These whales can avoid Navy sonar from ships but not from helicopters – public opinion sought on Naval exercises

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A recent Navy-funded research paper on Cuvier’s beaked whales and military sonar reveals that in one location these whales have learned coping strategies to avoid ship-mounted sonar – but those strategies can only go so far to protect them.

The whales’ behavior is nuanced and more complex than previously known, which demonstrates their remarkable intelligence and adaptability.

The longest deep dive in this study, lasting 163 min, occurred while the whale was intermittently exposed to mid-power MFAS at distances of 8–12 km.
While it may be possible for a whale to avoid conducting a deep dive while a surface ship is nearby, the same is not true for helicopters, which acoustically may appear without warning. Surface ships typically broadcast MFAS for extended periods while moving; thus whales probably know roughly where the ship is when exposure begins and how the ship’s position is changing through time, and can use this knowledge to mediate their response.
Helicopters deploy MFAS from a hover in bouts generally lasting under 20 min, moving rapidly between sequential deployments in an unpredictable pattern, and thus whales may react more strongly to these sudden, close-range exposures even though their duration of use and source level (217 dB) are generally well below those of a ship’s MFAS (235 dB) [27]. The difference in these responses underscores the importance of how the source is used, in addition to sound levels (source or received) and distance, in predicting whale behaviour, particularly for whales that are probably familiar with both MFAS types.

This study suggests that while these whales recognize Navy vessels and have adopted a suite of behaviors to avoid the sonar, they may be impacted by the unpredictable nature of aerial sonar. Long term, the avoidance behaviors may accumulate into loss of sustainability.
The paper is publicly available online, below is the abstract. Diving behaviour of Cuvier’s beaked whales exposed to two types of military sonar:

Cuvier’s beaked whales (Ziphius cavirostris) have stranded in association with mid-frequency active sonar (MFAS) use, and though the causative mechanism linking these events remains unclear, it is believed to be behaviourally mediated. To determine whether MFAS use was associated with behavioural changes in this species, satellite tags were used to record the diving and movements of 16 Cuvier’s beaked whales for up to 88 days in a region of frequent MFAS training off the coast of Southern California.
Tag data were combined with summarized records of concurrent bouts of high-power, surface-ship and mid-power, helicopter-deployed MFAS use, along with other potential covariates, in generalized additive mixed-effects models. Deep dives, shallow dives and surface intervals tended to become longer during MFAS use, with some variation associated with the total amount of overlapping MFAS during the behaviour.
These changes in dives and surface intervals contributed to a longer interval between deep dives, a proxy for foraging disruption in this species.
Most responses intensified with proximity and were more pronounced during mid-power than high-power MFAS use at comparable distances within approximately 50 km, despite the significantly lower source level of mid-power MFAS.
However, distance-mediated responses to high-power MFAS, and increased deep dive intervals during mid-power MFAS, were evident up to approximately 100 km away.

Cuvier’s beaked whale (Whaleopedia) 
As a result of similar research, the Navy is asking for your opinion on changes that are planned in the training areas off the Pacific Coast states. They are proposing changes to the environmental impact statements that are required for them to detonate explosives during practice sessions, and will consider new data (such as more accurate measures of marine mammal hearing levels) – there is even the option to scrap the practices altogether, although the latter is unlikely given the saber-rattling going on in the world at this time.
In California and Oregon the changes will only apply outside of state waters, but in Washington they will include inland waterways such as Puget Sound.
The question is, are these proposed changes good or bad for the whales and dolphins that live in these waters? At this point the Navy continues to practice maneuvers in the Olympic Coast National Marine Sanctuary, and Navy sonar is so loud around the San Juan Islands that it can drown out the calls of the orcas on the hydrophones put in place to monitor whales.
The Navy is dedicated to keeping us safe from enemies at our shores, and they are also answerable for needless destruction caused by the need to practice – a tricky balancing act…but they are trying.
Below is the basic information on the Navy’s planned changes. 
In the supplement to the 2015 Final EIS/OEIS, the Navy will analyze training and testing activities within the Study Area. The Study Area remains unchanged since the 2015 Final EIS/OEIS and includes:

  • Established maritime operating areas and warning areas in the northeastern Pacific Ocean, including areas within the:
    • Strait of Juan de Fuca
    • Puget Sound
    • Western Behm Canal in southeastern Alaska
  • Air and water space within and outside Washington state waters
  • Air and water space outside state waters of Oregon and Northern California
  • Navy pierside locations

Navy Acoustics

KEY UPDATES TO THE 2015 FINAL Training and Testing Final Environmental Impact Statement/Overseas Environmental Impact Statement (EIS/OEIS ) and why it needs your input on proposed supplemental information. (Comments can be submitted here).

Training and testing activities proposed in the Supplemental Statements are generally consistent with those activities analyzed in the 2015 Final Statement and earlier environmental planning documents.
Below are some key updates to be made. In the Supplemental Statement, the Navy will:
• Include a No Action Alternative in which proposed training and testing activities would not be conducted and Marine Mammal Protection Act authorization would not be issued by National Marine Fisheries Service (NMFS)
• Include analyses of increases in testing of some new vessels and weapons systems, and decreases in other testing activities
• Include analyses of both increases and decreases in the annual occurrence of certain activities
• Recategorize or rename some testing activities to be consistent with Navy testing activity categories
• Include improved acoustic models, updated marine mammal and sea turtle densities, and updated marine species criteria and thresholds based on NMFS’s 2016 guidance
• Use the most current and best available science and analytical methods
• Review procedural mitigations, where appropriate, and consider geographic mitigation, where applicable
The Supplemental Statement will include an analysis of training and testing activities using new information available after the release of the 2015 Final Statement. New information includes an updated acoustic effects model, updated marine mammal density data, and evolving and emergent best available science. As part of this process, the Navy will seek the issuance of federal regulatory permits and authorizations under the Marine Mammal Protection Act and the Endangered Species Act to support ongoing and future at-sea military readiness activities within the Study Area beyond 2020.
The 30-day scoping comment period begins Aug. 22, 2017 through Sept. 21, 2017. Comments must be postmarked or received online by Sept. 21, 2017 for consideration in the development of the Draft Supplemental EIS/OEIS. Comments may be submitted online at, or by mail to:
Naval Facilities Engineering Command Northwest
Attention: NWTT Supplemental EIS/OEIS Project Manager
3730 North Charles Porter Ave., Building 385
Oak Harbor, WA 98278-3500

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