Restoration

Fucoid algae, which are brown algae often called rockweeds, are conspicuous and important species in rocky intertidal communities world-wide. Their presence has been shown to modify the temperature of substrate, provide refuge, and facilitate other species’ survival. Fucoids have a very interesting sexual system. Unlike most algae, adult fucoids produce sperm and eggs (different fucoid species can have separate sexes or be hermaphroditic) which mix together locally, either on the plant or substrate below the plant. This reproductive strategy leads to very short range dispersal of propagules which can be problematic with respect to replenishment following a disturbance. Natural disturbances are typically very patchy. When such disturbances occur, there are usually patches of fucoids still present and these act to locally replenish the site because of short range dispersal.

Anthropogenic disturbances, on the other hand, are often much larger and less patchy. In particular, oil spills may lead to catastrophic disturbances and the abundance of intertidal fucoids has been documented to decline following oil spills. Because replenishment of such areas is likely to be prolonged, there has been great interest in the use of restoration by human intervention. However, many marine restoration efforts require the depletion of source populations to bolster negatively affected populations. The Raimondi lab at UCSC is conducting a project assessing the efficacy of a technique to restore Fucus populations with the least amount of depletion to source populations as possible. For more information on the restoration methods we use, please see this link: http://www.eeb.ucsc.edu/pacificrockyintertidal/data-products/fucus-restoration/index.html

Contact: Laura Anderson – lmanders at ucsc.edu

Mussel Restoration

Rocky intertidal habitats are home to some of the most diverse biological communities and provide a rich environment for education, research, and recreation. Human disturbances, like oil spills and overharvesting, negatively impact the biodiversity of these ecosystems and recovery can take as long as two decades. Despite many threats, the potential for restoration in the rocky intertidal has been entirely unexplored. The goal of this project is to address the growing need for restoration in rocky intertidal habitats. This work began in 2009 funded by the Torch Oil Spill Trusteeship in collaboration with the The Bureau of Ocean Energy Management, Regulation and Enforcement (BOEM). The primary objective of this work was to explore the effectiveness of using adult mussel (Mytilus californianus) transplants as a potential restoration tool following a disturbance like an oil spill.

The mussel Mytilus californianus is the primary space holder and an important foundation species in rocky intertidal communities along California’s coast. A disturbance to a mussel bed not only impacts the algal and invertebrate community that lives on and within the mussel bed matrix, but it can also impede the settlement of new mussels by exposing large areas of bare rock. This is because mussels are poor settlers of bare rock, preferentially settling on substrate such as the byssal threads of adult mussels or filamentous algae. In this situation, transplanting adult mussels may help facilitate the recruitment of new mussels along with the rest of the algal and invertebrate community.

Between late 2009 and early 2010, California mussels (Mytilus californianus between 20-60 mm) were collected from the Ellwood Pier north of Santa Barbara and transplanted into cleared 50 x 50 cm plots at two sites along the coastline of Vandenberg Air Force Base. The success and recovery of these plots has been monitored for over two years and compared to two additional plot types, a cleared plot with no transplanted mussels and a control plot with natural mussel bed. Preliminary results of this ongoing work have provided key insights into the role mussel beds play in facilitating and structuring rocky intertidal communities.

Contact: Kristin de Nesnera kdenesne at ucsc.edu