Currents flowing through the Gulf of Maine influence the underwater landscapes. Currents bring well-mixed, nutrient-rich water to the shores of the Gulf, where it supplies food to filter-feeding creatures, fertilizes kelp, and acts as a larval superhighway for species such as lobsters. Surface water completely circles the Gulf of Maine in three months, traveling approximately seven nautical miles a day. Driven by a cold current off the Nova Scotia coast — which enters the Gulf of Maine over Brown Bank and through the Northeast Channel — the Gulf's surface waters move in a counterclockwise pattern. This giant "gyre" gains momentum from the world's most powerful tidal surges released from the Bay of Fundy, and from the fresh water that flows into the Gulf from the major rivers of its watershed.