AE.org - website of the Acoustic Ecology Institute
newsCommunityResourcesSoundscapesAbout UsJoin Us
aeinews Home

New court ruling on Navy sonar has big implications

News, Ocean, Sonar Add comments

A new court ruling could fundamentally change the standards that the Navy and National Marine Fisheries Service have been using to regulate Navy sonar, by requiring more areas to be set aside as off-limits to the Navy’s routine peacetime operations.  A federal appeals court has ruled that simply determining that Navy activities will have “negligible impact” on populations is not sufficient; regulators must also, and separately, set standards for sonar use that assure the “least practicable adverse impact” on marine mammals and their habitats.  (Download the ruling; it’s only 35 pages, not a bad read!)  As those who have been following the evolution of the NMFS’s ongoing cycle of five-year authorizations for Navy activities will know, the routine procedure has been to dutifully tally the numbers of animals that may be affected—generally they predict relatively few injuries or deaths (more when explosives training is involved), as well as behavioral effects on millions of animals—and then to determine that the long term effects on each species’ population levels will be negligible.  This negligible-impact finding then allows NMFS to issue permits allowing for the predicted effects.

NMFS has been presuming that negligible impact is sufficient to also satisfy the requirement for “least practicable impact.”  Their basic argument was that you can’t get a lower impact than negligible.  However, there were a couple of flaws in this approach.  First, the threshold for population-level effects in this permit was presumed to be 12% of the regional population of any given species being able to hear, and have their behavior potentially changed, by sonar transmissions; clearly, there IS room to reduce this degree of impact.  But more importantly to this court, the NMFS’s approach to determining what areas are “biologically important,” and so worthy of some protection from routine sonar operations, was found to violate the “least practicable impact” standard—and it appears that designating more protected habitat will be essential to meeting this standard.

Note: This court case concerns the SURTASS-LFA low-frequency active sonar, currently deployed on four US surveillance vessels, rather than the mid-frequency active sonar that has been the focus of most of the previous legal wrangling.  This LFA lawsuit challenged routine, peacetime use of the sonar worldwide; by contrast, all the mid-frequency challenges up til now have only sought to constrain testing and training activities in Naval training ranges off the US coasts, not its widespread routine use by over a hundred Navy ships around the world.  So this case has a limited immediate scope, though the underlying theme of setting aside more areas as off-limits is a core element of all the sonar and naval training legal challenges, and this new clarification by the courts on the separate requirement for “least practicable impact” could apply to all NMFS permitting.  

This court ruling does not prescribe a new management plan; it merely found that the current one does not meet the letter of the law.  This case is now remanded back to the district court for further deliberation.  However, we are approaching the end of the 5-year authorizations that have been challenged here (2012-2017), so the most likely consequence of this ruling is that the NEXT round of authorizations, due in 2017, will need to take more care in meeting the “least practicable impact” standard, either by expanding the areas off-limits to sonar, or by more adequately justifying why NMFS feels they are meeting this standard in other ways.

An apparently deciding factor in the court ruling was a 2010 white paper written by four NMFS “subject matter experts,” which suggested a more precautionary approach to designating “offshore biologically important areas” (OBIAs).  These experts noted that there is a lack of data on population levels in much of the sea, and that if OBIA designation occurs only in areas with solid population data, we risk widespread under-protection of marine habitats.  So, they suggest a three-pronged approach that would proactively designate OBIAs using “proven ecological principles” to identify habitats that tend to be important to animals.  Their suggestions would greatly expand the areas considered worthy of protection, both in number and in scale.

The current permits designate 22 OBIAs worldwide; NMFS considered 51 other potential OBIAs that were not designated this time, due to lack of clear data to justify them.  The NMFS mitigation guidelines prohibit the use of low-frequency active sonar within 1km of the 22 OBIAs, as well as within 22km (12 miles) of all coastlines.  By contrast, the NMFS white paper suggests that OBIAs be designated proactively and at quite large scales, to cover the entire continental shelf and 100km from the continental slope, as well as 100km around any seamount that comes close to the surface, and in areas of “high primary productivity” (which, at least as excerpted in the court ruling, is not clearly defined).

The authors of the white paper don’t make explicit OBIA recommendations; they acknowledge that NMFS faces a policy choice about whether to use this precautionary approach or a “pure” approach that relies on the limited data that is available (which would prevent designation of areas that may not be particularly important, while missing some that are).  NMFS argued that it has the authority to decide what threshold to use in designating OBIAs, and that their multi-tiered approach represents equally valid science.  However, the court here has ruled that the “least practicable impact” standard effectively forces their hand and requires at least a thorough consideration of a more precautionary approach—and in particular, the court stresses that NMFS’s finding of “negligible impact” on population levels is totally separate from their legal obligation to achieve “least practicable impact” on habitats.

If this new reading of the law holds, it will mark a fundamental change in the ways that the Navy and NMFS have been approaching the operational and permitting questions.  However, going forward there are several still-unresolved questions:

It seems this interpretation would lead to a much larger number of designated OBIAs.  That alone is probably workable for the Navy, despite their objections.  But the large continental shelf and continental slope exclusion zones would not be acceptable; and the Navy probably could make a strong enough case that these exclusions would harm readiness, as well as necessary peacetime surveillance.  Seamounts are also key areas where the Navy likes (probably needs) to do at least some ongoing training and peacetime surveillance activity.  So all those 100km buffers are very unlikely to appear in next-round mitigations; the nub of the issue, though, is that behavioral impacts happen at very large distances, so the 100km buffer makes sense from some perspectives.

In previous rounds of Navy EISs, some alternatives have considered setting more areas aside as off-limits, but modeling suggested this would not lower the number of behavioral impacts in any significant way.  Again, this is because so many of the behavioral effects occur at great distances; keeping sonar ships out of a particular OBIA eliminates the already low danger of injury to animals in the OBIA, and may reduce the worst behavioral impacts that occur at moderate sound levels (cessation of feeding, or disruptions to mother-calf pairs), but does not reduce the overall number of mild noise exposures and small behavioral impacts in that OBIA.  So, even if this round of rulings increases the number of OBIAs in future 5-year plans and permits, it would not be surprising to see the 1km buffer become the focus of future legal challenges.  It’s unlikely that universal 100km buffers will satisfy the statutory requirements (since they probably would tip the balance between environmental protection and military readiness too far in the other direction), so it will be interesting to see what sort of middle ground does make sense to the NMFS, NRDC, and Navy.

Perhaps a few well-documented OBIAs deserve much larger buffers, keeping noise levels much lower within them.  Or, routine peacetime operations may be limited in duration or number near these key OBIAs.  Would a buffer of, say, 30km (or some other in-between choice) have significant-enough biological effect to be useful?

It’s kind of amazing to see how slow the process of moving through all these questions has been; each legal challenge seems to eat up the entire five-year span of the permits, so any new standards or approaches are adopted incrementally.  Complicating this gradual evolution is the fact that the rulings on the various challenges have varied quite a lot, even on this key question of whether the Navy and NMFS should be setting more areas off-limits.

To get up to speed on the current legal landscape, you may like to peruse some of our earlier AEInews coverage; each case and ruling includes distinct elements of the legal and policy issues that are in play.  Bear in mind that there are several separate legal challenges, each to a particular permit; ie, there is not one overarching, ongoing case involving all Navy sonars.  Also, only the LFAS case is sonar-specific; all the others involve Navy training that includes explosives (which are usually responsible for most or all of the predicted injuries and deaths, and many of the predicted behavioral impacts).   The key ongoing legal threads are:

It’s hard to know where all this may lead.  It seems likely that more exclusion zones will be added, though it’s not clear how much that will reduce overall impacts on marine life—certainly it will do some good in somewhat reducing the more severe behavioral impacts, and generally reducing our noise footprint in sensitive areas.  At the same time, it is entirely possible that NMFS can fulfill most of the requirements of the difficult rulings simply by being more diligent in laying out its justifications for the decisions it makes; the law gives a fair degree of deference to decision-makers, so long as they take the requisite “hard look” at all the options.

It’s also worth noting that the lack of solid data that has slowed the adoption of formal OBIAs is a problem that is constantly being addressed by researchers.  See this fascinating new dynamic mapping project that compiles all known surveys to show how each species concentration changes through the year.  And in 2015, a special edition of the journal Aquatic Mammals presented a series of papers from NOAA’s CetMap project, full of detailed distribution maps meant to identify Biologically Important Areas. (both of these cover only US waters, unfortunately).  At the very least, there’ll be more for both sides to work with as they continue this wrangling in the years to come.

Leave a Reply