Feeding Ecology of Cutthroat Trout in the Salmon River Estuary, Oregon
نویسندگان
چکیده
—Until recently, coastal cutthroat trout Oncorhynchus clarkii clarkii were thought to use estuaries primarily as a migration corridor to and from the ocean, rather than as a rearing environment. However, recent research in Oregon’s Salmon River estuary has defined an extensive estuarine life history for a portion of the population. This study was designed to assess the diet of coastal cutthroat trout that reared in the Salmon River estuary during the summer 2003. Fifty-five coastal cutthroat trout, ranging in size from 130-400 mm, were collected by beach seine at three locations in the Salmon River estuary from June 18 through August 1. Stomach samples were obtained by gastric lavage and described by taxonomy, total number, and weight. Fish community composition was also recorded at each site. Coastal cutthroat trout fed actively on pelagic and benthic fishes, benthic invertebrates, and some terrestrial insects. Only 4 of 55 cutthroat trout had empty stomachs. Overall, prey availability and diet varied by site. Active selection of various prey items was noted at each location and was site specific. Chinook salmon fry were not selected for, although they were found in stomach samples.
منابع مشابه
Across the great divide: genetic forensics reveals misidentification of endangered cutthroat trout populations.
Accurate assessment of species identity is fundamental for conservation biology. Using molecular markers from the mitochondrial and nuclear genomes, we discovered that many putatively native populations of greenback cutthroat trout (Oncorhynchus clarkii stomias) comprised another subspecies of cutthroat trout, Colorado River cutthroat trout (Oncorhynchus clarkii pleuriticus). The error can be e...
متن کاملIdentification of Steelhead and Resident Rainbow Trout Progeny in the Deschutes River, Oregon, Revealed with Otolith Microchemistry
—Comparisons of strontium:calcium (Sr:Ca) ratios in otolith primordia and freshwater growth regions were used to identify the progeny of steelhead Oncorhynchus mykiss (anadromous rainbow trout) and resident rainbow trout in the Deschutes River, Oregon. We cultured progeny of known adult steelhead and resident rainbow trout to confirm the relationship between Sr:Ca ratios in otolith primordia an...
متن کاملEarly Marine Migration Patterns of Wild Coastal Cutthroat Trout (Oncorhynchus clarki clarki), Steelhead Trout (Oncorhynchus mykiss), and Their Hybrids
BACKGROUND Hybridization between coastal cutthroat trout (Oncorhynchus clarki clarki) and steelhead or rainbow trout (Oncorhynchus mykiss) has been documented in several streams along the North American west coast. The two species occupy similar freshwater habitats but the anadromous forms differ greatly in the duration of marine residence and migration patterns at sea. Intermediate morphologic...
متن کاملEcology and status of a wilderness fishery| Westslope cutthroat trout in the South Fork Flathead River
متن کامل
Distribution and Status of Seven Native Salmonids in the Interior Columbia River Basin and Portions of the Klamath River and Great Basins
Ahstract.—We summarized presence, absence, current status, and potential historical distribution of seven native salmonid taxa—bull trout Salvelinus conjluentus, Yellowstone cutthroat trout Oncorhync/ins clarki houvieri. westslope cutthroat trout O. c. lewisi, redband trout and steelhead O. niykiss i^airdnen. stream type (age-1 migrant) chinook salmon O. tsha\\ytscha. and ocean type (age-0 migr...
متن کامل