MPA design using sliding windows: Case study designating a research area

Coastal managers presently rely on a limited set of decision support tools for designing marine protected areas (MPAs) or subzones. A new approach, defining potential sizes and shapes of MPA boundaries early in the design process, is presented in a case study. A sliding window of the same dimensions as potential boundary configurations was regularly shifted throughout the study area and used to quantify variables representing preferred biophysical and socioeconomic characteristics. The technique offers advantages in spatially restricted areas, areas where habitat connectivity is critical, and situations wherein providing stakeholders with an up-front understanding of potential boundaries is required.

Most approaches to MPA design concentrate on networks of
several reserves to meet conservation or management goals. While
a single zone was the focus in the present study, the approach can
be modified to include multiple areas to spread risk, achieve wider
biogeographic representation, and achieve other goals associated
with multiple and replicated protected areas [27]. In addition, to
position the RA at GRNMS the potential boundary shapes were slid
equally in the X and Y dimensions, but the general sliding window
approach could be modified to examine reserve placement in an
island or atoll setting or along a cross-section of coast/shelf habitats.
For example, a pie shaped wedge could be systematically
rotated around an island (Fig. 6a) or a cross-section of shelf could be
systematically slid down a coastal region (Fig. 6b).
Selecting acceptable boundary configurations at the start of the
MPA design process may in some cases be a better alternative than
the grid or parcel agglomerating approaches that currently dominate
the theoretical and applied literature. This may include situations
where some minimum acceptable contiguous area such as
home range size of a target organism is known, where certain
combinations of habitat types must occur adjacent to each other
such as those required for ontogenetic shifts, or where the space for
placing the reserve is limited and constrains the shape and size of
potential boundaries. The sliding window technique described here
provides comprehensive analysis of all possible placement options
within an area of interest, lacks complex equations, is easy to
understand by stakeholders, and allows an up-front understanding
of how large and what the boundaries of a potential reserve may
ultimately look like.