NMFS Biological Opinion on U.S. Navy training ... - Govsupport.us

FINAL PROGRAMMATIC BIOLOGICAL OPINION ON U.S. NAVY ACTIVITIES IN THE HAWAII RANGE COMPLEX 2008-2013
Our knowledge of the distribution and abundance of populations of endangered and threatened marine animals in the
Hawai’ian Archipelago varies widely. We have a better understanding of the distribution and abundance of humpback
whales, Hawai'ian monk seals, and the Hawai'ian population of green sea turtles than of any of the other
endangered or threatened species that occur in the Hawai'ian Islands. For example, there is still almost no information
on the distribution and number of blue, fin, and sei whales that occur in the Hawai’ian Islands and temporal
trends in their abundance; without that information, it would be impossible to determine if these population are
increasing or not. Our understanding of the at-sea distribution and abundance of green sea turtles from the Eastern
Tropical Pacific, hawksbill, leatherback, loggerhead, and Pacific ridley sea turtles remains very limited and primarily
consists of information from their interactions with commercial fisheries in the Hawai'ian Islands.
Few of the anthropogenic phenomena in the Hawai’ian Archipelago that represent potential risks to whales in
Hawai’ian waters seem likely to kill whales. Instead, most of these phenomena — close approaches by whalewatching
and research vessels, anthropogenic sound sources, pollution, and many fishery interactions — would
affect the behavioral, physiological, or social ecology of whales in Hawai’ian waters. The second line of evidence
consists of reports that suggest that the response of whales to many of the anthropogenic activities in the Hawai’ian
Archipelago are probably short-lived, which suggests that the responses would not be expected to affect the fitness
of individual whales. Most of these reports relate to humpback whales during their winter, breeding season; there are
very few reports of the behavioral responses of other whales species to human activity in the action area. For
example, annual reports from the North Gulf Oceanic Society and two other investigators reported that most whales
did not react to approaches by their vessels or only small numbers of whales reacted. That is, in their 1999 report on
their research activities, the North Gulf Oceanic Society reported observing signs that whales were “disturbed” in
only 3 out of 51 encounters with whales and that the whales’ behavioral responses consisted of breaching, slapping
tail and pectoral fin, and diving away from research vessels.
Gauthier and Sears (1999), Weinrich et al. (1991, 1992), Clapham and Mattila (1993), Clapham et al. (1993)
concluded that close approaches for biopsy samples or tagging did cause humpback whales to respond or caused
them to exhibit “minimal” responses when approaches were “slow and careful.” This caveat is important and is
based on studies conducted by Clapham and Mattila (1993) of the reactions of humpback whales to biopsy sampling
in breeding areas in the Caribbean Sea. These investigators concluded that the way a vessel approaches a group of
whales had a major influence on the whale’s response to the approach; particularly cow and calf pairs. Based on
their experiments with different approach strategies, they concluded that experienced, trained personnel approaching
humpback whales slowly would result in fewer whales exhibiting responses that might indicate stress.
At the same time, several lines of evidence suggest that these human activities might be greater consequences for
individual whales (if not for whale populations). Several investigators reported behavioral responses to close
approaches that suggest that individual whales might experience stress responses. Baker et al. (1983) described two
responses of whales to vessels, including: (1) “horizontal avoidance” of vessels 2,000 to 4,000 meters away
characterized by faster swimming and fewer long dives; and (2) “vertical avoidance” of vessels from 0 to 2,000
meters away during which whales swam more slowly, but spent more time submerged. Watkins et al. (1981) found
that both fin and humpback whales appeared to react to vessel approach by increasing swim speed, exhibiting a
startled reaction, and moving away from the vessel with strong fluke motions.
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