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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/3254/

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

macro-invertebrates, Offshore of Ventura 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., Kvitek, R.G., Greene, H.G., Krigsman, L.M., Endris, C.A., Seitz, G.G., 

Gutierrez, C.I., Sliter, R.W., Erdey, M.D., Wong, F.L., Yoklavich, M.M., Draut, A.E., and Hart, P.E. (S.Y. Johnson and S.A. Cochran, eds.), 

California State Waters Map Series—Offshore of Ventura, California: U.S. Geological Survey Scientific Investigations Map 3254, 

pamphlet 42 p., 11 sheets, scale 1:24,000, available at http://pubs.usgs.gov/sim/3254/.

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 Ventura 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 Ventura map area (Maps A–E). 

Almost the entire Offshore of Ventura map area is made up of soft sediment, with a few small areas of isolated 

rocks and boulders. Despite the large area of what is considered to be suitable habitat for tall and short sea pens 

(Maps A and B, respectively), the probability of occurrence for these two invertebrates was considerably low 

(see Krigsman and others, 2012). In areas of isolated rocks and boulders, the probability of occurrence for cup 

corals (Map D) was moderate, whereas, in the same habitat, the probability of occurrence for hydroids (Map C) 

was high. The probability of occurrence for brittle stars, seen in the sediment with arms protruding from the 

substrate, increased as water depth increased (Map E).

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

120° 119°40' 119°20' 119°

34°

34°20'

Kilometers 0 5 10

0 4 8

Nautical Miles

Santa Barbara Channel

Santa Barbara

Ventura

CALIF.

MAP LOCATION

Limit of California’s

 State Waters

Santa Cruz Island Santa Rosa Island

Area of

 Map

Anacapa

 Island

1

National Oceanic and Atmospheric Administration, National Marine Fisheries Service;

2

U.S. Geological Survey

Predicted Distribution of Benthic Macro-Invertebrates, Offshore of Ventura 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

25 20 15 10 5 0 25 KILOMETERS

70000 50000 30000 10000 0 70000 FEET

10 5 0 10 MILES

SCALE 1:400 000

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

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 March 11, 2013

Onshore elevation data from NOAA Coastal Services 

Center (data collected by EarthData International in 

2002-2003). 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 Ventura Map Area Map E – Predicted Distribution of Brittle Stars, Offshore of Ventura Map Area Map F – Predicted-Distribution Maps for Santa Barbara Channel Region

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

119°25' 119°20'

34°20'

34°15'

119°25' 119°20'

34°20'

34°15'

119°25' 119°20'

34°20'

34°15'

119°25' 119°20'

34°20'

34°15'

119°25' 119°20'

34°20'

34°15'

Ventura Ventura Ventura

Ventura Ventura

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.

Scientific Investigations Map 3254 

Sheet 11 of 11

Pamphlet accompanies map

U.S. Department of the Interior

U.S. Geological Survey