Voglio sapere a riguardo di…

Federal Register / Vol. 86, No. 106 / Friday, June 4, 2021 / Proposed Rules
30097

TABLE 5MARINE MAMMAL HEARING GROUPSContinued NMFS, 2018
Generalized hearing range

Hearing group Otariid pinnipeds OW underwater sea lions and fur seals

60 Hz to 39 kHz.

Represents the generalized hearing range for the entire group as a composite i.e., all species within the group, where individual species hearing ranges are typically not as broad. Generalized hearing range chosen based on 65 dB threshold from normalized composite audiogram, with the exception for lower limits for LF cetaceans Southall et al. 2007 and PW pinniped approximation.

The pinniped functional hearing group was modified from Southall et al.
2007 on the basis of data indicating that phocid species have consistently demonstrated an extended frequency range of hearing compared to otariids, especially in the higher frequency range Hemila et al., 2006; Kastelein et al., 2009; Reichmuth and Holt, 2013.
For more detail concerning these groups and associated frequency ranges, please see NMFS 2018 for a review of available information. Thirty-eight marine mammal species 33 cetacean and 2 pinniped 2 phocid species have the reasonable potential to co-occur with the proposed survey activities.
Please refer to Table 3. Of the cetacean species that may be present, 6 are classified as low-frequency cetaceans i.e., all mysticete species, 25 are classified as mid-frequency cetaceans i.e., all delphinid and ziphiid species and the sperm whale, and 3 are classified as high-frequency cetaceans i.e., harbor porpoise and Kogia spp..
Potential Effects of Specified Activities on Marine Mammals and Their Habitat This section includes a summary and discussion of the ways that components of the specified activity may impact marine mammals and their habitat. The Estimated Take section later in this document includes a quantitative analysis of the number of individuals that are expected to be taken by this activity. The Negligible Impact Analysis and Determination section considers the content of this section, the Estimated Take section, and the Proposed Mitigation section, to draw conclusions regarding the likely impacts of these activities on the reproductive success or survivorship of individuals and how those impacts on individuals are likely to impact marine mammal species or stocks.
We note that the potential effects from NEFSC fisheries and ecosystem research i.e., gear interaction and acoustic impacts remain the same as those described in the Federal Register notices associated with the issuance of the NEFSCs current LOA. Effects to marine mammals are also described in NMFS 2020 Draft Supplemental EA.

VerDate Sep<11>2014

17:49 Jun 03, 2021

Jkt 253001

We reiterate that information here and, where appropriate, we updated the information to reflect data contained within the NEFSCs annual monitoring reports received pursuant to the 2016
2021 LOA.
Ship Strike Vessel collisions with marine mammals, or ship strikes, can result in death or serious injury of the animal.
Wounds resulting from ship strike may include massive trauma, hemorrhaging, broken bones, or propeller lacerations Knowlton and Kraus, 2001. An animal at the surface may be struck directly by a vessel, a surfacing animal may hit the bottom of a vessel, or an animal just below the surface may be cut by a vessels propeller. More superficial strikes may not kill or result in the death of the animal. These interactions are typically associated with large whales e.g., fin whales, which are occasionally found draped across the bulbous bow of large commercial ships upon arrival in port. Although smaller cetaceans or pinnipeds are more maneuverable in relation to large vessels than are large whales, they may also be susceptible to strike. The severity of injuries typically depends on the size and speed of the vessel, with the probability of death or serious injury increasing as vessel speed increases Knowlton and Kraus, 2001; Laist et al., 2001; Vanderlaan and Taggart, 2007;
Conn and Silber, 2013. Impact forces increase with speed, as does the probability of a strike at a given distance Silber et al., 2010; Gende et al., 2011.
Pace and Silber 2005 found that the probability of death or serious injury increased rapidly with increasing vessel speed. Specifically, the predicted probability of serious injury or death increased from 45 to 75 percent as vessel speed increased from 10 to 14
nautical mile per hour kts, and exceeded ninety percent at 17 kts.
Higher speeds during collisions result in greater force of impact, but higher speeds also appear to increase the chance of severe injuries or death through increased likelihood of collision by pulling whales toward the vessel Clyne, 1999; Knowlton et al.,
PO 00000

Frm 00019

Fmt 4701

Sfmt 4702

1995. In a separate study, Vanderlaan and Taggart 2007 analyzed the probability of lethal mortality of large whales at a given speed, showing that the greatest rate of change in the probability of a lethal injury to a large whale as a function of vessel speed occurs between 8.6 and 15 kt. The chances of a lethal injury decline from approximately eighty percent at 15 kts to approximately twenty percent at 8.6
kts. At speeds below 11.8 kts, the chances of lethal injury drop below fifty percent, while the probability asymptotically increases toward one hundred percent above 15 kt.
In an effort to reduce the number and severity of strikes of the endangered NARW, NMFS implemented speed restrictions in 2008 73 FR 60173;
October 10, 2008. These restrictions require that vessels greater than or equal to 65 ft 19.8 m in length travel at less than or equal to 10 kn near key port entrances and in certain areas of right whale aggregation along the U.S. eastern seaboard. Conn and Silber 2013
estimated that these restrictions reduced total ship strike mortality risk levels by eighty to ninety percent.
For vessels used in NEFSC research activities, transit speeds average 10 kt but vary from 614 kt, while vessel speed during active sampling is typically only 2 to 4 kt. At sampling speeds, both the possibility of striking a marine mammal and the possibility of a strike resulting in serious injury or mortality are discountable. At average transit speed, the probability of serious injury or mortality resulting from a strike, if one occurred, is less than fifty percent. However, the likelihood of a strike actually happening is again discountable. Ship strikes, as analyzed in the studies cited above, generally involve commercial shipping, which is much more common in both space and time than is research activity. Jensen and Silber 2004 summarized ship strikes of large whales worldwide from 19752003 and found that most collisions occurred in the open ocean and involved large vessels e.g., commercial shipping. Commercial fishing vessels were responsible for three percent of recorded collisions,
E:FRFM04JNP2.SGM

04JNP2