The next step in regional assessments is to select conservation targets (a.k.a. features). These targets are often defined based on biological features (e.g. species, ecosystems) as well as physical features (e.g. seafloor targets based on bathymetry, geomorphology, sediments). Because it is impossible to identify or plan for all elements of biological diversity (e.g., the thousands of species in a region), a subset of targets is usually selected to best represent the diversity of the ecoregion. These targets are often defined based on biological features (e.g., species, ecosystems) and physical features (e.g., bathymetry, sediments).
Targets
Primary features of the planning effort include the identification of representative species, habitats, and ecosystems.
- Marine ecosystems are considered “coarse filter” features in that they represent multiple species and often habitat types. This approach presumes that the conservation of a representation of all the ecosystems (e.g., seagrass, salt marsh, offshore coral reefs, and hard bottom areas) will also conserve a representation of the diversity of species found in these ecosystems.
- Aggregations of species (e.g. spawning aggregations, haul-out or nesting sites), convergence of water bodies, upwelling zones and unique seafloor characteristics (e.g. seamounts, pinnacles) are used as “fine filter” features in that they represent single species or discrete physical elements.
- In areas where ecosystem data is not available, habitat or ecosystem models are developed based on combinations of biogeophysical data.
- Development of a comprehensive target list for a region’s biodiversity is very time consuming, and the data representing these features is often limited. Planners should weigh trade-offs between exhaustive list development and data collection and analysis.
One of the target maps from the Carolinian Assessment indicating shellfish distributions. Click on image to enlarge.
Case Study: Carolinian Ecoregion
In the Carolinian ecoregion, data was gathered spatial data for 36 targets including:
- Salt and brackish marshes
- Seagrass meadows
- Shoreline types (e.g., fine- and coarse-sand beaches)
- Oyster reefs
- Sea turtle nesting beaches
- Shorebird and water bird habitat
- Right whale calving grounds
- Short-nose sturgeon habitat
- Offshore hard-bottom areas