Exposure to elevated pCO2 does not exacerbate reproductive suppression of Aurelia aurita jellyfish polyps in low oxygen environments
"Eutrophication-induced hypoxia is one of the primary anthropogenic threats to coastal ecosystems. Under hypoxic conditions, a deficit of O2 and a surplus of CO2 will concurrently decrease pH, yet studies of hypoxia have seldom considered the potential interactions with elevated pCO2 (reduced pH). Previous studies on gelatinous organisms concluded that they are fairly robust to low oxygen and reduced pH conditions individually, yet the combination of stressors has only been examined for ephyrae. [...]"
Source: Marine Ecology Progress Series
Authors: Laura M. Treible et al.
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Oxic-anoxic regime shifts mediated by feedbacks between biogeochemical processes and microbial community dynamics
"Although regime shifts are known from various ecosystems, the involvement of microbial communities is poorly understood. Here we show that gradual environmental changes induced by, for example, eutrophication or global warming can induce major oxic-anoxic regime shifts. We first investigate a mathematical model describing interactions between microbial communities and biogeochemical oxidation-reduction reactions. [...]"
Source: Nature Communications
Authors: Timothy Bush et al.
Macroalgal Blooms on the Rise along the Coast of China
"A broad spectrum of events that come under the category of macroalgal blooms are recognized world-wide as a response to elevated levels of eutrophication in coastal areas. In the Yellow Sea of China, green tides have consecutively occurred 10 years, which is considered as the world’s largest Ulva blooms. However, in recently years, golden tides caused by Sargassum seaweed have also been on the rapid rise, resulting in dramatic damage to the environment and economy again. [...]"
Source: Oceanography & Fisheries
Authors: Jianheng Zhang, Yuanzi Huo and Peimin He
Historical records of coastal eutrophication-induced hypoxia
"Under certain conditions, sediment cores from coastal settings subject to hypoxia can yield records of environmental changes over time scales ranging from decades to millennia, sometimes with a resolution of as little as a few years. A variety of biological and geochemical indicators (proxies) derived from such cores have been used to reconstruct the development of eutrophication and hypoxic conditions over time. [...]"
Authors: A. J. Gooday et al.