| Title | Status of the European Green Crab, Carcinus maenas, in Oregon and Washington Coastal Estuaries in 2019 |
| Publication Type | Report |
| Year of Publication | 2020 |
| Authors | Yamada, Sylvia Behrens, Shon Schooler, Renee Heller, Luke Donaldson, Graham T. Takacs, Andrea Randall, Chelsey Buffington, and Adrianne Akmajian |
| Pagination | 31 p. |
| Institution | Pacific States Marine Fisheries Commission. Aquatic Nuisance Species Project |
| City | Portland, Or. |
| Call Number | OSU Libraries: Digital Open Access |
| Keywords | Alsea Bay, aquatic invertebrates, Coos Bay, Coquille River estuary, crustaceans, El Niño, European green crab = Carcinus maenas, introduced species, Nehalem Bay, Netarts Bay, Pacific Decadal Oscillation, population count, Tillamook Bay, Yaquina Bay |
| Notes | 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 Niños. “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 Niño 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 Niño, 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.” (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 |
| URL | https://ir.library.oregonstate.edu/concern/technical_reports/xk81js14x |
