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General News · 29th December 2011
Noba Anderson
As one of the outcomes of a meeting I had with the Minister of Agriculture and Lands in January 2010, his Ministry (since renamed) conducted field work in Gorge Harbour during the fall of 2010 and have finally now just released their reported findings and conclusions. The report is too big in size and exceeds the posting limit here. If you want an electronic copy please email me. The Province used this report in their decision making process when they issued the Klahoose Shellfish Limited Partnership's license in Gorge Harbour. The Regional District's public hearing for the rezoning application associated with this same site to the north of Ring Island will be held in the Gorge Hall Saturday, January 14th, at 1pm.

Here is the executive summary - contact info is below.

Executive Summary

Gorge Harbour, Cortes Island, is one of British Columbia’s key shellfish production areas, due to its biophysical suitability for shellfish culture. The semi-enclosed water body is highly productive for phytoplankton and it is well protected from adverse weather. Although it is a desirable location to carry out shellfish aquaculture, there has been conflict with other users. A planning process coordinated by the BC government commencing in 2002 developed recommendations as to limits that should be placed on aquaculture development around Cortes Island. The total number of existing and allowable new rafts in the Harbour (including 146 for expansions of current operations and 90 for one new Klahoose First Nation tenure) was capped at 557.

The KFN submitted an application (under the name Klahoose Shellfish Ltd. Partnership or KSLP) to the provincial government for a tenure to place 90 shellfish rafts in Gorge Harbour on Sept 29, 2009. This proposal was modified several times to meet other users’ concerns, before being finalized in August, 2010.

The Strathcona Regional District (SRD) expressed concerns regarding this proposal, in part because amendments to the proposal were accepted after the issuance of an Environment and Land Use Act (ELUA) order prohibiting the acceptance of new applications and due to its concerns regarding the environmental effects of additional shellfish culture in Gorge Harbour. The Statutory Decision Maker responsible for rendering a decision on the application determined that additional biological information was required in order to weigh all factors appropriately. At a meeting between SRD representatives and BCMAL staff on January 14, 2010, BCMAL committed to conducting an environmental survey that would be incorporated into the decision-making process.

The survey was conducted from September 29 – October 1, 2010. Data from the survey were analyzed and considered in concert with data gathered from previous studies on aquaculture in Gorge Harbour.

Seabed mapping and ground-truthing (using video and grab samples) indicated that much of the substrate of Gorge Harbour was made up of fine sediment (mixtures of silt, clay and sand of varying proportions). At the time of ground-truthing, there was evidence of organic enrichment throughout much of Gorge Harbour, with elevated sediment sulphide levels and negative redox values at reference and farm sites, with the exception of one reference site and a sample location within the new tenure. Grab and video samples also indicated widespread presence of Beggiatoa mats or patches, as well as the presence of marine “snow”, indicating that a plankton bloom had recently occurred and was decomposing. Videos taken at oyster and mussel farms, as well as information provided by Barnes (2007) showed a deposition of shell material that offered a hard substrate for a diverse range of marine organisms which was different from the benthic community associated with a sediment-topped seabed.

Water velocity profiles generated from data taken on September 29 and October 1, 2010, indicated that even near high slack tide, water movement across the site was suitable for shellfish culture, averaging 0.03 m/sec and 0.04 m/sec respectively. Water property profiles generated from data collected on October 1, 2010, showed that the water column was unstratified within the first 16 m, with temperature ranging from 13.39 to 13.22o C and salinity from 26.47 to 26.58 practical salinity units (psu). Chlorophyll levels were low (0.6 μg/L at surface to 1.2 μg/L at 12m), following a bloom of phytoplankton in early September, as was turbidity.

Analysis of previously collected water property data demonstrated changes in water column properties due to seasonal changes, with warming in the surface layer during March through August and cooling during September through winter. Salinity appears to be lowest during the early summer due to freshwater inputs from large mainland rivers. Although the water column is sometimes stratified, for much of the year the water column is well mixed.

Phytoplankton blooms (food available in surplus to cultured and wild shellfish, indicated by chlorophyll [Chl] levels over 5 μg/L) are frequently observed in the upper 10 m in east Gorge Harbour, during March through September. Several cycles of plankton bloom and decomposition can be observed each year.

There do not appear to be any significant changes to Gorge Harbour as a result of the shift towards mussel culture. Levels of phytoplankton in the water column appeared typical of the season, and were not depauperate, and benthic conditions do not appear to have changed significantly. Although elevated sulphide and negative redox levels were observed at farm-sites, they were no higher than those observed at reference stations.

The proposed KSLP site will not exceed the carrying capacity of Gorge Harbour, even taking into account the broader transition to mussel culture. The current survey indicated that the proposed site was suited to shellfish farming, with a suitable depth, currents and location.

Other information considered in this report includes the Transport Canada Canadian Environmental Assessment Act (CEAA) permit and the Navigable Waters Protection Act (NWPA) permit issued for the proposed shellfish farm application.

From a perspective of biological feasibility and environmental suitability the report recommends issuance of a tenure offer for a deepwater shellfish tenure for 11.0 ha, suitable for up to 90 rafts.
END of Executive Summary

Please direct any questions you have about the report to Bill Harrower or 250-897-7547 at the Ministry of Forests, Lands and Natural Resource Operations. Bill Heath was the lead researcher of the report – or 250-897-7548.

As always, you are welcome to contact me 250-935-0320,
Noba Anderson