Effects of Hypoxia on Fish Survival and Oyster Growth in a Highly Eutrophic Estuary

摘要: Human land use activities around estuaries can result in high levels of eutrophication. At Elkhorn Slough estuary, a highly eutrophic California we investigated the effects impaired water quality on two stress-tolerant estuarine species, common fish, staghorn sculpin, Leptocottus armatus and foundational invertebrate, Olympia oyster, Ostrea lurida. We caged indicator species at six wetlands with different impairment, four which had restricted tidal flow. also recorded parameters simultaneously all sites using YSI sondes, sampled nutrients chlorophyll-a monthly, building National Estuarine Research Reserve System-wide Monitoring Program. found that monitored environmental variables predicted ecological responses by species. In particular, duration severity hypoxia were negatively correlated fish survival oyster growth. Further, our results corroborate previous studies artificial restriction leads to increased stress. conclude large diurnal fluctuations dissolved oxygen extended nighttime have lethal sub-lethal even organisms estuary. While laboratory experiments often shown such effects, it is relatively rare demonstrate negative variation situ experiments, provide stakeholders concrete evidence for local wetlands. Tidally sites, experience largest longest periods hypoxia, harbor conditions harmful vertebrates invertebrates Reversing anthropogenically induced low levels, restoring more natural exchange decreasing agricultural runoff, could improve growth important organisms.