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

More documents

Recommendations

Info

FINAL PROGRAMMATIC BIOLOGICAL OPINION ON U.S. NAVY ACTIVITIES IN THE HAWAII RANGE COMPLEX 2008-2013 190 dB. Although these studies have demonstrated that humpback whales will exhibit short-term behavioral reactions to boat traffic and playbacks of industrial noise, the long-term effects of these disturbances on the individuals exposed to them are not known. Because their hearing range appears to overlap with the frequency range of mid-frequency active, we assume that some of the humpback whales that are exposed to mid-frequency active sonar during one or more of the proposed exercises might experience acoustic masking, impairment of acoustic communication, behavioral disturbance, and physiological stress responses as a result of their exposure. The evidence available suggests that humpback whales are likely to detect mid-frequency sonar transmissions. In most circumstances, humpback whales are likely to try to avoid that exposure or are likely to avoid areas specific areas. Those humpback whales that do not avoid the sound field created by the mid-frequency sonar might experience interruptions in their vocalizations. In either case, humpback whales that avoid these sound fields or stop vocalizing are not likely to experience significant disruptions of their normal behavior patterns because most of the activities the U.S. Navy plans to conduct in the Hawai'i Range Complex would occur before humpback whales arrive into waters off the Hawai'ian Islands. As a result, we do not expect these disruptions to reduce the fitness (reproductive success or longevity) of any individual animal or to result in physiological stress responses that rise to the level of distress. The U.S. Navy also identified five instances in which humpback whales might be exposed to pressure waves or sound fields associated with underwater detonations at received levels that would cause behaviors that would be considered behavioral harassment (as that term is defined by the MMPA) and in another four instances in which humpback whales might be exposed at received levels that might temporarily cause noise-induced hearing losses. that five humpback whales might be exposed to pressure waves or sound fields associated with underwater detonations and another four humpback whales might be exposed at received levels that might temporarily cause noise-induced hearing losses. Humpback whales were not reported to change the short-term behavior or distribution in feeding areas in response to explosions with received levels of about 150dB re 1 μPa/Hz at 350Hz (Lien et al. 1993, Todd et al. 1996). However, at least two individuals were probably killed by the high-intensity, impulsed blasts and had extensive mechanical injuries in their ears (Ketten et al. 1993, Todd et al. 1996). The explosions may also have increased the number of humpback whales entangled in fishing nets as they avoided the area in which the detonations occurred (Todd et al. 1996). As discussed in the Environmental Baseline section of this <strong>Opinion</strong>, the strongest evidence that of the probable impact of the Environmental Baseline on humpback whales consists of the estimated growth rate of the humpback whale population in the North Pacific Ocean and the increased number of humpback whale that are reported to occur in the Hawai'ian Islands. In the 1980s, the size of the North Pacific humpback whale population was estimated to range from 1,407 to 2,100 (Baker 1985; Darling and Morowitz 1986; Baker and Herman 1987). By the mid-1990s, the population was estimated to consist of about 6,000 whales (standard error = 474) in the North Pacific (Calambokidis et al. 1997; Cerchio 1998; Mobley et al. 1999). The most recent estimate places the current population of humpback whales in the North Pacific Ocean consisted of about 18,300 whales, not counting calves 244
FINAL PROGRAMMATIC BIOLOGICAL OPINION ON U.S. NAVY ACTIVITIES IN THE HAWAII RANGE COMPLEX 2008-2013 (Calambokidis et al. 2008). Almost half of the humpback whales that were estimated to occur in wintering areas, or about 8,000 humpback whales, occupy the Hawai’ian Islands during the winter months. Despite small numbers that are entangled in fishing gear in the action area, this increase in the number of humpback whales suggests that the stress regime these whales are exposed to in the Hawai'ian Islands have not prevented these whales from increasing their numbers in the action area. As discussed in the Environmental Baseline section of this <strong>Opinion</strong>, humpback whales have been exposed to U.S. Navy training activities in the Hawai'i Range Complex, including vessel traffic, aircraft traffic, active sonar, and underwater detonations, for more than a generation. Although we do not know if more humpback whales might have used the action area or the reproductive success of humpback whales in the Hawai'i Range Complex would be higher absent their exposure to these activities, the rate at which humpback whales occur in the Hawai'ian Islands suggests that humpback whale numbers have increased substantially in these important calving areas despite exposure to earlier training regimes. Although the U.S. Navy proposes to increase the frequency of some of these activities, we do not believe those increases are likely to affect the rate at which humpback whale counts in Hawai'i are increasing. Based on the evidence available, we conclude that training exercises and other activities the U.S. Navy plans to conduct in the Hawai'i Range Complex each year from December 2008 through December 2013 are not likely to adversely affect the population dynamics, behavioral ecology, and social dynamics of individual humpback whales in ways or to a degree that would reduce their fitness. As we discussed in the Approach to the Assessment section of this opinion, an action that is not likely to reduce the fitness of individual whales would not be likely to reduce the viability of the populations those individual whales represent (that is, we would not expect reductions in the reproduction, numbers, or distribution of those populations). As a result, the activities the U.S. Navy plans to conduct in the Hawai'i Range Complex from December 2008 to December 2013 would not be expected to appreciably reduce the humpback whales’ likelihood of surviving and recovering in the wild. SEI WHALES. During future Rim of the Pacific Exercises, the first scenario (which assumed that animals would not move) identified 70 instances in which sei whales might be exposed to mid-frequency active sonar at received levels between 140 and 195 dB. During the other anti-submarine exercises (USWEX, TRACKEX, and TORPEX) the U.S. Navy plans to conduct in the Hawai’i Range Complex each year, the first scenario identified another 105 instances in which sei whales might be exposed to mid-frequency active sonar transmissions at received levels between 140 and 195 dB. No sei whales would be exposed to received levels greater than 195 dB associated with these other training activities. Of the 165 instances in which <strong>NMFS</strong>’ exposure models identified sei whales that might be exposed to mid-frequency active sonar at received levels between 140 and 195 dB, about 196 of those instances would involve exposures at received levels between 140 and 150 dB. Another 49 of those instances would involve exposures at received levels between 150 and 160 dB. The balance of the exposures would occur at received levels greater than 160 dB. The U.S. Navy did not identify any instances in which sei whales might be exposed to low-frequency active sonar transmissions during each of the three missions the U.S. Navy plans to conduct in the Hawai'i Range Complex between late January and mid-August 2009 or underwater detonations associated with the activities the U.S. Navy plans to conduct in the Hawai'i Range Complex. As we discussed previously, we assume that these estimates 245
Page 4 and 5:
FINAL PROGRAMMATIC BIOLOGICAL OPINI
Page 6 and 7:
Page 8 and 9:
Page 10 and 11:
Page 12 and 13:
Page 14 and 15:
Page 16 and 17:
Page 18 and 19:
Page 20 and 21:
Page 22 and 23:
Page 24 and 25:
Page 26 and 27:
Page 28 and 29:
Page 30 and 31:
Page 32 and 33:
Page 34 and 35:
Page 36 and 37:
Page 38 and 39:
Page 40 and 41:
Page 42 and 43:
Page 44 and 45:
Page 46 and 47:
Page 48 and 49:
Page 50 and 51:
Page 52 and 53:
Page 54 and 55:
Page 56 and 57:
Page 58 and 59:
Page 60 and 61:
Page 62 and 63:
Page 64 and 65:
Page 66 and 67:
Page 68 and 69:
Page 70 and 71:
Page 72 and 73:
Page 74 and 75:
Page 76 and 77:
Page 78 and 79:
Page 80 and 81:
Page 82 and 83:
Page 84 and 85:
Page 86 and 87:
Page 88 and 89:
Page 90 and 91:
Page 92 and 93:
Page 94 and 95:
Page 96 and 97:
Page 98 and 99:
Page 100 and 101:
Page 102 and 103:
Page 104 and 105:
Page 106 and 107:
Page 108 and 109:
Page 110 and 111:
Page 112 and 113:
Page 114 and 115:
Page 116 and 117:
Page 118 and 119:
Page 120 and 121:
Page 122 and 123:
Page 124 and 125:
Page 126 and 127:
Page 128 and 129:
Page 130 and 131:
Page 132 and 133:
Page 134 and 135:
Page 136 and 137:
Page 138 and 139:
Page 140 and 141:
Page 142 and 143:
Page 144 and 145:
Page 146 and 147:
Page 148 and 149:
Page 150 and 151:
Page 152 and 153:
Page 154 and 155:
Page 156 and 157:
Page 158 and 159:
Page 160 and 161:
Page 162 and 163:
Page 164 and 165:
Page 166 and 167:
Page 168 and 169:
Page 170 and 171:
Page 172 and 173:
Page 174 and 175:
Page 176 and 177:
Page 178 and 179:
Page 180 and 181:
Page 182 and 183:
Page 184 and 185:
Page 186 and 187:
Page 188 and 189:
Page 190 and 191:
Page 192 and 193:
Page 194 and 195:
Page 196 and 197: FINAL PROGRAMMATIC BIOLOGICAL OPINI
Page 296 and 297:
Page 298 and 299:
Page 300 and 301:
Page 302 and 303:
Page 304 and 305:
Page 306 and 307:
Page 308 and 309:
Page 310 and 311:
Page 312 and 313:
Page 314 and 315:
Page 316:
show all

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

Create successful ePaper yourself

Delete template?

Save as template?