Main results
HOTSPOT-2 advanced the knowledge and competences in several areas including:
- Implementation of new observation technologies and seasonal monitoring at UCC allowed us to study temporal trends in the upwelling events. Our analysis of sea surface temperature showed that the upwelling area has been reduced by 70 % since 1990. This reduced upwelling in combination with an increased fishing effort have contributed to the collapse of Sardinella landings.
- The sampling campaigns provided a baseline description of the planktonic food web that sustains the coastal fisheries off Elmina and Anamabo and new insights into functioning of this tropical coastal ecosystem. For instance, we could quantify the importance of small phytoplankton, bacteria and the microbial food web, in particular outside the upwelling season.
- Many students have been carrying out experiments with different contaminants and climate scenarios in the coastal laboratory that was set up during HOTSPOT-1. These experiments have provided new understanding of the multiple interactions between contaminants and the marine food web and, for instance, revealed that the current water quality criteria for managing industrial discharge of heavy metals (cadmium) into Ghana’s coastal waters are > 40% higher than what can be tolerated by the key organisms of the marine food web.
DNA analysis of the plankton indicated low diversity close to the pollution sources, and a bio-assay approach documented detrimental effects of the polluted coastal water to the productivity of zooplankton. These results stress a high vulnerability of the off-shore plankton community to pollution, suggesting that the biodiversity and metabolic rates are inhibited close to the discharge points.
- Measurements of the contaminants in forage fish, predator fish and dolphins demonstrated that the tissue levels of PAH were far above the EU limit for safe consumption.
- Socio-economic research in Elmina and Anomabo has revealed the fragility of livelihoods in fishing communities. Male fishermen and female fishmongers are struggling due to dwindling catches, even when illegal fishing methods, such as using small nets, dynamite and poison, are used. When catches are low, everyone in the community suffers due to the lack of capital to purchase goods and services.
The imposition of a closed season, when no fishing activity is allowed along the Ghanaian coast, acts to exacerbate existing hardships. The compensation offered by the government is inadequate and the distribution system is prone to abuse. Although mobility is built into livelihoods in fishing communities, not everyone has the resources to migrate at times of hardship.
The institutional landscape for fisheries is complex, and the coexistence of two different institutional orders – formal and informal - poses challenges to the sustainable management of marine resources.
HOTSPOT-2 has involved many PhD, master and under-graduate students from UCC, providing research opportunities and training on research methods and scientific writing. This has resulted in several PhD and master thesis, international conference experience and preparation of manuscripts for international peer-reviewed journals.
HOTSPOT-2 activities have also introduced the importance of environmental protection for the local livelihoods and promoted the use of ESIA (Environmental and Social Impact Assessment) for environmental professionals and managers.
Conclusions
The HOTSPOT-2 project has documented that the coastal ecosystem is both impacted by climate change through changing upwelling patterns and challenged by the presence of multiple contaminants, many of which accumulate in the marine food webs. These biological changes have an impact on the livelihoods of coastal communities, and should be taken into account in environmental management. However, it is important to recognise the extensive knowledge, skills and informal institutions that exist in fishing communities.
Sidelining local knowledge leads to implementation failure, as local actors play vital roles in resource management by adapting institutions to align with their values and beliefs. Prevailing top-down decision-making processes and insufficient inclusion of fisherfolk in policy discussions have contributed to the marginalization of informal institutions. Although fishing communities have long adapted to seasons, the externally imposed closed season brings real hardship.
These new insights of HOTSPOT-2 that integrated socio-economic knowledge and biological observations could form a solid base for future research, education and management of coastal resources.
Recommendations
HOTSPOT-2 has resulted in following recommendations:
- Ghana should review its water quality criteria for managing coastal marine ecosystems. Ghana's water quality standards are currently based on ecotoxicological risk criteria developed by the US EPA, which in turn are based on single contaminant tests conducted with temperate and cold-water species. Results from HOTSPOT show that this approach to ecological risk assessment is not fit-for-purpose when applied to species adapted to warm, tropical waters of Ghana with its complex mixtures of contaminants.
- It would be advisable to establish a monitoring programme to follow the development of the state of the coastal waters as well as to monitor the bioaccumulation and magnification of contaminants in the fish.
- Collaboration between environmental authorities and managers should be strengthened for implementation of ESIA.
- Research skills and facilities need to be continuously developed to ensure FAIR data management and to enhance publication in international peer-reviewed journals.
- Fishers should be included in the management of coastal resources. In particular, there is the need for better knowledge sharing and communication regarding the closed season if this practice is to continue, and a fairer distribution of government subsidies and food rations.
- Further research is required that documents indigenous knowledge associated with artisanal fisheries and how this can be integrated with scientific knowledge.