Native and Introduced Larval Fishes of Suisun Marsh, California: The Effects of Freshwater Flow

Abstract

Abstract We sampled ichthyoplankton weekly in Suisun Marsh in the San Francisco Estuary from February to June each year from 1994 to 1999. We collected approximately 227,900 fish, predominantly shimofuri goby Tridentiger bifasciatus (60%) and prickly sculpin Cottus asper (33%). Principal components analysis and canonical correspondence analysis were used to explore relationships among several environmental variables and the 13 species that made up 99.96% of the catch. A group of native fishes (prickly sculpin, Sacramento sucker Catostomus occidentalis, threespine stickleback Gasterosteus aculeatus, longfin smelt Spirinchus thaleichthys, and Sacramento splittail (also known simply as splittail) Pogonichthys macrolepidotus) were associated with the cool temperatures and higher outflows characterizing early-season conditions in Suisun Marsh. In contrast, a group of introduced species (shimofuri goby, inland silverside Menidia beryllina, striped bass Morone saxatilis, and threadfin shad Dorosoma petenense) we...