Mother Whales Meet Seafloor Drilling

Alarmed by the ecological risks posed by drilling and mining in the indigo gulf, whale researcher Leigh Torres is collecting data at warp speed hoping to head off harm to the giant marine mammals she studies.


April 13, 2016

IN NEW ZEALAND THERE SHINES A MILES-WIDE GULF THE COLOR OF INDIGO where whales live. Geographically, it glistens at the nexus of two islands and two seas. Politically, it sits at a different nexus, the classic clash of nature and commerce. All across New Zealand, a longstanding conflict rages between greens (conservationists, marine biologists, environmental activists) and industrial interests over the impact of seafloor drilling and mining on wildlife in the gulf.

A pygmy blue whale surfaces in front of an oil rig in the South Taranaki Bight. (Photo: Deanna Elvines, Cawthron Institute, New Zealand)
A pygmy blue whale surfaces in front of an oil rig in the South Taranaki Bight. (Photo: Deanna Elvines, Cawthron Institute, New Zealand)

Alarmed by the ecological risks posed by drilling and mining in the indigo gulf, whale researcher Leigh Torres is collecting data at warp speed hoping to head off harm to the giant marine mammals she studies.

“These human activities have the potential to impact whales through habitat degradation, habitat displacement, acoustic interference and ship strikes,” says Torres, an assistant professor at Oregon State University’s Marine Mammal Institute.

whales-tbTorres’ latest research expedition in January and February, funded in part by National Geographic Explorer, went viral when her team’s rare footage of a mother-calf pair showing nursing behavior hit social media (see video at right). “Remarkable” is Torres’ term for the density of mother-calf pairs she observed during the expedition. Her findings so far suggest that the gulf is “an important area for mothers to raise their calves during the critical seven-month lactation period before weaning.”

A Mother’s Milk

The gulf — or “bight” as the Kiwis call it — separates the north and south islands of New Zealand and, through Cook Strait, links the South Pacific Ocean with the Tasman Sea. Once upon a time, it bore the sweet name “Mothering Bay” for the southern right whales that, by the hundreds or even thousands, birthed and suckled their young in its summer waters. But in the era when blubber was coveted for lantern oil and baleen for buggy whips, southern right whales were hunted to near oblivion.

Leigh Torres assists with the deployment of a Marine Autonomous Recording Unit (MARU), developed by the Cornell Bioacoustics Research Program. This hydrophone, and four others, will remain in the South Taranaki Bight for two years recording blue whale vocalizations. (Photo: Callum Lilley, New Zealand Department of Conservation)
Leigh Torres assists with the deployment of a Marine Autonomous Recording Unit (MARU), developed by the Cornell Bioacoustics Research Program. This hydrophone, and four others, will remain in the South Taranaki Bight for two years recording blue whale vocalizations. (Photo: Callum Lilley, New Zealand Department of Conservation)

Now called South Taranaki Bight, the gulf is named for snowcapped Mount Taranaki (“shining peak” in the Maori language), a Mount Hood lookalike rising from the northern shore. Whaling is gone in these waters. Yet human extraction goes on. And another once-hunted species — the blue whale — faces new threats in the bight, which Business Day recently described as the “jewel in the crown” of New Zealand’s petrochemical industry. Instead of seeking whale oil, companies like Origin Energy and OMV NZ Limited are exploring the seafloor for crude oil and natural gas. Others are scouring the fragile seabed for minerals like iron sands.

“The South Taranaki Bight is New Zealand’s most industrially active marine region, with seven active oil and gas platforms, significant seismic exploration for new petroleum deposits, drilling of new oil rigs, seabed pipeline, potential seabed mining for iron sands, and vessel traffic,” Torres says. “These human activities must be carefully managed to avoid direct, indirect and cumulative impacts on blue whales. Good management depends on robust science.”

Jet Propelled

Robust science is Torres’ mission in New Zealand’s indigo gulf. Just a few years ago, scientists didn’t know much about blue whales in the bight. The general view was that they were transients, just passing through. But after poring over decades of old whaling records, Torres found evidence of an historically high density of blues in the region.

So in 2014, she and her team made an exploratory study. The blue whales they found — a subspecies called pygmy blues — were indeed lingering long in the prey-filled bight, devouring enormous quantities of krill. Here, then, was preliminary evidence that blues use the gulf as a seasonal foraging ground, not just as a highway to somewhere else.

But how extensive was their presence? How many blues were there? Was this truly a nursery where calves were born and suckled? No one knew. So this past winter (which is summer in New Zealand), she and her team went back.

Aboard the research vessel RV Ikatere — a 45-foot jet-propelled catamaran with a “flying bridge” for whale spotting — they gathered extensive biological, behavioral and photographic data. They took 4,000 photos to ID individual blues. They collected tissue biopsies and fecal samples for genetic and hormonal analysis. And, by launching a drone equipped with a camera, they captured stunning video of a mother and calf swimming together, the calf drifting again and again beneath its mother, suggesting suckling. The video flew around the world on social media.

Leigh Torres at sunset off the northwest coast of New Zealand's South Island after a long day working with blue whales. (Photo: Kristin Hodge, Cornell University)
Leigh Torres at sunset off the northwest coast of New Zealand’s South Island after a long day working with blue whales. (Photo: Kristin Hodge, Cornell University)

Torres and her team also deployed five bright-yellow underwater hydrophones called “MARUs” (marine autonomous recording units) anchored to the floor of the gulf, where they will stay for two years. Designed and built by Cornell University’s Bioacoustics Research Lab — one of the partners on Torres’ research team — the hydrophones already are recording whale calls and songs around the clock.

There’s little doubt now that pygmy blues not only forage for krill in South Taranaki Bight but also raise their young in the indigo waters, Torres says. Anecdotally, fishermen and pilots have insisted that they’re seeing blues in the gulf all year-round.

Still, many questions remain to be answered. Planning is underway for another expedition in 2017.

“It’s urgent that we fill these knowledge gaps,” Torres says. “Protecting these whales and their habitat depends on collecting solid data, as quickly as possible, to inform environmental managers and other stakeholders about blue whale ecology in the region.”

For firsthand accounts from the field, check out Torres’ blog at the Geospatial Ecology of Marine Megafauna Lab at OSU’s Marine Mammal Institute.

Lee Sherman Gellatly is associate editor of Terra magazine and editor of Terra+.

CATEGORIES: Marine Studies Initiative