Bull Kelp Monitoring Program Expands

Something exciting is happening in the world of bull kelp monitoring around the Southern Gulf Islands! Our long-term monitoring program, which previously focused on seven sites off the shores of Mayne Island, has exploded to include 19 sites around the islands of Galiano, Mayne, North Pender, South Pender, and Saturna. This has been possible thanks to the amazing volunteers on each of these islands, and funding from the Department of Fisheries and Oceans Canada for project coordination and equipment. A special thanks to Chessi Miltner (Galiano Conservancy Association), Elizabeth Miles (Pender Islands Conservancy Association), and Robert Bruce (Saturna Island Marine Research and Education Society) for organizing volunteers within their communities. This program has been a great way to bring our island communities together to achieve a common goal and increase our ability to detect changes in an important marine ecosystem.

Bull kelp monitoring is a perfect candidate for citizen science in the Southern Gulf Islands, where waters are relatively calm, and most bull kelp beds are located only a short kayak from shore access points. After only a few hours of training, volunteers can participate as part of a monitoring team. To record the locations of bull kelp each year, volunteers and staff kayak out to the bull kelp beds at low tides in August and September and record GPS waypoints around the outside of the beds.

Our monitoring program, which just completed its 11^th year of data collection, is one of the longest running bull kelp monitoring programs in British Columbia. The data collected as part of this monitoring program has an important role to play, combining with other data collected along the west coast to inform management decisions and help develop new remote sensing technologies. For example, there is increasing interest in commercial harvest of canopy-forming kelps, and information from long term monitoring is essential for the provincial government to make informed management decisions and be held accountable for the impacts of any commercial activities they decide to allow. Our data is also being used by researchers from the University of Victoria to assess the ability of satellites to detect bull kelp from space. They compare what our survey teams record on the water to what shows up in the satellite images to determine if the satellite images can be relied on to accurately monitor changes in bull kelp.

As our planet warms because of increases in greenhouse gases, our oceans are also warming. This warming trend has been linked to declines in kelp in other parts of the world such as northern California, southeastern Australia, eastern Canada, and Norway. Our data, along with data collected by other monitoring programs along the coast, will allow us to observe any changes that happen, and that otherwise would not be detected.

A collapse of bull kelp would have far reaching impacts on our ocean environment. Since bull kelp is such a fast-growing species, it captures a lot of energy from the sun, and makes that energy available to marine food webs. In the process of capturing that solar energy, bull kelp also pulls carbon out of the ocean, helping offset the negative impacts of ocean acidification and global warming. Where bull kelp grows in dense forests, such as within our monitoring sites, it provides a place for juvenile fish and other marine animals to hide from predators, and shelter from ocean currents.

We’re pleased to say our results to date indicate there has not been any significant long-term decrease in the overall area extent of bull kelp around Mayne Island in the past 11 years. Our results do show that the area extent of bull kelp can change significantly from year to year, demonstrating that long-term monitoring programs are required to accurately detect any long-term changes. Two of our monitoring sites have still not recovered from decreases early on in our monitoring program. In particular, the bull kelp bed on the north side of Georgeson Island disappeared gradually between 2010 and 2017 and has not recovered in the past four years. While other sites have changed over the years, nowhere else have we observed that kind of total loss. This suggests a site-specific reason for the decline of bull kelp on the north side of Georgeson Island. Overall, our results support other long term monitoring programs that suggest bull kelp grows well in years of colder ocean temperature and poorer in years of warmer ocean temperatures. These fluctuations are mostly caused by the El-Nino Southern Oscillation cycle.

Long-term ecological monitoring is critical to understanding changes in our environment, but notoriously difficult to fund. So far, we have been able to string together the occasional grant to keep this program running, but we often rely on donations from individuals such as yourself to fill in the gaps. If you are interested in helping support the continuation of this cost effective and valuable monitoring program, please consider donating here.

If you are a researcher interested in access to our geospatial data, please contact Rob Underhill at biologist@mayneconservancy.ca