Laist et al. (2001), Jensen and Silber (2004), Vanderlaan and Taggart (2007), and Van Waerebeek and Leaper (2008) compiled information available worldwide regarding documented collisions between ships and large whales. Of the 292 ship strike records compiled by Jensen and Silber (2004), 75 of the records (26%) indicated that fin whales had been struck. In some areas studied, one-third of all fin whale strandings appeared to involve ship strikes.
From 1993–2002, a minimum of 15 fin whales were struck and killed by ships off the east coast of the U.S. (Jensen and Silber 2004). During the same time frame, a minimum of five were killed off the west coast of the U.S., one was killed off the Gulf Coast, one was hit but appeared uninjured in Alaska and 12 were hit in foreign waters (Canada, UK, France and Italy) (Jensen and Silber 2004). From January 2002–December 2006, six fin whales from the North Atlantic fin whale stock were struck and killed by ships off the east coast (Waring et al. 2009). During 2002–2006, ship strikes were implicated in the deaths of seven fin whales from the California/Oregon/Washington stock and the injury of another (Caretta et al. 2009) and in 2008, at least one confirmed mortality by ship strike of one fin whale occurred (California Marine Mammal Stranding Database, U.S. Department of Commerce 2009). Two additional fin whales from the
California/Oregon/Washington stock stranded dead in California in 2007, but cause of death was not determined. From 2006–2008, an additional five unidentified cetaceans (likely baleen whales) were killed due to ship strikes and were reported in California (California Marine Mammal Stranding Database, U.S. Department of Commerce 2009). Four fin whales were struck off the Northwest coast of the United States; three were identified in Washington and one was identified in Oregon (S. Norman, pers. comm. 2006). Because many ship strikes go either undetected or unreported, these are minimum estimates.
Within specified areas of U.S. waters in the Atlantic, NMFS has established ship speed restrictions, mandatory ship reporting systems, recommended routes, and an extensive sighting advisory system to protect North Atlantic right whales. While these measures were designed to protect right whales specifically, they are expected to also reduce the risk of ship strikes to other marine mammals, including fin whales (NMFS 2008a). The possible impacts of ship strikes on recovery of fin whale populations is not well understood. Because many ship strikes go unreported or undetected for various reasons and the offshore distribution of fin whales may make collisions with them less detectable than with other species, the estimates of serious injury or mortality should be considered minimum estimates, thus there is a high level of uncertainty associated with the evidence presented above. The threat occurs at a medium severity, but with the high level of uncertainty, the relative impact to recovery of fin whales due to ship strikes is ranked as unknown but potentially high (Table 1).
July 2010 I-27 NMFS G.3.2 Disturbance from Whale Watching and Other Vessels – LOW
Fin whales are among the main attractions of whale watching enterprises in eastern Canada and the northeastern United States (Hoyt 1984; Beach and Weinrich 1989). As a result, they are regularly subjected to close and persistent following by vessels.
Several investigators reported behavioral responses to close approaches by vessels suggesting that individual whales might experience a stress response (Watkins et al. 1981; Baker et al. 1983; Malme et al. 1983; Bauer 1986; Bauer and Herman 1986; Baker and Herman 1987; Richardson et al. 1995; Jahoda et al. 2003). Others suggest that there is mounting evidence that wild animals respond to human disturbance in the same way that they respond to predators (Harrington and Veitch 1992; Lima 1998; Gill and Sutherland 2000; Gill et al. 2001; Frid and Dill 2002; Beale and Monaghan 2004; Romero 2004). These responses have been associated with the abandonment of sites (Bartholomew Jr., 1949; Allen 1991; Sutherland and Crockford 1993), reduced reproductive success (Giese 1996; Müllner et al. 2004), and the death of individual animals (from expending energy and thus compromising their survival) (Feare 1976; Daan et al. 1996).
According to Schevill et al. (1964), the fin whale “seems somewhat to avoid ships.” In Cape Cod waters, fin whales were notably wary of vessels before the mid-1970s, but subsequently were observed to have become much less responsive to vessels (Watkins 1986). Edds and Macfarlane (1987) documented that a fin whale observed from an elevated site on the north shore of the St. Lawrence River, significantly reduced its mean dive time while it was being pursued by a ferry carrying whale watchers. Also in the St. Lawrence, Michaud and Giard (1998) documented short-term changes in dive behavior of fin whales approached by vessels. Fin whales observed from a lighthouse in Maine responded to the presence of vessels by decreasing dive times, surface times, and number of blows per surfacing (Stone et al. 1992). Fin whales observed in the Mediterranean had similar responses, including not returning to normal behaviors (e.g., feeding) observed prior to the disturbance (Jahoda et al. 2003).
Fin whales are subject to whale watching much less often in the eastern North Pacific than in the western North Atlantic. Thus, disturbance in the Pacific is more likely to come from industrial, military, and fishing vessel traffic off the Mexican, U.S., and Canadian coasts, than from the deliberate approaches of whale watching vessels. The low-frequency sounds used by fin whales for communication and (possibly) in courtship displays (Watkins 1981) could be masked or interrupted by ship noise.
The potential for injury or disturbance to cetaceans from military ships is also a concern. NMFS conducted an assessment in its Biological Opinion on Rim of the Pacific
(RIMPAC) exercises, focusing on ship traffic and mid-frequency sonar, and concluded that fin whales in the action area were likely to respond to ship traffic associated with the maneuvers (NMFS 2008b).
July 2010 I-28 NMFS Based on this information, the threat occurs at a low severity and there is a medium level of uncertainty. Thus, the relative impact to recovery of fin whales due to disturbance from vessels and tourism is ranked as low (Table 1).