Evaluating electro-optic imaging technology to characterize essential groundfish habitats and detect the impacts of fishing on them  (Year 1 of 1) Project Number: UAF(CA)-00-06 Principle Investigators: Yoklavich, M. M., C. B. Grimes, G. H. Greene, and W. W. Wakefield Region(s):  With the reauthorization of the Magnuson-Stevens Fishery Conservation and Management Act (MSFCMA) in 1996, NMFS now is required to designate essential fish habitat (EFH) and evaluate the effects of fishing on EFH for all Fishery Management Plans (FMP), which codify the federal government's management activities for marine fisheries. Habitat research within the NMFS has typically concentrated on estuarine and relatively shallow marine waters. Part of the reason has been the fundamental difficulty in adequately surveying deepwater habitats with spatial coverage sufficiently broad to have meaning to the geographic range of the exploited populations. Groundfish assemblages (those fish and macroinvertebrate species associated with the seafloor) are among the most diverse and economically valuable fishery resources on the U.S. West Coast. Of the 83 species included in the west coast groundfish FMP, 55 species are rockfishes found in water depths >50 m. Several of the rockfish species have recently been designated as overfished, having exhibited alarming declines in biomass and spawning output. In addition, there is increasing concern over potential impacts of mobile fishing gear (e.g., bottom trawling with roller gear and dredging) to critical seafloor habitats. There are no assessments to date of the impacts of this type of gear to rock habitats off Washington, Oregon and California, despite the fact that trawling with roller gear is widespread. Because of the close association between many groundfish species and often-rugged heterogeneous bottom substrata of varying relief in deep water, these resources are difficult to appraise using conventional survey techniques. Also, the broad spatial extent of these fisheries generally has precluded careful examination of the nature of the exploited habitats, the relationships among species and habitats, and the degree to which fishing activities have affected these habitats. Type of seafloor habitat, as characterized by a variety of geologic and biological descriptors, is a significant determinant of distribution, abundance, and diversity of rockfishes. Research to identify characteristics of deep marine habitats (i.e., >50 m water depth) and the relationship of fish to these habitats has employed a combination of acoustic geophysical methods such as side-scan sonar and multibeam systems, and in situ observations from submersibles or ROV's. The in situ methodologies acquire very high-resolution information on relatively small spatial scales. Acoustic images of the seafloor (collected with meter-scale resolution) require extensive verification of interpretations, usually from a submersible. The challenge is now to efficiently acquire high resolution information on both benthic heterogeneous habitats and associated highly diverse biological assemblages on a scale that bridges the gap between in situ observations and acoustic imaging. The overall aim of our proposed research is to rigorously field-test the recently developed underwater electro-optic imaging technology (e.g. Laser Line Scanner; LSS) for application in the characterization of deep-water fish habitats and the assessment of fishing impacts to these habitats off the U.S. west coast. Specifically we propose to 1. Use LLS to conduct high resolution mapping of seafloor habitats that have been previously identified with coarser-resolution acoustic mapping techniques (i.e., side scan sonar) and already have been groundtruthed with direct observations; 2. To determine the utility of LLS image technology for assessing the distribution and abundance of fish and macroinvertebrate groundfish species; 3. To detect the incidence of seafloor disturbance caused by fishing gear, as assessed by LLS image technology; and 4. To develop digital mosaics of seafloor habitats from LLS images having a format compatible with other georeferenced datasets used in a Geographical Information System (GIS). If LLS technology can be developed for habitat and fishery assessment, it will offer significant advantages over both the coarse-resolution acoustic survey techniques that simply cannot detect biogenic components of the habitat and requires extensive groundtruthing, and the very expensive and sea-state limited in situ techniques using an ROV or submersible for small-scale surveys. This proposal is part of a larger effort to evaluate various aspects of the fish, habitats and fisheries associated with the Big Creek Ecological Reserve (BCER) on the central California coast. In this proposal to NURP, we plan to image habitats at BCER sites that have been previously mapped with acoustic technologies (side scan sonar) and groundtruthed with in situ observations. This allows us to compare results from the acoustic and optic survey tools, as well as strengthen our interpretation of the LLS images, and corroborate and enhance the habitat information at these sites.   PURPOSE: In November 2001, we conducted a field-test of underwater electro-optic imaging technology (i.e., laser line scanner; LLS) for application in the characterization and exploration of deep-water habitats and the assessment of potential disturbance to these habitats in and around the Big Creek Ecological Reserve (BCER) off the central California coast. Our specific goals were to (1) use the LLS to conduct high resolution characterizations of seafloor habitats that have been previously identified with coarser-resolution side scan sonar; (2) compare images from LLS system with those from side scan sonar and a remotely operated vehicle (ROV); (3) determine the utility of LLS to assess the distribution and abundance of fish, megafaunal invertebrates, and habitats; (4) use the LLS to detect the incidence of seafloor disturbance caused by fishing trawl gear; and (5) develop digital mosaics of seafloor habitats from LLS images in a format compatible with other georeferenced datasets. Contribution to NURP & NOAA objectives? This study relates directly to all three of NOAAs Environmental Stewardship Missions as outlined in NURPs Opportunities and Research Guidance Plan: (1) Build Sustainable Fisheries; (2) Recover Protected Species; and (3) Sustain Healthy Coasts. Further, this study supports NOAAs renewed focus and efforts to maintain healthy fish stocks and rebuild protected species, achieve sustainable use and conservation of coastal, marine ecosystems, and improve assessment and prediction through maintenance of long-term ocean observation systems and development of improved technologies and integrated observations. Regionally, this study supports West Coast and Polar Regions NURC programmatic themes: fisheries research and shelf and slope ecology. The West Coast and Polar Regions NURC has sponsored research specifically on rockfish and their associated habitats over the past several years; this research has greatly increased our understanding of the population structure and habitat relationships of benthic marine fishes. In addition, a workshop on side scan and laser line scan methodologies for fisheries research, supported by WCPRNURC in 1995, offered the fisheries research community the first opportunity to learn about the laser line scan system. Now with our newest research, we are more fully evaluating the capabilities and effectiveness of LLS technology to bridge the gap between high-resolution information gathered on a small spatial scale with a submersible and that data acquired acoustically at lower resolution but on broader spatial scales. EFFORTS: We contracted Science Applications International Corporation (SAIC) to conduct this field test with us, using their SM-2000 LLS system integrated with the maneuverable FOCUS tow body, winch, conducting cable, and navigation equipment on board the 160-foot M/V Casitas. We used a Phantom S2 ROV, operated by NURC University of North Carolina at Wilmington, to compare ROV and LLS capabilities to characterize seafloor habitats. We chartered the F/V Relentless, a 60-ft trawler from Monterey, to evaluate LLS detection of trawl disturbance to seafloor habitats; an area inside the Reserve was used as a control for potential impact. We spent nine days surveying seafloor habitats at water depths of about 40 to 100 m in the southern end of the Big Creek Reserve and in adjacent unprotected area. We completed 51 parallel survey lines during a total of 45 hrs, and covered a total of about 1.5 km2 with the LLS. The LLS was towed at 2-3 kts, at an altitude of 3-9 m off the seafloor; the imaging swath width ranged from 4 to 13 m under these conditions. All LLS data were integrated with date, time (GMT), navigation, depth, attitude, and altitude. We also made four ROV dives from about 45 to70 m water depth during 12.5 hrs. ROV video was annotated with descriptions of seafloor habitats, fish and megafaunal invertebrates, encoded with time, date, and navigation information, and recorded on mini-DV tapes. We also made 11 CTD/transmissometer casts to measure temperature, salinity and optical properties of the water column in both survey blocks; we are using this information to help interpret the performance of the LLS under various environmental conditions. We collected laser images of various seafloor habitats and associated fish and invertebrate species. Our study site largely comprised sand and sand waves of low relief, some rock outcrops, and the heads of two submarine canyons. With the laser we imaged isolated rock outcrops with patches of large white sea anemone (Metridium sp.) and groups of fishes in about 60 m of water inside the Big Creek Ecological Reserve. One aspect of the laser survey of particular interest was the recurrence of sharp boundaries between sand waves and smooth seafloor. Analyses of the LLS, ROV, and transmissometer/CTD data are well underway. Biologists at the NMFS Santa Cruz Laboratory are in the process of identifying and quantifying fishes, megafaunal invertebrates, and habitat types from the LLS and ROV videotapes. Larry Mayer and Yuri Rzhanov (University of New Hampshire Center for Coastal and Ocean Mapping/Joint Hydrographic Center) are working with us and SAIC personnel to post-process the LLS data into a mosaic of seafloor habitats, which will assist us in evaluating the distribution and extent of various habitat types. Scott Pegau and Francoise Baratange (Oregon State University COAS Ocean Optic Group) are assisting in post-processing of data of water column physical properties. BENEFIT: Laser-line scan is a promising technology that may be applicable to a wide range of research and technical problems. If LLS can be developed for habitat and fishery assessment, it could result in the production of high resolution seafloor maps of both abiotic and biotic components of benthic habitats to address NOAA, NMFS interest in characterizing essential fish habitat. This technology could improve the efficiency and accuracy of the assessment of living benthic marine resources. From our research we will also evaluate LLS ability to detect anthropogenic disturbances, particularly impacts from trawl fishing activities, to benthic marine habitats. This information can be used to develop and implement a plan to characterize the impacts of fishing on essential fish habitat. Our site-specific study of benthic habitats within a no-fishing reserve and within the Monterey Bay National Marine Sanctuary also will be important in resource assessment and management planning for the Sanctuary and the reserve. The results are being disseminated through (1) presentations at public and scientific meetings, (2) reports and peer-reviewed scientific publications, (3) several websites, and (4) video documentation. SIGNIFICANCE Since 1992, we have been developing the tools, technologies, and partnerships to characterize deepwater fishes and habitats; West Coast NURC has supported these efforts from inception. In this new research survey we are evaluating a new tool to map and characterize benthic habitats and associated assemblages in deep water, and to possibly detect impacts of fishing on these habitats. Comparison of performance and products between this new LLS technology and that of our current tools of choice (side scan sonar and video and direct observations from submersibles) will assist NURP in supporting the appropriate methods and tools to most efficiently and effectively characterize both abiotic and biotic aspects of seafloor habitats. In addition to evaluating the performance of the LLS sensor, we (including the scientists and representatives from NOAA NURP) also had the opportunity to use and appraise the novel FOCUS tow body. This very stable and maneuverable vehicle has manual and autopilot-actuated horizontal and vertical flaps and electro-optical cable, and is capable of working in water depths to 1,500 m. The FOCUS vehicle is a notable, effective tool with broad applications to both optical and acoustic systems. Our study brought together individuals of complementary disciplines (fisheries, marine ecology, geology, and physical oceanography) from federal laboratories, academia, and industry, all with a common interest in understanding deep-water fisheries and habitats. Our study strongly relies on a partnership between investigators from NMFS’s Southwest and Northwest Fisheries Science Centers. The significance of this partnership to NOAA NMFS and NURP lies in sharing the knowledge and application of new technologies on a coastwide scale. This partnership has led to an improved, unified approach to fisheries habitat studies along the West Coast. From preliminary findings, the LLS system offers the advantage of imaging some of the biogenic components of various seafloor habitats, such as sea anemones, sea pens, kelp and other macro-algae, etc.; this type of detail is not possible with acoustic survey techniques such as side scan and multibeam sonar and affords the opportunity to investigate spatial relationships among biogenic components of habitats to a degree that previously was not possible using remotely sensed data. The LLS system also seemed to do an excellent job at imaging details of the low relief shelf sediments such as sand waves and ripples; evaluating these features in a broader context from a post-processed mosaic of the seafloor could help us understand coastal physical processes that influence dynamic benthic habitats. SUCCESS Accomplishments to date: M. Yoklavich,C. Grimes, and W. Wakefield convened a 2-day workshop in March 2001 on using laser line scan system to characterize deepwater groundfish habitats. This meeting brought together physicists, ocean engineers, geologists and biologists to discuss state-of-the-art techniques to image the seafloor and process the resultant data into products that are useful in describing fishery habitats. The meeting was a great success and helped focus our plans to field-test a laser line scan system off central California in November 2002. Presentations and Publications: Yoklavich, Mary, Churchill Grimes, and Waldo Wakefield. Using lasers to explore deepwater habitats in the Monterey Bay National Marine Sanctuary. "Best Poster Award" presentation at Currents 2002: Monterey Bay National Marine Sanctuary Annual Research Meeting, Monterey, CA, March, 2002. Wakefield, W., M. Yoklavich, and C. Grimes. Laser line scan to map seafloor habitats. Poster presentation to NMFS NW Region and Pacific States Marine Fisheries Commission, Seattle, WA, March, 2002. Yoklavich, M., C. Grimes, W. Wakefield, and G. Greene. Laser line scan technology to characterize deepwater habitats and associated organisms. Oral presentation at GEOHAB Marine Geological Habitat Mapping Conference, Moss Landing, CA, May 2002. Grimes, C. Laser line scan technology. Link Project workshop on new sensor/imaging technology. Kennedy Space Center, FL, May 2002. Wakefield, W. Groundfish Research at the Northwest Fisheries Science Center. Oral presentation at Oregon State University College of Oceanic and Atmospheric Sciences Departmental Seminar Series, May 2002. Grimes, C., M. Yoklavich, W. Wakefield, and G.Greene. Using lasers to investigate deepwater habitats in the Monterey Bay National Marine Sanctuary off central California. Poster presentation at American Fisheries Society Annual Meeting, Baltimore, MD, August 2002. Grimes, C., M. Yoklavich, W. Wakefield, and G.Greene. Using lasers to investigate deepwater habitats in the Monterey Bay National Marine Sanctuary off central California. Poster presentation at "Fishing and Benthic Habitats 2002", Tampa, FL, November 2002. Wakefield, W. Benthic habitat characterization and advanced technologies (acoustic and optical) and their applications. Oral presentation at "Fishing and Benthic Habitats 2002", Tampa, FL, November 2002. Yoklavich, M., C. Grimes, W. Wakefield, and G. Greene. A comparison of laser line scan, side scan sonar, and in situ submersible technologies to image organisms and their habitats off Big Sur, central California. To be submitted to Marine Technology Society Journal for publication in special issue on technologies, science, and management in National Sanctuaries. Websites: NOAAs West Coast and Polar Regions Undersea Research Center "In the Spotlight: Laser line scan for habitat assessment". http://www.westnurc.uaf.edu NOAAs Office of Ocean Explorations "Laser line scan for mapping seafloor habitats". http://www.oceanexplorer.noaa.gov/projects/laser01/laserlinescan.html NOAAs Office of Oceanic and Atmospheric Research "In the Spotlight: Laser line scan mapping of seafloor habitats". http://www.oar.noaa.gov/spotlite/archive PHOTOGRAPHIC DOCUMENTATION: To date, we have forwarded the following to the West Coast and Polar Regions Undersea Research Center: (1) CD-ROM with still photographs of deck operations during November 2001 laser survey. (2) Digital QuickLook Report, including several images of laser survey operation and underwater laser images of fishes and habitats. (3) Video documentary from the laser line scan survey. Grimes, C., M. Yoklavich, W. Wakefield, and G.Greene. Using lasers to investigate deepwater habitats in the Monterey Bay National Marine Sanctuary off central California. Poster presentation at American Fisheries Society Annual Meeting, Baltimore, MD, August 2002. Yoklavich, M., C. Grimes, W. Wakefield, and G. Greene. Laser line scan technology to characterize deepwater habitats and associated organisms. Oral presentation at GEOHAB Marine Geological Habitat Mapping Conference, Moss Landing, CA, May 2002. Yoklavich, M, C Grimes, and W Wakefield. 2002. Using lasers to explore deepwater habitats in the Monterey Bay National Marine Sanctuary. "Best Poster Award" presentation at Currents 2002: Monterey Bay National Marine Sanctuary Annual Research Meeting, Monterey, CA, March, 2002. Grimes, C. Laser line scan technology. Link Project workshop on new sensor/imaging technology. Kennedy Space Center, FL, May 2002. Grimes, C., M. Yoklavich, W. Wakefield, and G.Greene. Using lasers to investigate deepwater habitats in the Monterey Bay National Marine Sanctuary off central California. Poster presentation at "Fishing and Benthic Habitats 2002", Tampa, FL, November 2002. Wakefield, W. Groundfish Research at the Northwest Fisheries Science Center. Oral presentation at Oregon State University College of Oceanic and Atmospheric Sciences Departmental Seminar Series, May 2002. Wakefield, W., M. Yoklavich, and C. Grimes. Laser line scan to map seafloor habitats. Poster presentation to NMFS NW Region and Pacific States Marine Fisheries Commission, Seattle, WA, March, 2002. Yoklavich, M. and M. Love. 2005. Christmas tree corals: a new species discovered off southern California. Current. The Journal of Marine Education 21: 27-30.

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