Royal Belgian Institute of Natural Sciences, Operational Directorate Natural Environment, Marine Ecology and Management, Vautierstraat 29, Brussels 1000, Belgium; Marine Biology Research Group, Department of Biology, Ghent University, Krijgslaan 281/S8, Ghent 9000, Belgium.
Marine Biology Research Group, Department of Biology, Ghent University, Krijgslaan 281/S8, Ghent 9000, Belgium.
Sci Total Environ. 2023 Jan 20;857(Pt 1):159285. doi: 10.1016/j.scitotenv.2022.159285. Epub 2022 Oct 7.
The rapid development of blue economy and human use of offshore space triggered the concept of co-location of marine activities and is causing diverse local pressures on the environment. These pressures add to, and interact with, global challenges such as ocean acidification and warming. This study investigates the combined pressures of climate change and the planned co-location of offshore wind farm (OWF) and aquaculture zones on the carbon flow through epifaunal communities inhabiting wind turbines in the North Sea. A C-labelled phytoplankton pulse-chase experiment was performed in mesocosms (4 m) holding undisturbed hard-substrate (HS) communities, natural sediment with infauna, and mobile invertebrate predators. Carbon assimilation was quantified under current and predicted future-climate conditions (+3 °C and -0.3 pH units), as well as a future-climate co-use scenario with blue mussel (Mytilus edulis) aquaculture. Climate change induced an increase in macrofaunal carbon assimilation as well as an organic enrichment of underlying sediments. Dynamic (non-)trophic links between M. edulis and other HS epifauna resulted in shifts among the species contributing most to the phytoplankton-derived carbon flow across climate scenarios. Increased inter- and intraspecific resource competition in the presence of M. edulis aquaculture prevented a large increase in the total assimilation of phytoplankton by HS fauna. Lower individual carbon assimilation rates by both mussels and other epifauna suggest that if filter capacity by HS epifauna would approach renewal by advection/mixing, M. edulis individuals would likely grow to a smaller-than-desired commercial size. In the same scenario, benthic organic carbon mineralisation was significantly boosted due to increased organic matter deposition by the aquaculture set-up. Combining these results with in situ OWF abundance data confirmed M. edulis as the most impactful OWF AHS species in terms of (total) carbon assimilation as well as the described stress responses due to climate change and the addition of bivalve aquaculture.
海洋活动的协同布局和人类对近海空间的利用促使蓝色经济迅速发展，给环境带来了多种局部压力。这些压力与海洋酸化和变暖等全球性挑战相互作用。本研究调查了气候变化以及海上风力发电场 (OWF) 和水产养殖区的协同规划对北海风力涡轮机上附着生物群落碳流动的综合压力。在中观（4 米）培养箱中进行了 C 标记浮游植物脉冲追踪实验，其中包含未受干扰的硬底（HS）群落、带有底栖动物的天然沉积物和移动的无脊椎捕食者。在当前和预测的未来气候条件下（+3°C 和-0.3 pH 单位）以及未来气候协同使用蓝贻贝（Mytilus edulis）水产养殖的情景下，量化了碳同化作用。气候变化导致大型底栖动物的碳同化作用增加，以及底层沉积物的有机富化。M. edulis 与其他 HS 附着生物之间的动态（非）营养联系导致在不同气候情景下，对浮游植物衍生碳流动贡献最大的物种发生了变化。在 M. edulis 水产养殖存在的情况下，种内和种间资源竞争加剧，阻止了 HS 动物对浮游植物总同化作用的大幅增加。贻贝和其他附着生物个体的碳同化率降低表明，如果 HS 附着生物的过滤能力接近通过平流/混合更新，M. edulis 个体可能会长到小于理想的商业尺寸。在同一情景下，由于水产养殖设置增加了有机质沉积，底栖有机碳矿化作用显著增强。将这些结果与现场 OWF 丰度数据相结合，证实了 M. edulis 是对（总）碳同化以及气候变化和贝类养殖增加引起的所述应激反应最具影响力的 OWF AHS 物种。
