Science & Data

Underwater noise survey

The northern fur seal (Callorhinus ursinus) population in the Pribilof Islands Archipelago (on St. Paul and St. George Islands, Figs. 1-3) constitutes roughly half of the world population. Other breeding colonies are located on the Kuril and Commander Islands in Russia, Bogoslof Island (Fig. 4) in the southeastern Bering Sea, and on San Miguel Island (Fig. 5) off California. The rookeries at San Miguel and Bogoslof Islands probably originated in the late 1950s (DeLong 1982) and 1980 (R.R. Ream, NMML-AFSC, pers. comm.), respectively.

Aerial survey of the beluga population in upper Cook Inlet, Alaska, August 16-17, 2006 to document whale groups via video for an analysis of age structure.

This report describes field activities and data analyses for aerial surveys of bowhead whales (Balaena mysticetus) conducted during fall 2006 (2 September – 16 October), fall 2007 (3 September – 10 October), and fall 2008 (5 September – 18 October) in the Beaufort Sea, between 140°W and 158°W, south of 72°N and north of the Alaskan coastline.

National Oceanic and Atmospheric Administration Administrative Order 216-6 (NAO 216-6) (May 20, 1999) contains criteria for determining the significance of the impacts of a proposed action. In addition, the Council on Environmental Quality regulations at 40 C.F.R. §1508.27 state that the significance of an action should be analyzed both in terms of "context" and "intensity." Each criterion listed below is relevant to making a finding of no significant impact and has been considered individually, as well as in combination with the others. The significance of this action is analyzed based on the NAO 216-6 criteria and CEQ's context and intensity criteria.

The National Marine Fisheries Service (NMFS) has conducted aerial surveys of the beluga population in Cook Inlet, Alaska, each June and/or July since 1993. Results from 1993 to 2000 were published in Rugh et al. (2000a). The current document is a collection of field reports for the subsequent years, from 2001 to 2004.

The northern fur seal (Callorhinus ursinus) population in the Pribilof Islands Archipelago (on St. Paul and St. George Islands, Figs. 1-3) constitutes approximately 55% of the world population. Smaller breeding colonies are located on the Kuril and the Commander Islands in Russia, Bogoslof Island (Fig. 4) in the southeastern Bering Sea, and San Miguel Island (Fig. 5) off California. The rookeries at San Miguel and Bogoslof Islands probably originated in the late 1950s (DeLong 1982) and 1980 (R.R. Ream, pers. comm.), respectively.

The National Marine Fisheries Service (NMFS) conducted aerial surveys of the beluga whale (Delphinapterus leucas) population in Cook Inlet, Alaska, almost monthly between June 2001 and June 2002. The surveys were flown in a twin-engine, high-wing aircraft at an altitude of 244 m (800 ft) and speed of 185 km/hour (100 kt). Tracklines were approximately 1.4 km offshore, and systematic transects were made across the inlet, covering much of upper Cook Inlet. These methods were consistent with NMFS= abundance surveys conducted each June or July since 1993, except that only in June were there multiple surveys (repeat samplings) within a block of days. During the 2001­ 02 monthly surveys, aerial counts of belugas (median counts when more than one observer was counting) generally stayed high from June through October (n = 211 in June, 39 and 152 in July, 205 in August, 185 in September, 162 in October, respectively), but counts dropped from November to April (n = 24 in November, 15 in January, 0 in February, 18 in April, respectively) before rising again the following June (n = 192). Low counts in winter were probably due to ice in the inlet, making it hard to see the white whales. This study provides evidence of the presence of belugas in upper Cook Inlet in nearly every month of the year, but it is not clear what proportion of the population remains in the upper inlet year-round.

The northern fur seal population in the Pribilof Islands Archipelago constitutes roughly 70% of the world's population with an estimated 919,000 northern fur seals in 2000. Smaller breeding colonies are located on the Kuril Islands in Japan, the Commander Islands in Russia, Bogoslof Island in the southeastern Bering Sea, and San Miguel Island off California. The rookeries at Bogoslof and San Miguel probably originated in 1982 and the late 1950s, respectively.

Between 1911 and 1984, northern fur seal (Callorhinus ursinus) research was conducted by Canada, Japan, Russia, and the United States under the Treaty for the Preservation and Protection of Fur Seals and Sea Otters. Since 1984, studies have been carried out independently by former member nations.