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
animals (Kajiwara et al. 2002, Kuehl and Haebler 1995, Mignucci-Giannoni et al. 2000). These suggestions are
consistent with the conclusions of numerous other studies that have demonstrated that combinations of dissimilar
stressors commonly combine to kill an animal or dramatically reduce its fitness, even though one exposure without
the other does not produce the same result (Chroussos 2000, Creel 2005, DeVries et al. 2003, Fair and Becker 2000,
Foley et al. 2001, Moberg 2000, Relyea 2005a, 2005b, Romero 2004, Sih et al. 2004).
Those studies suggest that, in many animal species, disease, reproductive state, age, experience, stress loading,
energy reserves, and genetics combine with other stressors like body burdens of toxic chemicals to create fitness
consequences in individual animals that would not occur without these risk factors. The contribution of these
potential risk factors to stranding events (or causal relationships between these risk factors and stranding events) is
still unknown, but the extensive number of published reports in the literature suggests that an experiment
investigation into a causal relationship is warranted.
Over the past three decades, several “mass stranding” events — stranding events that involve two or more individuals
of the same species (excluding a single cow-calf pair) — that have occurred over the past two decades have
been associated with naval operations, seismic surveys, and other anthropogenic activities that introduce sound into
the marine environment. Although only one of these events involved a species that was listed as threatened or
endangered (and was unrelated to active sonar exposures), we analyzed the information available on stranding events
to determine if listed cetaceans are likely to strand following an exposure to mid-frequency active sonar. To conduct
these analyses, we searched for and collected any reports of mass stranding events of marine mammals and identified
any causal agents that were associated with those stranding events.
Global Stranding Patterns
Several sources have published lists of mass stranding events of cetaceans during attempts to identify relationships
between those stranding events and military sonar (Hildebrand 2004, IWC 2005, Taylor et al. 2004). For example,
based on a review of stranding records between 1960 and 1995, the International Whaling Commission (2005)
identified ten mass stranding events of Cuvier’s beaked whales had been reported and one mass stranding of four
Baird’s beaked whale (Berardius bairdii). The IWC concluded that, out of eight stranding events reported from the
mid-1980s to the summer of 2003, seven had been associated with the use of mid-frequency sonar, one of those
seven had been associated with the use of low-frequency sonar, and the remaining stranding event had been
associated with the use of seismic airguns.
Taxonomic Patterns
Most of the stranding events reviewed by the International Whaling Commission involved beaked whales. A mass
stranding of Cuvier’s beaked whales (Ziphius cavirostris) in the eastern Mediterranean Sea occurred in 1996
(Franzis 1998) and mass stranding events involving Gervais’ beaked whales (Mesoplodon europaeus), de
Blainville’s dense-beaked whales (M. densirostris), and Cuvier’s beaked whales occurred off the coast of the Canary
Islands in the late 1980s (Simmonds and Lopez-Jurado 1991). Other stranding events of beaked whales have also
occurred in the Bahamas and Canary Islands (which included Gervais’ beaked whales, Mesoplodon europaeus, de
Blainville’s dense-beaked whales, M. densirostris, and Cuvier’s beaked whales; Simmonds and Lopez-Jurado 1991).
The stranding events that occurred in the Canary Islands and Kyparissiakos Gulf in the late 1990s and the Bahamas
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