Any use of trade, product, or firm names in this publication is for descriptive purposes only and does not imply endorsement by the 

U.S. Government

This map was printed on an electronic plotter directly from digital files. Dimensional calibration may vary between electronic plotters 

and between X and Y directions on the same plotter, and paper may change size due to atmospheric conditions; therefore, scale and 

proportions may not be true on plots of this map.

For sale by U.S. Geological Survey, Information Services, Box 25286, Federal Center, Denver, CO 80225, 1–888–ASK–USGS

Digital files available at http://pubs.usgs.gov/sim/3281/

Suggested Citation: Dieter, B.E., Endris, C.A., Greene, H.G., Golden, N.E., and Erdey, M.D., 2013, Potential marine benthic habitats, 

Offshore of Santa Barbara map area, California, sheet 7 in Johnson, S.Y., Dartnell, P., Cochrane, G.R., Golden, N.E., Phillips, E.L., 

Ritchie, A.C., Greene, H.G., Krigsman, L.M., Kvitek, R.G., Dieter, B.E., Endris, C.A., Seitz, G.G., Sliter, R.W., Erdey, M.D., Gutierrez, C.I., 

Wong, F.L., Yoklavich, M.M., Draut, A.E., Hart, P.E., and Conrad, J.E. (S.Y. Johnson and S.A. Cochran, eds.), California State Waters 

Map Series—Offshore of Santa Barbara, California: U.S. Geological Survey Scientific Investigations Map 3281, pamphlet 45 p., 11

sheets, scale 1:24,000, http://dx.doi.org/10.3133/sim3281.

ISSN 2329-132X (online)

http://dx.doi.org/10.3133/sim3281

US Army Corps

of Engineers

Figure 1. Map showing video-observation locations and sample localities for Offshore of Santa Barbara 

map area.

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119°45' 119°40'

34°25'

34°20'

3-nautical-mile limit of California’s State Waters

# Sample locality

Bathymetric contours—Derived from modified 

10-m-resolution bathymetry grid. Contour interval: 10m

Habitat interpretation outline

! Video observation

Approximate modern shoreline—Defined as

Mean High Water (MHW) (+1.33 m), North

American Vertical Datum of 1988 (NAVD 1988)

EXPLANATION

CALIF.

0 4 8 Nautical Miles

Kilometers 0 5 10

120° 119°40' 119°20' 119°

34°

34°20'

MAP LOCATION

Ventura

Santa Barbara

Anacapa

Island

Santa Cruz Island Santa Rosa Island

Area of

Map

Santa Barbara Channel

Limit of California’s

State Waters

Sh_a-w

Sh_a-g

Sh_a-p

Shm_a-s*(q)

Smh_a-p/u

Ss_a-td/u

Ss(s/m)_a/u*(q)

Shm_e/l

Sh(b)/p_t?

Sh(b)/p_c

Shd_c/d

Smh_c/e/u

Sme_c/l/u

Sme_c/u

Ssr_u

Ssl_h/t/u?

Ssg_u

Ss(s/g)h/w_h/r/u

Ss(s/g)_u

Ss(s)t_r/u

Ss(s)_r/u

Ss(s/m)t_u?

Ss(s/m)h_r/u

Ss(s/m)h_e/u

Ss(s/m)_r/u

Ssm/y_h/u

20

DESCRIPTION OF MAP UNITS

UNCONSOLIDATED CONTINENTAL SHELF SEDIMENTS

Soft, unconsolidated, rippled sediment (sand and mud)

Pockmarks or depressions, in soft, unconsolidated sediment (sand and mud)

Rippled scour depression (sand and mud)

Terrace, or possibly delta or fan, made up of soft, unconsolidated sediment (sand and 

mud); inferred

Soft, unconsolidated sediment (sand), predominantly rippled

Terrace, or possibly delta or fan, made up of soft, unconsolidated, rippled sediment 

(sand)

Soft, unconsolidated sediment (sand and gravel), on flat shelf

Rippled scour depressions (sand and gravel)

Gully of soft, unconsolidated sediment

Sediment-covered tar flow; inferred

Hummocky mounds of soft, unconsolidated delta sediment

Rills of soft, unconsolidated sediment

MIXED SUBSTRATE ON CONTINENTAL SHELF

Mixed habitat of soft, unconsolidated sediment, overlying hard, consolidated 

sedimentary bedrock

Mixed habitat of soft, unconsolidated sediment, covering edges of hard, carbonate 

mounds

Hydrocarbon-seep depression, in soft, unconsolidated sediment 

HARD SUBSTRATE ON CONTINENTAL SHELF

Deformed and differentially eroded, consolidated sedimentary-bedrock outcrop

Hard, consolidated sedimentary rock, boulders, or pinnacle

Hard, consolidated boulders or pinnacles of exposed asphalt; inferred

Hard mound composed of carbonate rock

ANTHROPOGENIC FEATURES

Oil-platform-generated shell hash mixed with soft, unconsolidated sediment (sand and 

mud)

Trawl grooves and marks, in soft, unconsolidated sediment

Mixed habitat of soft, unconsolidated sediment, in linear trough overlying hard, 

anthropogenic feature (pipeline)

Oil-platform structural-foundation framework (legs and pipes) and shell mound

Hard anthropogenic feature (pipeline)

Hard anthropogenic feature (groin or jetty)

Hard anthropogenic feature (shipwreck)

EXPLANATION OF MAP SYMBOLS

Contact

Area of “no data”—Areas near shoreline not mapped owing to insufficient highresolution seafloor mapping data; areas beyond 3-nautical-mile limit of California’s 

State Waters were not mapped as part of California Seafloor Mapping Program

3-nautical-mile limit of California’s State Waters

Bathymetric contour (in meters)—Derived from modified 10-m-resolution bathymetry grids. Contour interval: 10 m

DISCUSSION

This map shows “potential” marine benthic habitats in the Offshore of Santa Barbara map area. Marine 

benthic habitats represent a particular type of substrate, geomorphology, seafloor process, or any other attribute 

that may provide a habitat for a specific species or an assemblage of organisms. Such maps are based largely on 

seafloor geology, and this map integrates seafloor geology (sheet 10) with information depicted on several other 

thematic maps of the Offshore of Santa Barbara map area: high-resolution bathymetry (sheet 1); shaded-relief 

imagery (sheet 2); backscatter (sheet 3); seafloor character (sheet 5); and ground-truth information (sheet 6). This 

map also uses information from the usSEABED bottom-sampling compilation by Reid and others (2006). The 

combination of remotely observed data (for example, multibeam bathymetry and backscatter, seismic-reflection 

profiles) and directly observed data (for example, camera transects, sediment samples) translates to higher 

confidence in the ability to interpret broad areas of the seafloor.

To avoid any possible misunderstanding of the term “habitat,” the term “potential habitat” (as defined by 

Greene and others, 2005) is used herein to describe a set of distinct seafloor conditions that in the future may 

qualify as an “actual habitat.” Once habitat associations of a species are determined, they can be used to create 

maps that depict actual habitats, which then need to be confirmed by “ground-truth” surveying using in situ 

observations, video, and (or) photographic documentation. 

Marine benthic habitats are classified using the Benthic Marine Potential Habitat Classification Scheme, a 

mapping-attribute code developed by Greene and others (1999, 2007). In this map series, habitat-classification 

codes are based on the deepwater habitat-characterization scheme developed by Greene and others (1999), which 

was created to not only easily distinguish marine benthic habitats but also to facilitate ease of use and queries 

within GIS and database programs. The code, which is summarized in chapter 6 in the accompanying pamphlet, 

is derived from several categories of the Benthic Marine Potential Habitat Classification Scheme (Greene and 

others, 1999, 2007), and it can be subdivided on the basis of the spatial scale of the data. 

High-resolution, multibeam-sonar data, converted to bathymetric depth grids (seafloor digital elevation 

models; sheet 1), are essential to development of the habitat map. Shaded-relief imagery (sheet 2) allows for 

visualization of seafloor terrain, providing a foundation for interpretation of submarine landforms. Areas of 

seafloor bedrock exposures are identified by their common sharp edges and high relative relief; these may be 

contiguous outcrops, isolated parts of outcrop protruding through sediment cover (pinnacles or knobs), or 

isolated boulders. High backscatter is further indication of “hard” bottom, consistent with interpretation as rock 

or coarse sediment. In many locations, areas within or around a rocky feature appear to be covered by a thin 

veneer of sediment, identified on the habitat map as “mixed” induration (in other words, containing both rock and 

sediment). Broad, generally smooth areas of the seafloor that lack sharp and angular edge characteristics are 

mapped as “sediment” and are further defined by various sedimentary features such as erosional scours and 

depressions, as well as depositional features such as dunes, mounds, or sand waves. Low backscatter, indicative 

of a “soft” bottom, also significantly aids identification and classification of sedimentary habitats.

The Offshore of Santa Barbara map area contains 26 potential marine benthic habitat types, which range 

from predominantly soft, unconsolidated sediment (mud to sand and gravel) to areas of hard bedrock exposures, 

including flat carbonate substrate and asphalt (tar) mounds. Differentially eroded, well-bedded sedimentarybedrock outcrops (some partly covered with soft, unconsolidated sediment to produce a mixed hard-soft habitat 

type), as well as pockmarks, rills, and possible hummocky tar flows, complete the variety of habitats identified in 

the map area. Significant anthropogenic features associated with oil production, such as platforms, pipelines, and 

shell mounds beneath platforms, as well as riprap and a shipwreck, all produce artificial habitats for rockfish 

(Sebastes spp.). Trawl marks also are present as anthropogenic features.

The soft, unconsolidated sediment habitat, which includes pockmarks and inferred sediment-covered tar 

flows, covers 97.41 km2

 of the map area, representing 86.6 percent of all of the potential habitat types identified. 

Sediment-covered bedrock, which includes the mixed hard-soft habitat type, covers 11.84 km2 (10.5 percent). 

Hard bedrock exposures cover 3.08 km2 (2.7 percent), whereas anthropogenic features cover about 0.17 km2

(<0.15 percent). The mix of potential marine benthic habitat types provides the varied relief, in addition to the 

rugosity and substrate hardness, that contribute to the concentration of a diverse ecosystem within an otherwise 

homogeneous, soft, unconsolidated sediment habitat.

Of special interest in the Offshore of Santa Barbara map area is the role of fluid flowing up to the seafloor 

from petroleum reservoirs at depth, which is inferred to have caused the formation of locally exposed hard, 

carbonate-cemented sediment substrate, carbonate mounds, pockmarks, and tar or asphalt flows. Notably, an 

extensive (7.09 km2) area of carbonate hardground (Sme_c/l/u), locally covered with sediment, is exposed about 

5 km offshore in the southwestern part of the map area, providing potential habitat for sessile organisms. In 

addition, a prominent lobe (Ssl_h/t/u), possibly a sediment-covered tar flow sourced by an inferred, upslope, 

sediment-covered tar-drain depression (Ss(s/m)h_r/u), 0.37 km2 in area, is present due south of Santa Barbara, 

on the northwest flank of a prominent, differentially eroded, east-west-trending bedrock platform (Shd_c/d). 

REFERENCES CITED

Greene, H.G., Bizzarro, J.J., O’Connell, V.M., and Brylinsky, C.K., 2007, Construction of digital potential 

marine benthic habitat maps using a coded classification scheme and its application, in Todd, B.J., and 

Greene, H.G., eds., Mapping the seafloor for habitat characterization: Geological Association of Canada 

Special Paper 47, p. 141–155. 

Greene, H.G., Bizzarro, J.J., Tilden, J.E., Lopez, H.L., and Erdey, M.D., 2005, The benefits and pitfalls of 

geographic information systems in marine benthic habitat mapping, in Wright, D.J., and Scholz, A.J., eds., 

Place matters: Portland, Oregon State University Press, p. 34–46.

Greene, H.G., Yoklavich, M.M., Starr, R.M., O’Connell, V.M., Wakefield, W.W., Sullivan, D.E., McRea, J.E., 

and Cailliet, G.M., 1999, A classification scheme for deep seafloor habitats: Oceanologica Acta, v. 22, p. 

663–678.

Reid, J.A., Reid, J.M., Jenkins, C.J., Zimmerman, M., Williams, S.J., and Field, M.E., 2006, usSEABED—

Pacific Coast (California, Oregon, Washington) offshore surficial-sediment data release: U.S. Geological 

Survey Data Series 182, available at http://pubs.usgs.gov/ds/2006/182/.

1

Moss Landing Marine Laboratories, Center for Habitat Studies;

2

U.S. Geological Survey 

Potential Marine Benthic Habitats, Offshore of Santa Barbara Map Area, California

By

Bryan E. Dieter,1 Charles A. Endris,1 H. Gary Greene,1 Nadine E. Golden,2 and Mercedes D. Erdey2

2013

ONE MILE = 0.869 NAUTICAL MILES

BATHYMETRIC CONTOUR INTERVAL 10 METERS

1 .5 0 1 KILOMETER

1000 0 1000 2000 3000 4000 5000 6000 7000 FEET

1 1/2 0 1 MILE

SCALE 1:24 000

APPROXIMATE MEAN

DECLINATION, 2013

MAGNETIC NORTH

12 / ° 1 2

TRUE NORTH

Potential marine benthic habitats mapped by Bryan E. Dieter, Charles 

A. Endris, and H. Gary Greene, 2011. Bathymetric contours by Andrew 

C. Ritchie, 2011

GIS database and digital cartography by Nadine E. Golden, Mercedes 

D. Erdey, and Charles A. Endris

Edited by Taryn A. Lindquist

Manuscript approved for publication December 12, 2013

Onshore elevation data from NOAA Coastal Services Center (data 

collected by EarthData International in 2002-2003) and from U.S. Army 

Corps of Engineers (data collected by Fugro Pelagos in 2009). 

California's State Waters limit from NOAA Office of Coast Survey

Universal Transverse Mercator projection, Zone 11N

NOT INTENDED FOR NAVIGATIONAL USE

Ss(s/m)_r/u

Ss(s)t_r/u

Sme_c/l/u

Ss(s/m)_r/u

Ss(s/g)_u

Ssm/y_h/u

Sme_c/u

Ss(s)_r/u

Shd_c/d

Ss(s/m)_r/u

Ssl_h/t/u?

Ss(s)_r/u

Sme_c/u

Shd_c/d

Ss(s/m)_r/u

Ss(s)t_r/u

Shd_c/d

Ss(s/m)_r/u

Ss(s/m)h_e/u

Sme_c/u

Ss(s/m)h_r/u

Ss(s/m)h_e/u

Ssg_u Sh_a-w Ss(s/m)t_u?

Shm_a-s*(q)

Ss(s/m)_a/u*(q)

Smh_a-p/u

Sh(b)/p_t?

Sme_c/u

Shd_c/d

Ss(s)t_r/u

Ss(s/m)h_e/u

Ss(s/m)_r/u

Ss(s/m)_r/u

Shd_c/d

Sme_c/u

Shd_c/d

Ss(s/m)_r/u

Ss(s/m)t_u?

Sme_c/u

Shd_c/d

Shd_c/d

Smh_c/e/u

Shd_c/d

Shd_c/d

Shd_c/d

Shd_c/d Shd_c/d Shd_c/d

Ss(s/m)h_e/u

Ss(s/m)h_e/u

Sh_a-w

Ss(s/m)h_e/u

Sh(b)/p_t?

Shm_e/l

Smh_c/e/u

Shd_c/d

Sh_a-g

Sh(b)/p_c

Ss(s/m)h_e/u

Ss(s/m)h_e/u

Sh_a-p

Ss(s/m)h_e/u

Sh(b)/p_t?

Shd_c/d

Ssr_u

Sh(b)/p_t?

Shd_c/d

Sh(b)/p_t?

Ss(s/g)h/w_h/r/u

Ss(s/g)h/w_h/r/u

Sme_c/u

Ss_a-td/u

Ss_a-td/u

Sme_c/u

Ss_a-td/u

Sme_c/u

Sh(b)/p_t?

Sh(b)/p_t?

Shd_c/d

Sme_c/u

Santa Barbara

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119°45' 119°40'

119°45' 119°40'

34°25'

34°20'

34°25'

34°20'

Scientific Investigations Map 3281

Sheet 7 of 11

Pamphlet accompanies map

U.S. Department of the Interior

U.S. Geological Survey