Kelp Mapping MethodologiesThe Mayne Island Conservancy has been mapping kelp beds in the island's coves and bays for three seasons. Staff consulted experts in the field to develop a methodology for mapping by kayak which is described in a this PDF document. It has been prepared for the Seagrass Conservation Working Group, a consortium of community groups, biologists, consultants, First Nations and government agencies who work to conserve nearshore habitats like eelgrass and kelp
This document will be of interest to those undertaking similar activities and they are welcome to make fair use of the information. Appropriate credit will be appreciated! Community group that would like to be trained to map and monitor bull kelp habitat should contact Leanna Boyer at firstname.lastname@example.org.
- Grows Quickly - Entire growth occurs spring to fall, up to half a meter per day. Can grow to 60 meters in ocean waters, but in protected Salish Sea, bull kelp often reaches 10 metres
- Huge Holdfasts - Attaches to rocks below low tide level with holdfasts bigger than your hand, up to 40 centimetres wide
- Gas Floats - Bulbous float at the end is filled with gas containing carbon monoxide
Rafts of kelp help reduce beach erosion. Kelp forests soften the force of waves against the shoreline. This protection can be seen along the Strait of Juan De Fuca where large kelp beds form bay-like areas along the shoreward side. In addition, kelp forests are a significant carbon sink, sequestering mega-tonnes of CO2 equivalent in the Pacific North West.
Anecdotal evidence is showing a decline in bull kelp in the Salish Sea. Measuring change in area of kelp beds over time (monitoring) will enable us to detect declining populations and determine why.
Experimental research shows that bull kelp ceases to grow with an increase in temperature. The federal government reports that Salish Sea ocean temperatures are increasing at all depths due to climate change effects. Grazing from sea urchins can also decimate kelp beds.
At present, kelp mapping is conducted manually via transects and aerial photography (Cavanaugh et al., 2010; Sutherland et al., 2007; Field, 1996). In British Columbia, the Ministry of Environment has conducted kelp surveys in allocated areas along the coast since the 70’s using field transects and infrared aerial photos (Sutherland, 1990; Sutherland et al., 2007; Lucas et al., 2007). Localized kelp inventory initiatives have also been established recently in the Gulf Islands area, such as through the Mayne Island Conservancy Society and the citizen science group Help the Kelp on Gabriola Island...Read the completed study here