Metapopulation structure of a semi-anadromous fish in a dynamic environment

Frederick Feyrer, James Hobbs, Shawn Acuna, Brian Mahardja, Lenny Grimaldo, Melinda Baerwald, Rachel C. Johnson, Swee J Teh

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8 Scopus citations

Abstract

The Sacramento splittail (Pogonichthys macrolepidotus) is a relatively large (400 mm), long-lived (8 years) demersal cyprinid of conservation importance endemic to the San Francisco Estuary (SFE), California, USA. It exhibits a semi-anadromous life cycle spending adult life in low to moderate salinity (0-12) habitat with migrations into upstream freshwater rivers and floodplains for spawning during winter-spring. The species persists as two genetically distinguishable populations - one dominant and one subordinate - separated by discrete spawning habitats that we suggest resemble an island-mainland metapopulation structure. The populations overlap in distribution in the SFE, yet segregation is maintained with individuals tending to aggregate or school with others of similar population heritage and natal origin. The populations are spatially connected via dispersal of the dominant population into the subordinate population's spawning habitat when climate patterns produce freshwater outflow sufficient to form a bridge of suitable low salinity habitat across the upper SFE. Habitat affinities of the two populations, hydrodynamic modeling studies, and historical outflow records together suggest such conditions occur in approximately 1/3 of years overall with an irregular frequency. This dynamic pattern of spatial connectivity controlled by climate variability may be an important driver of gene flow between the two populations.

Original languageEnglish (US)
Pages (from-to)709-721
Number of pages13
JournalCanadian Journal of Fisheries and Aquatic Sciences
Volume72
Issue number5
DOIs
StatePublished - Jan 6 2015

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ASJC Scopus subject areas

  • Aquatic Science
  • Ecology, Evolution, Behavior and Systematics

Cite this

Feyrer, F., Hobbs, J., Acuna, S., Mahardja, B., Grimaldo, L., Baerwald, M., Johnson, R. C., & Teh, S. J. (2015). Metapopulation structure of a semi-anadromous fish in a dynamic environment. Canadian Journal of Fisheries and Aquatic Sciences, 72(5), 709-721. https://doi.org/10.1139/cjfas-2014-0433