Natural and human-induced hypoxia and consequences for coastal areas: synthesis and future development

[摘要] Hypoxia has become a world-wide phenomenon in the global coastal ocean andcauses a deterioration of the structure and function of ecosystems. Based onthe collective contributions of members of SCOR Working Group #128, thepresent study provides an overview of the major aspects of coastal hypoxiain different biogeochemical provinces, including estuaries, coastal waters,upwelling areas, fjords and semi-enclosed basins, with various externalforcings, ecosystem responses, feedbacks and potential impact on thesustainability of the fishery and economics. The obvious external forcingsinclude freshwater runoff and other factors contributing to stratification,organic matter and nutrient loadings, as well as exchange between coastaland open ocean water masses. Their different interactions set up mechanismsthat drive the system towards hypoxia. Coastal systems also vary in theirrelative susceptibility to hypoxia depending on their physical andgeographic settings. It is understood that coastal hypoxia has a profoundimpact on the sustainability of ecosystems, which can be seen, for example,by the change in the food-web structure and system function; otherinfluences include compression and loss of habitat, as well as changes inorganism life cycles and reproduction. In most cases, the ecosystem respondsto the low dissolved oxygen in non-linear ways with pronounced feedbacks toother compartments of the Earth System, including those that affect humansociety. Our knowledge and previous experiences illustrate that there is aneed to develop new observational tools and models to support integratedresearch of biogeochemical dynamics and ecosystem behavior that will improveconfidence in remediation management strategies for coastal hypoxia.

[学科分类] 地球化学与岩石