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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: Krigsman, L.M., Yoklavich, M.M., Cochrane, G.R., and Golden, N.E., 2013, Predicted distribution of benthic 

macro-invertebrates, Offshore of Santa Barbara map area and Santa Barbara Channel region, California, sheet 11 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

Goleta

Oxnard

Ventura

Santa Barbara

Goleta

Oxnard

Ventura

Santa Barbara

Goleta

Oxnard

Ventura

Santa Barbara

Goleta

Oxnard

Ventura

Santa Barbara

Goleta

Oxnard

Ventura

Santa Barbara

E) Predicted Distribution of Brittle Stars 

D) Predicted Distribution of Cup Corals 

C) Predicted Distribution of Hydroids 

B) Predicted Distribution of Short Sea Pens 

A) Predicted Distribution of Tall Sea Pens 

INDEX TO MAP AREAS WITHIN SANTA BARBARA CHANNEL REGION

Goleta

Oxnard

Ventura

Santa Barbara

Offshore of

Refugio Beach

Offshore of

Coal Oil Point Offshore of

Santa Barbara

Offshore of

Carpinteria

Offshore of

Ventura

Hueneme Canyon

and Vicinity

DISCUSSION

Information presented on this sheet is based on ground-truth surveys (see sheet 6) conducted by the U.S. 

Geological Survey and National Oceanic and Atmospheric Administration (NOAA) National Marine Fisheries 

Service for the California Seafloor Mapping Program. Benthic community structure was determined from 35 

video towed-camera transects within California’s State Waters limit in the Santa Barbara Channel. These 

transects produced a total of 923 10-second observations from Refugio Beach (34.5 ̊ N., 120.1 ̊ W.) to Hueneme Canyon (34.1 ̊ N., 119.2 ̊ W.). Presence-absence data were collected for 29 benthic, structure-forming, 

nonmobile taxa. Generalized linear models were developed to predict the probability of occurrence and to 

create predictive-distribution maps for the most frequently observed macro-invertebrates (tall sea pens, short 

sea pens, cup corals, hydroids, and brittle stars), which are all structure-forming components of valuable 

habitat for groundfish species (Krigsman and others, 2012). This sheet shows five predictive-distribution maps 

(Maps A–E) for the Offshore of Santa Barbara map area, which is depicted by a red outline in the Santa 

Barbara Channel regional maps (Map F).

Covariates in the generalized linear models were geographic location, bathymetry, and seafloor character. 

Geographic location was derived from analysis of five of the six map areas along the mainland coast of the 

Santa Barbara Channel, excluding the Offshore of Carpinteria map area where data were insufficient. From the 

five map areas, three statistically different locations were identified on the basis of a community-structure 

analysis of the invertebrate taxa and associated covariates (sometimes resulting in distinctly different predicted 

distributions across map boundaries): (1) the Hueneme Canyon and Vicinity and Offshore of Ventura map 

areas; (2) the Offshore of Santa Barbara and Offshore of Coal Oil Point map areas; and (3) the Offshore of 

Refugio Beach map area. Data for the two other covariates were provided in sheet 2 (shaded-relief bathymetry) 

and sheet 5 (seafloor character map).

Although probability of occurrence for each invertebrate taxon was predicted for the entire Santa Barbara 

Channel region (Map F), this sheet highlights predictions for the Offshore of Santa Barbara map area (Maps 

A–E). Almost the entire Offshore of Santa Barbara map area is made up of soft sediment, with a large area of 

mixed sediment and rugose rock just beyond the Santa Barbara Harbor. Both soft sediment and mixed 

sediment are considered to be suitable habitat for tall and short sea pens. At water depths of about 45 m, tall 

sea pens (Map A) have a moderate probability of occurrence, which increases as depth increases. Short sea 

pens (Map B) have a moderate probability of occurrence that begins at depths of about 30 m, peaking in 

probability of occurrence at about 60 m. The probability of observing short sea pens out to the 3-nautical-mile 

limit of California’s State Waters is moderately high. Cup corals and hydroids (Maps D and C, respectively), in 

deeper depths, have a high probability of occurrence in areas of mixed sediment and rugose rock. In shallower 

depths of the same habitat, cup corals have a higher probability of occurrence than that of hydroids. Brittle 

stars (Map E) in the sediment, observed by arms protruding from the substrate, have a moderate probability of 

occurrence at moderate depths, but the probability of occurrence decreases as depth either increases or 

decreases.

REFERENCES CITED

Gotshall, D.W., 2005, Guide to marine invertebrates—Alaska to Baja (2d ed.): Monterey, Calif., Sea 

Challengers, 117 p.

Krigsman, L.M., Yoklavich, M.M., Dick, E.J., and Cochrane, G.R., 2012, Models and maps—Predicting the 

distribution of corals and other benthic macro-invertebrates in shelf habitats: Ecosphere, v. 3(1), article 3, 

16 p., doi:10.1890/ES11-00295.1.

EXPLANATION

Probability of occurrence

High (99.0%)

Low (0.0%)

Area of “no data”—Areas near shoreline not mapped owing to insufficient high-resolution 

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

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

1

National Oceanic and Atmospheric Administration, National Marine Fisheries Service;

2

U.S. Geological Survey

Predicted Distribution of Benthic Macro-Invertebrates, Offshore of Santa Barbara Map Area and Santa Barbara Channel Region, California

By

Lisa M. Krigsman,1 Mary M. Yoklavich,1 Guy R. Cochrane,2 and Nadine E. Golden2

2013

ONE MILE = 0.869 NAUTICAL MILES

1 0.5 0 1 KILOMETER

7000 3500 0 7000 FEET

2 1 0 2 MILES

SCALE 1:50 000

25 20 15 10 5 0 25 KILOMETERS

70000 50000 30000 10000 0 70000 FEET

10 5 0 10 MILES

SCALE 1:400 000

APPROXIMATE MEAN

DECLINATION, 2013

MAGNETIC NORTH

12 / ° 1 2

TRUE NORTH

Predicted distributions mapped in 2011

GIS database and digital cartography by Nadine E. 

Golden and Eleyne L. Phillips

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). Offshore 

shaded-relief bathymetry from map on sheet 2, this 

report. California's State Waters limit from NOAA Office 

of Coast Survey

Universal Transverse Mercator projection, Zone 11N

NOT INTENDED FOR NAVIGATIONAL USE

Map D – Predicted Distribution of Cup Corals, Offshore of Santa Barbara Map Area Map E – Predicted Distribution of Brittle Stars, Offshore of Santa Barbara Map Area Map F – Predicted-Distribution Maps for Santa Barbara Channel Region

Map A – Predicted Distribution of Tall Sea Pens, Offshore of Santa Barbara Map Area Map B – Predicted Distribution of Short Sea Pens, Offshore of Santa Barbara Map Area Map C – Predicted Distribution of Hydroids, Offshore of Santa Barbara Map Area

34°25'

34°20'

119°45' 119°40'

34°25'

34°20'

119°45' 119°40'

34°25'

34°20'

119°45' 119°40'

34°25'

34°20'

119°45' 119°40'

34°25'

34°20'

119°45' 119°40'

Photograph of brittle stars. Brittle stars are sea stars in class Ophiuroidea; 

commonly found buried in mud or sand, exposed only by their long, slender 

arms. 

Photograph of cup corals. Cup corals are sessile cnidarians; found solitary 

or in large colonies, from intertidal zone to 150 m deep (Gotshall, 2005), on 

mixed and rugose rock.

Photograph of hydroids. Hydroids are sessile cnidarians (class Hydrozoa); 

found from intertidal zone to deep ocean depths, on soft, mixed, and hard 

sediment. 

Photograph of short sea pen. Short sea pens are sessile cnidarians (order 

Pennatulacea) that are less than 60 cm in height; found on soft and mixed 

sediment.

Photograph of tall sea pen. Tall sea pens are sessile cnidarians (order 

Pennatulacea) that are greater than 60 cm in height; found on soft and mixed 

sediment.

Santa Barbara Santa Barbara

Santa Barbara Santa Barbara Santa Barbara

Scientific Investigations Map 3281

Sheet 11 of 11

Pamphlet accompanies map

U.S. Department of the Interior

U.S. Geological Survey