Continuous monitoring of dissolved oxygen in an estuary experiencing periodic hypoxia and the effect of hypoxia on macrobenthos and fish

摘要: ABSTRACT Hypoxic bottom water (defined as * ) is now a common occurrence in many estuarine and coastal systems. If prolonged widespread, hypoxia could present serious threat to the ecological balance of these In areas where intermittent not prolonged, its effect on macrobenthic behavior energetics may facilitate transfer energy oxygen-tolerant bottom-feeding fish. This study examined changes populations benthic fish invertebrates that were associated with periodic York River, Chesapeake Bay, USA. River tidally driven neap–spring cycles column stratification–destratification, lunar cycle, are primary factors regulating levels dissolved oxygen during summer. Automated continuous environmental data recording (every 20 min) was instrumental understanding response system stress allowed for timing collection at known times within normoxic–hypoxic cycle. Data indicated while community structure insensitive brief periods hypoxia, behavior, growth, production affected. Demersal feeding changed their habits quickly take advantage stressed macrobenthos came sediment surface. The apparent color redox-potential discontinuity layer slowly became shallower summer progressed.