Ecosystem service tradeoff analysis reveals the value of marine spatial planning for multiple ocean uses

Abstract

Marine spatial planning (MSP) is an emerging responsibility of resource managers around the United States and elsewhere. A key proposed advantage of MSP is that it makes tradeoffs in resource use and sector (stakeholder group) values explicit, but doing so requires tools to assess tradeoffs. We extended tradeoff analyses from economics to simultaneously assess multiple ecosystem services and the values they provide to sectors using a robust, quantitative, and transparent framework. We used the framework to assess potential conflicts among offshore wind energy, commercial fishing, and whale-watching sectors in Massachusetts and identify and quantify the value from choosing optimal wind farm designs that minimize conflicts among these sectors. Most notably, we show that using MSP over conventional planning could prevent >$1 million dollars in losses to the incumbent fishery and whale-watching sectors and could generate >$10 billion in extra value to the energy sector. The value of MSP increased with the greater the number of sectors considered and the larger the area under management. Importantly, the framework can be applied even when sectors are not measured in dollars (e.g., conservation). Making tradeoffs explicit improves transparency in decision-making, helps avoid unnecessary conflicts attributable to perceived but weak tradeoffs, and focuses debate on finding the most efficient solutions to mitigate real tradeoffs and maximize sector values. Our analysis demonstrates the utility, feasibility, and value of MSP and provides timely support for the management transitions needed for society to address the challenges of an increasingly crowded ocean environment.

Fig. 1.

Massachusetts Bay and spatial distributions of resources and sector values. (A) Habitat distributions. (B–E) Net present values of offshore wind energy, flounder and lobster fishery, and whale-watching sectors, respectively. The value in each grid cell is scaled relative to the maximum absolute value of the sector (based on logged, scaled boat density for the whale sector and profit for the other sectors; see Methods) across all grid cells, in the absence of other sectors.

Fig. 2.

Pairwise tradeoffs in sector values in relation to spatial management strategies and associated wind farm maps. (A) Conceptual example of sector tradeoffs. Orthogonal dashed lines with arrows illustrate how to measure the value of MSP over single sector management. (B–D) Offshore wind energy, flounder and lobster fishery, and whale-watching sector values in relation to wind farm designs in Massachusetts Bay. Sector values are scaled to 100% at maximum value without any intersectoral conflicts. Lettered triangles correspond with maps of wind energy farms in E–G. The inset in B shows a zoomed view for clarity.

Fig. 3.

Tradeoffs in sector values in relation to spatial management strategies. (A) Energy, lobster fishery, and whale-watching sector three-way tradeoff. Solid lines connecting circles (see legend inset) represent pairwise efficiency frontiers shown in Fig. 2 C and D. Squares and interpolated grid represent the three-sector efficiency frontier. Strategy E is beneath the surface (see Fig. 2 for pairwise perspectives). Dashed line indicates outcomes under single-sector management. (B) Energy–flounder fishery tradeoff in relation to pairwise, three-sector, and four-sector efficiency frontiers (see legend inset). Letters and triangles correspond with those in Figs. 2 and 4.

Fig. 4.

Value to sectors from MSP over strategic single-sector management, measured for each development scenario as shown in Fig. 2A. (A) Value of MSP to flounder, lobster, and whale-watching sectors in relation to a regulated level of energy development. (B) Value of MSP to the energy sector in relation to regulated target levels of fishery and whale-watching sector values (i.e., 100% minus a maximum percentage impact allowed). The table shows maximum net present value (NPV) in dollars of each sector alone (for the whale sector, NPV is to the whale-watching tourism industry), within the provisional energy zones (top row); NPVs are multiplied by percentage values of MSP to generate the dollar values in row 2 and for each lettered scenario in the plots. Values in row 2 correspond with the maxima of the curves in A for flounder, lobster, and whale watching and the peak of the dotted line in B for energy.