shallow southern extension of Hudson Bay, located between northern Ontario and Quebec, Canada. Generally less than 200 feet (60 m) deep, the bay is 275 miles (443 km) long and 135 miles (217 km) wide and contains numerous islands, all of which are administered by the Northwest Territories. Akimiski, the largest island, has an area of 1,159 square miles (3,002 square km). The many rivers that flow into James Bay, including La Grande, Eastmain, Rupert, Broadback, Nottaway, Harricana, Moose, Albany, Attawapiskat, and Ekwan, are responsible for its low salinity. Among the chief settlements on the bay's forested shores are the trading posts of Fort-George, Nouveau-Comptoir, Eastmain, Fort-Rupert, Lake River, Attawapiskat, Fort Albany, Moose Factory, and Moosonee (the northern terminus of the Ontario Northland Railway). Visited in 1610 by the English navigator Henry Hudson, the bay was named after Captain Thomas James, who explored it in 1631.