Diet of Beluga Whales, Delphinapterus Leucas, in Alaska from Stomach Contents, March–November

Diet of Beluga Whales, Delphinapterus leucas, in Alaska from Stomach Contents, March–November

LORI T. QUAKENBUSH, ROBERT S. SUYDAM, ANNA L. BRYAN, LLOYD F. LOWRY, KATHRYN J. FROST, and BARBARA A. MAHONEY

Introduction (Frost and Lowry, 1990; Richard et al., Beluga whales in Alaska appear to 2001), and were later confi rmed ge- follow one of two life history strate- At least fi ve stocks of beluga netically (O’Corry-Crowe et al., 1997, gies: migratory and nonmigratory. Mi- whales, Delphinapterus leucas, oc- 2002, 2010). The distribution of be- gratory stocks use shallow nearshore cur in the waters of Alaska (Fig. 1). luga whales in Alaska is discontinu- and deepwater offshore habitats (Haz- These stocks were tentatively iden- ous from Yakutat Bay1, 2 to Cook Inlet ard, 1988; Frost and Lowry, 1990), and tifi ed by their summer distributions to Bristol Bay. The entire area from include the eastern Chukchi Sea stock Bristol Bay northward and eastward to (population size ~4,000 (Allen and Lori T. Quakenbush is with the Alaska Depart- Canada is used by belugas; the Bering Angliss, 2011)) and the Beaufort Sea ment of Fish and Game, 1300 College Road, and Chukchi seas are used year-round or Mackenzie stock (population size Fairbanks, AK 99701 (e-mail: lori.quakenbush@ alaska.gov). Robert S. Suydam is with the De- and the Beaufort Sea is used in sum- ~39,000 (Harwood et al., 1996; Allen partment of Wildlife Management, North Slope mer (Frost and Lowry, 1990). and Angliss, 2011)). Borough, P. O. Box 69, Barrow, AK 99723. Anna L. Bryan is with the Alaska Department of Nonmigratory stocks use shallow, Fish and Game, 1300 College Road, Fairbanks, 1There is a small group of <20 belugas that ap- estuarine habitats year-round and in- AK 99701. Lloyd F. Lowry and Kathryn J. Frost pear to be resident in Yakutat Bay, a deepwater clude the Bristol Bay and Cook Inlet are at 73-4388 Pa’iaha Street, Kailua Kona, HI fi ord (Laidre et al., 2000; Allen and Angliss, 96740-9311. And Barbara A. Mahoney is with 2011) stocks. The Bristol Bay population the Alaska Regional Offi ce, National Marine 2O’Corry-Crowe, G., W. Lucey, C. Bonin, E. Hen- is increasing (Lowry et al., 2008) Fisheries Service, NOAA, 222 W. 7th Ave., #43, niger, and R. Hobbs. 2006. The ecology, status and is estimated to be ~3,000 (Al- Anchorage, AK 99513-7577. and stock identify of beluga whales, Delphinap- terus leucas, in Yakutat Bay, Alaska. Rep. to U.S. len and Angliss, 2011). Local sight- doi: dx.doi.org/10.7755/MFR.77.1.7 Mar. Mamm. Comm., NMFS-YSB-YTT, 22 p. ings and satellite telemetry confi rm that belugas occur in Bristol Bay in all months of the year (Harrison and Hall, 1978; Frost and Lowry, 1990; ABSTRACT— At least fi ve stocks of belu- (60% FO) and smoothskin octopus, Ben- Lensink3; Quakenbush and Citta4; ga whales, Delphinapterus leucas, are found thoctopus leioderma (42% FO) were found 5 in Alaska waters: Beaufort Sea, eastern more frequently. Although the eastern Chuk- Quakenbush ). Chukchi Sea, eastern Bering Sea, Bristol chi Sea stock ate more saffron cod, Eleginus The population in Cook Inlet is es- Bay, and Cook Inlet. The two northernmost gracilis (7% FO) than Arctic cod (3% FO), timated to be 312 whales and appears stocks (Beaufort Sea and eastern Chukchi shrimp (73% FO) and echiurids (27% FO) to be decreasing at 1.6% per year Sea) are highly migratory; the two south- were more prevalent than fi sh. The eastern ernmost stocks (Bristol Bay and Cook Inlet) Bering Sea stock had the most diverse diet, (Hobbs et al., 2015). The population are nonmigratory. Little is known about the and dominant fi sh species included saffron declined dramatically between 1994 seasonal movements and distribution of the cod (95% FO), rainbow smelt, Osmerus and 1998 (Hobbs et al., 2000) and the eastern Bering Sea stock. Beluga popula- mordax (62% FO), several species of scul- stock was determined to be depleted tions in Alaska are thought to be stable or pin (Family Cottidae) and fl atfi sh (Family increasing, except for the Cook Inlet stock Pleuronectidae), both at 48% FO, and Arc- under the Marine Mammal Protection which is listed as endangered under the En- tic cod at 43%. Dominant invertebrates in- Act in 2000 (NOAA, 2000); the origi- dangered Species Act. cluded shrimp (86% FO), with polychaetes, nal cause of the decline is believed We analyzed stomach contents from be- isopods, bivalves, amphipods, and echiurids to be overharvest. Between 1999 and luga whales collected between the months of ranging from 29 to 38% FO. Pacifi c salmon, 2006 the harvest was restricted to fi ve March and November taken in subsistence Onchorhyncus spp., predominated over cod harvests, from belugas found dead, and from in Bristol Bay (81% FO) and Cook Inlet 3Lensink, C. J. 1961. Status report: beluga stud- belugas collected for research. We describe (67% FO) beluga stocks, and invertebrates ies. Alaska Dep. Fish Game, Juneau. Unpubl. prey species and their percent frequency of appeared to be less prevalent prey. In Bristol rep., 38 p. occurrence (% FO) as well as potential bi- Bay, smelt were also eaten more often (43% 4Quakenbush, L., and J. Citta. 2006. Fall move- ases from the seasonality of prey relative to FO) than cod (3% FO), while in Cook Inlet ments of beluga whales captured in the Nush- the timing of sampling, and differential feed- cod were eaten more often (39% FO) than agak River in September 2006. Unpubl. rep. to ing and digestion. Diet was highly variable smelt (11% FO). Invertebrates were common Alaska Beluga Whale Committee, P.O. Box 69, among stocks. The predominant fi sh species in the diet of all Alaska beluga stocks and Barrow Alaska 99723, 9 p. of the Beaufort Sea stock was Arctic cod, Bo- shrimp (mostly from the family Crangoni- 5Quakenbush, L., Alaska Dep. Fish Game, 1300 reogadus saida (21% FO), although shrimp dae) were the most prevalent. College Road, Fairbanks. Unpubl. data.

70 Marine Fisheries Review belugas, and after 2006 no harvest and Game (ADFG) reports (Brooks7, 8; sink3; Vania10; Lowry et al.11; and has been allowed. Lensink3; Klinkhart9; Vania10) and by ADFG13). We assigned each beluga In October 2008, the Cook Inlet Frost et al. (1984). to a stock based on collection timing beluga whale population was listed Information collected since Seaman and location (Fig. 1). Collections were as endangered under the Endangered et al. (1982) from Kotzebue Sound is made between March and November. Species Act (NOAA, 2008). Aerial provided in an unpublished report by Stomachs and stomach contents surveys (1994–2011) and satellite te- Lowry et al.11 Based on traditional were handled in several ways: 1) stom- lemetry (1999–2002) have shown that ecological knowledge, Huntington et achs were collected whole and frozen, Cook Inlet beluga whales remain in al. (1999) described the diet of belu- 2) stomach contents were removed and the Cook Inlet area all year (Rugh gas in the nearshore areas of the east- frozen, or 3) stomach contents were et al., 2000, Hobbs et al., 2005). Ex- ern Bering Sea, Kotzebue Sound, and removed and placed in 10% forma- cept for Cook Inlet belugas, the other the eastern Chukchi Sea to include lin. In the laboratory, contents were four beluga stocks in Alaska contin- a variety of prey items, but primar- weighed to the nearest 0.1 g and then ue to be harvested for subsistence by ily fi sh. Cook Inlet beluga prey have rinsed with fresh water on a 1.0 mm coastal indigenous people and har- been indirectly described by relat- sieve stacked on a 0.5 mm sieve. For vests are sustainable (Allen and An- ing whale movements to seasonal frozen whole stomachs, all parts of the gliss, 2011). The Beaufort Sea stock fi sh runs in a publication on tradi- stomach were opened and rinsed over is also harvested in Canada during tional ecological knowledge from the sieves so that all otoliths, fi sh bones, summer; most of the Alaska harvest beluga hunters of Cook Inlet (Hun- and cephalopod beaks that tend to ad- of this stock occurs during the spring tington, 2000) and in published and here to the stomach lining were col- migration. unpublished reports (Fall et al., 1984; lected. In some cases, incomplete The eastern Bering Sea beluga Hobbs et al.12). stomachs or a subsample of contents stock is found in the Yukon-Kuskok- This paper provides: 1) an updat- were collected, and in other cases prey wim Delta area and in Norton Sound ed description of the diet of beluga items were identifi ed visually in the in summer. Aerial surveys conducted whales in Alaska using identifi able fi eld without collecting the stomach; there provide a population estimate prey items found in their stomachs be- these were noted by individual beluga of ~18,000 (Allen and Angliss, 2011). tween 1954 and 2012, and 2) a com- in the database. Prey items were sorted The winter range of the eastern Ber- prehensive description of diet from into major taxonomic groups and iden- ing Sea stock is unknown; therefore stomach contents of Cook Inlet beluga tifi ed to the lowest taxonomic level. it is not known whether this stock is whales. Fish were tabulated by counting migratory. whole fi sh when present and by add- Methods Throughout their range, belugas ing the maximum count of left or right feed on a variety of fi sh and inverte- Data included in this study came otoliths plus half of the count of oto- brates, often on prey that form con- from the stomachs of beluga whales: liths that could not be identifi ed as centrations such as schooling fi sh and 1) harvested for subsistence, 2) found left or right. Lengths of otoliths that shrimp (Seaman et al., 1982). Be- dead, and 3) collected for published did not appear degraded were mea- luga whale diet has been described (Frost et al., 1984) and unpublished sured to the nearest 0.1 mm. Otolith in Canada (Doan and Douglas, 1953; ADFG diet studies (Brooks7, 8; Len- lengths were converted to fi sh lengths Sergeant, 1973; Vladykov6), Rus- using conversion equations (e.g., Frost sia (Kleinenberg et al., 1964; Tomlin, 7Brooks, J. W. 1954. Beluga. In 1954 Annual and Lowry, 1981; Seaman et al., 1982; 1967), and Svalbard and northwestern Rep., Alaska Dep. Fish Game, Juneau, p. 51–57. Harvey et al., 2000) when possible. Europe (Lono and Oynes, 1961). In 8Brooks, J. W. 1955. Beluga. In 1955 An- Converted lengths are considered nual Rep., Alaska Dep. Fish Game, Juneau, p. Alaska, information on beluga whale 98–106. minimum lengths because erosion of diet is limited to one published pa- 9Klinkhart, E. G. 1966. The beluga whale in the otoliths caused by digestion is ex- per by Seaman et al. (1982) describ- Alaska. Alaska Dep. Fish Game Rep., 11 p. pected to decrease otolith length and ing stomach contents from 119 beluga 10Vania, J. 1967. Beluga. In 1966 Annual Rep., because some equations are known to whales from six locations in the Ber- Alaska Dep. Fish Game, Juneau, p. 21–24 have poor correlations (Harvey et al., ing and Chukchi seas but none from 11Lowry, L. F., K. J. Frost, and G. A. Seaman. 2000). 1986. Investigations of belukha whales in coast- Cook Inlet. Additional Bristol Bay al waters of western and northern Alaska. Part Cephalopods were identifi ed by diet information was recorded in un- III. Food habits. Final Rep. U.S. Dep. Com- their beaks (Clarke, 1986). We used published Alaska Department of Fish mer. NOAA, Anchorage, from Alaska Dep. Fish the maximum count of upper or lower Game, 24 p. beaks to determine the number con- 12Hobbs, R. C., K. E. W. Shelden, D. J. Vos, K. T. Goetz, and D. J. Rugh. 2006. Status review sumed. The lower beak hood lengths 6Vladykov, V. D. 1946. Etudes sur les mam- and extinction assessment of Cook Inlet belugas miferes aquatiques. IV. Nourriture du marsouin (Delphinapterus leucas). U.S. Dep. Commer., bloc ou beluga (Dephinapterus leucas) du fl euve NOAA, Natl. Mar. Fish. Serv., Alaska Fish. Sci. 13Alaska Dep. Fish Game. Unpubl. data on fi le Saint-Laurent. Dep. Pech., Quebec, 129 p. Cent. Proc. Rep. 2006-16, 74 p. at 1300 College Road, Fairbanks, AK 99701.

77(1) 71 Figure 1.—Known summer areas used by fi ve stocks of beluga whales in Alaska and the area within Kotzebue Sound where stock assignment is unclear. Belugas from the Beaufort Sea stock are harvested at Diomede and Point Hope while on spring migration and harvested in Canada in summer.

were measured to the nearest 0.1 mm tifi cations Inc.14, Victoria, British Co- and then calculated the percentage of and used to estimate cephalopod total lumbia, Canada. No invertebrate prey the total represented by each taxon. body weight using an equation for a items were recorded or identifi ed. For example, if we estimated 100 in- closely related species, Octopus vul- We present fi sh prey in beluga stom- dividual fi sh from fi sh taxon A (e.g., garis (Clarke, 1986). achs as the percent number (% N) of saffron cod, Eleginus gracilis) and 300 For 17 stomachs from Cook In- fi sh by taxon by beluga whale stock. fi sh from all fi sh taxa in all stomachs let beluga whales between 1992 and We determined the total number of sampled from that beluga stock, then 2001, only a subsample of the stom- fi sh identifi ed in all fi sh taxa for all the % N of taxon A (saffron cod) for ach contents was collected, and only stomachs of that stock of beluga whale that stock was 100/300 or 33%. For fresh or slightly digested material was invertebrates, % N was not calculated identifi ed. Few otoliths were recorded because we often could not determine 14Mention of trade names or commercial fi rms in these samples, but, diagnostic bones does not imply endorsement by the National the number of individuals from the of fi sh were identifi ed by Pacifi c Iden- Marine Fisheries Service, NOAA. parts available.

72 Marine Fisheries Review The percent frequency of occur- Table 1.—Number of stomachs analyzed from Alaska’s beluga whales belonging to fi ve stocks and from a Kotze- rence (% FO) is provided for all ma- bue Sound population collected between 1954 and 2012. jor prey types and was calculated for Number of Stomachs each stock as the number of stom- Stock ID Total Empty (%) Month Range of years No. of years achs containing that prey type divided Beaufort Sea 62 0 (0) 4–6 1983–2003 5 Eastern Chukchi Sea 67 37 (55) 6–8 1983–2010 13 by the total number of stomachs that Kotzebue Sound 29 7 (24) 6,7,10 1982–2008 3 contained any prey. For example, if Eastern Bering Sea 39 7 (18) 5–7,9,10 1993–2012 12 Bristol Bay 115 14 (12) 5–8,10 1954–2011 11 100 stomachs contained prey of any Cook Inlet 53 17 (32) 3–11 1961, 1992–2010 17 kind and 75 of those stomachs con- Total 365 82 (22) 3–11 1954–2012 30 tained parts of echiurid worms, the % FO of echiurids would be 75%. Due to differential digestion rates, volume some of them may have been from Theragra chalcogramma, and saffron measurements were not considered other stocks. cod, which were similar in estimated representative of the true volume of For all locations in Alaska, a mini- length at 10.7 cm (range 8.2–12.3) and prey consumed and were not analyzed. mum total of 37 fi sh species and 40 10.3 cm (range 7.6–16.3), respectively. invertebrate species were identifi ed in Pacifi c sand lance, Ammodytes hexa- Results beluga whale stomachs (Table 2, 3). pterus, were the smallest with a mean Our dataset includes 365 beluga Other species may have been pres- length of 9.9 cm (range 8.1–11.3; Ta- whale stomachs, 233 of which had ent that we were not able to identify. ble 5). never been reported before, and 132 Nonfood items included sand, pebbles, Most stomachs (n = 57; 92%) con- from unpublished ADFG reports. wood and other vegetation, kelp, feath- tained invertebrates that represented Stomachs from the ADFG studies in- ers, and a piece of bone. 16 species from multiple taxonomic cluded 22 collected in 1982 at El- groups: predominately shrimp (60% Beaufort Sea Stock ephant Point (Eschscholtz Bay) in FO), cephalopods (52% FO), echiurids Kotzebue Sound (Lowry et al.11) and We analyzed stomach contents from (19% FO), and amphipods (11% FO; 109 collected in Bristol Bay during 62 beluga whales from the Beaufort Table 3). Shrimp included at least fi ve 1954 and 1955 (Brooks7, 8), 1965 and Sea stock collected between 1983 and species from at least three families. 1966 (Vania10), and in 1982 and 1983 2003 at Point Hope and Diomede (Ta- All cephalopods were octopus (n = (Frost et al., 1984), and one collected ble 1). All were collected during April, 358), 266 (74%) of which were identi- in Cook Inlet (Baxter and Baxter15). May, and June. Sex was reported for fi ed as smoothskin octopus, Benthoc- Of the 365 stomachs, 82 were emp- all but one (19 males and 42 females) topus leioderma (Table 3). Three that ty (22%) or contained only nonfood and length was reported for all but were not identifi ed to species were of items and 283 (78%) contained prey two. The mean length for males was the same genus and 89 were only re- remains (Table 1). 355 cm (range 203–462) and for fe- corded as octopus. The number of oc- Stomachs were collected from Cook males 332 cm (range 240–396) (Table topus per stomach ranged from 0 to Inlet to Barrow from 217 beluga 4). Twenty-one stomachs (34%) con- 144 individuals, with two stomachs whales harvested for subsistence, 102 tained a minimum total of 418 fi sh of having >100 lower or upper octopus collected for research, 41 found dead, at least eight different species from beaks each. Based upon 35 measurable and for 5 animals for which the type fi ve families (Table 2). The predomi- beaks of 107 beaks present in a beluga of death was not recorded. Most of the nant species was Arctic cod, Boreoga- stomach harvested near Point Hope in whales found dead were in Cook Inlet dus saida, which comprised 82% N 1997, the average estimated weight per (n = 30; 73%). and 21% FO (Table 2) and one stom- octopus was 1,015 g (SD = 442, range Prior to 1982, beluga whales regu- ach contained otoliths from 190 Arctic 140–1,965). The average estimated larly occurred and were harvested in cod. Forty-one stomachs (66%) con- weight per octopus, calculated from Kotzebue Sound. After 1982, occur- tained only invertebrates. 50 of 144 octopus beaks in a beluga rence became irregular and infrequent, Otoliths from six fi sh species were whale harvested near Little Diomede and it is not known to what stock these measured to estimate the sizes of fi sh in 2003, was 881 g (SD = 415, range belugas belonged. For this study, we eaten. The largest fi sh were Arctic 155–1,965). considered stomachs collected from staghorn sculpin, Gymnocantheus tri- Eastern Chukchi Sea Stock belugas in Kotzebue Sound to be Kot- cuspis, with an estimated mean length zebue Sound belugas, even though of 17.9 cm (range 16.1–18.9), followed Stomachs from 67 beluga whales by shorthorn sculpin, Myoxocephalus from the eastern Chukchi Sea stock scorpius, at 16.2 cm (range 12.1–18.5; were collected between 1983 and 2010 15Baxter, R., and S. Baxter. 1961. Cook In- Table 5). Arctic cod were next in es- (Table 1). Most (58 or 87%) were col- let data report series 61-1, stream surveys west side Cook Inlet –1961. Alaska Dep. Fish Game, timated length (mean 14.2 cm, range lected near Point Lay during June Homer, 43 p. + 10. 8.2–21.2) followed by walleye pollock, and July, and most (37 or 55%) were

77(1) 73 Table 2.—Percent number and percent frequency of occurrence of fi sh identifi ed from stomach contents of beluga whales collected in Alaska by location, 1954–2012. Per- cent number is the number of fi sh from a taxa divided by the total number of all fi sh eaten (x 100). Percent frequency of occurrence is the number of stomachs that con- tained a fi sh taxon divided by the total number of stomachs that contained prey (x100).

1983–2003 1983–2010 1982–2008 1993–2012 1954–2005 2002–2010 Beaufort E. Chukchi Kotzebue E. Bering Bristol Bay Cook Inlet Percent Percent Percent Percent Percent Percent Percent Percent Percent Percent Percent Percent number frequency number frequency number frequency number frequency number frequency number frequency n = 21 n = 62 n = 9 n = 30 n = 21 n = 22 n = 21 n = 21 n = 99 n = 100 n = 17 n = 18 Stomachs that contained fi sh (%) 34 30 95 100 99 94 Taxon Stomachs that contained only fi sh (%) 8 7 5 10 76 50 Fishes All Petromyzontidae, lamprey spp. <1 19 <1 3 Arctic lamprey, Lethenteron camtschaticum <1 19 All Clupeidae <1 5 1 24 Pacifi c herring, Clupea pallasii <1 5 1 24 All Catostomidae 1 6 Longnose sucker, Catostomus catostomus 1 6 All Osmeridae <1 2 7 3 3 55 14 67 16 43 12 11 Pond smelt, Hypomesus olidus <1 1 Rainbow smelt, Osmerus mordax 7 3 3 55 13 62 2 5 Eulachon, Thaleichthys pacifi cus 12 11 Capelin, Mallotus villosus <1 24 All Salmonidae <1 10 83 81 38 67 Dolly Varden, Salvelinus malma <1 1 Pink salmon, Oncorhynchus gorbuscha <1 18 Coho salmon, Oncorhynchus kisutch <1 5 <1 10 21 28 Chinook salmon, Oncorhynchus tshawytscha <1 3 2 11 Chum salmon, Oncorhynchus keta <1 5 <1 15 8 17 Sockeye salmon, Oncorhynchus nerka 58 55 All Gadidae 86 23 40 13 95 95 78 100 <1 3 42 39 Arctic cod, Boreogadus saida 82 21 7 3 – – 29 43 Saffron cod, Eleginus gracilis 1 5 20 7 94 95 48 95 <1 2 26 22 Walleye pollock, Theragra chalcogramma 3 3 <1 10 10 17 Pacifi c cod, Gadus macrochephalus 1 6 All Gasterosteidae, stickleback spp. <1 2 <1 3 All Cottidae 9 5 1 9 4 48 <1 6 1 6 Arctic staghorn sculpin, Gymnocanthus tricuspis 1 3 <1 5 Sculpin species, Hemilepidotus spp. <1 5 Pacifi c staghorn sculpin, Leptocottus armatus 1 6 Belligerent sculpin, Megalocottus platycephalus <1 19 Shorthorn sculpin, Myoxocephalus scorpius 7 3 <1 14 Sculpin species, Myoxocephalus spp. <1 14 Ribbed sculpin, Triglops pingelii <1 5 Sculpin species, Triglops spp. 3 5 All Agonidae, poachers <1 5 All Liparidae <1 14 Variegated snailfi sh, Liparis gibbus <1 14 All Zoarcidae 13 3 <1 5 Canadian eelpout, Lycodes polaris 13 3 <1 5 All Stichaeidae <1 5 <1 38 1 7 1 6 Stout eelblenny, Anisarchus medius <1 5 Slender eelblenny, Lumpenus fabricii <1 5 <1 38 Slender eelblenny or snake prickleback, Lumpenus spp. 1 6 All Ammodytidae 3 8 13 3 <1 5 <1 24 Pacifi c sand lance, Ammodytes hexapterus 3 8 13 3 <1 5 <1 24 All Pleuronectidae 2 48 <1 10 3 11 Pacifi c halibut, Hippoglossus stenolepis <1 5 Flathead sole, Hippoglossoides elassodon <1 5 Starry fl ounder, Platichthys stellatus 1 6 Northern rock sole, Lepidopsetta polyxystra <1 14 Unidentifi ed rock sole, Lepidopsetta spp. <1 1 Longhead dab, Limanda proboscidea <1 29 Yellowfi n sole fl ounder, Limanda aspera 2 11 Arctic fl ounder, Pleuronectes glacialis <1 14 All Unidentifi ed fi sh 1 5 27 13 <1 14 <1 3 2 11 Minimum no. of fi sh species eaten (total = 37) 8 5 6 25 14 12 Minimum no. of fi sh eaten 418 15 1,354 5,781 26,721 106

empty. The other nine stomachs were Chukchi Sea belugas (Fig. 1; Richard families (Table 2), and 15 species of from belugas harvested near Barrow in et al., 2001; Suydam et al., 2001). invertebrates from nine taxonomic June, July, and August, none of which Sex was known for all 67 belu- groups were identifi ed (Table 3). Of were empty. Although it is not entirely gas; 36 were males and 31 were fe- the 30 stomachs that contained food clear whether belugas near Barrow in males (Table 4). Mean body length items nine (30%) contained fi sh for summer belong to the Beaufort Sea or for males (n = 26) was 390 cm which the most prevalent species was eastern Chukchi Sea stock, movements (range 280–478) and for females (n saffron cod (7% FO). from satellite telemetry data suggest = 25) was 349 cm (range 253–410). Otoliths from three fi sh species were they are more likely to be eastern At least fi ve species of fi sh from four measured to estimate the sizes of fi sh

74 Marine Fisheries Review Table 3.—Percent frequency of occurrence of invertebrates identifi ed from stomach contents of beluga whales collected in Alaska by location, 1954–2012. Percent frequen- cy of occurrence is the number of stomachs that contained an invertebrate taxon divided by the total number of stomachs containing prey (x100).

Percent frequency of occurrence 1983–2003 1983–2010 1982–2008 1993–2012 1954–2005 2002–2010 Beaufort E. Chukchi Kotzebue E. Bering Bristol Bay Cook Inlet n = 62 n = 30 n = 22 n = 21 n = 100 n = 18 Stomachs containing invertebrates (%) 92 93 95 90 24 50 Taxon Stomachs containing only invertebrates (%) 66 70 5 0 1 6 Invertebrates All Porifera 5 5 6 All Polychaeta 5 17 38 11 Polynoidae 7 24 Nereididae, Nereis spp. 7 10 Pectinariidae 5 All Bivalvia 5 33 3 Astartidae, Astarte spp. 5 Myidae 5 Clinocardiinae, Serripes groenlandicus 5 Tellinidae, Tellina spp. 5 All Cephalopoda 52 10 5 10 Squid, Gonatus spp. 3 Minimum number of squid 3 Octopus 42 7 5 Benthoctopus leioderma, smoothskin octopus 8 3 Benthoctopus spp. 2 Minimum number of octopi 358 4 1 All Gastropoda 7 36 10 Polinices spp. 27 All Cirripedia, barnacles 2 All Mysidae 14 24 6 Mysis oculata 24 Neomysis rayii 19 6 Neomysis spp. 14 All Isopoda 3 36 38 4 Saduria entomon 18 33 3 Saduria spp. 3 18 1 All Amphipoda 11 7 41 29 11 Ampeliscidae, Ampelisca spp. 2 Byblis spp. 3 Lysianassidae, Orchomene spp. 6 Uristidae, Anonyx spp. 2 Senticaudata Anisogammaridae, Anisogammarus pugettensis 2 Calliopiidae 3 Gammaridae 3 14 5 Gammarus spp. 2 3 27 19 Melitidae, Melita spp. 5 All shrimp 60 73 86 86 21 39 Caridea 3 29 17 Hippolytidae 2 Eualus spp. 2 Crangonidae 8 30 19 Argis dentata 3 Argis lar 3 3 5 Argis spp. 13 30 Crangon alaskensis or septemspinosa 32 29 6 Crangon franciscorum 6 Crangon spp. 11 59 10 2 6 Sclerocrangon boreas 2 23 5 Pandalidae, Pandalus spp. 3 All crabs 2 3 14 1 6 Majidae 5 1 Oregoniidae, Chionoecetes bairdi 6 Chionoecetes opilio 3 Hyas lyratus 2 All Sipuncula 3 All Echiuridae 19 27 5 29 6 All Bryozoa 10 Clypeasteroida, sand dollar 2 All Ascidiacea, tunicates 7 14 Chelysoma spp. 3 Pelonaia corrugata 7 5 All unidentifi ed invertebrates 3 10 6 Minimum no. of species eaten (t otal = 40) 16 15 9 22 4 8

eaten. The largest fi sh were saffron two Canadian eelpout, Lycodes polar- Of the 30 stomachs that contained cod with an estimated mean length of is, were also measureable, but because food items, 21 (70%) contained only 13.6 cm (range 6.5–20.7), followed by no size or weight conversions have invertebrates (Table 3). Shrimp oc- Pacifi c sand lance at 10.1 cm (range been developed for this species, fi sh curred most often (73% FO), followed 9.7–10.5; Table 5). The otoliths from size could not be estimated (Table 5). by echiurid worms (27% FO), poly-

77(1) 75 chaetes (17% FO), and cephalopods Table 4.—Sex and body length for some Alaska beluga whales belonging to fi ve stocks and from a Kotzebue (10% FO). Sound population analyzed for stomach contents collected between 1954 and 2012. Se x Male body length (cm) Female body length (cm) Between 1989 and 2010, 13 of 28 Stock n; mean (SD) n; mean (SD) stomachs (46%) were reported to Location Male Female Unknown range range contain sand or “mud balls” but no Beaufort 19 42 1 19; 355 (68.7) 41; 332 (32.0) Pt. Hope, Diomede 203–462 240–396 food. Whether the mud was ingested Eastern Chukchi 36 31 0 26; 390 (49.5) 25; 349 (30.9) incidentally or intentionally is un- Barrow, Pt. Lay 280–478 253–410 Kotzebue 14 13 2 3; 304 (44.7) 5; 346 (27.5) known; however, stomachs with food Escholtz Bay, Kotzebue 257–345 297–363 usually had only minor amounts of Eastern Bering 14 14 11 13; 389 (66.2) 9; 351 (66.9) Elim, Koyuk, Unalakleet, 279–475 238–414 nonfood items like sand and wood. In Hooper Bay 2012, we examined stomach contents Bristol Bay 31 55 27 29; 333 (78.6) 47; 317 (49.2) 187–470 193–387 from two of the belugas harvested Cook Inlet 20 21 10 8; 391 (72.7) 15; 337 (67.1) at Point Lay on 30 June 2009 where 256–463 160–391 the contents appeared to be mostly fi ne grain sand; however, we found evidence of both fi sh and inverte- ly but only two had contents. The only were collected between 1993 and 2012 brate prey. The fi rst stomach was that stomach with prey in 2007 contained during May (n = 17), June (n = 7), July of a white female and contained 3.9 a single gastropod operculum. The one (n = 1), September (n = 2), October kg of sand and parts of 63 tunicates stomach collected in 2008 contained (n = 9), and month unknown (n = 3). (3 Pelonaia corrugate, 10 Chelysoma both fi sh and invertebrates. Seven of the 39 (18%) stomachs, six spp., and 50 unidentifi ed to species), Of the 22 stomachs from Kotzebue of which were collected in mid-June parts of at least 53 shrimp (all from with food, 21 contained fi sh (Table 1995, were empty (Table 1). Of 28 be- the family Crangonidae, including 26 2). At least six species of fi sh were lugas where sex was known, the sex Sclerocrangon boreas), and 11 poly- identifi ed representing six families. ratio was even at 14 each. Body length chaetes (8 Nereis spp. and 3 from Saffron cod (95% FO) and rainbow of 13 males averaged 389 cm (range the family Polynoidea). The second smelt, Osmerus mordax, (55% FO) 279–475), and nine females averaged stomach, that of a white-gray male, were most prevalent, followed by 351 cm (range 238–414) (Table 4). contained 2.1 kg of sand, and parts sculpins (9% FO). Pacifi c sand lance; Stomachs from 11 beluga whales of 17 tunicates (7 Pelonaia corru- Pacifi c herring, Clupea pallasii; and harvested near Elim in 1996 were only gate, and 10 unidentifi ed), at least 15 slender eelblenny, Lumpenus fabricii, visually inspected and are not includ- crangonid shrimp (including 5 Sclero- were each represented at 5% FO (Ta- ed in Tables 2 or 3: those stomachs crangon boreas), and 4 otoliths; two ble 2). Saffron cod were also numeri- contained saffron cod, and one also each from saffron cod and Pacifi c cally dominant; 1,279 of 1,354 (94% contained rainbow smelt. One of the sand lance. It is possible that stom- N) total fi sh eaten were saffron cod 11 stomachs (9%) contained inverte- achs visually inspected in the past (Table 2). brates, which were only identifi ed as and thought to contain only mud balls Otoliths from 23 saffron cod were shrimp. also contained invertebrates and oto- measured to estimate the average fi sh Of the 21 stomachs with food that liths mixed with the mud. length at 23.8 cm (range 7.4–41.9; Ta- were fully analyzed all contained cod: ble 5). One otolith from a Pacifi c sand saffron cod (95% FO), Arctic cod Kotzebue Sound lance provided a length estimate of (43% FO), and walleye pollock (10% We analyzed stomach contents from 15.0 cm and two otoliths from rainbow FO; Table 2). In addition to cod, the 29 beluga whales harvested in Kotze- smelt estimated fi sh lengths at 12.2 cm overall fi sh diet by % FO included bue Sound; 22 were harvested in June (range 11.1–13.2). One otolith from a rainbow smelt (62%), several species 1982 (two (9%) were empty), six were slender eelblenny was measured but of fl ounder and sculpin (both at 48%), harvested in July 2007 (fi ve (83%) no conversion was available. slender eelblenny (38%), Pacifi c sand were empty), and one was harvested in All but one stomach with food con- lance; capelin, Mallotus villosus; and October 2008 (with food) (Table 1). Of tained invertebrates (n = 21; 95%); in- Pacifi c herring (all at 24%); Arctic 27 belugas where sex was known, 14 cluding at least nine species. Shrimp lamprey, Lethenteron camtschaticum were males and 13 were females. Body was the dominant group (86% FO) (19%); snailfi sh (14%); and two spe- lengths of three males averaged 304 followed by amphipods (41% FO); cies of salmon (coho, Oncorhynchus cm (257, 310, and 345 cm) and fi ve gastropods and isopods were repre- kisutch; and chum, O. keta, each at females averaged 346 cm (range 297– sented equally at 36% FO (Table 3). 5%). Nine stomachs contained evi- 363) (Table 4). In 1982, stomach con- dence of >100 individual saffron cod tents were identifi ed and counted only Eastern Bering Sea Stock (range 121–474). Overall, a minimum from subsamples. For the more recent Stomach contents from 39 belu- of 25 species of fi sh from 12 families stomachs, all were analyzed complete- gas from the eastern Bering Sea stock were identifi ed (Table 2).

76 Marine Fisheries Review Table 5.—Mean, standard deviation (SD), and range of otolith lengths (mm), fi sh length (cm), and weight (g) of fi sh collected from beluga whale stomachs. Fish length and weight were converted from equations or measured directly from whole fi sh.

Mean otolith length in Mean fi sh length in Mean fi sh weight in Fish Beluga stock n mm (SD) range cm (SD) range g (SD) range Source of equation Clupeidae Pacifi c herring E. Bering 18 4.9 (0.5) 24.1 (2.8) 228.6 (85.5) Harvey et al., 2000 4.0–5.8 19.1–28.5 99.4–388.3 Osmeridae Pond smelt Bristol Bay 2 2.7 (0.4) No conversion available 2.4–3.0 Rainbow smelt Kotzebue 2 4.4 (0.6) 12.2 (1.5) 14.1 (5.6) Harvey et al., 2000 4.0–4.8 11.1–13.2 10.1–18.0 E. Bering 233 5.0 (1.0) 13.9 (2.8) 24.6 (19.1) Harvey et al., 2000 2.0–9.5 5.7–25.9 1.1–162.6 Bristol Bay 6 5.0 (1.8) 13.7 (5.0) 27.0 (15.7) Harvey et al., 2000 1.4–6.2 4.1–17.0 0.4–41 Bristol Bay 2 19.6 (2.8) 67.3 (30.1) Length measured 17.6–21.5 46.0–88.6 Weight Harvey et al., 2000 Bristol Bay 1 53.1 (NA) Measured Eulachon Cook Inlet 4 4.3 (0.3) 17.4 (1.2) 51.2 (10.5) Harvey et al., 2000 3.9–4.5 15.7–18.5 36.4–60.6 Capelin E. Bering 5 2.5 (0.3) 12.4 (0.9) 15.6 (4.0) Harvey et al., 2000 2.3–3.0 11.6–14.0 12.3–22.4 Salmonidae Coho salmon Cook Inlet 10 4.9 (0.2) 4.5–5.2 Cook Inlet 3 62.1 (2.6) 3,124 (357) Measured 58.3–64.1 2,747–3,476 Chum salmon Cook Inlet 4 5.4 (0.2) 5.2–5.5 Cook Inlet 5 60.0 (3.8) 2,989 (600) Measured 56.0–65.0 2,275–3,661 Sockeye salmon Bristol Bay 2 5.4 (1.6) 64.4 (13.4) 3,478 (2,493) Measured 4.3–6.5 54.9–73.8 1,715–5,240 Gadidae Arctic cod Beaufort 84 5.9 (1.3) 14.2 (2.9) 24.6 (16.0) Frost and Lowry, 1981 3.0–8.9 8.2–21.2 2.8–78.3 E. Bering 467 5.9 (0.5) 14.5 (1.0) 21.5 (5.3) Frost and Lowry, 1981 4.7–7.3 11.9–17.6 10.5– 41.4 Saffron cod Beaufort 4 5.9 (2.2) 10.3 (4.0) 9.7 (12.4) Frost and Lowry, 19811 4.4–9.1 7.6–16.3 2.6–28.2 E. Chukchi 2 7.4 (5.1) 13.6 (10.0) 30.5 (40.7) Frost and Lowry, 19811 3.8–11.0 6.5–20.7 1.7–59.3 Kotzebue 23 12.1 (5.2) 23.8 (11.3) 151.6 (142.7) Frost and Lowry, 19811 4.3–20.1 7.4–41.9 2.4–522.7 E. Bering 558 10.3 (2.2) 19.3 (4.8) 56.9 (41.7) Frost and Lowry, 19811 4.9–17.6 8.4 – 36.0 3.7–329.2 Bristol Bay 1 4.2 (NA) 7.2 (NA) 2.3 (NA) Frost and Lowry, 1981 Cook Inlet 3 11.5 (3.3) 18.9 (6.2) 77.6 (55.8) Harvey et al., 2000 7.7–13.4 11.8–22.6 13.1–111.3 Walleye pollock Beaufort 3 5.0 (1.0) 10.7 (2.2) 8.1 (4.1) Frost and Lowry, 1981 3.9–5.7 8.2–12.3 3.5–11.3 E. Bering 1 4.2 (NA) 8.9 (NA) 4.5(NA) Frost and Lowry, 1981 Cottidae Arctic staghorn sculpin Beaufort 4 5.6 (0.3) 17.9 (1.2) 56.8 (11.3) Seaman et al., 1982 2 5.1–5.8 16.1–18.9 40.7–66.3 Belligerent sculpin E. Bering 7 6.8 (0.7) 23.0 (2.7) 125.2 (45.0) Seaman et al., 19822 6.2–7.8 20.5–26.9 84.9–194.3 Shorthorn sculpin Beaufort 17 5.1 (0.5) 16.2 (2.0) 43.0 (14.3) Seaman et al., 19822 4.1–5.7 12.1–18.5 17.0–62.1 E. Bering 4 6.1 (0.6) 20.2 (2.3) 83.7 (27.8) Seaman et al., 19822 5.4–6.6 17.3–22.1 50.6–106.8 Stichaeidae Stout eelblenny E. Bering 1 1.4 (NA) No conversions available Slender eelblenny Kotzebue 1 2.2 (NA) No conversions available E. Bering 9 2.5 (0.3) No conversions available 2.1–2.9 Liparidae Variegated snailfi sh E. Bering 2 2.7 (0.1) No conversions available 2.6–2.8 Zoarcidae Canadian eelpout E. Chukchi 2 5.9 (0.5) No conversions available 5.5–6.2 Ammodytidae Pacifi c sand lance Beaufort 3 1.9 (0.4) 9.9 (1.6) 3.9 (1.7) Harvey et al., 2000 1.5–2.3 8.1–11.3 2.2–5.5 E. Chukchi 2 2.0 (0.1) 10.1 (0.6) 4.0 (0.6) Harvey et al., 2000 1.9–2.1 9.7–10.5 3.6–4.5 Kotzebue 1 3.2 (NA) 15.0 (NA) 12.0 (NA) Harvey et al., 2000 E. Bering 1 1.7 (NA) 8.9 (NA) 2.8 (NA) Pleuronectidae Longhead dab E. Bering 3 3.1 (0.6) No conversions available 2.5–3.6 Arctic fl ounder E. Bering 3 4.3 (0.2) 4.1–4.4

1There are two different length regressions in Frost and Lowry (1981) for this species depending on otolith size. 2The length and weight regressions from Seaman et al. (1982) are the same for all Cottidae species.

77(1) 77 The average estimated lengths Table 6.—Number and type of prey identifi ed from stomach contents of fi ve belugas from the eastern Bering Sea of fi sh, from largest to smallest, stock collected in Hooper Bay, Alaska, on 27 October 2012. was Pacifi c herring (24.1 cm, range Beluga stomach 19.1–28.5); belligerent sculpin, Mega- 1 2 3 4 5 Gender Male Female Female Female Female locottus platycephalus (23.0 cm, range Taxon Color White White White-gray White-gray White-gray 20.5–26.9); shorthorn sculpin (20.2 Fishes cm, range 17.3–22.1); saffron cod All Petromyzontidae, lamprey spp. Arctic lamprey, Lethenteron camtschaticum 3 2 2 11 (19.3 cm, range 8.4–36.0); Arctic cod All Osmeridae Rainbow smelt, Osmerus mordax 41 174 128 200 203 (14.5 cm, range 11.9–17.6); rainbow Capelin, Mallotus villosus 4 9 7 1 smelt (13.9 cm, range 5.7–25.9); and All Gadidae Arctic cod, Boreogadus saida 78 347 399 440 380 capelin (12.4 cm, range 11.6–14.0). Saffron cod, Eleginus gracilis 181 242 390 83 147 Walleye pollock and Pacifi c sand lance All Cottidae Sculpin species, Hemilepidotus spp. 1 each had one otolith with an estimated Belligerent sculpin, Megalocottus platycephalus 4 9 4 5 fi sh length of 8.9 cm. Otoliths were Sculpin species, Myoxocephalus spp. 1 2 2 All Liparidae measured for several other species for Variegated snailfi sh, Liparis gibbus 1 4 1 All Zoarcidae which conversions were not available Eelpout species, Lycodes spp. 2 to estimate length (Table 5). All Stichaeidae Stout eelblenny, Anisarchus medius 1 Of the 21 stomachs that contained Slender eelblenny, Lumpenus fabricii 1 1 1 4 1 food items, 19 (90%) contained inver- All Ammodytidae Pacifi c sand lance, Ammodytes hexapterus 1 2 1 2 tebrates. At least 22 species of inver- All Pleuronectidae tebrates were represented, of which Longhead dab, Limanda proboscidea 4 2 2 1 Arctic fl ounder, Pleuronectes glacialis 1 3 shrimp was predominant at 86% FO All Unidentifi ed fi sh 4 followed by polychaetes and isopods Minimum no. of fi sh eaten 305 782 951 749 753 at 38% FO each, then bivalves at 33% Invertebrates All Polychaeta FO, echiurids and amphipods at 29% Polynoidae 18 11 19 8 8 FO each, mysids at 24% FO, crab Nereididae, Nereis spp. 11 2 All Bivalvia 3 and tunicates at 14% FO; gastropods, All Mysidae cephalopods, and bryozoans were each Mysis oculata 1 9 12 10 9 Neomysis rayii 5 3 2 1 represented at 10% FO (Table 3). All Isopoda Saduria entomon 1 3 4 1 1 Three of the belugas, whose stom- All Amphipoda ach contents are included above, were Gammaridea 3 Gammarus spp. 10 5 caught in the same net near Elim, in Melitidae, Melita spp. 1 Norton Sound, on 30 Sept. 2000. One All shrimp Crangon alaskensis or septemspinosa 1 50 60 40 35 was an adult male (357 cm) and two Shrimp spp. 20 were smaller females (238 and 245 All Ascidiacea, tunicates Pelonaia corrugata 1 cm). All three stomachs contained Minimum no. of taxon eaten 13 20 18 18 16 Arctic cod and saffron cod, but the male had also eaten two adult salmon (one coho and one chum); the female stomachs had no salmon but con- vertebrates (Table 6). The sixth stom- The dominant fi sh family was Sal- tained other smaller fi sh (e.g., slen- ach, from the calf, was empty. monidae (81% FO and 83% N), with der eelblenny, smelt, sculpin) and the all fi ve salmon species identifi ed (Ta- larger female’s stomach also contained Bristol Bay Stock ble 2). Sockeye, Oncorhynchus nerka, shrimp and cephalopods. Stomach contents from 115 belu- was the most prevalent species (55% Six stomachs were collected on 27 ga whales from the Bristol Bay stock FO and 58% N) followed by pink, O. Oct. 2012 in Hooper Bay, one white were collected between 1954 and 2011 gorbuscha, (18% FO), chum (15% male and fi ve females (one white, in May (n = 25), June (n = 31), July FO), coho (10% FO), and Chinook, three white-gray, and one dependent (n = 32), August (n = 26), and Octo- O. tshawytscha, (3% FO). Osmeridae, calf). These belugas were part of a ber (n = 1). Of the 115 stomachs, 14 the smelt family, was the only other larger group of about 80 belugas that (12%) were empty (Table 1). Of the prevalent family (43% FO), with rain- hunters noted were after fi sh, possibly 101 stomachs that contained prey bow smelt the majority by species. Al- cod (Simon16). Five of these stomachs 100 (99%) contained fi sh. One beluga though Table 2 shows rainbow smelt contained a wide variety of fi sh and in- stomach from August 2010 was only only representing 5% FO of the 43% visually inspected and is not included FO of all smelt, most smelt were not 16Simon, A., Native Village of Paimiut, P.O. Box in Table 2; this stomach was reported reported by species in the early data. 91, Hooper Bay, AK 99604. Personal observ. to be full of adult coho salmon. It is likely that the majority of these

78 Marine Fisheries Review unidentifi ed smelt were rainbow smelt Stomachs from the earlier time pe- 64.1) in length, and chum salmon av- as they are the predominant species in riod (1992–2001) were collected be- eraged 60.0 cm (range 56.0–65.0) Bristol Bay. Evidence of more than 300 tween April and October; 7 of the 24 (Table 5). Other fi sh in which lengths smelt per stomach was found in seven (29%) were empty. Eulachon, Tha- could be estimated included saffron stomachs (range 368–710 individuals). leichthys pacifi cus, and Chinook cod (18.9 cm, range 11.8–22.6), and Other stomachs with large numbers of salmon were the only prey identifi ed eulachon (17.4 cm, range 15.7–18.5) fi sh included 14 stomachs with >500 to species during this time period. No (Table 5). For three beluga whale salmon smolts (range 531–2,798) and invertebrates were reported in those stomachs that were relatively full when four stomachs with seven or more adult stomachs with prey, however, cursory collected one contained 12 whole coho sockeye salmon (range 7–9). visual inspections could have missed salmon (27.8 kg), the second had fi ve At least 14 different species from invertebrate remains. We believe that whole chum salmon (15.6 kg), and the eight fi sh families were represented invertebrates were part of the diet dur- third had three whole coho salmon and in Bristol Bay beluga stomachs during ing this time period, but they were not two partially digested salmon of un- this time (Table 2). The lengths of two identifi ed or reported. Empty stomachs identifi ed species (15.0 kg). sockeye salmon were measured at 54.9 occurred in summer and fall. Of the 24 Shrimp, polychaetes, and amphi- and 73.8 cm. The lengths of two rain- belugas sampled, 16 belugas were har- pods made up the bulk of the inver- bow smelt were measured at 17.6 and vested, 5 were found dead, and for 3 tebrate prey. Of the 18 stomachs that 21.5 cm, whereas the lengths of six the cause of death was unrecorded. contained prey, 9 (50%) contained rainbow smelt estimated from otoliths Twenty-eight stomachs analyzed eight species of invertebrates, predom- averaged 13.7 cm (range 4.1– 17.0) during 2002–2012 were collected be- inantly shrimp (39% FO), followed by (Table 5). tween March and November. Ten of 28 polychaetes and amphipods, each rep- Of the 101 stomachs that contained stomachs (36%) were empty; one col- resented at 11% FO (Table 3). prey, 24 stomachs (24%) contained in- lected in June, two in August, two in vertebrates from at least four species September, four in October, and one Discussion from four taxonomic groups. Shrimp in November. Of the 18 stomachs with Data Limitations was the most dominant invertebrate food 17 (94%) contained fi sh remains (21% FO), followed by isopods (4% and 9 (50%) contained invertebrates Diet studies using stomach con- FO) and bivalves (3% FO). A few (Tables 2, 3). Three beluga whales tents have well known biases (Tollit et shrimp were identifi ed as crangonids, were harvested, 24 were found dead, al., 2010; Bowen and Iverson, 2012). however, most were recorded only as and for one the type of death was un- Stomach contents represent some por- shrimp (Table 3). recorded. A minimum of 12 fi sh spe- tion of an individual’s most recent cies and 8 invertebrate species were feeding activity. Small and soft parts Cook Inlet Stock identifi ed (Tables 2, 3). digest more quickly and completely A total of 53 stomachs were ana- The 12 fi sh species represented sev- (Sheffi eld et al., 2001), which in our lyzed from Cook Inlet (Table 1); en families (Table 2). Salmon (67% dataset could result in an under-repre- however, stomachs collected between FO), cod (39% FO), smelt (11% FO), sentation of prey such as polychaetes 1992 and 2001 (n = 24) were analyzed and fl ounder (11% FO) were most and salmon smolts. Hard parts (e.g., separately from stomachs collect- prevalent (Table 2). Salmon that could otoliths and cephalopod beaks) can ed between 2002 and 2012 (n = 28). be identifi ed to species included coho remain in the stomach longer and can Contents were only visually inspected (28% FO, 21% N), chum (17% FO, accumulate through several feedings and not quantifi ed during the earlier 8% N), and Chinook (11% FO, 2% (Jobling and Breiby, 1986), which can time period, whereas entire stomachs N). Cod species included saffron cod result in an over-representation of prey were analyzed and all identifi able prey (22% FO, 26% N), walleye pollock such as saffron cod (large otoliths) items enumerated during the later time (17% FO, 10% N), and Pacifi c cod, and octopus (beaks tend to adhere to period. The contents of one stomach Gadus macrochephalus (6% FO, 1% stomach lining and are resistant to di- from one female beluga killed near N). Eulachon (11% FO 12% N) was gestion: Pitcher, 1980; Bigg and Faw- the mouth of the Katnu River in 1961 the only smelt identifi ed, and yellow- cett, 1985). Stomachs collected from was reported by Baxter and Baxter17 fi n sole, Limanda aspera (11% FO, belugas found dead may be less likely to include Dolly Varden, Salvelinus 2% N) and starry fl ounder, Platich- to contain prey than harvested belu- malma; Pacifi c staghorn sculpin, Lep- thys stellatus (6% FO, 1% N) were the gas; if the animals were sick or injured tocottus armatus; “gray sand shrimp” only fl ounders. One longnose sucker, they may not have been feeding nor- (likely a crangonid shrimp species), Catostomus catostomus, was the only mally prior to death. Because most of and other unidentifi able fi sh remains. freshwater fi sh found. the nonharvested belugas came from Only data from complete stomachs Salmon were the largest fi sh eaten Cook Inlet, this concern mostly ap- collected from 2002 to 2012 appear in by Cook Inlet beluga whales. Coho plies to that stock. Tables 2 and 3. salmon averaged 62.1 cm (range 58.3– In addition to biases due to differen-

77(1) 79 tial feeding and digestion, seasonality of fi sh in spring and summer, although Alaska. At the time it was published, of prey (relative to the time of sam- it is not known if other activities take diet data for Cook Inlet belugas were pling), individual prey preferences, precedence over feeding during this not available. Our study identifi ed 34 and perhaps other factors we have not time or how much feeding occurs in fi sh prey to species, one sculpin to identifi ed may also affect results of winter. Most stomachs (66%) collect- genus, Hemilephidotus, and two that diet studies. For example, adult salm- ed from Point Lay (eastern Chukchi could only be identifi ed to family; on runs occur at specifi c times of year, Sea stock) were empty. These belugas Gasterosteidae (sticklebacks), and Ag- and some species are available over were harvested in June and July when onidae (poachers). Fish eaten by belu- a longer period of time than others. migrating, molting, calving, or other gas in our study that were not found Many of the stomachs we examined behavior may have been more impor- by Seaman et al. (1982) included Arc- were from belugas harvested by sub- tant than feeding. Histological studies tic lamprey, pond smelt, Hypomesus sistence hunters. Thus, the timing of of liver and pancreas tissue from be- olidus; eulachon, capelin, fi ve species sample collection was often linked to lugas harvested at Point Lay indicated of Pacifi c salmon, Pacifi c cod, walleye the timing of subsistence activities. that they were likely fasting prior to pollock, poachers, variegated snailfi sh, Depending upon when stomachs are harvest (Woshner, 2000). Belugas may eelblenny, and Pacifi c sand lance. We collected, what is present (or not pres- fast during the annual skin molt. did not identify any whitefi sh, Core- ent) in them will vary. If no stomachs Another reason belugas may have gonus sp., in our study, which were were collected during a particular time empty stomachs, in addition to illness found by Seaman et al. (1982) and by of year, prey species specifi c to that or injury, may be due to the avoid- Huntington (2000). While Seaman et time of year would be missing from ance of marine mammal-eating killer al. (1982) reported the general catego- our analysis. Samples from the subsis- whales, Orcinus orca. Belugas har- ries of fl atfi sh and sculpin as prey; we tence harvest were collected in spring, vested in Kotzebue Sound in July 2007 identifi ed seven fl atfi sh and six sculpin summer, and fall when people hunt, were believed to be avoiding killer to species (Table 2). Two of the spe- and samples from belugas found dead whales because they would not leave cies identifi ed in our study alone were were collected in summer and fall when shallow water even while being ap- found exclusively in Cook Inlet: eula- people are most likely to observe and proached by boats to be hunted; fi ve chon and Pacifi c cod. respond to them. Furthermore, there of six stomachs examined were empty, Although capelin are sometimes appears to be considerable variation in and one contained only one opercu- observed in large concentrations near diet among individuals. For example, lum from a gastropod. Belugas some- Point Lay and Barrow and are likely the three belugas that were caught in the times regurgitate food when being important to belugas wherever they are same net on the same night near Elim in chased (Quakenbush5), which could available (Suydam17) we only found the eastern Bering Sea each contained result in empty stomachs at the time of them in fi ve stomachs from the East- different food items. sampling. ern Chukchi Sea stock, and they were In spite of such biases, stomach con- In Bristol Bay, Lensink3 found that not found by Seaman et al. (1982). tents collected from the harvest and in early June, beluga stomachs were Capelin may be an example of a prey from belugas found dead provide valu- mostly empty. Six stomachs collected species that has a strong regional and able information regarding prey con- during 6–15 Jun. 1959 and 1960 were seasonal component that our opportu- sumed (often identifi ed to species), empty except for a few shrimp frag- nistic collection regime does not often and the number and frequency of their ments, indicating there may be a pe- detect. occurrence. With adequate samples riod of reduced feeding after salmon We identifi ed invertebrates that were sizes, stomach content data provide smolts migrate to sea and before adult not found by Seaman et al. (1982), in- valuable information about the diet salmon are available. Lensink3 also cluding several additional taxa of am- of each stock. Other methods of diet reported that eight beluga stomachs phipods, shrimps, crabs, and bivalves. analysis (e.g., stable isotopes and fatty collected during 11–25 Sept. 1959 Our fi ndings relative to cephalopods acids) result in qualitative information and 1960 contained only small quan- were similar in that more octopus regarding trophic level and general tities of shrimp, small fl atfi sh, and a than squid was eaten (Table 3). Some categories of prey. Quantitative infor- lamprey, possibly indicating another of the invertebrates found in beluga mation from these indirect approaches reduced feeding period after adult stomachs could be due to secondary require complete prey libraries (often salmon runs end in the fall. Very few ingestion, because sculpin and saffron diffi cult to obtain) in order to interpret stomachs were collected in fall and cod eat shrimp, amphipods, crabs, and diet to the species level (Budge et al., winter for any beluga stock in Alaska. polychaetes. Seaman et al. (1982) con- 2006; Newsome et al., 2010). sidered octopus, shrimp, and some- Comparison with Other Studies Non-feeding Periods Prior to this study, Seaman et al. Beluga whales in some areas of (1982) provided the most complete 17Suydam, R., North Slope Borough, P.O. Box Alaska are known to eat large amounts information on beluga whale diet in 69, Barrow, AK 99723. Personal observ.

80 Marine Fisheries Review times isopods to be directly consumed most salmon were found, but they also their prey whole (Brooks8; this study), by belugas. ate smelt, cod, and shrimp; although thus smaller (i.e., young) belugas are By looking at stomachs with no invertebrates appeared to be much limited by the size of their esophagus fi sh remains (n = 65), we found that less important compared to the other to smaller prey (Fay, 1971). Brooks8 polychaetes, gastropods, cephalopods, stocks (Table 3). found that unweaned calves ate small isopods, amphipods, shrimp, echi- Prior to 2002, Cook Inlet beluga bottomfi sh and shrimp. Yearlings urids, and tunicates were present and stomachs were not completely ana- mainly ate smaller fi sh and few adult were likely ingested directly as prey lyzed, and therefore less information salmon. Therefore, many Chinook, by beluga whales. Echiurid setae are is available for this time period, espe- and some chum and coho salmon, may commonly found in beluga stomachs, cially regarding invertebrate prey. Al- be too large for smaller belugas to eat, appear to be resistant to digestion, and though Chinook salmon was identifi ed thereby limiting the suitability of some may have delayed passage through the in one of the earlier stomach samples adult salmon as prey even when they stomach. Evidence of echiurids was and subsistence hunters reported 19 are available. found in stomachs from all stocks, ex- adult Chinook salmon in one har- Our sample sizes of beluga sex and cept Bristol Bay, in this study. vested beluga (Huntington, 2000), length, and fi sh length did not allow Our fi ndings that the predominant we only identifi ed Chinook salmon in us to analyze diet by beluga sex or age fi sh species of the Beaufort Sea stock two stomachs sampled after 2002 (n = class, although subadult belugas have was Arctic cod was also found by 18). The main Chinook salmon runs in been found to eat more invertebrates, Loseto et al. (2009) using fatty acid Cook Inlet occur April–July (Barrett et while adult females ate smaller fi sh analysis. Overall however, we found al.18, 19; McKinley and Fleischman20, and adult males ate larger fi sh (Sea- invertebrates in more stomachs than 21). Six of the 18 stomachs we ana- man et al., 1982). fi sh; 66% of all stomachs contained lyzed after 2002 were collected during On the other hand, all sizes of be- invertebrates only. Loseto et al. (2009) this time period, and therefore could lugas likely eat salmon smolts during did not fi nd invertebrates to be impor- have contained Chinook salmon. smolt migration to the sea. Although tant prey relative to the importance of Otoliths of all species of salmon not represented in any samples, salm- Arctic cod. are small and degrade easily, mak- on smolts are known to be important ing identifi cation of salmon to species to Bristol Bay belugas in the spring Regional Differences more diffi cult. Similarly, in Bristol (Brooks7, 8) and may be important to Stocks were sampled during dif- Bay where all fi ve salmon species are Cook Inlet belugas as well. ferent seasons making seasonal com- available, Chinook salmon were the Prior to 2002 in Cook Inlet, more parisons diffi cult. A comparison of least represented in the beluga diet, beluga stomachs were collected from the overall diet of the different stocks, but again this may be due to the differ- harvested animals, while after 2002, however, showed that the northern- ence in the timing of collections rela- more stomachs were collected from most migratory stock (Beaufort Sea) tive to timing of specifi c salmon runs. stranded animals due to the restrict- predominantly fed on shrimp (60% ed harvest. No invertebrates were re- Other Differences FO), octopus (42% FO), and Arctic corded in the earlier sample of Cook cod (21% FO). The eastern Chukchi In addition to the seasonality of Inlet beluga stomachs. This is most Sea stock fed mostly on shrimp (73% prey availability, prey size may also likely due to an artifact of the fi eld FO), echiurids (27% FO), polychaetes infl uence diet. Beluga whales swallow methods used to determine diet. Stom- (17% FO), and saffron cod (7% FO). ach contents appeared to have been The eastern Bering Sea stock and Kot- examined in a more cursory fashion 18Barrett, B. M., F. M. Thompson, and S. N. zebue belugas fed mostly on saffron Wick. 1984. Adult anadromous fi sh investiga- that may have resulted in invertebrate cod (both 95% FO) and shrimp (both tions: May–October 1983. Sustina Hydro Aquat- prey items being missed. Although not ic Studies. Rep. No. 1. Alaska Dep. Fish Game, 86% FO). Six other invertebrate taxa Anchorage. detecting invertebrates in the earlier were notable for the eastern Bering 19Barrett, B. M., F. M. Thompson, and S. N. stomach samples does not necessar- stock; polychaetes and isopods each at Wicks. 1985. Adult salmon investigations: May– ily change the number of fi sh species 38% FO, bivalves at 33%, echiuriids October 1984. Susitna Aquatic Studies Program. eaten, it does indicate the difference in Rep. No. 6. Alaska Dep. Fish Game, APA Doc. and amphipods each at 29% FO, and No. 2748, Anchorage. the methods used to analyze diet could crabs and tunicates each at 14% FO. In 20McKinley, T. R., and S. Fleischman. 2010a. have infl uenced the fi sh results as well. addition to shrimp, four other inverte- Stock assessment of late-run Chinook salmon Seasonal distribution of stomachs was brate taxa were prominent for Kotze- in the Kenai River, 1999–2006. Alaska Dep. similar for both time periods. Fish Game, Fishery Data Series No. 10-96, bue belugas; amphipods (41% FO), Anchorage. Beluga distribution within Cook In- gastropods and isopods each at 36% 21McKinley, T. R., and S. Fleischman. 2010b. let has been shifting to the upper Inlet FO, and mysids at 14% FO. The two Stock assessment of early-run Chinook salmon from a broader distribution that more in the Kenai River, 1999-2006. Alaska Dep. nonmigratory stocks (Bristol Bay and Fish Game, Fishery Data Series No. 10-19, regularly included the lower (Kache- Cook Inlet) were the stocks in which Anchorage. mak Bay) and the mid-inlet (Rugh et

77(1) 81 al., 2000). Belugas used to feed on her- In addition to food, habitat selection viously sampled beluga whale groups ring in Kachemak Bay prior to the late may also involve molting and calving from Kotzebue Sound. As a group, 1920’s when herring declined there areas, protection from killer whales, the whales harvested in 2007 had very (Rounsefell, 1930). In April, hunters and human activity. strong genetic similarities (mtDNA from Nanwalek would harvest belugas Although the eastern Bering Sea and nDNA) to the Beaufort Sea stock. when they fed on herring in Halibut stock also has access to large multi- Genetic analysis is ongoing to deter- Cove within Kachemak Bay (Roun- species salmon runs in summer in the mine whether the 2007 belugas were sefell, 1930; Stanek, 1994). The distri- Yukon-Kuskokwim Delta and Norton from the Beaufort Sea stock, were a butional shift to the upper Inlet could Sound areas, these areas freeze more mix of two or more stocks of whales, be due to fewer belugas available to completely in winter due to weaker or were from a previously unidentifi ed fi ll the historic habitat, the upper Inlet tides that are unable to keep the ice stock (O’Corry-Crowe23). becoming better habitat, or the lower broken. It is not clear why more salm- Interspecies Overlap in Diet Inlet becoming poorer habitat. Fewer on were not found in stomachs of be- fi sh, however, does not explain why lugas from the eastern Bering Sea, but Interspecies overlap in fi sh prey is belugas use the Kenai River less than it may be due to timing of harvests and most likely to occur among belugas in the past, because salmon runs there the importance of commercial fi sh- and seals, although other possibilities are believed to be at least as large as ing in the area. Some hunters may be include Steller sea lions, Eumetopias those in the Susitna River in the upper fi shing instead of pursuing belugas at jubatus, and harbor porpoises, Pho- Inlet (McKinley and Fleischman20,21). a time when salmon may be an im- coena phocoena, in some areas. The Other activities, such as a commercial portant prey item. It is clear that the Beaufort Sea, eastern Chukchi Sea, beluga harvest in the 1960’s (Mahoney migratory stocks of belugas take ad- and eastern Bering Sea beluga stocks and Shelden, 2000) and increased boat vantage of the seasonal abundance of likely overlalp with ringed, Pusa his- traffi c, may be factors in the decline in forage fi sh nearshore in summer. pida, and spotted, Phoca largha, use of the Kenai River area. Beluga whales were harvested reg- seals, for all fi sh species (Gol’tsev, The two nonmigratory stocks, Cook ularly and in signifi cant numbers in 1971; Bukhtiyarov et al., 1984; Quak- Inlet and Bristol Bay, have several Kotzebue Sound prior to 1982 (e.g., enbush et al.24, 25) and with bearded things in common that may allow them Eschscholtz Bay belugas from Seaman seals, Erignathus barbatus, for Pa- to be resident year-round. Both regions et al.22 came from this harvest). After cifi c sand lance, Arctic cod, saffron are large, tidally infl uenced estuarine 1983, 10 or fewer belugas have been cod, sculpins, eelblenny, and fl atfi sh systems with multispecies salmon runs harvested in the sound in most years (Kosygin, 1971; Lowry et al., 1980; and shallow-water habitat for escape (Frost and Suydam, 2010). However, Antonelis et al., 1994; Quakenbush et from killer whales. Both regions also two unusual events have occurred re- al.26). In Bristol Bay, the most abun- have an abundance of smelt, although sulting in high harvests, one in 1996 dant seals are spotted and harbor, Ph- eulachon in Cook Inlet may be more and another in 2007. The belugas har- oca vitulina, seals and in Cook Inlet, seasonally restricted than rainbow vested in 1996 were genetically simi- only harbor seals are present. Overlap smelt in Bristol Bay. lar (using mtDNA) to those harvested with fi sh species important to humans The tides in both areas keep the in the late 1970’s and early 1980’s; is also possible for the eastern Ber- sea ice broken all winter, which al- however, those harvested in 2007 were ing Sea, Bristol Bay, and Cook Inlet lows belugas access to the bays, but not (O’Corry-Crowe23). stocks where commercial and subsis- the fl oating ice restricts killer whale Few belugas have been seen or har- tence fi sheries for herring and salmon access in winter. Beluga whales do vested near Kotzebue in recent years; exist. not have a dorsal fi n (an advantage however, in July 2007 a large group Interspecies overlap for invertebrate for surfacing in sea ice), and they can (~150) of mostly adult male belugas prey is most likely to occur among swim and feed in very shallow, mud- went deep into Kotzebue Sound, and dy water (<1 m). These adaptations many were harvested. The genetic 24Quakenbush, L., J. Citta, and J. Crawford. and their distribution may serve as (mtDNA haplotypic) composition of 2009. Biology of the spotted seal (Phoca larga) defenses against killer whales (Frost this group was distinct from all pre- in Alaska from 1962 to 2008. Prelim. Rep. Natl. and Lowry, 1990). Killer whales ap- Mar. Fish. Serv., Natl. Mar. Mammal Lab., Se- 22Seaman, G. A., K. J. Frost, and L. F. Lowry. attle, 66 p. pear to avoid ice likely because their 1985. Investigations of belukha whales in coast- 25Quakenbush, L., J. Citta, and J. Crawford. large dorsal fi n limits their ability al waters of western and northern Alaska. Part 2011a. Biology of the ringed seal (Phoca his- to surface and breathe in broken ice I. Distribution, abundance and movements. U.S. pida) in Alaska, 1960–2010. Final Rep. Natl. Dep. Commer., NOAA, OCSEAP Final Rep. Mar. Fish. Serv., Natl. Mar. Mammal Lab., Se- covered water (Matthews et al., 2011; 56:153–220 (avail. from NOAA-OMA-OAD, attle, 72 p. Higdon et al., 2012). The migratory Alaska Offi ce, 701 C. Street, P.O. Box 56, An- 26Quakenbush, L., J. Citta, and J. Crawford. stocks of belugas may rely on sea ice chorage, AK 99513). 2011b. Biology of the bearded seal (Erignathus 23O’Corry-Crowe, G., Fl Atl. Univ., Harbor Br., barbatus) in Alaska, 1960–2009. Final Rep. as escape habitat while the resident 5600 U.S. 1 North, Fort Pierce, FL 34946. Per- Natl. Mar. Fish. Serv., Natl. Mar. Mammal Lab., stocks may rely on shallow water. sonal commun., July 2012. Seattle, 71 p.

82 Marine Fisheries Review Table 7.—Fish and invertebrate prey diversity by stock In summary, beluga whale diets in Literature Cited of beluga whales in Alaska. Alaska waters varies somewhat by No. Allen, B. M., and R. P. Angliss. 2011. Be- No. fi sh invertebrate stock, with the northernmost stocks luga whale (Delphinapterus leucas). In Stock species species Month feeding mostly on shrimp, octopus, Alaska marine mammal stock assess- ments, 2011, p. 66–89. U.S. Dep. Commer., Beaufort 8 16 4–6 and Arctic cod. To the south, saffron NOAA-TM-AFSC-234. E. Chukchi 5 15 6–8 Kotzebue 6 9 6,7,10 cod replaces Arctic cod and octopus Antonelis, G. A., S. R. Melin, and Y. A. Bukti- E. Bering 25 22 5–7, 9,10 is no longer prevalent. In the two most yarov. 1994. Early spring feeding habits of Bristol Bay 14 4 5–8, 10 bearded seals (Erignathus barbatus) in the Cook Inlet (<2002) 2 01 4–10 southern stocks, Arctic and saffron Central Bering Sea, 1981. Arctic 47:74–79. Cook Inlet (>2002) 12 8 3,6–9,11 cod are largely replaced by salmon and Bigg, M. A., and I. Fawcett. 1985. Two biases 1No invertebrates were recorded during this time period smelt (rainbow smelt in Bristol Bay in diet determination of northern fur seals. In likely due to fi eld methods. J. R. Beddington, R. J. H. Beverton, and D. and eulachon in Cook Inlet). Shrimp M. Lavigne (Editors), Marine mammals and are common prey for all beluga stocks fi sheries, p. 284–291. George Allen Unwin, in Alaska. Beluga whales swallow Lond. Bowen, W. D., and S. J. Iverson. 2012. belugas and both Pacifi c walrus, Odo- their prey whole, thus size of prey may Methods of estimating marine mam- benus rosmarus, and bearded seals be related to beluga size (i.e., age) al- mal diets: a review of validation for many benthic invertebrates. Only experiments and sources of bias and uncer- though there also may be individual tainty. Mar. Mammal Sci. 29(4):719–754. the Cook Inlet stock is exempt from preferences. Younger belugas may be doi:10.1111/j.1748-7692.2012.00604.x such overlap as walruses and bearded more limited in prey available to them. Budge, S. M., S. J. Iverson, and H. N. Koop- man. 2006. Studying trophic ecology in ma- seals are not found there. Invertebrate Our results may be infl uenced by bi- rine ecosystems using fatty acids: a primer taxonomic groups of importance to ases due to stomach content analy- on analysis and interpretation. Mar. Mammal belugas that are also eaten by wal- ses, nonrandom hunting affecting our Sci. 22(4):759–801. Bukhtiyarov, Y. A., K. J. Frost, and L. F. Lowry. rus and bearded seals include poly- sample of stomachs, seasonal changes 1984. New information on foods of the spot- chaetes, gastropods, bivalves, octopi, in prey availability, lack of samples ted seal, Phoca largha, in the Bering Sea in mysiids, isopods, amphipods, shrimp, during winter, and other factors. Very spring. In F. H. Fay and G. A. Fedoseev (Edi- tors), Soviet-American cooperative research crabs, echiuriids, and ascidians (Low- little is known about what and how on marine mammals, Vol. 1. Pinnipeds, p. ry et al., 1980; Fay, 1982; Quaken- much beluga whales eat during winter 55–59. U.S. Dep. Commer., NOAA Tech. bush et al.26). Rep. NMFS 12. and whether accumulating fat stores Clarke, M. R. 1986. A handbook for the identifi - in summer and fall is important for Diversity and Amount of Prey cation of cephalopod beaks. Clarendon Press, survival. Oxford, U.K., 273 p. The greatest diversity of fi sh prey Doan, K. H., and C. W. Douglas. 1953. Beluga Acknowledgments of the Churchill region of Hudson Bay. Fish. was found in the eastern Bering Sea Res. Board Can. Bull. 98, 27 p. stock where 25 species of fi sh were We thank the many beluga hunters Fall, J. A., D. J. Foster, and R. T. Stanek. 1984. The use of fi sh and wildlife resources in Ty- eaten, followed by Bristol Bay with 14 who provided stomachs for this study onek, Alaska. Alaska Dep. Fish Game, Div. species and Cook Inlet with 12 species including Rex Tuzroyluk, Charles Subsistence, Anchorage. Tech. Rep. 105, 219 (Table 7). The greatest diversity of in- Saccheus, and Albert Simon. We also p. Fay, F. H. 1971. Belukha, Arctic white whales. vertebrates was also found in the east- thank ADFG personnel Geoff Carroll In A. Seed (Editor), Toothed whales in the ern Bering Sea stock where 22 species for collecting stomachs, and Gay Shef- eastern North Pacifi c and arctic waters, p. were found followed by the Beaufort fi eld, Letty Hughes, Juan Leon Guer- 23–27. Pac. Search Press, Seattle, Wash. ______. 1982. Ecology and biology of the Sea stock with 16 species and the east- rero, Louise Foster, Heidi Isernhagen, Pacifi c walrus, Odobenus rosmarus divergens ern Chukchi stock with 15 species. and others for processing them. Ad- Illiger. N. Am. Fauna No. 74. 279 p. Although we did not often deter- Frost K. J., and L. F. Lowry. 1981. Trophic im- ditional thanks go to members of the portance of some marine gadids in northern mine the total amount of a prey item stranding response crews who collect- Alaska and their body-otolith size relation- eaten by individual beluga whales, ed Cook Inlet stomachs. Fish otoliths ships. Fish. Bull. 79:187–192. ______and ______. 1990. Distribu- there were a few instances of whole and cephalopod beaks not identifi ed tion, abundance, and movements of beluga fi sh (e.g., 12 whole coho salmon within our own lab were identifi ed by whales, Dephinapterus leucas, in coastal wa- weighing 27.8 kg), numbers of oto- William Walker. Noncephalopod in- ters of western Alaska. In T. G. Smith, D. J. St. Aubin, and J. R. Geraci (Editors), Advanc- liths (e.g., otoliths indicating a total of vertebrates not identifi ed by us were es in research on the beluga whale, Dephi- 951 fi sh eaten including 128 rainbow identifi ed by Chris Stark and Ken napterus leuca, p. 39–57. Can. Bull.Fish. smelt, 390 saffron cod, and 399 Arctic Coyle at the University of Alaska, Aquat. Sci. 224. ______, ______, and R. R. Nelson. cod, Table 6), and numbers of octopus Fairbanks (UAF), Institute of Marine 1984. Belukha whale studies in Bristol Bay, beaks (e.g., > 144 for an estimated to- Science. Funding was provided by the Alaska. In B. Melteff (Editor), Proceedings tal weight of 127 kg) that suggest prey Alaska Beluga Whale Committee and of the workshop on Biological Interactions Among Marine Mammals and Commercial numbers and volumes consumed can the Alaska Regional Offi ce, National Fisheries in the Southeastern Bering Sea. Oc- be large. Such numbers indicate that, Marine Fisheries Service. Research tober 18–21, 1983, Anchorage, AK, p. 187– at least seasonally, beluga whales eat 200. Univ. Alaska Sea Grant Rep. 84-1. was conducted under NMFS research ______and R. S. Suydam. 2010. Subsis- substantial amounts of food. permits 782-1694 and 10091. tence harvest of beluga or white whales (Del-

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