(1) Navy EIS: Acoustics. What are the numbers?

If you haven't read it already, go read the Intro to the Navy EIS.


In this section, I will run through some of the Acoustic concerns addressed in the Navy EIS. For an introduction and explanation of what the Navy EIS is, please read the into.  The Navy EIS talks about several different types of effects from sound: Temporary Threshold Shift (TTS), Permanent Threshold Shift (PTS), Auditory Masking, Physiological Stress, and, Behavioral Reactions. Here are some simple definitions:

TTS: Temporary Deafness/Hearing Loss 

PTS: Permanent Hearing Loss 

Auditory Masking: When an animal can't hear important sounds because it gets lost in the ambient noise. This video does a good job letting you see how noise can hide a sound.

Physiological stress: Constant exposure to noise can cause stress in whales, which increases their stress hormones. Just like for humans, constant stress is bad for whales.

Behavioral Reactions: Whales and dolphins can change their behavior as a result of noise. These behavior changes may be relatively minor (from changing swimming speed) to very bad (separation of moms and calves, beaching).

The numbers of animals exposed to these sounds seems to be one of the most controversial issues on the internet, so I'll get to that first. Here are the tables which lay out how many individuals of each species will be exposed to sounds which are predicted to cause behavioral, TTS, and PTS reactions, depending on which "Action Alternative" the Navy uses. As you look at this table, notice that the numbers tend to be larger for more common species and species that have greater overall populations. For example, the numbers for short beaked common dolphins are very high, and this is also a very common species in the Naval Range. Other species, like Orcas, have very low numbers and occur very infrequently in the range (although they ARE known to occur).

Also, notice that there are two sources of impact on Marine Mammals - training and testing. Both of these are added up to get the total number of animals that may be exposed to sound.

The other thing to notice is that there are three "Alternatives," each with different levels of impact on marine mammals. These alternatives may  expose different numbers of marine mammals to sound, with the "No Action Alternative" having the least impact on marine mammals, and "Alternative 2" having the greatest impact.

Table 3.4-14: Annual Testing Exposures for Sonar and Other Acoustic Sources (You can look at Annual Training Exposures here at Table 3.4-13).

And then this is the summary of the impacts of each alternative.  The summary references Level A and Level B harassment, as defined by the Marine Mammal Protection Act.  According to the Marine Mammal Protection Act, harassment is defined as "any act of pursuit, torment, or annoyance," which (for Level A harassment) has the potential to injure a marine mammal or marine mammal stock in the wild or (for Level B harassment) "has the potential to disturb a marine mammal or marine mammal stock in the wild by causing disruption of behavioral patterns, including, but not limited to, migration, breathing, nursing, breeding, feeding, or sheltering but which does not have the potential to injure a marine mammal or marine mammal stock in the wild." For hearing, Level A harassment would be "the acoustic exposure associated with onset-permanent threshold shift." In layman's terms, Level A is anything that results in permanent hearing loss (which does not necessarily mean complete deafness). Level B is everything else, from temporary hearing loss to behavioral disturbance. One thing that bothers me about Level B is that it doesn't seem to account for cumulative hearing damage over time - but maybe when I get to the methods for calculating these numbers I'll find an explanation for that.

No Action Alternative:

Training and Testing Activities Under Alternative 1:

Training and Testing Activities Under Alternative 2:

So what is the difference between these three alternatives, and why do they predict that different numbers of marine mammals may be exposed to sound? Details of the three alternatives are here, but basically each alternative has increasing amounts of testing and training, and may cover a larger area (thus impacting more animals).

Up next: How were these numbers calculated?

P.S. Sorry if this is a little dense! I don't feel like I can summarize over 350 pages of controversial text in one short and hilarious blog post! Look, a beaked whale!

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Legal Documents Related to Impact of Naval Exercises on Marine Mammals

I was working on my thesis proposal today. Some of the sources I'm citing are court cases pertaining the the US Navy's impact on marine mammals, and I thought other people might be interested in reading these legal documents, as a supplement to the Navy EIS. This is not an all-inclusive list.

I'm going to link to the cases and then copy/add a summary

NRDC v. Evans, 2008: "This action challenges the United States National Marine Fisheries Service’s (“NMFS”) July 16, 2002 decisio n to authorize – and the United States Department of the Navy’s (“Navy”) decision to deploy – a powerful new global sonar system that will broadcast extraordinarily intense sound waves through as much as 75 percent of the world’s oceans.  

NRDC v. Gutierrez, 2008: Relates to the use of LFA Sonar in operations in the Western Pacific Ocean. 

NRDC v. Winter, 2008: "On June 28, 2006, the Natural Resources Defense Council (NRDC), along with several other environmental groups (collectively, Plaintiffs) filed suit (hereinafter NRDC II ) against Winter, in his capacity as Secretary of the Navy, alleging that the Navy had violated the National Environmental Policy Act (NEPA), the Marine Mammal Protection Act (MMPA), and the Administrative Procedure Act (APA).   Plaintiffs also filed an application for a temporary restraining order (TRO) and a preliminary injunction to enjoin the Navy's use of mid-frequency active sonar during its Rim of the Pacific (RIMPAC) 2006 training exercise. RIMPAC 2006 was a major multi-national Navy training exercise that took place in the waters surrounding the Hawaiian Islands from June 26 to July 28, 2008.   Starting July 6, the training included the use of mid-frequency active sonar, which is known to disrupt some of the marine mammals that live in those waters." More info from Cornell School of Law.

Here are some articles on the outcome of NDRC v. Winter in the US Supreme Court:

Beyond Winter v. NRDC: A Decade of Litigating the Navy's Active SONAR Around the Environmental Exemptions

Whales and Sonar: Environmental Exemptions for the Navy's Mid-Frequency Active Sonar Testing 

Top US Court Allows Navy Sonar Use

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(Intro) Navy Environmental Impact Statement: Effect on Marine Mammals

A couple of weeks ago, the US Navy released their Environmental Impact Statement for the Hawaii and Southern California Training Complexes.  Here's a fairly good summary of the reaction all over the internet:

I had a friend (a scientist, but not a marine mammal person) contact me last week to find out more information, and I thought there would probably be more people out there that were wondering what the heck is going on.  I mean, that's a LOT of dolphins and whales that the Navy is, according to the SignOn petition "going to deafen."


The information from the petition is based on the Department of the Navy's Hawaii-Southern California Training and Testing Environmental Impact Statement (EIS)/Overseas Environmental Impact Statement (OEIS). Quite a mouthful, so I'm just going to call it the Navy EIS from now on. Environmental Impact Statements are required by the National Environmental Policy act (NEPA) of 1969, for actions that "significantly affect the human environment." They also provide information that demonstrates compliance with other environmental laws, such as the Clean Air Act, the Endangered Species Act, and the Marine Mammal Protection Act.  If you look at the Navy's EIS, there is a chapter for the applicable different environmental laws.


The Marine Mammal Chapter of the Navy EIS is related to the National Marine Fisheries Service Letter of Authorization  to the U.S. Navy for Taking and Importing Marine Mammals (aka their permit). I haven't been able to dig up the application for this permit (which is more detailed), so I'm not sure if the text for the permit is exactly the same as the wording in the Navy's EIS. From what I've heard, the Marine Mammal Protection Act Permit won't be released to the public for another couple of months. Superficially, however, the EIS chapter looks a lot like the format I used in our lab's permit to research dolphins in Hawaii.


Let's take a look at the Navy EIS itself, and see what it says about the impact of Naval Activities on whales and dolphins.  These impacts include:

And these impacts will be occurring in the California and Hawaii range complexes, which cover quite a large area:

The area inside the red, blue, and yellow boxes, as well as the blue dotted line are where impacts will occur.

43 species of whales, dolphins, seals, sea lions, and sea otters are known to occur in these areas. That's 7 species of baleen whale, 29 species of dolphin and toothed whale, 6 species of seal and sea lion, and a sea otter.

These are just the marine mammals in Hawaii.

There are descriptions of all the species individually (this takes a long time), along with their estimated population sizes, conservation status, management issues, and a short summary of specific threats to each species. Next, is a list an explanation of all the potential impacts.


I am going to take these one section at a time, and just skim over them. It's pretty detailed, and I'm not an expert in everything. I'm also not going to explain every single detail - if you want to know ALL the details, read it yourself.  However, if you read it and have any questions about something I left out, feel free to ask and I will address it to the best of my ability.


 Read on for more information:


Court Cases involving Naval Activities
Acoustics: What are the numbers of whales that may be affected by sound?

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