Photo Credit: Pat Kight, Oregon Sea Grant (2011)
Marine fisheries are a significant source of seafood and economic support for billions of people around the world. In Oregon, commercial fisheries generate an average of $149 million in revenue each year. Oregon marine fisheries include finfish, such as salmon and rockfish, but also shellfish such as crabs, clams, and shrimp and other marine organisms, such as seaweed. For many fishery species, populations have been depleted over the years, but some are recovering. For example, two groundfish populations in Oregon that were declared overfished in 1999 and 2000 have been rebuilt as of 2017. While several issues are associated with fisheries (e.g., lost fishing gear, bycatch), research on ecologically sound fishing techniques, fish stock assessments, and effective management practices are improving the long term sustainability of marine fisheries. In particular, Oregon fisheries have a reputation for high quality products and environmental stewardship, leading to success in the global marketplace. Three main types of fishing occur in marine systems: commercial, recreational, and subsistence.
Photo Credit: Oregon Sea Grant (2010)
In 2017, a study was conducted by researchers at the National Oceanic and Atmospheric Administration (NOAA) to evaluate effects of bottom trawl fishing on deep-sea corals and sponges in Southern Oregon and California (Yoklavich et al. 2017). Trawling is a fishing method in which a net is dragged along the seafloor to catch bottom-dwelling organisms (e.g., groundfish and shrimp) and often results in high rates of bycatch and damage to the seafloor. In this study, the researchers used visual surveys to assess disturbance and damage in areas with previously high trawl bycatch of deep-sea corals. They conducted these surveys in underwater vehicles and took high resolution images. A total of 22,567 corals and 1,721 sponges were found in the study areas, and 4% of corals and 0.2% of sponges on average showed damage. While these numbers seem small, they could indicate that corals have recovered after disturbance. Additionally, there are no historical data from these sites for comparison, so there is no way to assess the amount of damage sustained over past decades of fishing. This study set an important baseline for future monitoring of deep-sea corals and sponges in Oregon and California. At the NOAA Northwest Fisheries Science Center (NMFS), researchers are evaluating effects of a warm “blob” on salmon fisheries. “The Blob,” a warm water mass in the Northeast Pacific ocean that showed up in fall 2013, led to anomalously warm ocean conditions. The warm temperatures continued through 2016, most likely due to strong El Niño conditions at the equator. Warmer temperatures can decrease the fat content of marine zooplankton that salmon eat, leading to poor feeding conditions. Salmon returns to freshwater habitats have also declined due to these warmer temperatures. Click here to see the report on effects of the warm blob on Oregon ecosystems.
Sources
https://www.un.org/depts/los/convention_agreements/reviewconf/FishStocks_EN_A.pdf
http://www.worldfish.org/GCI/gci_assets_moz/Fact%20Card%20-%20Subsistence%20Fishing.pdf
https://www.dfw.state.or.us/MRP/docs/Backgrounder_Comm_Fishing.pdf
https://www.dfw.state.or.us/MRP/docs/Backgrounder_Rec_Fish.pdf
https://www.qualityinfo.org/-/oregon-s-commercial-fishing-in-2017
http://www.pcouncil.org/2017/06/48752/two-important-groundfish-stocks-rebuilt/
Yoklavich, M. M., Laidig, T. E., Graiff, K., Elizabeth Clarke, M., & Whitmire, C. E. (2017). Incidence of disturbance and damage to deep-sea corals and sponges in areas of high trawl bycatch near the California and Oregon border. Deep Sea Research Part II: Topical Studies in Oceanography. https://doi.org/10.1016/j.dsr2.2017.08.005
Authored by Amy Ehrhart, Portland State University (2017)