Parting the Curtain on Whales And Dolphins in Hawaiian Waters

posted in: February 2017 | 0

9780824859985_p0_v1_s192x300Robin W. Baird. The Lives of Hawai`i’s Dolphins and Whales: Natural History and Conservation. University of Hawai`i Press, 2016. 342 pages (including bibliography and index).

Less than two decades ago, knowledge of and research into Hawai`i’s cetaceans was pretty much limited to just two of the more common species. And then Robin Baird began his work in the islands.

“When I started working in Hawai`i in 1999, there was a crowded research environment,” Baird writes in the preface to The Lives of Hawai`i’s Dolphins and Whales, “but with one or two exceptions, every publication on whales and dolphins in Hawaiian waters in the previous thirty years had focused on just two species: humpback whales or spinner dolphins.”

It made no sense to him, he continues, “to focus on those well-studied species, and when opportunities arose to work with any of the rarer, lesser-known species, I took them.” Since then, he has made hundreds of marine surveys, criss-crossing thousands of miles of ocean around the main Hawaiian islands, in an effort to document both the resident populations of whales and dolphins and the species that merely pass through these waters. Those that reside here, Baird writes, find the islands to be an “oasis in a desert sea,” thanks to the complex ocean currents and other phenomena that combine to bring nutrient-rich waters from the deep ocean closer to the surface. “It is not the productivity itself around the islands that creates the oasis; it is the discontinuity between the extremely low productivity waters of the central tropical Pacific and the slightly more productive waters immediately surrounding the islands that creates it,” he writes.

“Of the twenty-five species of whales and dolphins that have been recorded in Hawaiian waters, more than half (eighteen) of the species are odontocetes – the toothed whales and dolphins. The remaining seven species are mysticetes – the baleen whales. Most of the baleen whales come to Hawaiian waters only in the winter, and some of the odontocetes just move through the area, part of large open-ocean populations. But for eleven of the species, all of them odontocetes, this oasis has created a year-round home, with populations living off the island shores, taking advantage of the increased predictability of prey.”

All 25 species (and a few more baleen whales that are rare visitors) are described in Baird’s book, but he gives disproportionate attention to five species of oceanic dolphins collectively known as “the blackfish.” His presentation of species starts with this group, he writes, “both because they are my favorite group and because the best-known populations of several of these species anywhere in the world are found in Hawai`i.” (By now, it should go without saying that the reason these several species are the world’s “the best-known populations” rests firmly on Baird’s own shoulders.)

Many of the astonishing results of his having taken this less-traveled research road are evidenced in this recent volume.

It is, perhaps first and foremost, a reference book. More than 20 species of whales and dolphins are described and illustrated in sections organized around general types: oceanic dolphins, beaked whales, sperm whales, and baleen whales. Meticulously documented, it is as scientifically rigorous as any peer-reviewed publication, yet it is written in a style that is accessible to the layperson.

It is a story book. The interactions of these highly intelligent, social animals not only among themselves but also with humans and other species, make for fascinating narratives.

On top of all that, the book’s large format – 10 inches by 8 ½ inches – and stunning full-color photographs make it suitable to display on any coffee table.

Societies of Friends

Several of the more endearing social behaviors of false killer whales have been widely described well before this book was published. But in this volume, they’re documented as to date, location, and parties involved. One of the best known encounters involves inter-species prey-sharing and took place in 1984, when Dan McSweeney, a researcher who has worked closely with Baird, was following a group of false killer whales off the Kona Coast.

As Baird recounts, McSweeney “slipped into the water with a mask, a small scuba tank, and an underwater camera. Two black shapes moved by below, vocalizing. Dan turned, and a third individual was swimming rapidly toward him, carrying most of a large ahi, a yellowfin tuna, weighing over 45 kilograms …. The whale stopped a couple of meters away and opened its mouth, letting the fish go, and the momentum carried the fish toward Dan. The whale was obviously offering the fish to him, and Dan reached out and took it. The false killer whale started blowing bubbles, moved away, then turned rapidly and came back, stopping next to him again. Dan pushed the fish back toward the whale; it took it slowly and deliberately, then moved away and joined its companions. The whales passed the fish back and forth and started to consume it, and all had a share.”

This type of behavior, says Baird, “probably serves to reinforce the strong bonds among individuals that may be constant and long-term hunting companions in an environment where the benefits of cooperatively finding and catching prey allow them to survive as top predators.”

The false killer whales and other species of blackfish have “enduring bonds among individuals,” he writes. Females begin to give birth to their first calves somewhere around nine years of age and continue to calve every couple of years until their mid-40s, when they go through menopause, “unusual in the animal kingdom,” Baird writes, and probably evolved “because older females perform a more important role as a grandmother or auntie than they would by having more calves themselves.”

The population of false killer whales in the waters around the Main Hawaiian Islands is low enough – around 120 individuals – and threatened enough, to have been listed as endangered in 2012, largely thanks to Baird’s work. For this, he has not been thanked by the Western Pacific Fishery Management Council and the commercial fishermen it represents. As a result of the listing, additional restrictions have been placed on longline vessels fishing in waters around Hawai`i. Baird is frequently vilified in comments made during council discussions of protected species management measures. In 2013, he was named to the council’s Protected Species Advisory Committee but after a rancorous meeting in January 2014, when Baird and others say he was treated in a highly uncivil manner, he resigned. (For more on this, see the May 2014 edition of Environment Hawai`i.)

In contrast to false killer whales, short-finned pilot whales are probably the most abundant blackfish residing around the main Hawaiian islands. Baird notes that estimates of their population range between 19,000 and 20,000 individuals, with the highest concentration off Hawai`i Island. They also live in distinct communities. These whales dive deep for their prey, up to 1,000 meters, so prey-sharing hasn’t been documented.

Yet they obviously have strong social ties. One of the most touching photos in the book is of a trio of pilot whales – an adult male and two adult females, most likely a mother and daughter – seeming to grieve the death of a calf carried in the mouth of the male.

Pygmy killer whales are the least common of the blackfish sighted in Hawaiian waters. Estimates of their numbers range from roughly 1,000 (a National Marine Fisheries Service survey in 2002) to more than 10,000 (a 2010 NMFS survey).

As Baird describes the species, it seems particularly ill tempered, attacking other species of dolphins and even having dangerous encounters – whether playful or otherwise can’t be known – with humans. Their social groups are generally small, with an average size of nine individuals, he writes, adding, “From analyses of associations, pygmy killer whales have extremely strong and enduring social bonds. Two adult females first seen together in 1994 were still together twenty years later, and in almost every sighting of either individual in the intervening years, both were present.”

Pygmy killer whales are also subject to mass strandings, especially, in Hawai`i, around the Ma`alaea area of Maui. “There are probably many reasons why such strandings occur,” Baird says. “With such strong social bonds, if one individual in a group is sick, all members of the group might move into shallow water to support it during its last days, placing themselves at risk.”

Melon-headed Whales

Baird opens his chapter on this group of whales by recounting an event witnessed by Charles Wilkes in 1841. Wilkes, commander of the U.S. Exploring Expedition, described “the chase of blackfish.” A shoal of them had been seen on a February afternoon in Hilo Bay, upon which “the natives who were fishing, and those on shore, put off in their canoes to get seaward of them; when this was effected, they began making a great noise, to drive the fish in; and finally succeeded in forcing many of them into shoal water, from whence they were dragged on the beach, when about twenty of large size were taken.” The whales “offered a fine feast … besides yielding plenty of oil.”

Wilkes measured one of the animals, which was later determined to be one of just four type specimens of melon-headed whales.

More than a century and a half later, in July 2004, a group of 150 to 200 melon-headed whales moved into the shallows of Hanalei Bay. “The reaction of local residents was quite different than in 1841,” Baird notes. The next morning, “community members, volunteers, the local stranding network, and others helped herd the whales out of the bay, where they had spent over 28 hours. Only one melon-headed whale, a calf, was found dead the next day.”

That “pre-stranding” behavior, he writes, was probably the result of a different “great noise” – generated by naval vessels to the north using mid-frequency active sonar (MFA sonar) as part of the RIMPAC military exercises.

Baird has identified two populations of melon-headed whales. The Kohala population ranges in a narrowly prescribed area from the northern tip of the Big Island down to Kona, in waters between 300 and 1,000 meters deep. By contrast, individuals from the Hawaiian Islands population “spend almost all their time in depths greater than 1,000 meters, regularly move among islands and into offshore waters, and at least occasionally move to international waters.” The estimated sizes of the two populations are 400 to 500 for the Kohala group and more than 8,000 for the Hawaiian Islands group, Baird says.

At times, “the entire Kohala resident population may be together in one large group,” he writes. “Given the frequency of naval training operations in Hawai`i, it is not hard to imagine a scenario where all or most of the Kohala resident population could be exposed to high-intensity sonar and either be forced out of its normal range into unfamiliar waters or even end up stranding while trying to get away from the sonar. Until and unless the high-intensity sonars are prohibited in the area surrounding the range of this population off the northwest coast of the island of Hawai`i, I think they will always be at risk of a catastrophic event potentially affecting the entire population.”

Baird closes his discussion of this species by mentioning yet another source of harm. “Individuals from both the Hawaiian Islands population and the Kohala resident population have dorsal fin injuries suggestive of line entanglements. … Whether they are sometimes taking bait off fishermen’s lines is unknown, but that is one potential source of such injuries. There are also five melon-headed whales that we have photos of that appear to have bullet wounds in the dorsal fins. I suspect that melon-headed whales may have been occasionally targeted as a result of their resemblance to false killer whales, and fishermen have mistakenly shot at them, thinking they were taking their catch. It is ironic, given that melon-headed whales feed only on small squid and deep water fish and do most of their feeding at night.”

‘Lessons Learned’

Unlike many researchers and scientists, Baird doesn’t shy away from making strong recommendations for the conservation of the full range of animals he describes in this book. His discussion of the conservation of false killer whales in Hawai`i, near the end, describes the long process of winning protection for their populations in the islands – a process involving, first and foremost, painstaking research, peer-reviews publications, court action, and finally, federal regulation.

“While science, both environmental and social, is critical for understanding the implications of the conflicts between fishermen and whales and dolphins in Hawaiian waters,” he writes, “mitigating these conflicts will require a long-term approach. Working with fishermen to find solutions will be the key, and educating and inspiring new generations of fishermen to accept the role of dolphins and whales in the ocean ecosystem is essential.”

— Patricia Tummons

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