Anthropogenic Sources

Subsistence Harvest

Alaska Natives harvested CI belugas for cultural, subsistence, and handicraft purposes prior to and after passage of the MMPA in 1972. The effect of past harvest practices on the CI beluga population is significant, particularly the harvests of the mid-to late-1990s. While harvests occurred at traditional (but undocumented) levels for decades, the subsistence harvest removals apparently increased substantially beginning in the 1980s, with unsustainable removals in the 1990s (Figure 14) (CIMMC [Cook Inlet Marine Mammal Council] 1996, 1997; Mahoney and Shelden 2000; Angliss et al. 2001; Angliss and Lodge 2002; National Oceanic and Atmospheric Administration [NOAA] 2007; NMFS AKR, unpub. data).

CIB subsistence harvest
Figure 14. Summary of reported CI beluga subsistence harvests and estimated numbers struck and lost, 1987 to 2016. Source: Angliss and Lodge 2002; CIMMC 2007; NMFS 2008b; NMFS AKR, unpub. data.

This increase in harvest numbers may have been the result of an increased Alaska Native population in the Cook Inlet region, with new participation by hunters who previously lived in areas without a traditional history of hunting in the Inlet.

A study conducted by ADF&G, in cooperation with the Alaska Beluga Whale Committee and the Indigenous People’s Council for Marine Mammals, estimated the subsistence take of belugas in Cook Inlet in 1993 at 17 whales. In consultation with Native Elders from the Cook Inlet region, the CIMMC estimated the annual number of belugas taken by subsistence hunters during this time to be over 30 per year. However, without a complete survey of hunters, this most likely is a minimum estimate (Hill and DeMaster 1998; DeMaster 1995). There was no systematic CI beluga harvest survey in 1994; instead, harvest data were compiled at the November 1994 Alaska Beluga Whale Committee meeting. The most thorough CI beluga subsistence harvest surveys, including struck and lost estimates, were completed by CIMMC during 1995 and 1996 (CIMMC 1996, 1997; Angliss and Lodge 2002). While there was no survey during 1997 or 1998, NMFS estimated the subsistence harvest from hunter reports. The known annual subsistence harvest by Alaska Natives during 1995 to 1998 averaged 77 belugas per year which, in combination with struck and lost estimates, can account for the estimated population decline during this interval (Figure 14). The harvest was sufficiently high to account for the nearly 50% total decline in the population during the period from 1994 through 1998 (Hobbs et al. 2000). Hunters have described harvest numbers and effort in the late 1980s as similar to the 1990s (B. Mahoney, NMFS AKR, pers. comm.). If subsistence takes prior to 1994 were at levels approaching those recorded in the mid-1990s that potentially unsustainable level of take could account for the CI beluga decline from 1,300 whales to 653 whales from 1979 to 1994.

In 1999 and 2000, Public Laws 106–31 and 106–553, established a requirement that hunting of CI belugas for subsistence uses by Alaska Natives must be conducted pursuant to cooperative agreements between NMFS and the affected Alaska Native organizations. A voluntary moratorium by hunters in 1999 resulted in no CI beluga harvest that year. During 2000 to 2003 and 2005 to 2006, NMFS entered into co-management agreements for the CI beluga subsistence harvest, limiting harvest to one or two belugas per year starting in 2000. From 2000 to 2006, subsistence harvests were 0, 1, 1, 1, 0, 2, and 0 belugas, respectively. There has been no subsistence harvest of CI belugas after 2005.

Commercial Whaling

A brief commercial whaling operation existed along the west side of upper Cook Inlet during the 1920s, where 151 belugas were killed in five years (Mahoney and Sheldon 2000). There was also a recreational hunt for belugas in Cook Inlet prior to enactment of the MMPA (Mahoney and Shelden 2000). The potential impacts of these pre-MMPA hunts on the present status of this stock cannot be determined.

Poaching or Intentional Harassment

Due to their approachable nature, the potential for poaching belugas in Cook Inlet exists. NOAA Law Enforcement has investigated several incidents of reported harassment of CI belugas, and as of September 2016, there has been one civil conviction of harassment (L. Cockreham, NOAA, Office of Law Enforcement, pers. comm.). There are reports and photographs of CI belugas with wounds consistent with harpoon or gunshot trauma (McGuire et al. 2011), but these animals have not been examined further, and no poaching incidents have been confirmed.

Incidental Mortalities or Injuries

The following section discusses mortalities or injuries to CI belugas incidental to the associated human activity. In this context, “incidental” refers to the death or injury (to include entanglement) of animals where death or injury was not intended. Activities with the potential to cause incidental injury or death include fisheries activities, vessel activities, or research projects. There is also documented evidence of CI belugas being entangled in marine debris. This section does not consider injuries that may occur as a result of noises associated with human activities. Those are discussed separately.

Fisheries activities: NMFS has only documented one CI beluga whale mortality associated with personal use, subsistence, or recreational fisheries (see Burek-Huntington et al. 2015). In May 2012, a yearling CI beluga carcass was recovered from a 60 ft subsistence set net with 8 inch mesh located approximately 1–2 miles south of the Kenai River. Histopathological analysis of tissues indicated cause of death was most likely drowning. However, this animal also suffered from severe bronchopneumonia, and it appeared unusually small for its age. The whale may have been unable to extract itself from the net when an otherwise healthy individual may have escaped. While there have been other sporadic reports over the years of single belugas becoming
entangled in fishing nets, mortalities were not confirmed.

The only other reports of fatalities of CI belugas incidental to fishing in Cook Inlet are from the literature. Murray and Fay (1979) stated that commercial salmon gillnet fisheries in Cook Inlet caught five belugas in 1979. Burns and Seaman (1986) estimated incidental take rates by commercial salmon gillnet fisheries in the Inlet at 3–6 belugas per year during 1981 to 1983. Neither report, however, differentiated between set gillnet and drift gillnet fisheries.

NMFS placed observers in the Cook Inlet salmon drift net and upper and lower Inlet set gillnet fisheries in 1999 and 2000 (Angliss and Lodge 2002, Manly 2006). During the two years of observations, an estimated total of 384 net-days were observed for the drift gillnet fishery, and an estimated 614 net days were observed for the set gillnet fishery. Only three sightings of belugas were made at set gillnet locations in upper Cook Inlet (Moore et al. 2000). Although one harbor porpoise was reported dead in the Upper Cook Inlet driftnet fishery, belugas were never observed within 10 m (32.8 ft) of a net (i.e., within a distance categorized as an interaction) in the drift or set gill net fisheries; therefore, no beluga injuries or mortalities were reported from drift or set gillnets in either 1999 or 2000 (Manly 2006). The most likely impacts from personal use, subsistence, recreational, and commercial fisheries include disturbance from the operation of watercraft in stream mouths and shallow waters, ship strikes, displacement from important feeding areas, harassment, and prey competition.

Vessel activities: Ship strikes have not been confirmed, but could not be ruled out in CI beluga deaths caused by trauma. For example, in September 2007, a dead beluga was found to have a wide, blunt trauma along the right side of its chest (NMFS AKR unpub. data). While a cause of the trauma was not determined, it may have been caused by the animal being hit by a boat or other watercraft (e.g., jet ski). Additionally, there are reports and photographs of CI belugas with scarring patterns consistent with propeller injuries (McGuire et al. 2011).

Research activities: Passive research with a low potential to affect CI belugas may include aerial surveys, shore-based observations, passive acoustic studies (non-tagging), prey studies, habitat studies, pathology and disease studies on dead animals, and contaminant studies. Other research may change the behavior of, harass, injure, or kill belugas. Such activities include capturing belugas, applying satellite tags, applying suction cup dive tags, taking blood and biopsies from live animals, and any boat or in-water work that changes whale behavior or movements. Between 1999 and 2002, NMFS researchers captured and affixed satellite tags to a total of 18 CI belugas. In 2002, data from one satellite-tagged CI beluga indicated a weak swim pattern for 32 hours post-tagging; the whale was found floating dead a short time later and was positively identified by a fin tag. The beluga’s belly-up position while floating prevented detection of satellite tag transmissions. Two other satellite-tagged whales captured during the same season exhibited similarly weak swim patterns prior to the loss of the satellite tags’ signals less than 48 hours post-tagging. These whales were not found, but were presumed to have died less than 54 hours after tagging. While the available data do not conclusively point to the cause of death of these three belugas, NMFS concluded the most apparent explanation is that they died as a result of the capture and tagging activities (NMFS, unpub. data).

Photo-identification studies by McGuire et al. (2013) reported identification of seven individual belugas with scarring due to satellite tags, providing evidence that at least seven of the previously tagged CI belugas survived at least four years after the tagging event, with five of the seven whales re-photographed in 2011 (McGuire et al. 2013). Five of these seven whales are presumed to be females based on close associations with calves (McGuire et al. 2013).

Marine debris: There have been reports of CI belugas alive, but entangled in marine debris. In 2005, a CI beluga was photographed in Eagle Bay, entangled in an unknown object, perhaps a tire rim or a culvert liner (McGuire et al. 2013). In 2010, 2011, 2012, and 2013, another CI beluga was repeatedly photographed with what appeared to be a rope entangled around the upper portion of its body near the pectoral flippers (McGuire et al. 2014a, 2014b). NMFS determined that attempts to disentangle the whale were not warranted because there was no apparent physical injury due to its entanglement, and the benefit of disentanglement did not outweigh the harassment-induced risks that such an operation would posed to that and other whales.