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7_BEACON Tech Report (FINAL)

Turbidity plumes may interfere with the foraging of seabirds including the California

brown pelican and double-crested cormorant. Turbidity plumes would affect temporarily

a relatively small portion of the foraging area for these species. Impacts of turbidity on

seabird foraging would be adverse but insignificant.

The beach downcoast of the Ash Avenue site is designated Critical Habitat for wintering

western snowy plovers. Beach fill activities at Ash Avenue should not have a significant

adverse impact on the Critical Habitat. Snowy plovers foraging downcoast from Ash

Avenue would not be disturbed by equipment placing sand at the Ash Avenue site.

Because littoral transport in fall and winter is primarily downcoast, the placement of

sand at the Ash Avenue site during these seasons will not cause the mouth of

Carpinteria Marsh to close. There may be a slight potential that sand placed on Ash

Avenue could move downcoast and close the mouth of Carpinteria Creek. Sand will be

monitored during beach fill operations. If it is observed to move downcoast and close

the mouth of Carpinteria Creek, BEACON will reopen the mouth with a bulldozers. With

this measure in place, significant impacts to Carpinteria Creek will be avoided.

3.3.3 Oil Piers

All of the intertidal substrate within the area proposed for beach enhancement at Oil

Piers is sand. Placement of sand on the beach at this site would have an adverse but

insignificant impact on sandy intertidal animals. Offshore of the beach enhancement

site, the substrate in the shallow subtidal also is primarily sand but scattered low rocks

are found at the western end. The movement of sand offshore may bury these rocks.

The rocks that were observed in the shallow subtidal at Oil Piers supported little marine

life indicating that they may be scoured and/or buried naturally. The impacts of sand

burial to this habitat would be adverse but insignificant.

A significant rocky intertidal area is located about 1,200 ft. west of the western end of

the Oil Piers beach placement site. Sand movement is almost never upcoast in this

area, and significant impacts to this habitat would not be expected.

Kelp occurs about 1,500 ft. off the downcoast end of the Oil Piers site. Offshore

movement of sand at this site was not analyzed but, based on the analysis done for

Goleta Beach and Ash Avenue (Moffatt & Nichol 2000) sediment deposition would be

expected to be minimal. To insure that kelp in this area is not adversely affected by the

BEACON project, the kelp bed will be monitored.

Depending on the method and rate of placement as well as the percentage of fine

sediment, the proposed project would create temporary turbidity plumes in nearshore

coastal waters. Scattered rocky habitat and kelp beds offshore of the proposed sand

placement site would be expected at times to be subjected to turbidity from BEACON's

beach enhancement project. Brief pulses of turbidity that lasted a day or two would not

be expected to have a significant adverse impact on these resources. However,

extended turbidity could have a significant adverse impact. BEACON proposes to

monitor turbidity during beach fills. If the monitoring indicates turbidity is occurring in

3208 Bio Report

06/12/02