GORGE WATERWAY INITIATIVE infosheet

WORKING TOGETHER TO BALANCE CONSERVATION, RECREATION AND COMMUNITY VALUES [email protected] • www.gorgewaterway.ca

E STUARIES: WHERE FRESH WATER MEETS THE SEA Driving along the Trans-Canada Highway or on Gorge Road, many residents and visitors to Victoria are unaware that the adjacent bodies of water — Portage Inlet and the Gorge Waterway — form a saltwater arm of the ocean called an estuary. The semi-protected waterway is a regionally distinct coastal feature that supports highly productive estuarine habitats and a unique array of important marine life.

I MPORTANT INTERFACE is very shallow. At low tides, large

Estuaries are formed when fresh mud flats are exposed such as in Jody Watson water mixes with salt water in a Portage Inlet near the mouth of Eelgrass meadows in the Gorge partially enclosed body of water. Craigflower Creek. At high tides, that supply a diversity of food Estuaries comprise only 2.3 per cent shoreline tidal marshes are sources and habitats to support a of British Columbia’s coastline but inundated with salt water. large array of fish, birds and other play a very significant role in the The constantly moving, nutrient- wildlife species. ecology, which is why they are often rich waters, especially in the Three significant habitat types referred to as the “nurseries of the Gorge, provide lots of food and occur in the waterway — tidal sea.” Protecting estuarine habitat in excellent habitat for dense colonies marshes and meadows, mudflats, the waterway is a very high priority. of sponges, anemones, sea squirts and eelgrass beds. and other marine animals that filter food from the water. Tidal marshes and meadows T IDES OF TIME Historically, most of the shores of Most of the waterway is calm and the Gorge and Portage Inlet were protected but in the Gorge V ARIETY OF SPECIES lined with wetlands known as tidal Narrows, the rocky opening under AND HABITATS marshes and meadows. Because the Gorge Bridge, the currents are Gorge Waterway and Portage Inlet, these wetlands occur in the very strong at certain times of the like most estuaries, are very intertidal zone, they are the most tidal cycle, sometimes reaching as productive ecosystems. The vulnerable areas of the estuary. much as eight knots. waterway is constantly being Long-term disturbance of the The tides of the Gorge Waterway supplemented with sediments from shoreline and filling and building and Portage Inlet have a profound inflowing streams and rivers, which walls and other structures has effect on the physical habitat, the become trapped by vegetation such significantly impacted this valuable visual appearance, and the biology as eelgrass. habitat. Shoreline tidal marshes act of the waterway. Tidal variations The sediments provide a home for as a natural buffering system, prevent appear quite extreme because much plants, algae, bottom-dwelling erosion, and play a key role in the of the area, especially Portage Inlet, worms, clams and other species biological productivity of the area. Today, tidal meadows and marshes maintain your septic system. are mostly restricted to around the These actions will help stop mouths of incoming creeks that polluted water from entering the drain into the waterway. Both stormdrains and the waterway Colquitz River and Craigflower where it causes poor water quality. Creek, which empty into Portage • Use best practices to reduce the Inlet, have these important areas impact of shoreline structures associated with their outflows. on habitat. Mud flats • Estuary plants are very sensitive to At low tide, some of the mud trampling and can be destroyed Jody Watson substrate of the Gorge becomes Portage Inlet mud flats when walked on. Be aware of exposed. These mud flats have large where you or your dog are populations of clams, burrowing Overharvest, pollution, and walking and stay on existing worms and other invertebrates that competition from larger introduced pathways and trails. provide a significant food source for oysters, have led to a decline in • Try to navigate watercraft away birds. One of the largest of these populations in other parts of BC, from resting waterfowl and mud flats is at the mouth of and federal scientists have declared sensitive waterway vegetation such Craigflower Creek. the native oyster a “species of special concern.” as eelgrass and sensitive marsh Eelgrass Meadows habitats to minimize damage to Extensive beds of this marine plant Native oysters are filter feeders and these habitats and disturbance to are found throughout the Gorge and help keep the water clear, but this the species that inhabit them. also makes them very susceptible to Portage Inlet. These are the most • Support local government initiatives abundant populations of eelgrass contaminants from land-based activities. Historically, the oysters to upgrade failing storm and found anywhere in the greater sanitary sewer infrastructure to Victoria area. were an important food for local First Nations. They are also eaten by minimize pollution to the waterway. Eelgrass is a perennial plant that has birds and larger mollusks. dark green, ribbon-like leaves and tiny, L EARNING MORE rarely seen flowers. It grows near the low-tide line in up to six metres of H OW CAN YOU HELP Learn more about the significance of water, sometimes deeper in clear water. PROTECT THE ESTUARY? the Gorge and Portage Inlet by visiting the GWI website or consult the online Young salmon and cutthroat trout People can do many things to help Harbours Atlas (www.harboursatlas.ca). find food and shelter, and herring protect the estuary habitats: use eelgrass for shelter and spawning. • Ensure that sediment from land- The best way to find out more about Birds such as great blue herons often based construction activities is the waterway is to join a local natural feed in eelgrass and others such as contained to prevent it from history group, come out to one of the American Wigeon actually feed on entering nearby streams or the GWI public talks, or check out your the eelgrass. waterway where it can smother local library or bookstore for more information on estuaries. Eelgrass helps prevent erosion by vegetation and clog the gills of fish. anchoring shifting sands and • A naturally vegetated shoreline For more information on the dampening the force of waves. helps to filter pollutants from Gorge Waterway Initiative: surface water flowing into the Email: [email protected] estuary, protects the soil from S PECIAL OYSTERS Phone: 360-3065 eroding, and provides habitat for Website: Small native or Olympia oysters are a fish and other wildlife. very significant feature of the www.gorgewaterway.ca waterway in the sub-tidal zone — • Take measures to reduce or avoid the use of lawn and garden This GWI Infosheet is one in a series on the natural and below the lowest tides. The Gorge cultural features of the Gorge Waterway, Portage Inlet population of these oysters is pesticides and synthetic fertilizers, and surrounding watersheds probably the largest remaining on properly recycle and dispose of oil, Funding for this info sheet provided by City of Victoria, the West Coast. paints and other chemicals, and Township of Esquimalt and the CRD May 2007