Restoration Project

University of Alaska - Herring Bay

Restoration Objective:

The aims of this study were to determine the geographic extent of regions showing slow recovery, determine the factors causing the slow recovery, and determine if cost-effective methods could be developed to restore Fucus to regions where populations are not recovering.

Site Selection Criteria:

The primary restoration site was selected as an area where Fucus populations have been extensively documented since 1991 and have not recovered. The site is a region of steep rocky shore, which can be exposed to intense solar radiation during clear days in the summer months. In addition, the site is in a location protected from wave action so there is no wave spray to moisten and cool the rock surface. The Oil Spill GIS was used to identify unoiled sites with physical characteristics similar to the oiled sites that were not recovering (i.e. southern exposure, protected rocky habitat, and shore steepness).

Cause Of Decline:

The oil spill and subsequent clean-up activities from the Exxon Valdez accident in March 1989 caused considerable injury to the intertidal seaweed community, especially to Fucus gardneri, the dominant species in this region. Studies carried out during the summer of 1990 showed that Fucus populations were injured throughout the intertidal zone. By the summer of 1992, populations in the low and mid-intertidal zones at many locations were showing signs of recovery. Surveys of mid and high intertidal zones with a southern exposure in Herring Bay showed almost no recovery by the third year after the spill. These habitats remained as bare rock with sparse barnacle and littorinid snail populations.

Key Reasons For Decline:

Water Pollution

Scientific Paper

Recolonization and restoration of upper intertidal Fucus gardneri (Fucales, Phaeophyta) following the Exxon Valdez oil spill

M.S. Stekoll, L. Deysher, , Hydrobiologia, Vol. 327.https://doi.org/10.1007/BF00047824

Organisation:

University of Alaska

Site Observations:

Observation Date

1st Jun 1993 – 1st Sep 1994

Action Summary:

Restoration of Fucus populations was carried out on a small-scale at a heavily oiled rocky site in Herring Bay, Prince William Sound. Mats of biodegradable erosion control fabric were deployed to act as a substratum for Fucus germlings and to protect germlings from heat and desiccation stress. A series of plots were covered with mats made from a resilient coconut-fibre fabric in June 1993. Half of the mats were inoculated with Fucus zygotes. A series of uncovered control plots was also monitored.

Lessons Learned:

Fucus recruitment in the high intertidal requires a large population of adults to provide both a constant supply of zygotes and a sheltered environment for survival of the young thalli. Colonization by new thalli, there-fore, progresses from the edges of existing natural beds.

Project Outcomes:

Dense populations of Fucus developed on the surface of all germling mats by the summer of 1994. The natural rock surfaces in control plots, both inoculated and not, had no macroscopic algal cover. By September 1994, the juvenile thalli on the mats were approximately 2 cm in length. Inoculating the mats had an effect only in the upper region of the intertidal. It is expected that the thalli will become fertile during the 1995 season, and that they may serve as a source of embryos to enhance the recovery of new Fucus populations in this high intertidal area.

Key Reasons For Decline:

Water Pollution

Area of Restoration (In Square Metres)

48

Indicator Data:

Indicator:

Ending Value:

Starting Value:

Adult Kelp Count

539.06256
Costings:
Cost Currency:USD