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Terms of Reference
Science Advisory Process on Sediment contaminant criteria, disposal at sea, and killer whale Critical Habitat
Thursday, March 25, 2010
Institute of Ocean Sciences, Sidney BC Canada
Chairperson: Peter Ross
Context
SARA-listed killer whales in British Columbia are highly contaminated with several classes of environmental contaminants, including PCBs, as a result of their feeding on contaminated prey, their position in the marine food web, and their long lives. The Recovery Strategy identifies persistent contaminants, including PCBs, as a threat to the long term viability of killer whales. The contamination of killer whale food webs is due to a combination of proximity to pollution source, and the amplification of chemicals with persistent, bioaccumulative and toxic (PBT) properties in aquatic food webs. Such chemicals are hydrophobic and therefore readily attach to particles (suspended solids, organics, detritus, sediments) and/or to lipids at the bottom of the food web (membranes of phytoplankton, bacteria). These two environmental matrices, however, are connected, with contaminated sediments delivering PCBs and other persistent chemicals into aquatic food webs. Contaminated sediments have been shown to contaminate adjacent aquatic food webs, and therefore represent a source of contaminants to aquatic biota. Given the special vulnerability of killer whales to contamination by PCBs and related contaminants, and their associated health effects, it is important that current CEPA 1999 guidelines and regulations be critically evaluated in this regards, with an emphasis on contamination within the species’ Critical Habitat (CH). Four ocean disposal sites exist within killer whale CH, including Johnstone Strait (2), Sand Heads (1), and Victoria (1).
Objectives
Based on initial teleconference June 17, 2009 (DFO: Al Cass, Karen Calla, Peter S. Ross, Robie W. Macdonald, Patrice Simon, Ghislain Chouinard, Simon Nadeau, and Atef Mansour; absent: Robin Brown; EC: Sean Standing and Barry Jeffries)
General question:
Do PCBs in disposal materials deposited in SARA-designated Critical Habitat increase the risk of adverse health effects in resident killer whales (northern and southern)?Science questions to be addressed:
- What disposal materials represent a concern to the health of killer whales and killer whale Critical Habitat?
- What are ‘acceptable’ concentrations of contaminants (notably PCBs) in sediments or disposal materials for the protection of killer whale health?
- Are current Disposal at Sea rejection/screening limits for environmental contaminants (including PCBs) in disposal materials under CEPA 1999 sufficient to protect the Critical Habitat of resident killer whales as defined by SARA?
- Are current analytical and monitoring standards as required by CEPA 1999 of sufficient calibre to enable defensible science-based advice with regards to impacts of Disposal at Sea on killer whale health, and especially within killer whale Critical Habitat?
- Are there other contaminants of concern in dredge/disposal materials that are either presently screened under CEPA (mercury, cadmium, hydrocarbons, PCBs, and persistent plastics other persistent synthetics) or not screened (PBDEs) under CEPA that may present a risk to killer whales?
Management questions:
- should new sediment quality objectives (to complement or replace rejection/screening limits as set forth by CEPA 1999) be developed for the protection of killer whale health to guide disposal at sea permitting in killer whale Critical Habitat under SARA?
- Can guidance on disposal site selection and disposal practices be provided that would reduce contaminant risks to killer whales and killer whale Critical Habitat?
A two-stage evaluation is proposed. In the first-stage (described herein), an initial “rapid” assessment will be undertaken to scope out the impact by site using existing information and models where appropriate. The outcome of this first-stage scoping session will determine the potential next steps for the second and longer term effort as required depending on the outcome of stage one. A working paper based on the stage-one assessment will be produced and it will be the basis for a formal science peer-review by the Pacific Scientific Advice Review Committee (PSARC) in March of 2010.
