WHALE MASS STRANDING 

ATTRIBUTED TO SONAR MAPPING 

FOR FIRST TIME

WCS researchers and other stranding team members 

worked to capture some of the melon-headed whales 

in order to transport them to the open ocean. 

(Credit: Photo credit: T. Collins/WCS)

Sep. 25, 2013 — An independent scientific review panel has concluded that the mass stranding of approximately 100 melon-headed whales in the Loza Lagoon system in northwest Madagascar in 2008 was primarily triggered by acoustic stimuli, more specifically, a multi-beam echosounder system operated by a survey vessel contracted by ExxonMobil Exploration and Production (Northern Madagascar) Limited.

In response to the event and with assistance from IFAW, WCS led an international stranding team to help return live whales from the lagoon system to the open sea, and to conduct necropsies on dead whales to determine the cause of death.

According to the final report issued today, this is the first known marine mammal mass stranding event of this nature to be closely associated with high-frequency mapping sonar systems. Based on these findings, there is cause for concern over the impact of noise on marine mammals as these high-frequency mapping sonar systems are used by various stakeholders including the hydrocarbon industry, military, and research vessels used by other industries.
The report concluded: "The potential for behavioral responses and indirect injury or mortality from the use of similar MBES [multi-beam echosounder systems] should be considered in future environmental assessments, operational planning and regulatory decisions."
The full report can be found at: 
http://iwc.int/2008-mass-stranding-in-madagascar

The Wildlife Conservation Society (WCS) and the International Fund for Animal Welfare (IFAW) welcomed the report and praised all those involved in the process, including governments, NGOs, and industry.

"WCS and IFAW support these conclusions that add to a mounting body of evidence of the potential impacts of anthropogenic noise on marine mammals," said Dr. Howard Rosenbaum, Director of the Ocean Giants Program for WCS. "Implications go well beyond the hydrocarbon industry, as these sonar systems are widely used aboard military and research vessels for generating more precise bathymetry (underwater mapping). We now hope that these results will be used by industry, regulatory authorities, and others to minimize risks and to better protect marine life, especially marine mammal species that are particularly sensitive to increasing ocean noise from human activities. "
Added Dr. John G. Robinson, Executive Vice President for Conservation and Science for WCS: "We greatly appreciate the efforts of the U.S. government agencies and authorities and the International Whaling Commission for facilitating and overseeing this process, and we are particularly grateful to the Government of Madagascar for authorizing this work and their continued interest in the outcome. Understanding what causes mass strandings of marine mammals is critical to prevent this in the future. In this case, the cooperation by industry, conservation organizations, and government regulatory authorities led to best science being evaluated by an independent panel, which came up with conclusion based on weight of considerable evidence made available."

"Mass stranding response is challenging under the best of circumstances. Together with local individuals and the government of Madagascar, we provided the expertise to rescue as many animals as possible and medical care to those that stranded alive," said Katie Moore, Director of Animal Rescue at IFAW. "Equally important was to gather as much data as possible from the animals to address the root cause of the stranding. We are pleased to see the ISRP report and its conclusions, which will hopefully be used in shaping future conservation policies."

The report was written after a formalized process was established to investigate the mass stranding. The process was undertaken with endorsement of the Government of Madagascar. Several have contributed to this report including organizations involved in the mass stranding response effort, the International Whaling Commission, and several relevant U.S. federal agencies.

A multi-stakeholder steering committee was established to provide guidance in setting up and structuring the review panel and to ensure completion of the process and public release of the report. Those on this steering committee included: Dr. Howard Rosenbaum (WCS); Dr. Rodger Melton and Dr. Linda Zimmerman (ExxonMobil); Dr. Teri Rowles (NOAA Marine Mammal Stranding Network); Dr. Jason Gedamke (NOAA Ocean Acoustics Program); Dr. Peter Thomas (Marine Mammal Commission); Jill Lewandowski (BOEM); Dr. Greg Donovan (IWC); Dr. Brandon Southall (SEA), also head of the independent scientific review panel.
While aspects of the stranding remain unknown, the panel concluded that a multi-beam echosounder system, operated intermittently by a survey vessel moving down the shelf-break the day before the event was the most "plausible and likely behavioral trigger for the animals initially entering the lagoon system."

http://www.sciencedaily.com/releases/2013/09/130925132211.htm

MILITARY SONAR CAN ALTER BLUE WHALE BEHAVIOR: 
HUMAN-MADE NOISES CAUSE OCEAN GIANTS TO MOVE 
AWAY FROM FEEDING SPOTS

Duke researcher Ari Friedlaender 

attaching a suction-cup tag to the back 

of a blue whale off the coast of southern California. 

(Credit: Courtesy of Ari Friedlaender; 

NMFS Permit 14534)

July 3, 2013 — Some blue whales off the coast of California change their behavior when exposed to the sort of underwater sounds used during U.S. military exercises. The whales may alter diving behavior or temporarily avoid important feeding areas, according to new research.
The Southern California Behavioral Response Study exposed tagged blue whales in the California Bight to simulated mid-frequency (3.5-4 kHz) sonar sounds significantly less intense than the military uses.

"Whales clearly respond in some conditions by modifying diving behavior and temporarily avoiding areas where sounds were produced,” said lead author Jeremy Goldbogen of Cascadia Research. "But overall the responses are complex and depend on a number of interacting factors," including whether the whales were feeding deep, shallow or not at all.
The study, funded by the U.S. Navy Chief of Naval Operations Environmental Readiness Division and the U.S. Office of Naval Research, appears July 3 in the Proceedings of the Royal Society B.

The scientists tagged the whales with non-invasive suction cups, which recorded acoustic data and high-resolution movements as the animals were exposed to the controlled sounds.
"The tag technology we use offers a unique glimpse into the underwater behavior of whales that otherwise would not be possible," said Ari Friedlaender, a research scientist at the Duke Marine Laboratory.a

The scientists found that some of the whales engaged in deep feeding stopped eating and either sped up or moved away from the source of the noise. Not all of the whales responded to the noise, and not all in the same way.
"Blue whales are the largest animals that have ever lived. Populations globally remain at a fraction of their former numbers prior to whaling, and they appear regularly off the southern California coast, where they feed," said John Calambokidis, one of the project’s lead investigators of Cascadia Research.

That area of the ocean is also the site of military training and testing exercises that involve loud mid-frequency sonar signals. Such sonar exercises have been associated with several unusual strandings of other marine mammal species (typically beaked whales) in the past. Until this study, almost no information was available about whether and how blue whales respond to sonar.

"These are the first direct measurements of individual responses for any baleen whale species to these kinds of mid-frequency sonar signals," said Brandon Southall, SOCAL-BRS chief scientist from SEA, Inc., and an adjunct researcher at both Duke and the University of California Santa Cruz. "These findings help us understand risks to these animals from human sound and inform timely conservation and management decisions."

A related paper published July 3 by the same research team in Biology Letters has shown clear and even stronger responses of Cuvier’s beaked whales to simulated mid-frequency sonar exposures. Beaked whales showed a variety of responses to both real, military sonar in the distance and nearby simulated sonar. What the beaked whales were doing at the time appeared to be a key factor affecting their reactions.

http://www.sciencedaily.com/releases/2013/07/130703120637.htm

STRANDED ORCAS HOLD CRITICAL CLUES FOR SCIENTISTS

This killer whale was stranded in California in 2005. 

Increased necropsies on stranded killer whales 

are helping scientists learn more about the species. 

(Credit: Jeff Jacobsen/Humboldt State University)

June 7, 2013 — The development of a standardized killer-whale necropsy system has boosted the collection of complete data from killer-whale strandings from 2 percent to about 33 percent, according to a recent study from a team of scientists, including a University of California, Davis wildlife veterinarian.

The study, published recently in the journal Marine Mammal Science, suggests that the data can help scientists better understand the life history of the orca species.
The killer-whale necropsy system was co-developed by Joe Gaydos, director of the SeaDoc Society -- a program of the UC Davis Wildlife Health Center within the School of Veterinary Medicine -- and Stephen Raverty, veterinary pathologist with the British Columbia Ministry of Agriculture.
"Because killer whales are apex predators and flagship conservation species, strandings are sad events," said Gaydos. "But this study confirms that if we make every effort to understand why the strandings occurred, we will ultimately improve the fate of the species."

Gaydos and Raverty developed the standardized killer-whale necropsy system in 2004. The analysis of strandings since then has shown that the protocol, along with increased funding for southern resident killer-whale recovery, has increased the collection of complete data from killer-whale strandings. Traditionally, only one in 50 stranded whale cadavers would be analyzed; now one in three get a full examination.

The increased recovery funding was provided by the U.S. National Marine Fisheries Service and Canadian Department of Fisheries and Oceans.
For the study, researchers analyzed North Pacific killer-whale strandings dating back to 1925. The report noted that while orcas are some of the most widely distributed whales on Earth, very few dead ones are ever found. Over the last two decades, an average of just 10 a year have been discovered stranded across the entire North Pacific Ocean.
"Each stranded orca should be viewed as a unique opportunity to enhance our understanding of this magnificent species," said co-author Raverty.

The study found that 88 percent of all reported killer-whale strandings are fatal, while only 12 percent of the stranded killer whales make it off the beach alive. The dead whales can provide critical clues to the species' overall life history, genetics, and health, as well as the causes of death. With such limited opportunity to do comprehensive sampling and studies, the authors noted the disturbing fact that, until recently, less than 2 percent of dead killer whales were thoroughly examined.

While the study was designed to look at stranding trends and did not evaluate the causes, necropsies on beached orcas have shown that they absorb extremely high loads of humanmade toxins, suffer from infectious diseases and, in the case of fish-eating populations, depend primarily on severely depleted salmon stocks. With the standardized protocol now in place -- providing much more complete data on strandings -- researchers are getting a clearer picture of killer-whale life and death.

"This was a herculean effort to learn more about one of the ocean's top predators," said lead author Michelle Barbieri, a former SeaDoc Society scientist and UC Davis graduate who is currently the lead veterinarian for the National Oceanic and Atmospheric Administration's Hawaiian Monk Seal Research Program.
"We could not have done this without the collaboration of dozens of killer-whale scientists from around the world, who provided stranding and population data from Washington, Oregon, California, Alaska, Hawaii, British Columbia, Mexico, Japan and Russia," she said.

http://www.sciencedaily.com/releases/2013/06/130607131012.htm

ROLE OF KINSHIP IN MASS STRANDINGS OF PILOT WHALES QUESTIONED

Thousands of pilot whales have died in mass strandings 

the last few decades and recent genetic analysis 

challenges one of the popular hypotheses 

for why they strand. 

These pilot whales stranded at Stanley, in northeast Tasmania in 2008. 

(Credit: photo courtesy of 

DPIPWE Marine Conservation Program)

Mar. 14, 2013 — Pilot whales that have died in mass strandings in New Zealand and Australia included many unrelated individuals at each event, a new study concludes, challenging a popular assumption that whales follow each other onto the beach and to almost certain death because of familial ties.

Using genetic samples from individuals in large strandings, scientists have determined that both related and unrelated individuals were scattered along the beaches -- and that the bodies of mothers and young calves were often separated by large distances.
Results of the study are being published this week in the Journal of Heredity.

Scott Baker, associate director of the Marine Mammal Institute at Oregon State University, said genetic identification showed that, in many cases, the mothers of calves were missing entirely from groups of whales that died in the stranding. This separation of mothers and calves suggests that strong kinship bonds are being disrupted prior to the actual stranding -- potentially playing a role in causing the event.

"Observations of unusual social behavior by groups of whales prior to stranding support this explanation," said Baker, who frequently advises the International Whaling Commission and is co-author of the Journal of Heredity article. The OSU cetacean expert is a professor in the Department of Fisheries and Wildlife at the university's Hatfield Marine Science Center in Newport, Ore.
The mass stranding of pilot whales is common in New Zealand and Australia, involving several thousand deaths over the last few decades, according to Marc Oremus of the University of Auckland, who is lead author on the study. The researchers say their genetic analysis of 490 individual pilot whales from 12 different stranding events showed multiple maternal lineages among the victims in each stranding, and thus no correlation between kinship and the grouping of whales on the beach.

This challenges another popular hypothesis -- that "care-giving behavior" directed at close maternal relatives may be responsible for the stranding of otherwise healthy whales, Oremus said.

"If kinship-based behavior was playing a causal role in strandings, we would expect that whales in a stranding event would be related to one another through descent from a common maternal ancestor, such as a grandmother or great-grandmother -- and that close kin would be clustered on the beach," Oremus said. "Neither of these was the case."
Because of the separation of mothers and calves, or in some cases, the outright absence of mothers among the victims, the study has important implications for agencies and volunteers who work to save the stranded whales, Baker said.

"Rescue efforts aimed at 'refloating' stranded whales often focus on placing stranded calves with the nearest mature females, on the assumption that the closest adult female is the mother," Baker pointed out. "Our results suggest that rescuers should be cautious when making difficult welfare decisions -- such as the choice to rescue or euthanize a calf -- based on this assumption alone."

Long-finned pilot whales are the most common species to strand en masse worldwide, the researchers noted, and most of their beaching events are thought to be unrelated to human activity -- unlike strandings of some other species. Both naval sonar and the noise of seismic exploration have been linked to the stranding of other species.
The phenomenon is not new. In fact, mass strandings of whales or dolphins were described by Aristotle more than 2,000 years ago and were thought to have some kind of natural cause, Baker said, although it is unclear what that may be.

"It is usually assumed that environmental factors, such as weather or the pursuit of prey, brings pilot whales into shallow water where they become disoriented," Baker said. "Our results suggest that some form of social disruption also contributes to the tendency to strand."

"It could be mating interaction or competition with other pods of whales," Baker said. "We just don't know. But it is certainly something that warrants further investigation."
The researchers hope their study will lead to better genetic sampling of more pilot whales and other stranded whale species, as well as the use of satellite tags to monitor the survival and behavior of whales that are helped back into the ocean.

"The causal mechanisms of these strandings remain an enigma," Oremus said, "so the more avenues of research we can pursue before and after the whales beach themselves, the more likely we are to discover why it happens."

http://www.sciencedaily.com/releases/2013/03/130314124607.htm

MASS STRANDINGS OF PILOT WHALES MAY NOT BE DRIVEN BY KINSHIP, DNA PROFILES SHOW

Rescuers help refloat pilot whales stranded in New Zealand. 
Recent research has shed some light on whether family relationships play a role in beachings of otherwise healthy whales. Investigators used genetic data to describe the kinship of individual long-finned pilot whales involved in mass strandings. The study found that stranded groups are not necessarily members of one extended family, contradicting the hypothesis 
that stranding groups all descend from a single ancestral mother. Further, many stranded calves were found with no mother in evidence. 
(Credit: Project Jonah New Zealand Inc.)

Mar. 14, 2013 — Biologists since Aristotle have puzzled over the reasons for mass strandings of whales and dolphins, in which groups of up to several hundred individuals drive themselves up onto a beach, apparently intentionally. Recent genetic research has shed some light on whether family relationships play a role in these enigmatic and often fatal beachings of otherwise healthy whales.

One hypothesis regarding the reason for strandings is that "care-giving behavior," mediated largely by family relationships, plays a critical role. In this scenario, the stranding of one or a few whales, because of sickness or disorientation, triggers a chain reaction in which healthy individuals are drawn into the shallows in an effort to support their family members.

A recent study published in the Journal of Heredity questions this explanation, using genetic data to describe the kinship of individual long-finned pilot whales involved in mass strandings in New Zealand and Tasmania. The largest of these strandings included more than 150 whales, all of which died.

The study found that stranded groups are not necessarily members of one extended family, evidence that contradicts the hypothesis that stranding groups all descend from a single ancestral mother. Further, many stranded calves were found with no mother in evidence.

Long-finned pilot whales are the most common species to strand en masse and it has long been assumed this tendency was related to the species' social organization. Previous studies have shown that pilot whales have a matrilineal social organization, in which neither males nor females disperse from the group into which they were born. This group structure is also found in killer whales, but is otherwise thought to be rare in mammals.

"If kinship-based social dynamics were playing a critical role in these pilot whale strandings, first, we would expect to find that the individuals in a stranding event are, in fact, all related to each other. Second, we would expect that close relatives, especially mothers and calves, would be found in close proximity to each other when they end up on the beach during a stranding event," explained Marc Oremus of the University of Auckland and first author of the study.
Researchers analyzed both mitochondrial DNA, which is inherited exclusively from the mother, and microsatellite genotypes, which are inherited from both parents, from 490 whales involved in 12 stranding events. Contrary to the hypothesis that stranding groups consist of whales descended from a single ancestral mother (the "extended matriline" hypothesis), multiple matrilines were found in the groups stranded together.

In some strandings, the researchers assessed the spatial relationships of individual whales on the beach. The position of each stranded whale was mapped to determine if individuals found near each other were related. No correlation was found between location and kinship, even when considering only the location of nursing calves and their mothers, who were often widely separated when the group drove itself onto the shore.

Most surprising was the evidence of "missing mothers" -- that is, many of the stranded calves and juveniles had no identifiable mother among the other beached whales.
"Several scenarios could account for the lack of spatial cohesion, including the disruption of social bonds among kin before the actual strandings," commented Oremus. "In fact, the separation of related whales might actually be a contributing causal factor in the strandings, rather than simply a consequence."

The results of this study have important implications for rescue efforts aimed at "refloating" stranded whales. "Often, stranded calves are refloated with the nearest mature females, under the assumption that this is the mother," explained Scott Baker, co-author and Associate Director of the Marine Mammal Institute at Oregon State University. "Well-intentioned rescuers hope that refloating a mother and calf together will prevent re-stranding. Unfortunately, the nearest female might not be the mother of the calf. Our results caution against making rescue decisions based only on this assumption."

The researchers acknowledge an important remaining question: where are the "missing mothers?" Had these adult females successfully refloated or had they never stranded in the first place? To answer this question, the researchers conclude that genetic samples are needed from all whales involved in strandings, including from those individuals that do eventually make it back to sea.

http://www.sciencedaily.com/releases/2013/03/130314124603.htm

NAVAL SONAR EXERCISES LINKED TO WHALE STRANDING, 
ACCORDING TO NEW REPORT

Dtag on a beaked whale. 

(Credit: Photo by Todd Pusser, 

taken under NMFS permit 14241)

Mar. 16, 2011 — Scientists have long been aware of a link between naval sonar exercises and unusual mass strandings of beaked whales. Evidence of such a link triggered a series of lawsuits in which environmental groups sued the U.S. Navy to limit sonar exercises to reduce risk to whales. In 2008, this conflict rose to the level of the US Supreme Court which had to balance potential threat to whales from sonar against the military risk posed by naval forces inadequately trained to use sonar to detect enemy submarines. The court ruled that the Navy could continue training, but that it was essential for the Navy to develop better methods to protect the whales.

The knowledge most critical to protecting these whales from risk of sonar involves measuring the threshold between safe and risky exposure levels, but until now it has not been known how beaked whales respond to sonar, much less the levels that pose a problem. "We know so little about beaked whales because they prefer deep waters far offshore, where they can dive on one breath of air to depths of over a mile for up to an hour and a half," said Peter Tyack, a senior scientist at Woods Hole Oceanographic Institution (WHOI).

Now, an international team of researchers reports in a paper led by Tyack the first data on how beaked whales respond to naval sonar exercises. Their results suggest that sonar indeed affects the behavior and movement of whales.
Tyack and his colleagues used two complementary methods to investigate behavioral responses of beaked whales to sonar: "an opportunistic approach that monitored whale responses to multi-day naval exercises involving tactical mid-frequency sonars, and an experimental approach using playbacks of simulated sonar and control sounds to whales tagged with a device that records sound, movement, and orientation," the researchers report in the current issue of the online journal PLoS ONE, published by the Public Library of Science.

That research team developed experiments to slowly increase the level of sonar at a tagged whale, to stop exposure as soon as the whale started responding, to measure that exposure, and to define the response. The experimental approach used tags to measure acoustic exposure and behavioral reactions of beaked whales to one controlled exposure each of simulated military sonar, killer whale calls, and band-limited noise.

"These experiments were very difficult to develop, and it was a major breakthrough simply to be able to develop a study that could safely study these responses," Tyack said. "All three times that tagged beaked whales were exposed experimentally to playback of sounds when they were foraging at depth, they stopped foraging prematurely and made unusually long and slow ascents to the surface, moving away from the sound.

Beaked whales use their own biosonar to find prey when they are foraging; this means that one can monitor cessation of foraging by listening for when they stop clicking. Once the researchers found that beaked whales responded to sonar by ceasing clicking, they were able to monitor reactions of beaked whales during actual sonar exercises on the range. The research was conducted on a naval testing range where an array of underwater microphones, or hydrophones, covered the seafloor, allowing whale sounds to be monitored over 600 square miles. "During actual sonar exercises, beaked whales were primarily detected near the periphery of the range, on average 16 km away from the sonar transmissions. Once the exercise stopped, beaked whales gradually filled in the center of the range over 2-3 days," they report.

A satellite tagged whale moved outside the range during an exercise, returning over 2-3 days post-exercise. "The combined results indicate similar disruption of foraging behavior and avoidance by beaked whales in the two different contexts, at exposures well below those used by regulators to define disturbance," the scientists report.
"This suggests that beaked whales are particularly sensitive to sound. Their behavior tended to be disrupted at exposure levels around 140 decibels (dB), so they may require a lower threshold than many current regulations that anticipate disruption of behavior around 160 dB, " said Tyack. "But the observations on the naval range suggest that while sonar can disrupt the behavior of the whales, appropriate monitoring and management can reduce the risk of stranding."

The research was supported by the United States Office of Naval Research, the U.S. Strategic Environmental Research and Development, the Environmental Readiness Division of the U.S. Navy, the U.S. Chief of Naval Operations Submarine Warfare Division (Undersea Surveillance), NOAA and the Joint Industry Program on Sound and Marine Life of the International Association of Oil and Gas Producers. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

http://www.sciencedaily.com/releases/2011/03/110316153133.htm

U.S NAVY SONAR LINKED TO WHALE STRANDINGS, 
ENVIRONMENTAL SCIENTISTS ARGUE

Beached sperm whale. 

"Sonar is killing more whales than we know about," 

said Prof. Chris Parsons of George Mason University. 

(Credit: iStockphoto/Alan Drummond)

Oct. 6, 2008 — Earlier this summer, the U.S. Supreme Court agreed to review a series of lower court rulings that restrict the Navy's use of sonar in submarine detection training exercises off the coast of Southern California. The court is due to hear the case after its term begins again this month.
For many years, professor Chris Parsons has been tracking the patterns of mass whale strandings around the world. In his most recent paper, "Navy Sonar and Cetaceans: Just how much does the gun need to smoke before we act?" Parsons and his co-authors bring together all of the major whale and dolphin strandings in the past eight years and discuss the different kinds of species that have been affected worldwide. They also strongly argue for stricter environmental policies related to this issue.

"Generally, if there is a large whale stranding, there is a military exercise in the area," says Parsons. "Sonar is killing more whales than we know about."
Parsons is a national delegate for the International Whaling Commission’s scientific and conservation committees, and on the board of directors of the marine section of the Society for Conservation Biology. He has been involved in whale and dolphin research for more than a decade and has conducted projects in South Africa, India, China and the Caribbean as well as the United Kingdom.

Though Parsons believes that there is a good chance the U.S. Supreme Court will rule in favor of the Navy, he thinks there is a chance for a win-win situation on both sides.
"If the Navy uses proper mitigation efforts, it can still perform its exercises and affect less of the whale population," he says. However, he argues they need to avoid sensitive areas completely, and have trained, experienced whale experts as lookouts when performing these exercises—"not just someone who has watched a 45-minute DVD, which is sadly the only training most naval lookouts get with respect to finding and detecting whales."

Even with all these efforts, however, Parsons worries that sonar is affecting many more whales than we even know about. "Eventually the Navy may have to reconsider the use of certain types of sonar all together. They could be wiping out entire populations of whales, and seriously depleting others."

http://www.sciencedaily.com/releases/2008/10/081006112057.htm