Surge or Swell			as an Abiotic Factor at Race Rocks

							Surge Channel and Surge as an Abiotic Factor A video showing the action of the swell which floods tidepool # 4 on the west side of Great Race Island. Middle -Island Surge from East 35 Knot wind.Taken on Camera 1, Jan1, 2006. The sealions and elephant seals normally on this island had a difficult time staying that afternoon.
						On Jan 7 2008, GF took the series of photos below from the remote camera 5. The water was calm but storms occuring the day before still sent energy shoreward that piled up against the shore and broke as surf. The implications for organisms living in this zone are varied. Only those with sturdy attachments can survive and many algae and diatoms are allowed to grow well above the highest tide level. Goose neck barnacles thrive as this energy brings in their planktonic food. This action is not constant. A set of swells may be followed by 5 minutes of calm shores and then it starts again. The video on the left above shows the surge channel closeup from this same area.
				The water retreats from the shore It then builds up as the swell approaches Water piles up The surf flies Organisms normally on dry land are soaked n the spray zone. It sprays back seaward Waterfalls run down as the swell subsides. Ready for the next swell.
	The location of the Race Rocks Archipelago at the Eastern entrance of the Strait of Juan de Fuca means that the water column is particularly influenced by events which occur far out to sea in the North Pacific Ocean. Storms in the Pacific impart energy to the water column which eventually ends up in the Strait of Juan de Fuca and then on the shores of Race Rocks. Scenes like that above are typical. Here at North Rocks, the surge can send columns of water up several metres as the swells break on the island which is the first shallow mound that long wave energy encounters as they come up the Strait of Juan de Fuca. Of course this energy is originally solar derived. The effect on intertidal organisms on Race Rocks is significant. On the west side of Great Race Island in particular, the intertidal zonation of algae and invertebrates is directly influenced by the level and frequency of swell or surge.The stills videos above give an idea of how these swells come ashore on the island. In the picture on the left, Garry Fletcher shows Paul Kennedy the surge channel which is featured in the video on the South West corner of Race Rocks To get an idea of what the sea state is off our shore that causes the swells that break on Race Rocks, go to the buoy locations from the National Buoy Data Center Note in particular the data from our closest marine buoy stations: Buoy #TT1W1Tatoosh Island , WA.Longitude = 124.74W Latitude = 48.39N and La Perouse Bank (Longitude = 126.00W Latitude = 48.84N) are closest to the Strait of Juan de Fuca. Information provide by these stations is often useful for those planning on going Surfing out on the West Coast of Vancouver Island, 50 Km up the Strait from Race Rocks. The same swells that surfers look for producing ideal waves at Jordan River and Long Beach represent the energy that contributes to the swells and surge at Race Rocks some time later.
In order to visualize the spread of energy from storms, a weather model developed from current data from weather buoys moored in the Pacific is shown here: Weather Model - North Pacific Surface Pressure and Wind StormCast Coming Soon!: With the deployment of the Tidal Current Generator in the spring of 2006, a set of sensors for environmental monitoring will also be deployed. Included will be a Wave-height determination, so the swells from energy in the Pacific will be able to be detected and presented here in graphical form in real time...More Later!
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