Ocean Carrying Capacity Program
Unusual Observations of Fish and Invertebrates From the Gulf of Alaska, 2004-05
Figure 1. Wade Loofborough, skipper of the ADF&G research vessel Medeia, with a
jumbo squid (Dosidicus gigas). Photo by Joe Orsi.
During 2004-05, unusual fish and invertebrates were reported off the coasts of southcentral and southeastern Alaska.
Most but not all of these occurrences are presumably associated with the unusually warm oceanographic conditions in
the North Pacific Ocean and the Gulf of Alaska during these years. The records of occurrences are compiled from personal
communications with Alaska Department of Fish and Game (ADF&G)
biologists and port observers, who receive their information from commercial fishers, charter boat operators, and sport fishers.
Some observations are from NMFS personnel conducting surveys of juvenile salmon and sablefish. Where possible, the identifications
were confirmed through photographs or actual specimens submitted to the Auke Bay Laboratory (ABL).
The helicid pteropod (Limacina helicina) was reported in 2005. When abundant, it is preyed on extensively by chum salmon,
pink salmon, herring, and whales. In spring 2004, Limacina was reported as a dominant zooplankton in plankton net tows from Chatham
Strait, Peril Strait and Icy Strait. The opalescent inshore squid (Loligo opalescens) was also reported in 2005. Previously
reported in northern Southeast Alaska in the early 1980s, no additional occurrences were noted until spring of 2005 when they were
abundant in the Sitka area and in northern Clarence Strait. The eight-armed squid (Octopoteuthis deletron) was reported in
2004; this was the first record for Alaska Inside waters. It has previously been reported only as far north as central
The jumbo squid (Dosidicus gigas) (Fig. 1 above) was reported in 2004 and 2005, and was first taken off the Fairweather Grounds
in 2004. This very large squid forms an important fishery in the Gulf of California. The neon flying squid (Ommasterphes bartrami)
was reported in 2005. At times, it is very abundant off the Washington and British Columbia coasts. The boreal clubhook squid
(Onychoteuthis borealijaponicus) also was found in Alaska during 2005. Its northern distribution is typically along the southern
edge of the Gulf of Alaska.
The blue shark (Prionace glauca) occurred along Alaska’s outer coast in 2004 and 2005. Blue sharks were reportedly common along
the outer coast of Alaska in 2005. Blue sharks are frequently reported during strong El Niño years. The white shark (Carcharodon
carcharias) was reported in 2004. Although white sharks are known to occur in Alaska waters, they are not abundant. Most notable
was a white shark photographed off Yakutat after taking a bite of a sport-caught halibut. The thresher shark (Alopias vulpinus)
was reported in 2004. The 2004 record from west of Yakobi Island is the farthest north record for thresher sharks.
The Pacific sardine (Sardinops sagax) was reported for 2005 in unusual abundance in southern Southeast Alaska and were captured
as far north as Cross Sound. They were previously reported in 1998 following a 67 year absence. The 2005 reports represent the highest
abundance and most northerly reports of sardines in Alaska. Northern anchovy (Engraulis mordax) were also reported in 2005.
Previously reported only in 1997 from the Yakutat area, they were reported in 2005 from southern Clarence Strait. Surf smelt
(Hypomesus pretiosus) were reported in 2005. Their biology in Alaska is poorly known and populations are not followed by Alaska
biologists. Its apparent increase in abundance may be real or due to increased awareness by field biologists.
Figure 2. Opah (Lampris guttatus)
Other unusual species (or species captured outside their normal range) reported for Alaska during 2004 and 2005 include Pacific barracuda
(Sphyraena argentea), Pacific pomfret (Brama japonica), Pacific saury (Cololabis saira), opah (Lampris guttatus) (Fig. 2),
cabezon (Scorpaenichthys marmoratus), green sturgeon (Acipencer medirostris), and Pacific ridley turtle (Lepidochelys
olivacea). During the past 2 years, unusual catches of fish and invertebrates have been reported by fishermen and fisheries biologists
working in the coastal waters of the eastern and central Gulf of Alaska.
These observations are associated with anomalously warm water in the eastern North Pacific Ocean. This is not the result of an El Niño but
rather an overall warming of the whole North Pacific Ocean. The long-term implications of this ocean warming and these changes of
distribution and abundance to Alaskan fisheries are not clear. The nearshore distributions and abundance of blue shark, pomfret, saury and
the pteropod, Limacina helicina may be due to strong downwelling as a result of the decadal shift of the Aleutian Low.
Monthly average sea surface temperatures at the Auke Bay Laboratory have been about 0.75°C above average for most of 2004 and 2005.
Peak anomalies were +2.48°C and +2.83°C in May of each year. Similar anomalies were observed throughout most of the eastern North Pacific
Ocean and the Gulf of Alaska. The temperature patterns observed differ from the classical El Niño conditions in that the warming was
initially observed in the central Pacific Ocean and gradually extended east and north to include the Gulf of Alaska and Bering Sea. A
typical El Niño begins in the equatorial western Pacific Ocean, moves east to the coast of South America, and then moves north and south
along the coast of the eastern Pacific Ocean.
By Bruce Wing
JAS2005 quarterly sidebar
Research Reports July-Sept 2005