lines
indicating their location are cut by boat propellers, storms or other
causes. Lost on the bottom, they
continue to catch fish, crabs or lobsters until their bait is all eaten
up. At that point any animals inside the
traps usually starve and themselves become bait for still more ghost fishing.
Since plastic, metal and even wood last for a very long time, especially where the water is cold, some of these ghost nets or traps can last for decades and even hundreds of years before they disintegrate.
No place in the ocean is safe from ghost fishing, because derelict nets can drift for thousands of miles. The UN Food and Agriculture Organization (FAO) and the UN Environment Program (UNEP) detailed the magnitude of gear losses from fisheries across the world, documenting the tens of thousands of derelict nets, traps and pots that continually increase the deadliness of the ghost fishing fleet.
In Ghostbusters, Bill Murray, Harold Ramis and Dan Ackroyd had a hard enough time eliminating ghosts from one building. How can we rid whole oceans of their ghosts? World Animal Protection’s report, Untangled, describes the global impacts of ghost fishing and possible solutions, and their Sea Change Initiative video highlights some ocean ghostbusters who are taking up that challenge.
Other notable efforts include the Northwest Straits Initiative which removed 4,358 derelict fishing nets and 2,889 crab pots from Puget Sound from 2002-2012, restoring 616 acres of critical marine habitat. That gear has killed more than 291,015 entangled animals, representing more than 270 species, including porpoises, sea lions, scoters, grebes, cormorants, canary rockfish, Chinook salmon, and Dungeness crab. The Initiative estimated that ghost fishing gear kills over a half million sea-creatures each year.
In the Indian Ocean, Marine Savers have been studying the color, type of material, type of knots used and other features of nets that entangle and kill olive ridley turtles in the Maldives Islands. The nets are illegal and not used in the Maldives, but drift in from other places and kill turtles. Marine Savers hope to find the source of those nets and take actions to prevent their further loss or discard. They have also partnered with businesses to recycle the plastic from retrieved ghost nets.
At the huge and remote Papahānaumokuākea Marine National Monument in the western Hawaiian Islands, two staffers from NOAA’s Marine Debris Program work to remove more than 52 tons of derelict fishing gear that washes up onto the reefs each year. Their blog describes the challenges and progress of that work.
Ghostnets Australia, an alliance of indigenous communities stretching along 3,000 km of Australia’s coastline and now including rangers from 40 different clan groups has retrieved more than 13,000 discarded or lost fishing nets, stopping the cycle of wildlife death that they cause. You can read more about marine stewardship carried out by indigenous Australian communities here.
Ocean ghostbusters can reduce animal suffering and death, but no matter how dedicated they are, they cannot fully solve the ghost fishing problem, because the ocean is too big and retrieval of derelict nets, traps and pots is time consuming, expensive and potentially dangerous.
The real solution will be to stop fishing gear from being lost,
abandoned or discarded. That can’t be
accomplished quickly, because each fishery, habitat and gear type will require
different actions. However, the sooner
those processes begin, the better, because every gear loss avoided prevents the
needless suffering and deaths of hundreds or thousands of marine animals whose
lives could otherwise rebuild populations, improve fisheries and enrich the marine
habitats and ecosystems that support ocean health and human well being.