Coastal marine ecosystems worldwide are threatened by multiple human-induced stressors, ranging from global stressors to local pollution, habitat loss and over-exploitation of resources, and resulting in fast degradation of coastal ecosystems and the services that they provide. Gulf of Guinea large marine ecosystem is a hotspot of multiple stressors. The maritime threats to GGLME include oil, heavy metals and litter from shipping and offshore oil exploration, which - together with land-based pollution and climate change - can result in unknown synergistic, antagonistic or additive effects to the marine biota, with unknown detrimental effects on the marine ecosystem. Ghana’s government is giving priority to prevention of pollution of the marine environment, consistent with the Sustainable Development Goals and the regulations from International Maritime Organisation. However, lack of regulatory capacity and data on maritime and marine pollution for research-based management result in challenges in implementation and enforcement of the regulations. HOTSPOT addresses these challenges, focusing on 1) promoting the sustainable management of Ghana’s coastal waters, 2) facilitating the implementation of the IMO regulations in Ghana and 3) building research capacity in maritime pollution management. HOTSPOT will produce new scientific results on spatial and temporal distribution and proportional importance of maritime pollution, on cumulative context-specific effects of multiple stressors on plankton communities, and on the mechanisms governing species responses to multiple stressors. HOTSPOT results are disseminated to the authorities through an established platform in Centre for Coastal Management and through collaboration with the Ghana Environmental Protection Agency. HOTSPOT contributes to the Sustainable Development Goals, particularly SDG 14 – Life below water, which is one of the priority SDGs of the Danish development strategy in growth and transition countries
The results obtained during the first project year include 1) an investigation of the main sources and concentrations of pollutants (appendix 6), and 2) estimation of the single and combined effects of selected contaminants. During a laboratory campaign in October 2018, the effects of oil (pyrene), heavy metals (nickel) and microplastic were tested on zooplankton species under different heatwave scenarios, representing present day and future conditions in the coastal Ghana (appendix 4&5). We showed that a combination of oil and heavy metal induces synergistic effects on survival and eco-physiology, and that increasing temperatures make the organisms more sensitive to pollutants. In contrast, the negative effects of microplastic were limited. We suggest that oil exploration and shipping can be a threat for the food web efficiency (and thus fisheries), and that the effects are likely to intensify when the sea surface temperatures increase.