Inclusion of Critical Areas
It is important to protect communities and systems that are naturally positioned to survive global threats. These areas serve as refuges to secure and maintain sources of larvae to replenish damaged areas. Protection of areas that are known to be resistant or resilient to threats, including bleaching events or other localized impacts, is also important. This section is intended to highlight the importance of considering special biological and ecological elements of a coral reef system.
Ecologically Significant Areas
Biologically and ecologically significant areas include:
- Sources of larvae and spawning aggregations;
- Nursery and breeding grounds of fish and other marine organisms;
- Developmental and feeding habitats; and
- Migration corridors
- Sea turtle nesting areas
These areas play an important role in ecosystem functions, thus they require consideration in the MPA design.
Unique or Vulnerable Habitats
The presence of rare, endangered, relict, restricted-range species, and populations with unique genetic composition should be considered for MPA placement. Including unique places in the network will ensure that the network is comprehensive and adequate to protect biodiversity and known sensitive or unique areas.
Some marine habitats are more vulnerable to natural and human impacts than others. These habitats include:
- coral reefs
- deep-sea coral communities
- oyster reefs
- salt marshes
- seagrass beds
These ecosystems often provide essential processes that many target species rely on, acting as nurseries or other key habitats at certain life stages for specific species. Therefore special attention should be given to vulnerable systems when designing an MPA network.
Protection of Source Populations
It is also important to provide special protections to areas that are known to be a source of larvae for other areas. To maintain the balance between immigration and extinction rates, a steady source of recruits (eggs, larvae, and juveniles) is needed to replenish stressed areas. Protection of important sources of reproduction (e.g., nurseries, spawning areas, egg sources), and protection of areas that will receive recruits and be future sources of spawning potential, are important targets for self-sustaining MPAs.
MPAs that are strategically located at source populations not only retain recruits and larvae to sustain local populations, but also serve to export surplus larvae to other areas. Source areas functioning as a refuge from fishing for individuals of certain species lead to an increase in the number of larger, older individuals who carry a more important role for reproduction in the community, and can also potentially act as sources of propagules for other areas. Aim to include MPA sites located at source populations (if they can be identified).