North in the Spring #31: The Salish Sea - Part One by John Neville The Salish Sea is a region,“where the grass grows in January and the airways and waterways run together in a near constant interchange of water and mist.” Robert Michael Pyle This huge estuary is named to honour the Coast Salish People. It is separated from the Pacific Ocean by the Olympic Peninsula in the State of Washington and Vancouver Island in British Columbia. The distance from Campbell River in the north to Olympia in the south,is about 400km. Because of the islands and many inlets, the coastal shoreline is about 7600km long. The broad Strait of Juan de Fuca connects the Salish Sea to the Pacific Ocean. The daily tide flows in through the strait with a rise of 3 4m. The delayed smaller secondary tide arrives around the northern end of Vancouver Island and in through the Broughton Archipelago. This giant estuary or inland sea has been created by movement of the Pacific and Juan de Fuca Tectonic Plates pressing against the North American Plate. Many of the tall mountain features have guided the Coastal Salish People for millennia. For example Mt Baker, Kwelshanexw, an ancient volcano, is 3,200m high in Washington and can be seen easily from Vancouver Island on a clear day! Fresh water flows in from many rivers, 80% of which is from the mighty Fraser. About 3.475 cubic m/sec of water descend the Fraser Canyon into the estuary. The river flow deposits 20 million tons/annum of silt and nutrients. Because fresh water is less dense than salt water, it stays on the surface and flows out through the Strait Juan de Fuca. The out-flow of fresh water on the surface draws deeper, cooler,nutrient laden water in from the deep ocean. The tidal currents mix the rich soup of nutrients. The Salish Sea is often referred to as the Emerald Sea because the multitude of Phytoplankton, which produce chlorophyll, giving the water its greenish hue. Phytoplankton are technically plants and carry out about half of the world's Photosynthesis, taking up carbon and producing oxygen in our atmosphere and oceans! The next step of the food chain is the Zooplankton, tiny animals such as Krill, which feed on Phytoplankton. Other microscopic organisms such as Copipods(which are crustaceans) and Diatoms(algae) also occupy the lower part of the food chain. These minute organisms,the size of dust motes, feed small fish, filter feeding shellfish, up to the size of Basking Sharks and Baleen whales. In the intertidal zone of some beaches, during the summer breeding season, a mysterious humming sound can be heard that reminds me of a BC ferry hooter. It is the mating call of alpha male Plainfin Midshipman Fish*. This natural playground attracts many of us to experience nature. Whales are possibly the most ionic species. We have enjoyed close-ups of Southern Killer Whales many times. Unfortunately, decline in Chinook Salmon means that these whales have become rare, not Resident, in B.C. waters. However, Gray and Hump-backed are returning in greater numbers. My daughter's family were recently rafting their kayaks off Bowen Island when an amazing experience began. Bubbles and small fish started appearing 3m away. Then, in a vertical posture, out came the head of a Hump-back whale towering over them! If it had moved it's pectoral fin they would have been swamped! A nervous grandson muttered, "do they eat humans?". The Salish Sea provides habitat for many species: 36 mammal, 172 bird, 235 fish, and more than 3000 invertebrate! The Coastal Temperate Rainforest around the Salish Sea includes Red Cedar, Douglas Fir, Maple, Western Hemlock, Dogwood, Arbutus, Gary Oak, Pacific Willow, Ocean Spray, Salal, Sword Fern etc. Birds and animals take Salmon into the forest where their remains provide fish fertilizer to the plants. For millennia Coast Salish people lived in harmony with these natural riches, but now human numbers are booming, close to 9 million, with the densest populations around Seattle and Vancouver creating pressure on the natural world. In the summer issue of this magazine, I will describe how life forms exploded in a shallow North American sea, now part of the Rockies. In the Fall issue, we'll cover some of the diverse life forms in our Salish Sea today, reflecting the Cambrian Explosion. * The mating call of alpha male Plainfin Midshipman Fish. Check out https://www.youtube.com/watch?v=2j1rZU5opJ8