Diving Into the Right Whale Gene Pool
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Diving into the right whale gene pool What is compromising n the first study, scientists from the New profiles. Inbreeding and genetic similar- England Aquarium (NEAq) in Boston ity in animals (including humans) often re- the endangered species’ andI Trent University in Ontario extracted sult in unsuccessful fertilization and in high ability to reproduce? DNA from skin samples collected from rates of spontaneous abortion. The study 56 percent of North Atlantic right whales suggests that the low level of genetic varia- ike forensic detectives, a multi-institu- identified since 935, including 66 percent tion in the small North Atlantic right whale tional team of scientists has followed a of the current population. By correlating population may partly explain its low repro- threadL of DNA from the highly endangered the samples with a photographic catalog of duction rate, said Moira Brown and Rosa- right whale population across the oceans whales identified over 6 years by NEAq, lind Rolland at NEAq. and back through generations. the researchers created “family trees” or ge- Using genetic techniques, the scientists nealogical charts for right whales. or the second study, scientists from undertook two studies: The first explored “It shows us who mated with whom, who NEAq, Trent, and Woods Hole Ocean- whether 6th-century Basque whalers struck had successful calves, and who isn’t having ographicF Institution traveled to remote re- a devastating blow to the North Atlantic offspring anymore,” said Trent University gions of eastern Canada to search for old right whale population and gene pool. The biologist Brad White. bones left behind by Basque whaling. second sought to determine if a lack of ge- The DNA profiles turned up genetic “In 535, Basque fishermen initiated a netic diversity (inbreeding) is now compro- material in calves from fathers that have whale fishery in the Strait of Belle Isle, be- mising the species’ ability to reproduce. never been identified. These new paternity tween what we now call Newfoundland and Both studies resulted in surprising find- data suggest that there may be many more Labrador,” said WHOI biologist Michael ings that change the explanations for the male right whales—representing perhaps Moore. “To the Basque it was a land of op- whale’s near-extinction. They also will re- an uncounted 0 to 5 percent of the entire portunity, a gold rush for whale oil to light vise strategies to conserve the species, which male population—living in currently un- Europe, which lasted to the early 600s.” has not recovered in the 70 years since known habitats. In the 980s, scientists exhumed pre- whaling was banned. Fewer than 350 re- Family tree analyses also showed that served whale bones from the wreck of a main, and the whales are having fewer off- successful pregnancies occur only between Basque galleon that sank in 565 in Red spring than expected. whales with sufficiently different genetic Bay, Labrador. Based on their physical characteristics, half the bones were initially identified as right whale bones. That led scientists to believe that extensive Basque whaling caused a dramatic decrease in the North Atlantic right whale’s population and extensive genetic loss. With the advent of molecular genetic techniques, scientists began to extract DNA from the old bones. A pilot study in 003 showed that DNA could be gathered from more weathered bones found on land, sig- nificantly increasing the potential number of samples to test the Basque theory. In 004, the research team launched an expedition aboard Moore’s sailboat Rosita to search for samples that had rested un- disturbed on beaches for 500 years. They ventured near previously identified Basque whaling ports on the Strait of Belle Isle, which Moore called “a place of cold water, icebergs, gales, and fog, often all at once.” Moira Brown, New England Aquarium Many sites were identified by the pres- � Equipped with bug jacket and sterile drill bits (lower right), Trent University graduate student ence of terra cotta tiles, which the Basques Brenna McLeod extracts samples for DNA analyses from two whale rib bones, perhaps left used first for ballast and then for roofing th behind by 16 -century whalers, in Five Leagues Harbour on the lower north shore of Quebec. over cooperages and blubber-rendering ov- 8 OCEANUS MAGAZINE Vol. 44, No. 3, 005 oceanusmag.whoi.edu The “Kleenex” Family Tree Combining DNA analyses with an extensive catalog of photo-identified whales, researchers can now construct “family trees” for right whales, like this one for a matriarch whale named “Kleenex.” Nea 1050 ♂ Nea 114 “Kleenex” ♁ Unknown father(s) Nea 1144 “Dingle” ♂ Nea 1411 ♂ Nea 1123 “Snotnose” ♁ Nea 188 ♂ Nea 264 ♁ ♁ Unknown father(s) Nea 204 Nea 3123 ♁ Nea 34 ♁ calf (sex unknown) Nea 2123 ♁ calf (sex unknown) Unknown father(s) Photo unavailable Carolyn Angell, WHOI Photos courtesy of the ♂ ♁ New England Aquarium, Nea 333 00 calf Nea 344 unless credited otherwise. Wildlife Trust Right Whale Consortium ens. The researchers walked along the shore, The studies suggest that the Basques had This research was funded in part by the sometimes through vegetation infested with little impact on right whales and that the Penzance Foundation, through the WHOI mosquitoes and black flies, to collect bones. species’ population size and genetic variabil- Ocean Life Institute’s Right Whale Re- In 005, the team investigated 6 more po- ity has been low for much longer than pre- search and Conservation Initiative. The re- tential Basque whaling stations in ever more viously believed. If that’s true, the species’ search team for the genetic diversity study, led remote areas, many inaccessible by road. potential to recover is lower and may take by Moira Brown and Rosalind Rolland at DNA analyses were conducted on 8 of longer than previously assumed. NEAq, included Heather Pettis (NEAq); Brad the 215 bones collected in 004. The results “These initial analyses have rewritten White, Roxanne Bower, Tim Frasier, and showed that 80 came from bowheads, one the history of the species, revised estimates Brenna McLeod (Trent University); marine from a finback, and none from right whales. of historic population size, and revealed archaeologists Robert Grenier and Willis Ste- To date, 210 bones from 0 known Basque previously unknown aspects of reproduc- vens from Parks Canada, and Stephen Cum- whaling sites have been analyzed, and only tive success,” the researchers said. “They baa from the Canadian Museum of Nature. one specimen came from a right whale. The could have significant implications for The research team for the Basque bone study genetic characteristics of that single right present recovery strategies.” included Brown, McLeod, White, and Michael whale bone resembled those of whales in the —Lonny Lippsett Moore (WHOI). current population. WOODS HOLE OCEANOGRAPHIC INSTITUTION 9.