The Bay of Fundy () is a bay between the Canadian provinces of New Brunswick and Nova Scotia, with a small portion touching the U.S. state of Maine. It is an arm of the Gulf of Maine. Its tidal range is the highest in the world. The name is probably a corruption of the French word , meaning 'split'.
Hydrology
Tides
The tidal range in the Bay of Fundy is about ; the average tidal range worldwide is only . Some tides are higher than others, depending on the position of the moon, the sun, and atmospheric conditions. Tides are semidiurnal, meaning they have two highs and two lows each day, with about six hours and 13 minutes between each high and low tide.
Because of tidal resonance in the funnel-shaped bay, the tides that flow through the channel are very powerful. In one 12-hour tidal cycle, about 100 billion tons (110 billion short tons) of water flows in and out of the bay, which is twice as much as the combined total flow of all the rivers of the world over the same period. The Annapolis Royal Generating Station, a 20 MW tidal power station on the Annapolis River upstream of Annapolis Royal, was, until its shutdown in 2019, one of the few tidal generating stations in the world, and the only one in North America.
Most of the rivers have a tidal bore, a wave front of the incoming tide that "bores" its way up a river against its normal flow. Notable ones include those on the Petticodiac, Maccan, St. Croix, and Kennetcook rivers. Before the construction of a causeway in 1968 and subsequent siltation of the river, the Petitcodiac River had one of the world's largest tidal bores, up to high. Since the opening of the causeway gates in 2010, the bore has been coming back, and in 2013 surfers rode it a record-breaking .
Other phenomena include the Reversing Falls near the mouth of the Saint John River, a rip tide at Cape Enrage, and the Old Sow whirlpool at Passamaquoddy Bay.
Geology
The story of the Fundy Basin begins about 200 million years ago in the early Jurassic, when all land on earth was part of a supercontinent called Pangaea. At that time what is now the Maritimes was situated near the equator and had a warm tropical climate and lush vegetation. As continental drift reshaped the world, rift valleys formed, including the Cobequid–Chedabucto fault system.
During the continental breakup, magma erupted as basaltic lavas and left igneous rock formations such as the columnar jointing which can be seen on Brier and Grand Manan islands, among other places around the bay. These flows often are the sites of rarer mineral deposits including agate, amethyst, and stilbite, the latter being the provincial mineral of Nova Scotia.
These rifts filled with sediment which became sedimentary rock. Many fossils have been found along the Fundy shoreline. The oldest dinosaur fossil in Canada was found at Burntcoat Head. Very early reptiles have been discovered in Carboniferous tree trunks at Joggins. Wasson Bluff has a rich trove of Jurassic fossils.
The bay is a member of the Global Geoparks Network, a UNESCO initiative to promote and conserve the planet's geological heritage.
Flora and fauna
Although some land areas are protected, there is no formal marine protection zone in the bay. The Conservation Council of New Brunswick works to protect the ecosystem of the bay. A result of shipping traffic has been the potential for increased collisions between ships and the critically endangered North Atlantic right whale. In 2003, the Canadian Coast Guard adjusted shipping lanes crossing prime whale feeding areas at the entrance to the Bay of Fundy to lessen the risk of collision. Many other marine mammals are found in the bay including fin whales, humpback whales, minke whales, Atlantic white-sided dolphin and the harbour porpoise.
The Bay of Fundy mudflats are a rare and unique intertidal habitat. Major mudflats are found on around the Maringouin Peninsula which lies between Shepody Bay and the Cumberland Basin and at the northern end of Chignecto Bay. On the Nova Scotia side, mudflats are found on the southern side of the Minas Basin and in Cobequid Bay. In the Minas Basin, the size of the mudflats from low to high water marks is as much as . Due to tidal turbulence, the water in these area contains very high amounts of fine sediment, source from tidal erosion of Carboniferous and Triassic sedimentary rock. Primary producers include hollow green weed, phytoplankton, algae, and sea lettuce.