High cadmium levels in Baynes Sound a concern

Expansion of aquaculture leases could put consumer health at risk

Dear editor,

Like others in the Comox Valley, I support regional economic sustainability and  applaud shellfish aquaculture industry values of producing healthy shellfish and preserving and protecting a fragile marine ecosystem.

On the surface, then, expanding oyster and geoduck leases in subtidal and intertidal zones can appear to answer the need for economic development in the Baynes Sound.

However, these initiatives that involve expanding oyster tenures and introducing hundreds of hectares of subtidal and intertidal geoduck operations violate two recently published government scientific advisories.

These advisories would call an immediate halt due to excessively high cadmium levels in Baynes Sound and the lack of scientific research to predict long range cumulative effects of either intertidal or subtidal commercial-scale geoduck operations.

Baynes Sound waters are verified as having some of the highest cadmium levels in the world and oysters grown in the Baynes Sound have cadmium levels that exceed health levels set by WHO, EU, New Zealand and China.

B.C. oysters exceeding the Chinese maximum level of two ppm have been returned. Recognizing the potential market impact of high cadmium levels, the Aquaculture Collaborative Research and Development Program (ACRDP) Fact Sheet (Issue 7/May 2010) on cadmium in deepwater-cultured oysters advises the industry to site leases in waters that are known to be low in cadmium and to harvest in the summer months when the levels are known to be a little lower.

Given Baynes Sound verified high levels, any expansion of oyster leases violates this advisory and puts consumer health at risk.

After the Chinese returned B.C. oysters, Health Canada issued an advisory to limit consumption of B.C. oysters  to 12 per month, but those at high health risk — individuals with renal failure, smokers, women, children and First Nations individuals — should show extra caution.

This advisory can be read in the BC Disease Registry where it is accompanied by the misleading claim that the research linking consumption and health risk is not strong. Some scientists argue the 12-per-month limit should be lowered.

It is alarming, therefore, to note that one local company is now licenced to harvest oysters in the Union Bay coal beds, an area slated for reclamation as a highly contaminated sites.

Government scientists also warn the industry to be cautions about lifting a moratorium on entering the highly lucrative geoduck market. The Canadian Science Advisory Secretariat explicitly states that small-scale studies cannot predict long term cumulative effects of commercial-scale subtidal and intertidal operations.

This caution would call for maintaining the Precautionary Principle on entering the geoduck market, not putting hundreds of hectares under cultivation.

The fact that government shellfish aquaculture management is ignoring its own scientists is alarming. More alarming is the potential cost to consumer health and to a fragile marine ecosystem.

Sharon Small,

Denman Island

 

Comox Valley Record