In addition to the ongoing ecological and oceanographic assessment, monitoring, benthic habitat mapping, and characterization activities, CRED receives input from fishery and resource management agencies such as the Office of Habitat Conservation at NMFS Headquarters, NMFS SWR, PIAO, WPRFMC, NOAA National Marine Sanctuary Program, USFWS, National Park Service, State of Hawaii, Territories of American Samoa, Guam, and CNMI on additional focused research activities that are needed to better manage and protect the coral reef ecosystems of the U.S. Pacific Islands. Based on these inputs, the CRED has initiated the following focused research activities:
Larval Transport and Recruitment
Critical to the establishment and monitoring of effective MPAs is an understanding of the ocean circulation patterns affecting the transport and eventual settlement and recruitment of larvae. CRED oceanographers are using satellite-tracked drifters to complement shipboard ADCP and satellite remote sensing observations to examine the ocean circulation patterns in the NWHI and other U.S. Pacific Islands areas. Two types of satellite-tracked drifting buoys have been deployed to examine upper ocean currents and their role in the dispersal and recruitment of some larvae, as well as the transport and accumulation of marine debris.
Development of Ocean Atlases for the U.S. Pacific Island Regions
As an additional step in developing an understanding of the marine ecosystem dynamics of different regions of the Pacific basin, CRED staff are collaborating in a program funded by the the University of Hawaii/NOAA Joint Institute for Marine and Atmospheric Research (JIMAR) Pelagic Fisheries Research Program(PFRP) to compile available oceanographic and environmental data and develop a set of oceanographic atlases for each of the U.S. EEZs in the central and western Pacific. The leadership and primary work on this project is provided by the NOAA Hawaii CoastWatch site located at the Pacific Islands Fisheries Science Center. These atlases will provide a compendium of oceanographic data that may be used to examine relationships between coral reef resources and environmental changes. The compiled data sets include both satellite-based and in-situ measurements.
Development of Bottomfish Stock Assessment Methodologies
While most of the reef fish surveys are conducted in shallow areas (0-20 m), it is recognized that many commercially exploited fish stocks utilize both coral reef environments and deeper habitats (50-400m). Often times, traditional fishery-dependent methods (e.g., hook-and-line) for sampling these bottomfish species cannot be used in many areas of the Northwestern Hawaiian Islands Coral Reef Ecosystem Reserve and other restricted fishing areas. The ability to assess and monitor the living marine resources likely to be exploited is important for ecosystem management as well as determining the effectiveness of Marine Protected Areas (MPAs). To address these needs, the Science Center, University of Hawaii's Hawaii Undersea Research Laboratory (HURL), the State of Hawaii, and other partners are collaborating to develop and deploy non-extractive sampling methods such as autonomous camera systems to collect information about the spatial distribution and relative abundance of bottomfish species. To learn more about the Bottom Fish Camera (BotCam) click here.
Development of Passive Acoustic Methods for Monitoring Coral Reef Ecosystems
Deployment of passive acoustic devices in coral reef habitats is a cost-effective method to monitor coral reef ecosystems and to collect information about the frequency and occurrence of human activities in marine protected areas, remote bays, underwater pinnacles and other marine areas. Many animals associated with coral reefs, including various fish and invertebrate species are soniferous - that is, they produce sound. Marine mammals that interact with the coral reef environment are also quite vocal.
Passive vs. Active Acoustic Methods
Various technologies are used to study sounds in the sea. A passive acoustic device simply listens to the sounds around it, such as noise from marine mammals, crustaceans and fish, or the noise from the propellers, engines, and auxiliary machinery of boats. An active acoustic device broadcasts an acoustic signal (or several signals) through the water and listens to the return signal (echo) reflected back from objects in the path of the broadcasted sound wave, including fish and other marine life. The active acoustic device interprets characteristics of the echo(s) to provide information about the detected objects. Active acoustic devices are typically more complex, consume more power, and are more expensive than passive devices. A well-known example of active acoustics is the Sonar (SOund NAvigation and Ranging) used by submarines.
Tracking the acoustic activity of these animals with passive monitoring instruments is a promising way to assess patterns of change, stability, and seasonality in biological processes over time. Passive acoustic methods are also well suited for monitoring human activities on the reef. The noise produced by boat engines, blast fishing, anchor chains, and other anthropogenic sources are readily detectible and identifiable along with naturally occurring sounds.
The Ecological Acoustic Recorder (EAR) is a passive acoustic device developed specifically for monitoring fish, invertebrates, and human activity in marine habitats. Click here to learn more about the EAR and passive acoustic monitoring of coral reef ecosystems. Click here to listen to some of the sounds recorded by EARs.