Esquimalt Harbour

Eelgrass 

Esquimalt Harbour has very little eelgrass, with only about 0.5 ha spread out over several small locations. Eelgrass was likely much more extensive prior to the industrial activity in the harbour, but dredging, log booming and infilling of the foreshore has undoubtedly had a major impact on eelgrass distribution and survival. As eelgrass provides critical habitat for juvenile fish such as salmon and herring, as well as a multitude of other forms of marine life, it is vital to protect and enhance the few remaining pockets that persist here. 

Estuary and mudflats 

Millstream watershed drains into Esquimalt Harbour. This watershed is located along the eastern flanks of the Gowlland Tod range in the Highlands, and also includes urbanized areas in Langford and Colwood. 

The Millstream Creek estuary and mudflat is an important feeding area for birds, providing a valuable source of worms, shellfish and other mudflat-dwelling organisms. The extensive mudflats here are home to a variety of intertidal clams that once were an important food source for First Nations people of the area. The harbour is currently closed for clam harvesting due to sanitary contamination and concerns about the potential impact of contaminated marine sediments on human health. 

High Current Areas 

Esquimalt Harbour does not have many areas of high currents, adding high ecological value to the few that do occur there. Paddy Passage and the channel between Smart and McCarthy Islands are two such high current areas, where sponges, tube worms and bryozoans are common. 

Kelp Beds 

The more wave-exposed rocky outcrops near the harbour mouth support dense kelp beds dominated by sugar kelp and five-rib kelp. Dense but less diverse kelp beds occur around Smart and McCarthy Islands and along the shoreline between Yew Point and Rodd Point. 

Canopy forming kelp beds are rare, but a small bed of bull kelp is located on Whale Rock, the largest subtidal rock outcrop in the harbour. 

Learn more: Subtidal Survey of Physical and Biological Features of Esquimalt Harbour [PDF/5.1MB] 

Since the 1800’s Esquimalt Harbour has been home to many different industrial activities including shipbuilding and repair, coal storage, shipping, sawmills and gristmill. Chemical wastes from these industries were historically washed directly into the harbour. New technologies are now used to minimize and eliminate pollution to the harbour, but sediment contamination remains a concern. Extensive log booms used to supply local sawmills throughout most of the 1900’s have also had serious ecological impact on the harbour. Today, wood and logging debris such as cable and chain blanket about 16% of the harbour seabed. Masses of wood waste radically alter the chemical and physical nature of the seabed, smothering bottom-dwelling organisms and creating sulfide-rich anoxic conditions during the decomposition of the debris. 

The Department of National Defence (DND) has initiated an extensive contaminated sites remediation and monitoring program, and many of the historically contaminated sites have now been remediated. 

In 2013, DND created three nearshore reefs in Esquimalt Harbour to offset any future sub-marine works that may occur near their jetties. Each reef is composed of large boulders and about 20 m x 40 m in size. It is estimated that the reefs will create about 11,000 m² of rocky reef habitat, providing substrate and cover for invertebrates, seaweeds and fish. 

• Size (total area): 342.7 ha 
• Total length of shoreline: 19,997m (excluding islands) 
• Depth of harbour (maximum): 16m (at harbour entrance) 
• Creeks that flow into the harbour: Millstream Creek 
• Number of stormwater discharges: 97 
• Protected areas: Duntz Head Rockfish Conservation Area 
• Species at risk: Northern abalone, southern resident killer whales, great blue heron