Grand Manan’s isolation has resulted in a far greater diversity of marine mammals and bird species than land animals. The Grand Manan Archipelago one of North America’s top ten birdwatching locations.
Migrating whales – fin, minke and humpback – abound. Harbour porpoise and white-sided, and white beaked dolphin may sometimes be seen, and occasionally large fish, including basking sharks and bluefin tuna, put in an appearance. Birding is a year round past time, with thousands of seabirds – common murres, razorbills and kittiwakes – seen just offshore during the winter months; the spring migratory period is the best time for visiting birds, followed by the summer nesting season and the autumn migratory period, when many shorebirds and phalaropes return from nesting in high Arctic regions.
Whale watching tours also double as pelagic–species watching trips, with the seabirds crowding the whales' feeding grounds, and on shore there are numerous shore lookouts, from prominent headlands. The area east of Grand Manan, including the Grand Manan Basin, is important to right whales in the Bay of Fundy, and was established as the North Atlantic Right Whale Critical Habitat in 2009, as part of the Species at Risk Act, to provide additional protection for endangered North Atlantic right whales.
From spring to early autumn Grand Manan’s fields are awash with wildflowers and the island also has an impressive diversity of seaweeds, many of which are edible.