Written by Dr. Jennifer Tennessen
In early March, Dr. Jennifer Tennessen participated in a 3-day expert workshop on Southern Resident killer whale biology and conservation in Vancouver, British Columbia. The workshop was motivated by the increasingly dire situation facing this endangered population of orcas, which spends a large part of the year in the inland waters around Seattle and Vancouver. Southern Residents continue to face a high probability of eventual extinction if current conditions persist. These conditions include widespread and increasing underwater noise pollution from commercial and recreational vessels, dwindling stocks of salmon, especially chinook (king), coho (silver) and chum (dog) populations that make up the vast majority of their diet, and persistence of legacy contaminants in the environment which work their way up the food chain to become concentrated in the tissues of apex predators like orcas.
Over the past couple of decades several measures have been implemented at local, state and federal levels to address underwater noise, prey availability and legacy pollutants, on both sides of the border. Recently, Dr. Tennessen’s research helped provide the scientific basis for increases in the separation distances between vessels and whales, based on her team’s discovery that vessel presence disproportionately reduces female foraging behavior. However, more work is needed to ensure a bright future for the population, which has virtually flat-lined in recent years while a population to the north – the Northern Residents – has continued to grow at a rate of 3-5 % annually.
This workshop, organized by NGOs and independent researchers in response to the need for robust scientific dialogue on the effectiveness of the conservation measures implemented to date, examined how existing measures could be improved, and what additional actions could be applied to further reduce threats and promote recovery of the population. The specific objectives of the workshop were to:
- Evaluate the health and population status of the Southern Resident population using the best and most current data available
- Evaluate effectiveness of current conservation measures in reducing the intensity, duration and spatial scale of primary threats to the population, and on the overall
health of the population - Propose specific long-term recovery actions, taking into consideration prospects for cross-border cooperation, and extended spatial and temporal scales.
Following the workshop, Dr. Tennessen and colleagues produced a report and are currently preparing a peer-reviewed manuscript articulating a path to Southern Resident recovery. They hope that these documents will serve as foundations for implementation of meaningful, efficacious science-based measures and actions going forward.
