Shellfish logo used by permission, courtesy of the Pacific Coast Shellfish Growers Association (PCSGA).

Website hosted by:

Drayton Harbor Projects

Circulation Studies

Since the Drayton Harbor Shellfish Advisory Committee was first formed in 1995, there have been numerous attempts to determine the possible sources of fecal coliform within the watershed. Because no “smoking gun” has been found as the main source of the pollution, comprehensive studies that look at how the entire system works may help to target several specific problem areas. Looking at the circulation patterns within and around Drayton Harbor is one way to track how fecal coliform bacteria move throughout the system. Having a better handle on bacterial transport can assist groups in developing more targeted studies focused on a particular area/source.

Semiahmoo Bay

Shared Waters Circulation Study 2002/2003- In 2002, the Shared Waters Roundtable Group, a trans-boundary organization of Canadian and United States citizens and agencies, contracted with Hay and Company Consultants, Inc. to create a circulation model for Semiahmoo Bay, incorporating data from both Canada and the United States. The following is a list of the project contributors that funded this work: Environment Canada, Georgia Basin Ecosystem Initiative, the Greater Vancouver Regional District, the City of Surrey, the Nooksack Tribe and the Puget Sound Action Team.

The circulation model looked at impacts and loading from several Canadian sources (Nickomekl, Serpentine and Little Campbell Rivers) and from several U.S. sources (Dakota and California Creeks and the sewage treatment plant outfall for the City of Blaine). A report was produced as part of this project; it documents the methodologies used as well as the results obtained from the modeling.
Semiahmoo Bay Circulation Study and Figures (This file is 3.98MB, if you can't download it a copy is available for review at Water Resources). Please note: there are several additional appendices associated with this report that provide additional details on the data from the project. Copies of these appendices, along with the report and figures, are available for review at the Water Resources Library (322 N. Commercial St., Suite 110, Bellingham, WA).

Blaine Marina/Drayton Harbor Circulation Studies

In 2002, the Drayton Harbor Shellfish Advisory Committee asked the Department of Health (DOH) to provide direction on what criteria DOH would need in order to consider a re-classification of portions of the harbor. One of DOH’s recommendations was that circulation work occur in and around the Blaine Marina to determine whether waters in this area (which have high fecal coliform counts) have the ability to impact other areas of the harbor, in particular Sites #4 and #6, which are closer to the marina than Sites #3, #5, and #12, are which represent the Community Oyster Farms shellfish beds.

In response to this recommendation, several preliminary circulation studies were conducted in August and September 2002.

August 19, 2002 Circulation Study Report
September 9, 2002 Circulation Study Report
September 10, 2002 Circulation Study Report

This preliminary work indicated that there was little surface movement of water within the Blaine Marina- surface water within the marina did not leave the marina. These preliminary studies made it evident that additional work would need to be done, incorporating deep-water drogues (floats) to better understand the water circulation patterns in and around the marina area.

After sharing these initial studies with DOH and receiving input and feedback from DOH staff on how additional work should be accomplished (appropriate depths for deep-water drogues, deployment times, deployment locations, etc.), an initial field assessment was conducted on January 27, 2003 to determine if the drogues would work correctly, etc. After the initial trial, circulation studies were conducted on four dates in March and April of 2003: March 20, 2003, March 21, 2003, March 22, 2003 and April 17, 2003.

Results from these studies indicate that it is the deeper water that is leaving the Blaine Marina and it leaves the marina and then returns to the marina, indicating it has no impact to the shellfish growing areas. Drogues placed in the harbor on a returning tide generally tended to track straight in and to the southeast slightly, indicating that waters from Sites #15 and #8 probably aren’t affecting the shellfish beds at Sites #4 and #6. Follow-up work will probably occur after additional discussions with DOH staff. Dye studies at Sites #8 and #15 will hopefully be conducted with DOH staff in July of 2003 to further define the level of impact water quality at these sites might have on the shellfish beds. As a result of this circulation work, it is hoped that stratified fecal coliform monitoring can occur to give a better picture of fecal coliform impacts at various depths.

Blaine Harbor Circulation Studies Report 2003

Photos courtesy of Geoff Menzies