@article {83146, title = {Status of the European Green Crab, Carcinus maenas, in Oregon and Washington Coastal Estuaries. Report for 2020 and 2021}, year = {2022}, note = {The COVID-19 pandemic affected this report, leading to combined years and trapping on a reduced number of estuaries. The invasive European green crab is a voracious predator of bivalve molluscs, small crustaceans and other organisms. It has been present in Oregon since the late 1990s. The population grows when winter waters are warm, as they are during El Ni{\~n}os. Since 2015, however, {\textquotedblleft}recruitment has been good every year. Since green crabs live for 6 years, these recent strong year classes can produce larvae until 2027. . . Now that populations in Oregon, Washington and British Columbia have built up, we have evidence for local production and for larvae sources from a genetically distinct population on Vancouver Island. . .{\textquotedblright} (from the Executive Summary) This report is accompanied by a dataset, available at: https://ir.library.oregonstate.edu/concern/datasets/b8515w17z }, pages = {27 p.}, institution = {Pacific States Marine Fisheries Commission. Aquatic Nuisance Species Project}, address = {Portland, Or.}, keywords = {aquatic invertebrates, Coos Bay, crustaceans, El Nino, European green crab = Carcinus maenas, Grays Harbor (Wa.), introduced species, Netarts Bay, Pacific Decadal Oscillation, population count, Tillamook Bay, Willapa Bay (Wa.), Yaquina Bay}, url = {https://ir.library.oregonstate.edu/concern/technical_reports/g445cn70c }, author = {Yamada, Sylvia Behrens and Royer, Cameron and Schooler, Shon and Fisher, Jennifer and Randall, Andrea and Buffington, Chelsey and Stote, Alex and Akmajian, Adrianne} } @article {82984, title = {Status of the European Green Crab, Carcinus maenas, in Oregon and Washington Coastal Estuaries in 2019}, year = {2020}, note = {The invasive European green crab is a voracious predator of bivalve molluscs, small crustaceans and other organisms. It has been present in Oregon since the late 1990s. The population grows when winter waters are warm, as they are during El Ni{\~n}os. {\textquotedblleft}After the arrival of a strong year class in 1998, significant recruitment to the populations occurred only in2003,2005,2006,2010, 2015, 2016, 2017, 2018 and 2019. Warm winter water temperatures, high Pacific Decadal Oscillation (PDO) and Multivariate ENSO (El Ni{\~n}o Southern Oscillation) Indices, and a high abundance of southern copepods are all correlated with strong year classes and vice versa. . . Prior to 2015, green crabs were too rare (<0.2 per trap) to exert measurable effects on the native benthic community and on shellfish culture in Oregon and Washington. But after the 2015-2016 El Ni{\~n}o, we document the arrival of five strong year classes. Average catches steadily increased from 0.5 crabs per trap, in 2015 to around 3 crabs per trap in 2017 to 2019. The catches in the last 3years are much higher than in any of the previous years, including 1998. Catches in some hotspots exceed 10 crabs per trap, a level at which measurable ecological impact can be expected. . . Since green crabs live for 6 years, these five consecutive year classes can produce larvae until 2025.{\textquotedblright} (from the Executive Summary) Coos Bay, in particular, has experienced shocking growth of this population, going from 9 crabs captured in 2002 to 1,397 crabs captured in 2019. This report is accompanied by a dataset, available at: https://ir.library.oregonstate.edu/concern/datasets/028712995 }, pages = {31 p.}, institution = {Pacific States Marine Fisheries Commission. Aquatic Nuisance Species Project}, address = {Portland, Or.}, keywords = {Alsea Bay, aquatic invertebrates, Coos Bay, Coquille River estuary, crustaceans, El Ni{\~n}o, European green crab = Carcinus maenas, introduced species, Nehalem Bay, Netarts Bay, Pacific Decadal Oscillation, population count, Tillamook Bay, Yaquina Bay}, url = {https://ir.library.oregonstate.edu/concern/technical_reports/xk81js14x }, author = {Yamada, Sylvia Behrens, and Schooler, Shon and Heller, Renee and Donaldson, Luke and Takacs, Graham T. and Randall, Andrea and Buffington, Chelsey and Akmajian, Adrianne} } @article {82861, title = {Status of the European Green Crab, Carcinus maenas, in Oregon and Washington coastal Estuaries in 2017}, year = {2018}, note = {The invasive European green crab is a voracious predator of bivalve molluscs, small crustaceans and other organisms. It has been present in Oregon since the late 1990s. The population grows when winter waters are warm, as they are during El Ni{\~n}os. {\textquotedblleft}Prior to 2015, green crabs were too rare to exert measurable effects on the native benthic community and on shellfish culture in Oregon and Washington. Following the recent strong El Ni{\~n}o, however, we documented the arrival of three strong year classes in 2015, 2016 and 2017. Average catch rates in over the last three years steadily increased from 0.5 to 0.8 and to 1.9 crabs per trap. These catches are much higher than in any of the previous years, including 1998. Since green crabs live for 6 years, these three consecutive year classes will provide larvae until 2023. A switch to cooler ocean conditions in the coming years will result in poor recruitment, but a return to high PDO and strong El Ni{\~n}o patterns would signal good recruitment and higher green crab densities.{\textquotedblright} (from the Executive Summary) Coos Bay, in particular, has experienced shocking growth of this population, going from 9 crabs captured in 2002 to 1,653 crabs captured in 2017. This report is accompanied by a dataset, available at: https://ir.library.oregonstate.edu/concern/datasets/rn3016632 }, pages = {29 p.}, institution = {Pacific States Marine Fisheries Commission. Aquatic Nuisance Species Project}, keywords = {Alsea Bay, aquatic invertebrates, Boat ramp (Netarts), Coos Bay, Coquille River estuary, crustaceans, El Nino, European green crab = Carcinus maenas, Grays Harbor (Wa.), Hatfield Marine Science Center, introduced species, Johnson{\textquoteright}s Slough (Yaquina), Makah Bay (Wa.), Nehalem Bay, Netarts Bay, North of Nevor Shellfish (Netarts), Oregon Coast Aquarium mudflat, Pacific Decadal Oscillation, population count, Sally{\textquoteright}s Bend, Tillamook Bay, Whiskey Creek Salmon Hatchery, Willapa Bay (Wa.), Yaquina Bay}, url = {https://ir.library.oregonstate.edu/concern/technical_reports/rx913w156 }, author = {Yamada, Sylvia Behrens and Yednock, Bree and Indivero, Julia and Geierman, Christina and Prickett, Joel A. and Randall, Andrea and Akmajian, Adrianne} }