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

Not OK!—Military jets mar Olympic National Park wilderness experience

Human impacts, News, Wildlands No Comments »

Pat McMahon says it so well that I’ll simply reprint this letter to the editor, published in the Peninsula Daily News:

LETTER: Jet noise takes away from natural beauty
Olympic National Park has lost a vital component with the persistent sounds of jets overhead.

Many of us visit national parks as a way to balance the rigors of everyday life with an experience of wilderness and solitude.

During the last week of June, while participating in the annual sea otter census near Hoh Head north of the Hoh River, my colleague and I experienced persistent and loud military jet noise.  The noise would suddenly erupt as the aircraft transitioned from land to sea. One of the abrupt sounds echoed such that we thought we might be experiencing the beginnings of a landslide. During the three days I participated in the sea otter census, we experienced persistent, loud jet sounds most of the day.

One week later while backpacking with my grandchildren at Toleak Point, we experienced the same persistent, loud jet noise. It was not what I was expecting on a coastal wilderness hike in Olympic National Park.

We have suffered a loss in Olympic National Park, where you will no longer be able to get lost in the natural sounds of moving water and marine animals. When you least expect it, the loud sounds of military aircraft will take you away from peacefulness and remind you of the reality of everyday life. There are over 7 billion humans on our planet now, and we need quiet natural places more than ever. Someplace to go where your spirit can regenerate.

It is so sad that we have lost this component of Olympic National Park.

Pat McMahon,
Sekiu, Washington

Humpback bottom-feeding is (somewhat) affected by shipping noise

Ocean, Science, Sonar No Comments »

AEI lay summary of:  Blair HB, Merchant ND, Friedlaender AS, Wiley DN, Parks SE. 2016. Evidence for ship noise impacts on humpback whale foraging behaviour. Biol. Lett. 12: 20160005. http://dx.doi.org/10.1098/rsbl.2016.0005

Sand lance 350pA new study looks for the first time at the impact of human noise on an important type of humpback whale foraging activity, bottom-feeding on sand lance.  The research took place in the Stellwagen Bank National Marine Sanctuary in the southern Gulf of Maine, where humpback whales routinely do deep dives at night, rolling to their sides when they reach the bottom to forage for the small fish.

To assess the whales’ responses to human noise, D-Tags were placed on ten individuals over the course of two years.  These temporary suction-cup tags record received sound levels that the animal is hearing, as well as tracking the details of their dives.  The tagged whales made 218 dives, 83 with ship noise exposure and 135 without ships nearby.

Here’s an example of the sort of picture that the D-tags can provide:

Blair 2016 Humpback side roll Dtag track plot

The results show a 29% decrease in the number of “bottom side-roll feeding events” as the received level of the ship noise increased, as well as a 13-14% decrease in both the descent and ascent rate of the dives.  Interestingly, the increase in received noise level was rather small overall (received level was higher when ship noise was present, but not statistically significantly higher), perhaps indicating that the ships were, on average, not all that close.  As is typical, the team used advanced statistical techniques to tease out modest effects from the subtle and varied data. (In case you’re wondering, they used “linear mixed-effects models” with data “square root transformed to approximate normality,” then calculated effects by “summing Akaike weights of all models.” Sounds good to me!)

The raw numbers put the effects into some more straightforward perspective.   Read the rest of this entry »

Belugas struggling in Cook Inlet, St. Lawrence rivers

Bioacoustics, Ocean, Science 2 Comments »

Two troubling reports have surfaced regarding beluga whale populations in waters that have become increasingly industrialized and noisy in recent years.  In Quebec’s Saguenay River, the major river system draining into the St. Lawrence, recent years have seen a sharp uptick in dead beluga babies and pregnant mothers; in 2015, these sensitive individuals were half of all known mortalities.  Increased noise is the primary culprit; according to the CBC, “The researchers are working from the theory that beluga calves have soft calls, which may be drowned out by the noise from ships, ferries and boats in the Saguenay and St. Lawrence rivers.”

In Alaska’s Cook Inlet, beluga range has shrunk dramatically over the past couple of decades (see map below), and accelerated in recent years, as ongoing port construction and oil and gas development has introduced increasing levels of noise into these key waters.  It’s unclear whether the smaller range is simply a reflection of a reduced local population, meaning they don’t need to range so far to avoid competing with each other for food, or if they are responding to the increasing chronic noise.  See previous AEInews coverage of the Cook Inlet belugas here.  Recent NMFS research papers on the changes can be accessed at this link, and this in-depth article from a couple years back is a good overview of the current development and research activities.

Beluga range Cook Inlet 1978-2014

Marine invertebrates also affected by ocean noise

Bioacoustics, Effects of Noise on Wildlife, Ocean, Science, shipping No Comments »

Some of the most interesting new work in ocean noise is revealing the myriad ways that humanity’s sounds can have negative impacts on ocean life other than marine mammals.  Sure, everyone loves our warm-blooded kin, but there’s way more to the ocean ecosystem than dolphins, humpbacks, and seals.  AEInews has been covering this leading edge for years (see these posts on shellfish larvae, crabs, and squid).  Recently, at the triannual Effects of Noise on Aquatic Life conference, held this year in Dublin, a slew of new papers revealed further concerns.

blue-banded_hermit_crabThis post from NRDC summarizes the highlights.  One of the most striking findings was that 6 hours of shipping noise can damage the DNA in the cells of mussels, perhaps due to a stress response; similarly, protein structures in the sensory cells of cuttlefish were damaged by low-frequency noise.  These would be some of the most profound impacts yet discovered; note, though, that the brief summary here does not specify the sound levels—some research on health effects use much higher exposures than are likely in the wild, as a way of identifying possible effects for further study at lower exposure levels.  Other new studies followed on previous ones that suggest many animals respond to noise as if it were a predator; these responses often suggest increased stress, and are waste of precious energy, or disrupt feeding.  Also of note is a one-off anecdotal observation (not yet studied systematically) of a hermit crab exiting its shell after exposure to low-freqency sound; it appeared to be examining its shell, perhaps trying to determine the source of the disruption, or checking for physical damage. While out of its shell, it would be vulnerable to predation.

All this new research is both exciting, as it reveals the vast and subtle role of sound in the natural world, and sobering in facing us with the widespread consequences of our heedless sonic intrusions into wild ecosystems.