CRAMP: Evaluating MPAs
1. Observed spatial patterns in benthic structure and fish biomass.
Correspondence analysis of the initial CRAMP dataset by Alan Friedlander and Eric Brown produced insights into the spatial relationship and effectiveness of MPAs in Hawai‘i. The comparison of benthic habitat patterns to fish biomass patterns is shown below:
Correspondence analysis of the benthic data yields no clustering or patterns in the benthic data. This suggests that the MPAs selected for the CRAMP monitoring sites extend across the full range of habitats. Further, the MPA designation probably probably does not have much impact on the sessile benthic communities. These organisms are not fished and more prone to be impacted by other anthropogenic forcing functions such as sedimentation or nutrification. (Click for a larger view)
In striking contrast to the benthic correspondence analysis, the MPA designation has a strong impact on the fish communities. Fully protected MPAs designated P in the figure form a cluster above the no protection sites labeled N. Note that partial protection (designated PP) sites cluster with the non-protected sites. Partial protection does little to enhance the overall fish community at a given site, although in some cases partial protection might be useful in managing species of concern. Further, note that the fish assemblages of Kaneohe Bay form a separate cluster, with the protected sites (Coconut Island Marine Lab. Reserve) clustering as a subset above the other sites. (Click for a larger view)
2. Observed fish biomass in open access, partially protected MPAs and fully protected MPAs.
MPAs under full protection contain over twice the fish biomass over those areas given partial protection or no protection. There is no difference in the biomass of fish at open access vs. partially protected reef areas. Partial protection is of dubious value to maintaining overall sustainable fisheries. Partial protection might be of value in limited cases where certain groups (i.e. aquarium fish collection) are being managed. (Click for a larger view)
3. Biomass of fish in various MPAs under full protection.
All of the MPAs under full protection show high biomass. The site at the extreme right (Kanahena Point) and the site at the extreme left (Kanahena Bay) are both in the Ahihi Kinau Natural Area Reserve. Kanahena Bay is located closer to areas open to the public and is possibly more vulnerable to poaching. (Click for a larger view)
4. Pupukea MLCD - Application of CRAMP data to a management problem.
Various types of fishing are allowed in the Pupukea MLCD including shore casting with hooks, spear fishing by skin diving, and netting in the deeper western portion. Recently DAR initiated a process to revise the rules and possibly increase the size of the reserve. Tentative recommendations from the Task Force are to restrict fishing and increase the size of the reserve. (Click for a larger view)
Fish data from the Pupukea CRAMP site support the perception that fish stocks in the MLCD are devastated. Standing crop of fish is low. A County Park adjacent to the Pupukea MLCD provides ready access, parking and public facilities and appears to act as a magnet for fishermen into the MLCD. If the new rules are put into effect it will be important to continue monitoring the fish populations to determine if there is an increase. (Click for a larger view)
Last Update: 04/21/2008
By: Lea Hollingsworth
Hawai‘i Coral Reef Assessment & Monitoring Program
Hawai‘i Institute of Marine Biology
P.O. Box 1346
Kāne‘ohe, HI 96744