Derelict Fishing Gear

In December of 2007, four divers found a massive abandoned gill net covering a deep-water reef six miles off  San Pedro on Angels Gate.  The divers explored the first 200 feet of net, where they found 21 dead sea lions, numerous cormorants and other trapped marine life.  The net stretched two miles and was the final resting place for countless fish and mammals until concerned environmentalists were able to work with the California Department of Fish & Game, the U.S. Coast Guard, and the Long Beach Harbor Patrol to locate the net’s owner to retrieve it. This seemingly obscure event is an example of a growing epidemic facing our oceans today.

NOAA scientist removes derelict fishing gear off Pearl and Hermes Atoll.
Courtesy of NOAA’s PIFSC CRED Marine Debris Team

Abandoned, lost, and discarded fishing equipment, known as derelict fishing gear, is recognized as a serious marine issue that harms marine creatures and humans alike.  In past 50 years, there has been an explosion of synthetic materials such as plastic in fishing nets, pots, and line.  As these synthetic materials are often nonbiodegradable, the age-old problem of derelict fishing gear has transformed from a temporary marine hazard into a death sentence for commercially valuable fish, lobster, and crab caught long after the equipment was lost or abandoned.  As international fisheries continue to crash due to many factors, we must pursue strategies to protect marine ecosystems from this damaging material.

Studies estimate 52 tons of derelict fishing gear is lost around the Northwest Hawaiian Islands annually; and this gear is thought to be the largest anthropogenic threat to the endangered Hawaiian monk seal. In 2008, marine debris specialists from the National Oceanic and Atmospheric Administration (NOAA) removed more than 5.9 metric tons of derelict fishing nets off the island of Oahu alone. Since 1998, federal and state agencies have removed 579 metric tons of derelict fishing nets from the Northwest Hawaiian Islands.

California is not exempt from this phenomenon.  According to SeaDoc, nearly ten percent of brown pelicans and gulls treated at marine wildlife centers are admitted for injuries associated with derelict fishing gear.  Since 2006, California has removed over 14 tons of derelict fishing gear, including over 1 million feet of fishing line from recreational fishing piers.  It is vital for the public to understand that when traps, lines and nets are lost below the ocean’s surface, they do not disappear. If we are going to move towards restoring some of California’s historic fishing centers, solutions to the derelict fishing gear problem must be advocated.

Washington and Hawaii have adopted programs to combat the problems caused by derelict fishing gear through a collaborative effort between regulators and fishermen. Citizens or fishermen are encouraged to report the type and location of lost or abandoned gear in order for trained personnel to retrieve the items and preserve the natural marine environment necessary for sustainable fisheries.  The focus of the Washington and Hawaii initiatives is not to apportion blame to commercial and recreational for the derelict fishing gear problem, but rather to work with individuals and the industry to restore and rehabilitate areas of the ocean littered with traps and line.

Case Study: Puget Sound, Washington

Courtesy: Northwest Straits Commission.

The Puget Sound is a rich marine environment with a storied commercial and recreational fishing history.  Heavy fishing during the twentieth century left tons of man-made fishing equipment on the bottom of the sound.  Wrecks, bad weather, poor maintenance, human error and mechanical failures have resulted in fishermen losing or abandoning crab pots and nets.  These devices continue to capture fish and crabs long after they are lost.

In 2002, the Washington State Legislature passed SB 6313, mandating the removal of derelict fishing gear and creating a foundation for a retrieval program.  Washington State also requires commercial and sport crabbers to adopt biodegradable cotton “rot cord” on their crab pots.  If a crab pot is lost or abandoned, these cotton cords are designed to degrade and prevent the trap from continuing to capture crabs indefinitely.  Research by the Northwest Straits Commission has found only one-third of all retrieved crab pots are fitted with the mandatory rot cord.  These illegal crab pots continue to trap crabs for years after they have been lost or abandoned.

The Northwest Straits Commission estimates 12,193 crab pots are lost annually in the Puget Sound alone, each catching approximately 30 crabs a year until the pots deteriorate.  These derelict crab pots are a continuous weight on the crab fishery in the Puget Sound, reducing the amount of available crab and driving up the cost of Washington crab to consumers.  Derelict pots, as well as nets and long-lines, are also a persistent impediment to the recovery of threatened and endangered species, such as salmon, and a general marine hazard to boaters, divers, and all marine species.

In 2010, the Marine Pollution Bulletin published a report authored by the SeaDoc Society at University of California Davis School of Veterinary Medicine on the cost-benefits of derelict fishing net removal in the Puget Sound.  The costs associated with removal included surveys, vessel use, dive removal operations, planning, unloading and disposal of the recovered equipment, government agency notification, disposal fees, repatriating the equipment to the gear’s owner, storage, and onboard data collection.  The benefits began with an assumption that the species caught in the derelict gear would have been caught in non-derelict commercial gear and included the market value of the captured adults.  The study found if the cost-benefit analysis was limited only to Dungeness crabs caught by derelict fishing gear in the Puget Sound it would result in a cost-benefit ratio of 1:14.5.  In real terms, the average single net harmed the Dungeness crab fishery by trapping over 4,000 crabs in its lifetime at a cost of $19,656 while the cost to remove the net was calculated to be $1358.  When considering this ratio and the additional benefits of avoided harm to divers, navigation, habitat and marine species, and future fouling by gear caught on derelict gear, removing hazardous derelict fishing gear is clearly advantageous for all parties.

Methods for Derelict Gear Recovery

Entangled Sea Turtle off the coast of Oahu. Courtesy of NOAA/NMFS

Derelict fishing gear recovery efforts have three essential elements: location, removal, and disposal.  Locating lost or abandoned gear is the most challenging task; and all organizations are heavily reliant on recreational and commercial fishermen to either report equipment they found or report their own lost equipment.  Without known locations, crews use sidescan sonar to search for derelict pots and traps in high-traffic fishing areas.

Once identified, the coordinates and the anticipated items are cataloged for SCUBA divers to return and begin the recovery effort, using diving knives, float bags, and onboard winches.  The condition of the gear is cataloged as well as the number and type of species found in the gear.  If the gear is identifiable after recovery, the equipment is returned to the owner, saving them significant amounts of money.  If the gear cannot be identified it is treated as a bio-hazard and disposed of with the proper care or recycled.

The Northwest Straits Commission developed protocols for reporting derelict fishing gear, which are as applicable in southern California as in northwest Washington:

  1. Stay safely away from it!
  2. Do not attempt removal – you may be violating state and/or federal law
  3. Record as much information as you can while on-site:
    1. Location - GPS coordinates/chart location (latitude-longitude), water depth, distance from landmarks and/or common place names;
    2. Type of Gear - Nets (monofilament gillnet or twine-like purse seine, trawl or fish farm pens), Pots/Traps (round or square for crab or shrimp, singular or multiple), Ropes/Lines, Floats, Trawl Doors or other;
    3. Details – Date and time of sighting, activity during sighting (swimming, fishing, diving), type of seabed, size of gear, number and types of invertebrates, fish, birds, mammals entangled of dead in gear, perceived level of threat to humans/vessels;
    4. Contact Name – Name, phone number, address, email are helpful to officials.  Anonymous reports are accepted.;
    5. Report what you see – Report, even if you aren’t sure if the gear is “lost.”  Also, prevent your own gear from trapping marine life in the event it becomes lost by using “rot-cord” on traps and pots.

Efforts in Southern California

Monofilament Recycling Bin

On January 9-10, 2009, the Ocean Defenders Alliance coordinated a recovery effort off the coast of Santa Catalina Island to recover derelict fishing nets  from the Infidel.  The Infidel, a squid trawler, sank while returning to the mainland with 8,000 pounds of fishing net.  Over time, this net became entwined with the wreck and continued to harvest fish and sea mammals long after the trawler was lost.

The Ocean Defenders Alliance rallied the diving community to recover dangerous fishing nets from the Infidel and transformed the wreck from a hazard to marine life into the beginnings of  vibrant artificial reef.

Today, the Ocean Defenders Alliance have a 38′ recovery vessel and over 40 volunteer divers committed to removing derelict fishing nets throughout the waters of Orange and Los Angeles Counties.  Coastkeeper is dedicated towards advancing the retrieval of derelict fishing nets and pots and begin the restoration of southern California’s fisheries and habitat with the help of organizations such as the Ocean Defenders Alliance.

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