Ghost Fishing Nets: Invisible Killers in the Oceans

Unseen below the surface, fishing gear reaps the oceans bounty the world over. Viewed from below, nets appear as veil walls lightly dancing the currents with a serene and silent intent. Ever since nets began to be cast out at sea eons ago, more and more fishing gear has been entering our oceans daily. And much of this gear remains in the water — lost, torn away, or simply abandoned.

Photo by Tim Sheerman-Chase/Wikimedia CommonsSome abandoned nets and lines wrap themselves on reefs, shipwrecks, or rocks, ensnaring marine animals, maiming, drowning or simply starving hundreds of thousands of them.

Abandoned fishing gear devours sea-life with insatiable hunger. To a number of conservationists, these derelict nets are darkly referred to as “ghost gear.” In more technical terms, it can be called Abandoned, Lost, or Discarded Fishing Gear (ALDFG).

ALDFG functions in a number of ways. Floating nets wander around, collecting a plethora of organisms, and eventually sink under the weight. As this biomass breaks apart in the ocean’s benthic regions, the nets shake their load and lumber upwards again, ready to wreak more havoc. Some nets and lines wrap themselves on reefs, shipwrecks, or rocks, ensnaring marine animals, maiming, drowning or simply starving hundreds of thousands of them. Pots intended for crab, lobster, and shrimp see an eclectic range of visitors. Entire crab or lobster lineages, scavenging bottom dwellers that venture inside for a hapless predecessor’s remains, perish in these traps.

Abandoned gear makes no distinctions, capturing marine mammals, fish, turtles, whales, birds, sharks, rays, and invertebrates.

To combat the problem, an organization called Ghost Fishing arose from a hardy band of clean up divers in the North Sea. The group started out clearing shipwrecks near their native Netherlands. Now, it’s grown into a global network of cleanup groups, working with organizations such as European Center for Nature Conservation.

Cas Renooij, director of Ghost Fishing, explains how the organization began. “About five years back some people in the Netherlands started to clean up nets from wrecks. It turned into an environmental attempt to not just make the wrecks more attractive, but also to prevent fish from dying in those nets. Later in the process it [saving marine life] became a number one priority.”

Abandoned fishing gear has become a global problem. One report, jointly issued by the Food and Agriculture Organization and the UN Environment Program (UNEP), estimates that 640,000 tons of such abandoned nets are spread across the world’s oceans, comprising up to a staggering 10 percent of oceanic litter. In the Puget Sound alone, derelict fishing gear kills over a half million sea-creatures each year, according to a Northwest Straits Marine Conservation Initiative estimate.

Fifty or sixty years ago, nets were commonly made from biodegradable hemp or cotton. With the advent of synthetic, degrade-resistant materials such as nylon, nets now can remain active in the water for hundreds of years. Some plastics can remain in the marine environment for up to 600 years. When gear does finally break apart, further damage is done when marine animals eat plastic particles and polyurethane chemicals leach into the water.

After seeing the destruction wrecked by derelict gear, Ghost Fishing began reaching out for help worldwide. “We looked around to see if there were more initiatives like this in the world, and we actually found some. We also found out there was no connection between them. That’s why we came up with the Ghost Fishing network. We reach out to those groups to give them a platform to get stories told, and raise awareness for the problem. We did some research and found that it wasn’t just a local problem, but a global problem,” says Renooij.

Divers and conservations worldwide are now tackling their own localized projects. Since 2010, the Olive Ridley Project freed and rehabilitated 51 endangered turtles trapped or injured in nets in the Maldives, illustrating how such gear puts added strain on an already endangered species. In Mediterranean waters off the Turkish coast, a cleanup effort to rehabilitate ecosystems damaged by ALDFG is currently underway. GhostNets Australia has a partnership with indigenous groups working in the area to remove ALDFG.

“Depending on the area where we clean fishing gear, it’s a different situation everywhere,” says Renooij.

While ALDFG cleanup projects are primarily small, a few large-scale ones do exist. The Washington state, aided by a $4.5 million grant from the American Recovery and Reinvestment Act, began the Derelict Fishing gear removal program in Puget Sound’s shallow water in cooperation with the Northwest Straits Foundation. The project’s has to date removed 4,500 nets, 3,081 crab pots, and 47 shrimp pots.

However, preventing gear being lost in the first place has proven far less expensive than retrieval from the depths. Washington State, for instance has to spend approximately $190 to retrieve a single crab pot.

Photo by Courtesy of Doug Helton/NOAA A sea turtle entangled in a ghost net.Since 2010, the Olive Ridley Project
freed and rehabilitated 51 endangered turtles trapped or injured in nets in
the Maldives, illustrating how such gear puts added strain on an already
endangered species.

Still, many projects lack funding for something so comprehensive. “So far we’ve been funding almost everything ourselves. Setting up the foundation with legal costs, notaries, costs a lot of money. We have been helped by a lot of unexpected sources, including private persons sponsoring us with donations” says Renooij.

Though fishermen are the source of ALDFG, they have perhaps the strongest investment in fisheries’ sustainability. Due to extremely variability in gear, regional conditions, and catch rates, and due also to insufficient data, it is exceedingly difficult to ascertain total catch killed by ghost gear. What data does exist, however, is liable to make fishermen listen. According to the California SeaDoc cleanup initiative, one abandoned net can kill $20,000 Dungeness crabs in one year. Removing the net costs $1,358. According to one study cited in a UNEP report, lost tangle nets catch around 5 percent of total commercial catch globally.

Unfortunately, there is little immediate incentive to use gear that is biodegradable. Polyurethane based nets became popular in fisheries largely because they were resistant to breaking down. Implementing new technologies that would reduce ghost gear’s longevity is vital to solving the problem. The difficulty lies in convincing fishermen to take on added expenditures and trips to the net shop.

“We are trying to walk to diplomatic route and convince [fishermen] to use biodegradable technologies,” Renooij says. There’s been some initial success with Dutch fishermen. “One success was switching lead weights to steel weights, it’s a definite change, not a hundred percent, but the awareness we need is starting to come up. And they are using lines that over time biodegrade, but the problem is it still takes a long time,” he says.

Since much fishing takes place in international waters implementing comprehensive regulation on ALDFG has proven difficult. Furthermore, data is lacking to accurately assess the impacts and extent of ALDFG, as noted in the UNEP report. As with so many “tragedy of the commons” scenarios, the responsibility to act lies with everyone, and the incentive with no one. The 1973 International Convention for Prevention of Pollution from Ships is a start in curtailing marine pollution, but it does not adequately address the problem of ghost fishing gear.

Another area that needs attention is shoreline collection facilities. Whether due to barriers to access, unwanted costs, or downright absence of facilities, not enough used gear is making its way to shore. While it is difficult to build consensus and take action to clean international waters, fostering a sense of national stewardship could motivate people to repair coastal areas in their own countries and localities. Yet in many countries, the infrastructure simply does not exist to create these programs.

In the United States there has been one encouraging development — Fishing for Energy program that promotes creative reuse. This partnership between Covanta Energy, the National Oceanic Atmospheric Administration’s Marine Debris Program, National Fish and Wildlife Foundation, and Schnitzer Steel, is converting old fishing gear into energy.

According to the project website, “through December 2013, the Fishing for Energy partnership has provided removal services at 41 ports in nine states, collecting over 2.2 million pounds of fishing gear. Gear collected at the ports is first sorted at Schnitzer Steel Industries for metals recycling, and the remaining non-recyclable material is converted into energy at Covanta Energy locations. Through the Fishing for Energy grants fund, close to $800,000 has been awarded with about $500,000 matched from grantees for thirteen projects engaging over 1,000 fishermen.”

NOAA estimates that one ton of derelict nets can power a home for 25 days. Another group, the Healthy Seas initiative, works to convert ALDFG into material for consumer goods, such as socks, swimwear, and carpets.

Though the problem of ghost fishing gear has no foreseeable solution as of yet, there are many groups out there like Ghost Fishing, California SeaDoc, Healthy Seas, and Fishing for Energy, that are doing commendable work. In August in the Dutch North Sea, divers cleaned their hundredth shipwreck of lead, lines, and net, a milestone in the “protect a wreck initiative.”

“The thing about this problem is it happens on the bottom of the sea and no one sees it — it’s an invisible problem,” Renooij says. “We are very lucky to have a group of skilled and enthusiastic divers. We are able to collect those images, put a story to them, and make them known to the world. We do try to do as much diving and cleaning up as possible.”