Assessing Derelict Fishing Gear and Other Marine Debris in Deepwater Benthic Habitats Off California
Efforts to address marine debris have focused primarily on monitoring and clean-up of the shoreline and subtidal areas (<30m depth) that are accessible to scuba divers. However, many of the activities that may contribute significantly to marine debris (e.g. from fishing and shipping) occur in deeper waters (>30 m) in coastal and open oceans, where little is known about the extent of marine debris and its potential impacts to seafloor habitats.
Using extensive survey databases and video catalog, this project examined the extent of derelict fishing gear and other debris in deepwater off central and southern California. During the period 1992 through 2006, more than 400 hours of quantitative video transects in 22 locations at depths of 20-365m were conducted. These surveys were conducted to assess demersal fishes and their habitats, and marine debris was recorded when encountered. Surveys comprise most seafloor habitat types throughout the Southern California Bight, including the Cowcod Conservation Areas and the Channel Islands National Marine Sanctuary, and the Monterey Submarine Canyon system and shelf rock habitats within the Monterey Bay National Marine Sanctuary.
The distribution, abundance, type, and potential impacts of 476 debris items were quantified from 150 dives conducted off southern and central California in 1992-2002. Eighty-two of these video surveys were conducted within the Monterey Bay National Marine Sanctuary (MBNMS) from 1993 to 1998. With substantial funding from the California Ocean Protection Council, in fall of 2007, 96 additional video dives were conducted at many of these same sites within the MBNMS.
Over the last 15 years, scientists with NOAA Fisheries and other agencies and academia have partnered to survey groundfish assemblages and associated habitats in deep water (20-365m) off California. Observations are made from within the manned submersible, Delta, and recorded by video cameras. The quantitative surveys record information on demersal fishes, invertebrates, and seafloor habitats, as well as the types and locations of derelict fishing gear and other marine debris.
This study will build on previous work by quantifying the distribution, abundance, type, and potential impacts of marine debris from our 2007 surveys and assessing changes that have occurred over the past 10-15 years. The current extent of marine debris will be mapped and debris “hotspots” will be identified and compared to previous analyses. This assessment will advance the understanding of debris impacts within the MBNMS and the persistence or transformation of debris over time. The information will be integrated into an existing web-based database of debris and habitat information.
- NOAA National Marine Fisheries Service, Southwest Fisheries Science Center (SWFSC), Fisheries Ecology Division
- University of California Santa Barbara
- Pacific States Marine Fisheries Commission
- Cordell Bank National Marine Sanctuary
- Monterey Bay National Marine Sanctuary
- California Ocean Protection Council
- California Department of Fish and Game, Marine Life Protection Act Initiative
- Enhance NOAA’s capability to monitor and assess the extent and impacts of marine debris in deepwater seafloor habitats within the Monterey Bay National Marine Sanctuary, and inside and outside of marine protected areas.
- Provide information necessary to develop the best management practices to reduce and eliminate marine debris in deepwater, and improve associated seafloor habitats.
- Raise public awareness (specifically that of the fishing communities) of issues related to marine debris.
Commercial gillnet snagged on rock outcrop in 80 meters of water at 43-Fathom Spot inside the Cowcod Conservation Area off Southern California, November 2002. Photo courtesy of Donna Schroeder (Minerals Management Service).
Commercial spot prawn trap full of box crabs and continuing to fish in 240 meters of water off San Nicolas Island inside the Cowcod Conservation Area, October 2002. Photo courtesy of Milton Love (University of California Santa Barbara).
Location of marine debris dive surveys conducted from the research submersible Delta off central California during 1993-1998 (yellow crosses) and in 2007 (open circles).
Examples of marine debris from 2007 surveys conducted from research submersible Delta off central California. (A) basketstar and other encrusting organisms attached to an abandoned fishing net in water depth of 90m; (B) spot prawn and rockfish associated with discarded commercial trap at 250 m depth; (C) red gorgonian corals and branched bryozoans entangled in monofilament fishing line at 100m depth; and (D) white-plumed anemones attached to metal coils on sunken vessel at 100m depth. Photos courtesy of
(A & D) T. Laidig, NMFS SWFSC FED; (B) D. Watters, NMFS SWFSC FED; (C) M. Yoklavich, NMFS SWFSC FED.
View the video, "Exploring Marine Debris Found in Deep Water" recorded in 2002 in the Cowcod Conservation Area, CA. Video courtesy of NOAA Southwest Fisheries Science Center.
Biologists from the SWFSC Fisheries Ecology Division (FED), in collaboration with researchers from the University of California Santa Barbara and John Dutton Media, have launched "Keepers of the Deep." This 6-minute video focuses attention on deepwater marine debris off California’s coast.
Download the 2007 1-pager handout (pdf 919KB) on this project here.
Download the 2008 1-pager handout (pdf 363KB) on this project here.
This program is funded through NOAA's Ocean Service, Office of Response & Restoration, Marine Debris Program.