Sonar & Wildlife
Navy Sonar Range and Fish, Sea Turtles, Marine Mammals, Seabirds
Fish
The National Marine Fisheries Service believes that the construction and operation of the USWTR could directly and indirectly impact federally managed fishery species. Repeated exposure to active sonar could harm fish by potentially affecting their reproductive capacity, growth rate, foraging ability, navigation, and communication. Dr. Joe Luczkovich and Dr. Mark Sprague stated in a letter to the Navy about the proposed sonar range that, " We expect behavioral avoidance responses to occur, for these responses to be large, and for there to be a decline in catches from nearby fisheries, as has been observed in other studies where acoustics sources have been used for long periods." Read more
A blue marlin surfaces off of the North Carolina coast. Photo courtesy of
Captain Brian Patteson
Right Whales
The North Atlantic right whale is an endangered species, and only 300 to 350 of these animals remain. The right whale’s migration path follows North Carolina’s coast, and sightings of right whales have occurred in the vicinity of the proposed sonar range. According to the National Marine Fisheries Service, it is important to protect the right whales migration corridor. The mid-Atlantic region is a vital corridor between the right whale's feeding areas and calving grounds. Because intense underwater noise such as active sonar can propagate over great distances, the Navy should avoid constructing a sonar training range in the vicinity of the migration path of these endangered whales.
A right whale surfaces off of Morehead City, North Carolina. Photo courtesy of
Captain Joe Shute
Sea Turtles
Even though North Carolina’ sea turtles have no external ears, they are extremely sensitive and responsive to sound. (In fact, a volunteer with the Karen Beasley Sea Turtle Rescue Rehabilitation Center in Topsail Island describes how a blind turtle, that the Center cares for, follows the sound of its caregivers’ voices when they are in the room, learn more.) Sound is conducted entirely through their ear bones and, it is thought, through their shells. Sea turtles are particularly sensitive to low-frequency sounds. Some species have been observed to surface, startle, and move away from deep-pitched noise sources. Studies done on sea turtles and acoustics show that these marine animals have acute hearing and react to undersea noise.
Leatherback sea turtle in Pine Knoll Shores, NC and leatherback hatchlings in Emerald Isle, NC. Photos courtesy of Richard Ehrenkaufer
Whale strandings
The use of military active sonar has been implicated in mass strandings of whales including the January 2005 stranding of 37 whales, of three different species, on the Outer Banks of North Carolina. Stranding is among the most dramatic impacts associated with active sonar, but tissue damage observed in stranded whales in the Canary Islands in 2002 indicates that even whales that did not strand in that sonar-related event may have suffered serious injury. After another stranding incident in the Bahamas in 2000, when a sonar exercise caused three different species to strand across 150 miles of beach, one of the affected populations virtually disappeared from the area.
Mass stranding of beaked whales in the Canary Islands after sonar use.
Photo courtesy of V. Martin (SECAC)
Marine mammals and marine acoustics
Marine mammals, as well as many species of fish, use sound to navigate their migratory paths, to locate each other over great distances for mating, to find food, and to care for their young. Any interference that undermines their ability to hear each other’s acoustic signals jeopardizes their ability to function and survive. The intense sound of active sonar has been shown to affect essential communication activities of humpback whales and to disrupt feeding activities of orca whales.
Multi-species stranding of whales on North Carolina's Outer Banks after military active sonar use. Photo courtesy of Roger Jarrell,
Outer Banks Free Press
Habitat
The proposed range location covers “hard bottom” marine habitat, which is vital to NC’s reef fish resources. The area is one of six in the NC Coastal Habitat Protection Plan targeted for protection and enhancement, and is federally-designated Essential Fish Habitat. Constructing the sonar range would require destructive drilling through the hard bottom habitat. The reef fish resource is already stressed, and destruction of important habitat and potential spawning areas would likely hinder its recovery.
North Carolina reef. Photo courtesy of Captain Robert Purifoy,
Morehead City, NC
Seabirds
According to the NC Wildlife Resources Commission, seabirds hear in the acoustic frequency range to be used at the proposed USWTR. Additionally, and of greater concern, are the potential impacts to prey resources through use of sonar and loss of hard bottom habitat. Collisions with lighted ships and entanglements with discarded debris such as parachutes are also of concern.
A Black -capped Petrel seabird, photographed offshore North Carolina.
This species is endangered with only 2000 left in the world.
Photo courtesy of Captain Brian Patteson, Hatteras, NC
Natural Resources Defense Council, Sounding the Depths II: The Rising Toll of Sonar, Shipping, and Industrial Ocean Noise on Marine Life (2005) p. 16, fn. 115 (citing, inter alia, M.L. Lenhardt, “Seismic and Very Low Frequency Sound Induced Behavior in Captive Loggerhead Marine Turtles (Caretta caretta),” in Proceedings of the Fourteenth Annual Symposium on Sea Turtle Biology and Conservation, K.A. Bjorndal, A.B. Bolton, D.A. Johnson, and P.J. Eliazar, comps., (Miami: NMFS, 1994), pp.238-40).
Luczkovich et al, Using Spectral Analysis to Identify Drumming Sounds of Some North Carolina Fishes in the Family Sciaenidea, The Journal of the Elisha Mitchell Scientific Society (2000), Vol. 116(2), pp. 124-145.
Luczkovich et al, Sounds of Sex and Death in the Sea: Bottlenose Dolphin Whistles Suppress Mating Choruses of Silver Perch, Bioaccoustics (2000) Vol. 10, pp. 323-334.