Bodega Canyon Dive Tracks

Bodega Canyon (2011)


Cordell Bank Dive Tracks

Cordell Bank (2011)


Gulf of Farallones Dive Tracks

Gulf of Farallones (2012)

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DSCRTP-Funded Surveys off the Central California Coast

A Characterization of the Deep-sea Coral and Sponge Community

Access Surveys

Area Map Central California is characterized by the California Current and the seasonal upwelling that drives these highly productive waters. Bodega Canyon, Cordell Bank NMS, and Gulf of the Farallones NMS have all had deep-sea coral surveys.

In Bodega Canyon, a broad-scale characterization of deep-sea coral/sponge habitats and communities was conducted during late summer of 2011 using still photo observations from an Autonomous Underwater Vehicle (AUV). The goal of this study was to provide information regarding this unexplored canyon system to compare with other well-studied canyons in the region. The area is currently open to trawling; however, fishing effort data suggest that it is an area of lower trawl intensity and may provide a good contrast to those areas with high trawling intensity.

In Cordell Bank NMS, a Remotely Operated Vehicle (ROV) was deployed from the NOAA ship McArthur II to survey potential DSC habitat during fall of 2010. The objectives of the research were to: survey and characterize the distribution, abundance, and condition of DSC communities in Cordell Bank (CBNMS); quantify fish and invertebrate associations with DSC to help understand the value of DSC as habitat; collect limited DSC specimens to confirm taxonomic identification; make visual observations of sea floor substratum to refine habitat classifications derived from multibeam sonar data.

Benthic surveys were conducted in the Gulf of Farallones National Marine Sanctuary (GFNMS) aboard R/V Fulmar, October 3-11, 2012 using the large observation-class remotely operated vehicle (ROV) Beagle. The purpose of the surveys was to groundtruth mapping data collected in 2011, and to characterize the seafloor biota, particularly corals and sponges, in order to support Essential Fish Habitat designations.

NOAA Deep-Sea Coral Research and Technology Program

Survey off the California Coast in the Bodega Canyon

A Characterization of the Deep-sea Coral and Sponge Community

[ 2011 DSCRTP-Funded Survey ]

Overview 2011 Report [Download size: 7.5 Mb]

Area Map A total of 14,271 m² of seafloor was classified during the 4 completed dives. The original two- character-code habitat types were aggregated into three general categories for this analysis: the ‘hard’ category included ridge, boulder, cobble and flat rock in various proportions; ‘mixed’ comprised one of the ‘hard’ classifications combined with mud or sand; and ‘sediment’ was represented by mud and sand or a combination of the two. The overall area surveyed by the AUV was approximately 90% sediment substrate.

A total of 310 corals and anemones, 469 sponges and 2,166 fishes were enumerated during the 4 dives analyzed. Densities of corals, sponges, fishes and invertebrates were estimated by dividing the abundance of each taxon by the area covered during each dive. Area was determined using the constant altitude of the camera and known field of view for each image. Overall densities varied greatly by dive, the ranges were 2.1-34 corals and anemones/1,000m² 1.6-90 sponges/1,000m² and 40-383 fishes/1,000m².

These dive reports (see '2011 Report' button) present summaries of the diversity and density of corals, sponges, invertebrates and fishes along with their associated habitats. They also present profiles of sea temperature, salinity, dissolved oxygen and pH with depth.

NOAA Deep-Sea Coral Research and Technology Program

Survey on the Continental Slope West of Cordell Bank

A Characterization of the Deep-sea Coral and Sponge Community

[ 2011 DSCRTP-Funded Survey ]

Overview 2011 Report [Download size: 2.9 Mb]

Area Map While the continental slope and shelf region targeted by this survey is well known to fishers and mariners, in situ observations are rare owing to the difficulty posed by the elements, depth, and distance from shore. This first glimpse of the continental slope region of CBNMS revealed some expected as well as some unexpected findings.

Summary observations of abundance patterns of invertebrates were similar in quantitative and qualitative dive segments. A higher number of taxa were observed on qualitative segments owing to the greater area searched by this class of observation. While twelve taxa of corals and sponges were observed, the category was dominated by a single species of sea pen in the family Virgulariidae, which made up 89% of the corals and sponges observed in the quantitative dive segments and 86% of the corals and sponges in the qualitative dive segments. The abundance of fan-like gorgonians was similar on quantitative and qualitative segments (8%), for which Plumarella longisipina was the dominant structure-forming coral species. The abundance of sponges was overall low, representing 3% of the quantitative dive segments and 5% of the qualitative segments. The small invertebrate group was dominated by echinoderms and a single species, the fragile pink sea urchin, Allocentrotus fragilis, represented 59% of the taxa observed on quantitative segments and 53% of the taxa observed on qualitative segments. Notably, 30 of the 32 feather star crinoids (Florometra serratissima) observed on all quantitative and qualitative segments were living on two vase sponges and twelve P. longspina.

These dive reports (see '2011 Report' button) present summaries of the diversity and density of corals, sponges, invertebrates and fishes along with their associated habitats. They also present profiles of sea temperature, salinity, dissolved oxygen and pH with depth.

NOAA Deep-Sea Coral Research and Technology Program

Surveys on Rittenburg Bank, Cochrane Bank, and Farallon Escarpment

A Characterization of the Deep-sea Coral and Sponge Community

[ 2012 DSCRTP-Funded Survey ]

Overview 2012 Report [Download size: 1.7 Mb]

Area map Report Summary:

Benthic surveys were conducted in the Gulf of Farallones National Marine Sanctuary (GFNMS) using the remotely operated vehicle (ROV) Beagle. A total area of 25,416 m2 of sea floor was surveyed during 34 ROV transects.

Rittenburg Bank had complex, hard-bottom over 58% of the seafloor observed during 18 ROV transects. Sponges were predominant. A total of 2673 individual sponges, in nine taxa, were enumerated. We estimated an average density of 184 sponges per 1000 m2 of sea floor. We estimated an average density of 139 fish per 1000 m2, mostly rockfish (Sebastes sp.). Rosy rockfish (Sebastes rosaceus) and Yelloweye rockfish (Sebastes ruberrimus) were commonly (28 -42%) in association with sponges. Half the Yelloweye displayed juvenile coloration, suggesting that Rittenburg Bank's biogenic habitats are important for the recruitment of this species.

At Cochrane Bank, a total of 549 individual sponges were observed, in at least nine taxa. Rosy rockfish (Sebastes rosaceus) were associated with sponges over half (57%) of the time. Greenspotted rockfish (Sebastes chlorostictus) were observed with sponges 7% of the time. One large colony of the black coral Antipathes dendrochristos, a species previously thought to be endemic to Southern California was discovered. A. dendrochristos is vulnerable to habitat damage from bottom fishing gear.

The Farallon Escarpment differs significantly from adjacent areas of the continental slope. It ranges from 150 meters to over 2000 meters in depth. The escarpment is extensively dissected by submarine canyons and gullies, which stretch from the shelf break to the deep basin. A single transect yielded 65 coral records in five species, including Paragorgia stephencairnsii, a bubblegum coral. Bedrock was found on the fault scarps. Previous interpretations of this substrate suggested primarily soft substrate. Visual ground-truthing was not conducted until this study.

These dive reports (see '2012 Report' button) provide summaries of the diversity and density of corals, sponges, invertebrates and fishes along with their associated habitats. They also present profiles of sea temperature, salinity, dissolved oxygen and pH with depth.

Report Citation:

Etnoyer, P. J., G. Cochrane, E. Salgado, K. Graiff, J. Roletto, G. Williams, K. Reyna, and J. Hyland. 2014. Characterization of deep coral and sponge communities in the Gulf of the Farallones National Marine Sanctuary: Rittenburg Bank, Cochrane Bank and the Farallon Escarpment. NOAA Technical Memorandum NOS NCCOS 190. NOAA National Centers for Coastal Ocean Science, Charleston, SC. 32 pp.

NOAA Deep-Sea Coral Research and Technology Program