Coastal ecosystem services amongst trophic cascades

PI’s and Collaborators: Kai Chan (IRES, UBC), Chris Harley (Zoology, UBC), Evgeny Pakhomov (EOS, UBC), Jon Shurin (UC San Diego),Terre Satterfield (UBC), Anne Salomon (SFU), Villy Christensen (UBC), Rashid Sumaila, West Coast Aquatic, Parks Canada, and Fisheries and Oceans Canada

Post-Doctoral Associates: Russel Markel, Rebecca Martone, Jessica Clasen

Graduate students: Ed Gregr, Gerald Singh, Brock Ramshaw, Jordan Levine, Jordan Tam, Maria Espinosa Romero

Undergraduate students: Christina Mak, Jocelyn Nelson, Sarah Frioult, Theraesa Coyle

Widespread ecosystem change caused by human activities, such as over-exploitation of resources or the loss of top predators, leading to economic depression and cultural loss, are dilemmas faced by human-communities worldwide. In response, management agencies strive to integrate information on ecosystem structure and productivity and human perceptions and values into models of resource management. Following extirpation of sea otters from the BC coast during the Maritime Fur Trade (~1778-1911), populations of some nearshore benthic invertebrates, including sea urchins, abalone, and geoduck, became “hyper-abundant”. Although coastal First Nations have harvested these and other invertebrates for thousands of years, reliance upon these resources increased in the absence of sea otters. Furthermore, beginning in the early 1970’s, burgeoning commercial fisheries targeting these same species became highly lucrative. Thus, re-introduction of sea otters to the west coast of Vancouver Island, also in the early 1970’s, set the stage for conflict between this native keystone predator and coastal communities, economies and cultures dependent upon shellfish resources.

In order to inform how human-communities are affected by and can adapt to ecosystem changes along the west coast of Vancouver Island, we formed a consortium of researchers at UBC to investigate the ecological and social effects of sea otter re-introduction. The objectives of this inter-disciplinary research project are framed in the context of “ecosystem services”, broadly defined as the benefits to humans provided by ecosystems. We ask what are the consequences of trophic cascades for nearshore ecosystems and the benefits they provide for people?

Specifically:

• How will entire ecosystems be affected across the seascape?

• What are the consequences for nearshore diversity and productivity?

• How do changes in ecosystem states and functions link to ecosystem-service provisioning?

• What are the consequences and responses of human communities?

To do this, we are developing an ecosystem-service model that integrates information on the ecology of the system (e.g. nearshore food webs and productivity, maps and models of kelp forest size and areal extent, and the distribution and fate of kelp-derived carbon) and data on the socio-economic system (e.g. human values, perceptions of resource change on well-being) (Fig. 1). Our goals are to understand the workings of complex social-ecological systems to facilitate decision-making that promotes well-being and justice.

Figure 1.