A generally shallow depth causes strong tidal currents, water turbulence and a high concentration of suspended red silt and clay, which led early French colonists to name the strait "la mer rouge." Shallowness is also largely responsible for the warmest summer water temperature in eastern Canada (July, 20°C or higher) and a consequent concentration of summer tourist activity, as well as a prolific shellfish and lobster fishery. Equable climate and extensive tillable soils form the basis for mixed agriculture and vegetable growing (particularly POTATOES) on both coasts.
The strait is crossed by a ferry from Caribou, NS, to Wood Islands, PEI. Canada's longest bridge (12.9 km), Confederation Bridge, links Prince Edward Island to New Brunswick. It opened in 1997 replacing a ferry that ran between Cape Tormentine, NB and BORDEN-CARLETON, PEI. The strait's coastal areas were settled by ACADIAN French from the early 16th century, and by English, LOYALISTS and SCOTS in the 18th century. The principal coastal cities and towns are CHARLOTTETOWN and SUMMERSIDE, PEI; PICTOU, NS; and SHEDIAC, BOUCTOUCHE and Richibucto, NB. The strait was named for HMS Northumberland, flagship of Admiral Colville.