Remotely Operated Vehicle Provides a Deep Water Window into California’s MPAs

fish and coral
Copper rockfish and red gorgonian coral, Anacapa Island State Marine Reserve

Throughout 2014, the California Department of Fish and Wildlife (CDFW) and Marine Applied Research and Exploration (MARE) engaged in deep-water habitat surveys off the California coast using a remotely operated vehicle (ROV). MARE’s ROV Beagle was deployed twice in Southern California and once in northern California, kicking off an unprecedented three-year, statewide survey of marine protected areas (MPAs) and nearby, comparable rocky habitats.

Recovering the ROV Beagle, Campus Point State Marine Conservation Area

This video-based survey provides a first look at many recently established MPAs, and will generate much needed data on abundance and distribution of fish species harvested from rocky habitats. Many of the areas visited by the ROV Beagle during the surveys have probably never been directly observed by human eyes. Data gathered from video and still imagery collected during the expeditions will provide much needed information about California’s vast deep water habitats.

This work is funded by a $1.9 million dollar research grant awarded to CDFW in 2013 to survey state waters from Mexico to the Oregon border using state-of-the-art underwater technology operated by MARE. During the first three deployments in 2014, hundreds of hours of video were collected in standard and high definition formats, as well as over 10,000 digital still photographs. At MARE’s video processing laboratory in Eureka, Calif., trained technicians are methodically characterizing habitat and identifying species of fish and invertebrates from high definition video and still photography. MARE also collects detailed information from along the ROV path across the seafloor, which can be used to accurately identify the location of each observation. CDFW scientists will use the data for future analysis of abundance, size estimates, and patterns of distribution for important species, among other applications.

rockfish and coral
Flag rockfish and orange and purple gorgonian coral off Arrow Point, Catalina Island

Preliminary examination of observations from the first ROV deployments have already uncovered interesting findings about species and habitats. In Southern California, small reef patches surrounded by soft sediments showed a high abundance of rockfish in many locations. These habitats are sparsely scattered throughout the Southern California near shore waters, and may be important to overall fish abundance in areas lacking prominent rocky reefs.

Not surprisingly, the northern California surveys uncovered different findings. Rocky reefs in northern California had patchy distributions of fish, with some areas surprisingly devoid of common species. Strong ocean currents, large waves, and increased sedimentation from rivers create complex dynamics on the north coast, and may be influencing the patchy distribution. One striking observation throughout all areas visited statewide was the high abundance of the predatory lingcod.

Lingcod near Point Cabrillo State Marine Reserve

CDFW scientists and MARE have explored underwater habitats together throughout the state since 2003, and have developed highly refined ROV survey methods and processing techniques. When completed in 2016, this latest endeavor will result in the most comprehensive and thorough visual survey of California’s deep water rocky habitats ever achieved. Information gathered from the data will provide insights into how species may be benefiting from protections afforded by MPAs and give resource managers greater knowledge of managed marine species.

More photos taken from the ROV Beagle during the 2014 surveys can be seen on the CDFW flikr web page. For more information about marine protected area monitoring efforts, please visit the CDFW website.

post by Michael Prall, CDFW Environmental Scientist    ROV photo credits: CDFW/MARE