Oceanic-Atmospheric Modes of Variability and Their Effect on River Flow and Blue Crab ( Callinectes sapidus ) Abundance in the Northcentral Gulf of Mexico

• Main Author: Sanchez-Rubio, Guillermo Humberto
• Format: Text
• Language: unknown
• Published: The Aquila Digital Community 2009
• Subjects: blue crab; callinectus sapidus; northcentral Gulf of Mexico; river flow; oceanic-atmospheric modes of variability; Biology; Marine Biology; Terrestrial and Aquatic Ecology; Pacific; North Atlantic; North Atlantic oscillation
• Online Access: https://aquila.usm.edu/dissertations/1042; https://aquila.usm.edu/context/dissertations/article/2073/viewcontent/SANCHEZ_DISSERTATION_2009_Redacted.pdf

Oceanic-atmospheric modes of variability occur on interdecadal, multidecadal, decadal, and interannual timescales and their influence on climate around the world has been confirmed. The present study investigates Mississippi River and Pascagoula River flows in response to the influence of one or more of the four oceanic-atmospheric modes of variability: the Pacific Decadal Oscillation (PDO), the Atlantic Multidecadal Oscillation (AMO), the North Atlantic Oscillation (NAO), and the El Nino Southern Oscillation (ENSO). These modes of variability are present in phases: PDO warm (PDOw) and cold (PDOc), AMO warm (AMOw) and cold (AMOc), NAO positive (NAOp) and negative (NAOn), and ENSO warm (ENSOw), neutral (ENSOn), and cold (ENSOc). High Mississippi River mean flow was associated with the PDOw, AMOc, and NAOp phases, with low river flow linked to their opposite phases. High Pascagoula River mean flow was related to the AMOc and NAOp phases, with low river flow linked to their opposite phases. Pascagoula River flow was significantly higher during the ENSOw than ENSOc events, within PDOw/AMOw/NAOp and NAOn phase. Blue crab data on abundance were taken from fishery-independent trawl survey programs conducted by the Gulf Coast Research Laboratory, Ocean Springs, Mississippi and the Louisiana Department of Wildlife and Fisheries in coastal waters of Mississippi and Louisiana, respectively. Four long-term climatic phases (PDOc/AMOc/NAOn, PDOc/AMOc/NAOp, PDOw/AMOc/NAOp, and PDOw/AMOw/NAOp and NAOn) overlapped with four distinct periods of annual blue crab abundance that were identified using hierarchical agglomerative clustering and non-metric, non-parametric multidimensional scaling techniques. The following abundance periods were delineated: period I (1967-1970), period II (1971-1980), period III (1981-1998), and period IV (1999-2004). For all but three years (1991, 1995, 2005) the overall abundance of blue crabs fell into chronological sequences under climatic phases. A single year (1990) did not group with any of the ...