Georgia Strait Alliance


or click here for the atlas

Georgia Strait Alliance is the only citizens' group focused on protecting the marine environment in and around the whole Strait of Georgia – Canada's most at-risk natural environment, and the place where 70 percent of British Columbians live, work and play. We are committed to a future for our region that includes clean water and air, healthy wild salmon runs, rich marine life and natural areas, and sustainable communities.  For more than a dozen years, volunteer "Straitkeepers" have been hitting the beaches at low tide to take part in Georgia Strait Alliance’s Intertidal Quadrat Studies – getting “up close and personal” with marine life!   Participants use an established set of techniques and tools to identify and catalogue the plants and animals found in the intertidal zone – the area exposed at low tide. They go back to the same beaches each summer, in order to identify changes over time in the number and diversity of species found on each beach.  Through these studies, Straitkeepers are deepening their understanding of intertidal ecology, and they are gathering data that can help local communities monitor biodiversity and make wise decisions in terms of shoreline development. And they’re having fun!  This new on-line system through the Community Mapping Network allows the volunteers to enter and manage the data they collect, as well as allowing others access to the data.  This will help volunteers to be able to detect changes over time in the intertidal areas they’re monitoring.    What are intertidal quadrat studies? Quadrat studies are biological assessments that use a grid system as a method of collecting data. Georgia Strait Alliance's intertidal quadrat studies gather data on the abundance and diversity of species on the beach, at specific tide heights. We repeat the studies each year, at the same locations, in order to gather data on changes in the marine life. This information is important in assessing the overall biodiversity of local beaches.  In our intertidal quadrat studies, we use square frames (quadrats) that are 50cm x 50cm and are strung with string to form a grid with 36 intersections.   These quadrats are put down on the beach along a transect line (a line that runs perpendicular to the shoreline) at 1.0m, 1.5m, 2.0m, 2.5m, 3.0m, and 3.5m above the zero tide line. Intertidal life within each quadrat frame is identified and recorded, using one method to identify what is on top, and another for what lives underneath the rocks.   What is required to do quadrat studies?  1. A bedrock and/or cobble beach, with rocks that are no smaller than the size of a fist and not so large that they are difficult to turn over.  2. A low tide that goes below 1.0m (the best times for low daytime tides in our region are spring and summer).   3. Volunteers must learn to lay out the transect line and position the quadrat frames along it. The line can be set up with measurements taken in relation to stable landmarks, so that we can reposition it in the same place for later studies.  4. Volunteers must learn how to identify common species on the beach and how to look at and record what is there.   What is Georgia Strait Alliance’s history with quadrat studies? Our inspiration came from in 1991 at the State of the Strait conference, which we hosted in Nanaimo. Shannon Bard, a biology student at the time (now a professor at Dalhousie University), presented a paper titled, “The Effects of Pulp and Paper Mill Effluent on the Marine Environment and its Life”, which summarized the results of an intertidal population study that she had conducted using quadrat studies.   We began using quadrat studies in 1992. Since then, we have introduced hundreds to quadrat studies. We have worked with schools in the Nanaimo area and have produced two educational resources: The Straitkeeper’s Handbook, a book of activities for teachers, and Beach Critters, a short video showing a group of young people carrying out a quadrat study.  In 1994, we began working with the Burrard Inlet Environmental Action Program to train adult volunteers in a more rigorous methodology, in order to gather usable data. In 1998 the program was taken over by the Vancouver Aquarium.  Starting in 1997, we coordinated a series of quadrat studies in the mid-Vancouver Island area. Today, active teams of these volunteers, called “Straitkeepers”, carry out quadrat studies each summer in the Victoria area and on Pender and Cortes Islands.  

Contact Organizations

Cathy J Booler Marine Wildlife and Habitat Coordinator IT Support Georgia Strait Alliance 195 Commercial St., Nanaimo, BC V9R 5G5 www.GeorgiaStrait.org Office: 250.753.3459 Home office:  250.741.0253 Cell:  250.668.5553

Atlas Documents

Atlas Training Videos

Atlas Categories

Atlas Software Versions: 
Atlas Special Tools: 

You can click on the terms above to be presented with a list of all atlases tagged as such.

Atlas Data

Last Updated: 07th Feb '13
Atlas supports Data Entry: Yes

Web Links (These links will load into another browser window)


Atlas Update & News