Saanich Inlet at a Glance:
- Region: Southeastern coast of Vancouver Island, in an inlet just north of Victoria, B.C.
- Number of Instrument Platforms: 4
- Depth: 100 m
- Location: Latitude: 48o 39.054' N, Longitude: 123o 29.203' W
- Seafloor Composition: Variable: soft, sandy, and gravel sediments.
- Principal Research: Low Oxygen Ecology, Inlet Renewal and Chemical Cycles, and Forensics.
Just to the north of Greater Victoria, the largest metropolitan area on Vancouver Island, many residents of the South Island are familiar with the annual salmon spawning occurring through Saanich Inlet into Goldstream Park. While the abundance associated with this event is hard to miss, what many take for granted is the incredible marine diversity which lays below the surface of the inlet itself, and the dynamic oxygen conditions which make it such an interesting ecosystem.
The warming of surface waters in the spring cause dense ‘blooms’ of diatoms and dinoflagellates (types of photosynthetic ‘phytoplankton’) to form. These blooms feed the growth of predatory plankton species (known as zooplankton), which, in turn, support the abundance of secondary and tertiary consumers such as herring, hake, Pollack, dogfish and salmon.
This rapid growth also results in significant plankton die-off, with countless plankton bodies sinking to the floor of the inlet and undergoing decomposition by bacteria who rapidly consume available oxygen. A layer of oxygen poor water is thus created at depth until replenished with oxygen rich water in the fall. This biologically dynamic and seasonally variable environment has been studies for over 80 years.
What Makes Saanich Inlet Unique?
The seasonal variations in dissolved oxygen, complex biogeochemical cycles, diverse benthic ecosystem, abundant plankton and active lower trophic levels make Saanich Inlet is an ideal place to study the effects of changes in the oxygen content on ocean biodiversity.
Low Oxygen Ecology, Inlet Renewal, and Chemical Cycles:
Dense populations of zooplankton and fish respond to conditions in the inlet that change throughout the year. Studies of the temporal variations in the vertical distribution of oxygen and nutrients and the response of various biological communities to these variations will be monitored by network sensors. Associated research can be found in the following study briefs:
- AUV used to map and study key parameters of oxygen cycling
- Saanich Inlet Digital Camera suggests significant changes on continental shelf as ‘Dead Zone’ grows
- Photography in near real-time helps researchers assess biorhythms in Saanich Inlet.
- Sediment trap used to monitor plankton fossilization in Saanich Inlet
Richard Dewey, expedition leader for the Tully expedition, recaps a successful day a sea:
Dr. Gail Anderson introducing the Ocean Forensics Project: