Pacific Islands Network Benthic Marine Community Monitoring Protocol: Version 2.0

Brown, Eric; Minton, Dwayne; Daniel, Raychelle; Klasner, Fritz; Basch, Lawrence; Snyder, Alison; Craig, Peter; DeVerse, Kimbery; Jones, Tahzay; Dicus, Gordon

The benthic marine community in the Pacific Island Network (PACN) is a complex ecologic system and a diverse taxonomic environment, including algae and corals and other invertebrates. Reef-building corals are the primary architectural organism and are sensitive to environmental degradation; therefore, they are a good indicator of overall health for nearshore park’s marine ecosystems. Primary stressors to coral reefs include disease, bleaching, sedimentation, eutrophication, storms, and global climate change. The United Nations Environment Programme (UNEP) has proposed using coral reefs as a worldwide indicator ecosystem for global climate change (Spalding et al. 2004). For these reasons, the PACN has nominated benthic marine communities as the #2 Vital Sign for network implementation. The benthic marine community Vital Sign is most closely linked with the marine fish Vital Sign, and monitoring efforts will be conducted at the same time and location to maximize data value.The benthic marine protocol will be implemented initially in four parks: Kaloko-Honokohau National Historical Park (KAHO), Kalaupapa National Historical Park (KALA), National Park of American Samoa (NPSA), and War in the Pacific National Historical Park (WAPA). The protocol addresses two monitoring questions: 1) what are the changes over time in the composition (e.g., species or assemblage) and physical structure (rugosity) of the coral reef benthos? And, 2) what are the changes over time in settlement, growth, survival, and health of target coral assemblages, species, or individuals? The first monitoring question has two objectives. The first objective is to determine long-term trends in the abundance (percent cover of the benthic substrata) of sessile benthic marine macroinvertebrate (e.g., corals, zooanthids, octocorals, sponges, and echinoderms) and algal (including large fleshy macroalgae, crustose coralline, and turf algae) assemblages at sites that are randomly selected on hard substratum, between 10 and 20 meters depth. The second objective is to determine trends in benthic local scale topography or rugosity at a subset of these sites. The second monitoring question has three objectives. The first is to determine trends in settlement rate of hard corals to uniform artificial surfaces at monitoring sites on the fore-reef between 10 and 20 meters depth. The second objective is to determine trends in growth rate and survival of randomly selected coral colonies of a common, trans-Pacific species (e.g., Pocillopora eydouxi) growing at similar depth. The last objective is to determine long-term trends in the incidence of coral disease and bleaching. The sampling frame (hard substratum between 10 to 20 meters depth) was selected for ecologic and safety reasons.A split panel sampling design will be implemented for monitoring, with thirty randomly selected sites sampled annually. Fifteen of the sites will be fixed (permanent) and revisited annually. The remaining sites will be randomly selected each year and will not be revisited. This sampling regime represents the maximum sustainable effort given current logistic and fiscal realities. Initially, this sampling design should have statistical power to have a 40% chance of detecting a 25% relative change in percent cover of the benthos. After several years, we anticipate the power will increase due to an increase in temporal replication to give an approximate power of an 80% chance to detect a 25% change. This increase in power over time will result from the ability to conduct parameter corrections because of repeated analysis.

Pacific Islands Network Benthic Marine Community Monitoring Protocol: Version 2.0

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