NEW & NOTEWORTHY: Focus on Cetaceans

posted in: November 2009 | 0

<b>Stranding Mystery – Solved:</b> July 3, 2004, saw some 150 melon-headed whales milling about in Hanalei Bay, apparently trying to beach themselves. Most were herded out to sea by a rescue team organized by the National Oceanic and Atmospheric Administration; one calf was known to have died.

The incident was quickly laid at the door of the U.S. Navy, which had been using mid-frequency sonar during RIMPAC training exercises. Not surprisingly, the Navy disputed the claim. Pointing to another mass stranding of melon-headed whales that occurred the same day in Rota, an island in the Marianas chain nearly 6,000 miles away, the Navy argued that the two incidents must be related and were possibly caused by lunar cycles.

In July, scientists with NOAA’s Southwest Fisheries Science Center published a paper in Marine Mammal Science that pretty much blows the Navy’s argument out of the water. Principal author Robert Brownell and colleagues looked at nearly two dozen stranding incidents involving melon-headed whales – and determined that there was no relation at all between the events and lunar phases. “You can’t blame the moon for what happened in Hawai`i,” Brownell told ScienceNOW Daily News reporter Virginia Morell.
<b>False Killer Whales, I:</b> Will Judge David Ezra require the National Marine Fisheries Service to develop at once a plan to protect false killer whales from interactions with the Hawai`i-based longline fishery? A request that he do so was the subject of a hearing in his courtroom October 26. Asking for the order to find that NMFS is in violation of the Marine Mammal Protection Act by not developing such a Take Reduction Plan were Hui Malama I Kohola, the Center for Biological Diversity, and Turtle Island Restoration Network, represented by Earthjustice attorney David Henkin.

NMFS’ attorneys do not deny that the MMPA requires the agency to establish a Take Reduction Team and a TRP, but only when they have the funds to do so. Since Congress did not appropriate the funds, they say, there is no mandate. In any event, they say, NMFS has hired facilitators to begin the process of establishing a Take Reduction Team, with the preliminary meeting of potential members to occur November 16.

Joining in opposition to the conservation groups’ request is the Hawai`i Longline Association, which has been admitted as an intervenor in the case. HLA claims that the groups’ lawsuit is “part of a misguided conservation campaign to litigate commercial longline fisheries in Hawai`i out of existence.” HLA even denies that there is such a thing as a Hawai`i pelagic false killer whale population, describing it instead as a “legal construct (e.g., faux subgroup)” of the much larger Eastern North Pacific population.
<b>False Killer Whales, II:</b> Accepting (as NMFS does) that the group of false killer whales that inhabit pelagic waters around the Hawaiian islands is a vrai population and qualifies for the protective measures called for in the Marine Mammal Protection Act, it’s in the pink of health compared to the insular population of false killer whales. That group, genetically and behaviorally distinct from the pelagic population, numbers in the low 100s, inhabits waters that are less than 75 miles from shore, and is thus far more likely to be affected by land-based activities.

Recent research shows that the Hawai`i insular population of false killer whales has high levels of persistent organic pollutants (POPs). Researchers who authored the study, published in the Marine Pollution Bulletin, collected blubber samples from nine individuals and analyzed them for the presence of POPs, which are generally fat-soluble and accumulate in tissue over time. Adult females generally had lower levels of DDT and PCBs than adult males and juveniles. Levels of chlordane, DDT, PCBs and mirex “were at least an order of magnitude higher in the subadult male offspring than those measured in his mother,” the authors wrote. This, they suggest, is “due to the transfer of lipids and POPs associated with these lipids from mother to calf during gestation and lactation.”

“These findings of elevated contaminant levels in subadult whales are a concern,” they write, “as these animals are still developing biologically and may be at higher risk to deleterious effects associated with exposure to these compounds than adults in the same population.”

Exposure to toxic chemicals was one of the reasons given by the Natural Resources Defense Fund to support its petition, filed September 30, asking that NMFS list the insular population of false killer whales as endangered. Other threats cited in the petition were interaction with fishing gear, suppression of prey as a result of fishing, deliberate injury to the animals by fishermen, and possible injury from mid-frequency sonar used by the Navy.

— Patricia Tummons

Volume 20, Number 5 November 2009

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