Читать книгу Fish and Fisheries in Estuaries - Группа авторов - Страница 74

Threats to reproductive and recruitment success of estuary‐dependent and ‐associated fishes include natural and anthropogenic stressors. We briefly review these threats, primarily addressing human threats. We refer readers to chapters that address other aspects of threats to estuary‐associated fishes and fisheries; for example, Fishes and Estuarine Environmental Health (Cabral et al. 2022), Global and Climate Change Trends (Gillanders et al. 2022) and Estuarine Degradation and Rehabilitation (Lepage et al. 2022) for additional information.

As human impacts on estuaries have increased worldwide, multiple stressors associated with anthropogenic activities and inputs have lowered the productive and reproductive potential of fish populations in estuaries (Breitburg et al. 2015, Toft et al. 2018). The interactions amongst stressors and cumulative effects of multiple stressors may reduce productivity of spawning and nursery habitats (Breitburg et al. 2009, Breitburg et al. 2015, Elliott et al. 2019). The most observable short‐term threats in estuaries are overfishing and fish kills, which can remove large numbers of juveniles and adults from populations and thus eliminate their reproductive potential. Fish kills in estuaries are reported (Biernacki 1979, Burkholder et al. 1995, Whitfield 1995, Whitfield & Cowley 2018) from both natural and anthropogenic causes, but sub‐lethal impacts often are not appreciated (Rose 2000, O'Connell et al. 2004). Below, we briefly describe threats to reproduction and recruitment of estuary‐associated fishes. These threats are largely attributable to human activities (e.g. overfishing; habitat destruction; impoundments and freshwater‐flow regulation; power plants; deteriorating water quality with associated increases in contaminants; eutrophication; urbanisation; climate change and associated degradation and manmade and natural catastrophes). These occur disproportionately in estuaries and their catchments relative to other marine ecosystems, adding to concerns regarding threats to success of reproduction and recruitment in estuary‐associated fishes.