The effect of new breaching in a Prudhoe Bay causeway on the coastal distribution of humpback whitefish

West Dock is a solid-gravel petroleum production causeway 4.3 km long that was constructed along the Beaufort Sea coast near Prudhoe Bay, Alaska, in t he late 1970s. In the winter of 1995-96, a breach 200 m wide was constructe d 1 km from the base of the causeway. Fish monitoring studies conducted dur ing the summers of 1996 and 1997 indicated that the catch of adult (greater than or equal to 200 mm fork length) humpback whitefish (Coregonus pidschi an) had increased significantly east of West Dock relative to levels observ ed in the 11 previous years. Data suggest that humpback whitefish dispersin g eastward along the coast from their overwintering grounds in the Colville River had been blocked from moving east of West Dock and that construction of the breach has allowed these fish to extend their summer foraging range farther to the east.