Ecosystem services assessment of the Simpson Bay Lagoon, Saint Martin (2019)

Similar to many other Caribbean coastal wetlands, the Simpson Bay Lagoon in Saint Martin suffers from heavy development, wastewater pollution, and overexploitation. These pressures have severely degraded the ecological integrity of the lagoon. Almost all mangrove forests have been removed for development, and sewage inflow and illegal waste dumping have deteriorated the water quality. This is problematic, not only for ecological reasons, but also because local livelihoods depend on the ecosystem services provided by the lagoon. Over the period March 2019 to June 2019 three scientific assessments have been conducted on the Simpson Bay Lagoon, respectively focussing on the three pillars of the Triple Bottom Line – Planet, People & Profit. Central in these three studies was the implementation of a household survey in Saint Martin, in which 219 households were interviewed about how they perceive and value the Simpson Bay Lagoon. The results of the three studies are summarized in a report, see Publications below.

Simpson Bay Lagoon

The ‘Planet’ study mainly focused on the water quality in the lagoon, and identified the main pollution sources. This study found that in many parts of the lagoon, the levels of nitrate-nitrogen, total coliform and faecal coliform were unacceptably high, and often rising over time. This confirms the acute problem of poor water quality in the lagoon. The main identified pollution sources were sewage discharge, destruction from development, sunken boats, domestic waste pollution, and the release of toxic chemicals in the lagoon. 

The ‘People’ study assessed the issue from a societal perspective. It shows that the population of Saint Martin greatly values the Simpson Bay Lagoon, given their high willingness to pay for the lagoon’s continued ecosystem service provisioning. The survey results revealed that the degrading environmental condition of the lagoon is noticed by the vast majority of the respondents. People also highly supported better environmental management of the lagoon (e.g. through mangrove restoration or building a sewage treatment plant). The results further signify that more educational opportunities could change people’s environmental behaviour in a positive way. Engaging the public to come more into contact with nature, for instance by involving them in recreational activities, could improve environmental behaviour as well. 

The results of the ‘Profit’ study, the economic analysis, show a clear economic rationale for improved environmental management of the Simpson Bay Lagoon. The study reveals that although the current total economic value of the lagoon is still nearly US$20 million per year, this value would nearly be completely lost if the current business-as-usual scenario continues. This decline can be avoided by intervening in the lagoon. Mangrove restoration or the installation of a sewage treatment plant would significantly raise the annual economic value to US$28 or US$31 million, respectively. A cost-benefit analysis shows that the benefits of mangrove restoration and the construction of a sewage treatment plant far outweigh their costs, and that in all aspects these environmental management scenarios economically outperform a business-as-usual scenario. 

Overall, the results of all three studies imply that better environmental management of the lagoon is highly needed, simultaneously benefiting the environment, society, and the economy. Opportunities to improve environmental management are ubiquitous; it is now the turn  of local policy makers to put them into practice.

Publications:

Theses related to the ‘Planet’ study, ‘People’ study, and ‘Profit’ study 

Duijndam, S.J., Fralikhina, H., Molenaar, A. & van Beukering, P.J.H. (2019). Better environmental management of the Simpson Bay Lagoon pays off: For the environment, society, and the economy. IVM report (R-19/03). Institute for Environmental Studies (IVM), Vrije Universiteit Amsterdam. 

Choice card Simpson Bay Lagoon
Example choice card employed to estimate the value that local people assign to the Simpson Bay Lagoon. Better protection from storms, better water quality and more habitat for species were valued most by the respondents