The State of Circumpolar Walrus Populations

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Alaska may be a successful management tool for reducing disturbance-related mortalities
(USFWS 2014).
Young animals and those in poor condition are particularly vulnerable to trampling if herds are
stampeded onshore or offshore (Kavry et al. 2006, 2008). Pacific walruses sometimes haul out in
very large numbers along the Chukotka coast on Cape Vankarem (30,000 walruses) and Cape
Kozhenikov (40,000), and nearby on Karkapko Islet (1,000). The majority of these animals are
females and calves. In autumn 2007, disturbance by humans who approached too close was a
major contributor to unprecedented high mortality of walruses in the vicinity of capes Kozhenikov
(577 carcasses) and Venkarem (>200) (Kavry et al. 2006, 2008; Arnbom 2009; T. Arnbom, WWF
Sweden, pers. comm.). A similar mortality event occurred in 2008 (Arnbom 2009). At St.
Lawrence Island in the Bering Sea where at least 537 Pacific walruses died in October-November
1978, trampling may have been one cause of the mortality (Fay and Kelly 1980). Some of the
animals examined had been attacked by killer whales (Orcinus orca), which may have stampeded
the large herd ashore, resulting in death by trampling of smaller or weaker individuals. About 400
carcasses also washed ashore from various sources and about 15% of the total mortality consisted
of aborted foetuses. The latter likely resulted from physical trauma but an infectious or toxic agent
could not be ruled out. Mortality on such a scale has not been reported for Atlantic walruses, but
stampedes do cause some mortality (Loughrey 1959). Prolonged or repeated disturbances may
cause walruses to abandon a haulout (Salter 1979a). Haulout disturbances are a particular
concern in areas where ship-based tourism is occurring, such as Svalbard and Canada (Wiig et al.
2014).
Ship-based tourism is relatively recent in Franz Josef Land and in Severnaya Zemlya where it is
less common (M. Gavrilo, pers. comm.). In 2015 a marine border check point was established in
Franz Josef Land, enabling direct cruise ships passage from Svalbard and increasing traffic.
Cruise ships bring thousands of visitors to the coastal areas, and walrus watching is one of the
main attractions. Disturbance by tourism may have serious negative impacts on walruses using
the haulouts, especially in Franz Josef Land, at Victoria Island, and in northern Novaya Zemlya
where many females and calves are present.
Ship strikes
The threat of mortality or injury from ship strikes is uncertain (D.B. Stewart et al. 2014b).
Walruses are quick and maneuverable in the water and should be able to detect and avoid vessels
approaching in open water. Icebreaking may represent a bigger threat, especially during the
breeding season when animals may be clustered, males are aggressively defending territories, and
escape options are limited by ice. The species’ gregarious nature and vigorous defense of calves