Thursday, December 13, 2018

Missing Hawaiian humpback whales? They're staying late in Alaskan waters, but it's still not certain why.



Hawai`i's humpback whales are missing, and now there are new clues about why.

In Hawai`i as well as other southern migration areas, steep declines in whale numbers are being reported. Researchers in Alaskan waters now report that they're seeing whales that are staying in northern waters instead of migrating.

(Image: Humpback in Sitka Sound, Mt. Edgecumbe: Humpback whale flukes are visible just on the surface with Mt. Edgecumbe on the horizon in Sitka, Alaska Sunday, October 28, 2018. Credit: Seanna O’Sullivan/UAS.)
What's not yet clear is whether they will just delay migration, perhaps because of warmer conditions in areas like Sitka Sound, or whether they can't migrate because changes in food availability have deprived them of the energy for the 30-day migration.

It is also not yet clear whether the delayed or omitted migrations will impact populations. Humpback whales make the trip to southern waters to give birth to their young.

“We are concerned that the offshore warm water anomaly known as 'the blob' and other ocean conditions has had a negative impact on humpback whale prey.” said Ellen Chenoweth, a UAS Adjunct Professor at University of Alaska Fairbanks.

Researchers are trying to raise the funds to figure out what's going on, she said.  It is not just that the whales are staying longer, but there are indications they are in distress. A release from the University of Alaska Southeast suggests there's something serious going on: "The researchers noted that they are seeing fewer calves, skinnier whales and more whales staying longer into winter feeding on herring, partially migrating and returning or possibly not migrating at all."

“We would like to quantify the changes in the numbers and distribution of whales present in winter and try to get at the cause and effect. But we need more monitoring funds. This means we need gas in the boat, time to be out there later in the season and, more technicians to manage the data and document the whales and more time on the water,” Chenoweth said.

The UAS Whale Research and Education Support fund will support the research. Donations can be made here. 

The dramatic change in migration habits mars a textbook success story in whale conservation.
Humpback whale populations had been drawn so low by whaling that they were listed as endangered in 1973 under the Marine Mammal Protection Act. 
By the 1980s, numbers that winter in Hawai`i had risen from a few thousand to more than 11,000. Almost all of those whales summer in southeastern Alaskan waters where the feed on schools of capelin, juvenile walleye pollock, sand lance, Pacific herring and krill.  

The dramatic increase in humpback populations continued into the 2010s, but appeared to stop and then drop a couple of years ago.

“There is a substantial decline in the number of whales we’re seeing. But when we look very closely at least in the waters off Lahaina (Maui), which is where most of the whales congregate, that decline is very much accounted for by the drop in the number of mother and calf pairs,” said Rachel Cartwright, a California State University researcher who heads the Keiki Kohola project.

An Associated Press story reviewed the reports of declining whale numbers in the islands. 

Cartwright said that reduced food supplies in the northern feeding waters are among the suspects for the decline. Chenoweth said Alaskan fisheries officials are also concerned about the impact of feeding whales on winter populations of schooling herring.
Early indications are that the first decline in humpback whales was caused by direct killing of the animals by the whaling fleets of the 1800s and 1900s. The cause of the new decline may be indirect: the impact of climate change on water temperatures and prey availability. 

©Jan TenBruggencate 2018

Friday, November 30, 2018

Kauai pilot whale strandings punctuated by seven separate stranding incidents in a week down under


Dead pilot whales Kalapaki Beach. Credit: Author
Whale strandings—like the one that killed five pilot whales on an East Kaua`i beach last year--remain among the most mysterious of natural occurrences.

Kaua'i residents were traumatized the morning of Oct. 13, 2017, as glossy black pilot whales lay gasping on the sand at Kalapaki Bay. When well-meaning citizens shoved them back into deep water, most returned to the sand.

Boaters in canoes and power craft patrolled the bay, trying to keep remaining members of the pod from stranding. Eventually, five big whales were dead.

Seven strandings within the past week of more than 200 whales of several species in New Zealand and Australia has refocused attention on marine mammal strandings.

In all those southern hemisphere strandings, as in the Kaua`i stranding, the cause was not immediately apparent.

And in the Kaua`i case, despite intensive studies over a full year, scientists have been able to identify no obvious trigger.

"We still have no smoking gun but we're still looking," said David Schofield, stranding coordinator for NOAA's Pacific Islands Regional Office.

One of the Kaua`i animals, an older one, had signs of degenerative disease in earbones, but that was unlikely a cause of stranding, he said. One whale had about 10 pounds of marine debris in its gut, but that, too, was not a likely cause, Schofield said.

When animals are diseased, they are often malnourished. These whales weren't starved. There was fresh food in their bellies. There were no obvious signs of disease identified in a well-staffed mass necropsy that continued through the night of the strandings.

They weren't damaged by sonar: No sonar vessels were operating in the area, and in any case, the necropsies found none of the kind of inner ear damage caused by high-intensity sonar.

There were no signs of disease apparent within the first few weeks after the stranding.

Muscle and organ samples were sent to specialized laboratories, but tests for pesticides or rat killers like diphacinone were negative. (Diphacinone was of interest because it had been used in a rat control effort on Lehua Islet in the weeks before the strandings.)

Researchers are still working on laboratory studies of possible contaminants in the whale tissues, and tissue samples remain in storage.

"We keep the file open. As new science becomes available, we may go back and look again," Schofield said.

A series of seven separate strandings by different whale species in New Zealand and Australia—all within the past week--adds to the enigma.

Mystery is often the case in explaining whale strandings. And it’s just as much a puzzle this week in New Zealand and Australia.

Within the space of seven days, whales drove themselves on five separate New Zealand beaches from the North Island down to little Stewart Island, which lies south of Aotearoa's South Island, and even to the remote Chatham Islands, which lie in the Pacific east of New Zealand. And another two species died this week on the same beach, but in separate strandings in southern Australia.

Ninety pilot whales went ashore on the Chatham Islands today. An estimated 50 were dead or in such bad shape that wildlife officials euthanized them. A few were able to refloat themselves and may survive.

Four days earlier, 145 pilot whales went ashore on remote Mason's Bay on Stewart Island. They were the same species as in the Kaua`i 2017 stranding. All the Stewart Island whales died on a beach so isolated that it is only accessible by foot trail or by air. An aerial photo shows the one to two-ton whales scattered by the dozens along the shore, like so many akule drowned in a surround net.

On the North Island, 12 pygmy killer whales went ashore on one beach this past week. A few were reportedly pushed back into the water and may have survived, but at least half were dead. A sperm whale died on another North Island beach, and a pygmy sperm whale on still another.

Meanwhile, in Australia, 27 pilot whales and a humpback whale were spotted dead this week on a remote beach in Croajingolong National Park, which is in Victoria, the southernmost district on the Australian mainland.

They were spotted by air. By the time wildlife officials were able to get there, some of the pilot whales were still alive, but were so severely traumatized that they were put down. The humpback seems to have stranded earlier and was already dead, Australian wildlife officials said.

And once again, at this point nobody knows why. It is a long distance between these locations. From Stewart Island to the northern beaches of North Island is nearly 1,000 miles. From the Chathams in the Pacific to Victoria in the Tasman Sea is 2,000 miles.

There are lots of theories, many being proposed without evidence.

Folks looking for a common thread in the latest strandings have suggested climate change, but that's a guess. And it wouldn’t explain that the largest known stranding occurred a century ago. One thousand pilot whales stranded and died in the Chatham Islands in 1918.

The New Zealand stranding response organization Project Jonah, says it might be illness, parasites, pollution, injury from boat strikes, human undersea seismic work or sonar, disorientation due to shallow waters, boat noise, undersea volcanic or earthquake activity, and in some cases, simple geological traps—whales swimming into a bay a high tide an being unable to leave at low tide.

There is, in many of these cases, a kind of community unity. Once one whale is in trouble, the others stay in support—even at the risk of dying.

"Whatever the reason for the initial stranding, social cohesion may result in mass beaching. Their strong social bonds may prevent them deserting a helpless member. Going to their aid, these animals may then also become stranded themselves," says Project Jonah.

Strandings occur seasonally in some parts of the world, although not in Hawai`i. The stranding season is just beginning in the Australia-New Zealand area. Schofield recalls working Cape Cod, where there was also seasonality.

"In wintertime, when you saw certain tides, sea conditions and moon phase, you could almost predict them," he said.

And even so, the causes remain a mystery.

© Jan TenBruggencate 2018

Friday, November 23, 2018

New federal climate report: Hawaii impacts severe and already here


Climate change isn't coming; it's already here.

A new national report lays out the many ways in which the Hawaiian Islands are already in the grip of severe changes, from our nearshore waters to our highest peaks.

The short version: Fresh water supplies are threatened in multiple ways; Coastlines are eroding and rising salt water is damaging coastal infrastructure; Fisheries are seeing lower yields; Wildlife is disappearing.

The Fourth National Climate Assessment, Volume II, prepared by the U.S. Global Change Research Program, looks at the effects of the global climate crisis across the nation, and includes an entire section on Hawai`i and the Pacific.

Climate indicators and impacts.
From 4th NCA Vol2
It follows up on Volume 1, the Climate Science Special Report, which came out about this time last year. The research effort was established by congress in the Global Change Research Act of 1990, and was signed into law by President George H.W. Bush.

“This report makes it clear that climate change has arrived far sooner and as a greater threat than we previously thought,” said the East-West Center's Victoria Keener, who served as regional lead for the Hawai`i-Pacific chapter.

The Union of Concerned Scientists said the latest version of the report adds new information in the ways different climate impacts interact. "There is now information available on the interconnectedness of different sectors, and how this can lead to ripple effects," said Rachel Licker, senior climate scientist with the organization. Examples: heat waves are linked to power outages, drought to crop losses, warming oceans to loss of coral reefs.

Keener emphasized the local impacts, and said immediate action is crucial:

"We're already seeing threats in Hawai`i and the Pacific… In the mid-2000s, Hawai`i had the worst drought on record… Here on O‘ahu, we already see road closures during morning rush hour because of flooding, and with sea level rise we’ll see this more and more. Our Pacific Island neighbors on atolls will face sustainability challenges sooner rather than later. The world’s largest insurers recently stated that climate change is creating an ‘uninsurable’ world. Only by acting now can we hope to effectively manage these risks,” Keener said.

The City and County of Honolulu's chief resilience officer Josh Stanbro said one action is particularly critical: " Given the hurricane threats and flooding we’ve already seen, everyone’s new year resolution should be to get off of fossil fuel as fast as we possibly can—it’s the only way to protect our safety and long-term security.”

The islands depend on fresh water, and water supplies are threatened by droughts that reduce groundwater recharge, reduced rainfall that shrinks streamflow, flooding during increasing storm events that spread pollutants, saltwater intrusion along coasts that turns nearshore groundwater brackish and much more.

Zena Grecni, a Yale-educated climate assessment specialist with NOAA at the East-West Center, said "the leadership at the state and county level is critical."

Both Grecni and Keener cited the city Board of Water Supply for its aggressive efforts to protect Honolulu water supplies from the impacts of climate change. Keener said community groups in various places on the Islands are also leaders in addressing climate change.

In a public statement on the climate report, the East-West Center listed some of its key findings:

Dependable and safe water supplies are threatened by rising temperatures, changing rainfall patterns, sea level rise, and increased risk of extreme drought and flooding. Islands are already experiencing saltwater contamination due to sea level rise, which is expected to catastrophically impact food and water security, especially on low-lying atolls.

Sea level rise has accelerated and is now damaging critical infrastructure such as transportation and housing, as well as beaches, ecosystems and cultural sites. In Hawai‘i, the value of all structures and land expected to be flooded by 2100 amounts to more than $19 billion statewide. The Pacific Islands will experience sea level rise higher than the global average, projected to further accelerate strongly after mid-century. Adaptation strategies that are implemented sooner can better prepare communities and infrastructure.

Increasing ocean temperatures and acidification threaten fisheries, coral reefs, and the livelihoods they support. Widespread coral reef bleaching and death are occurring more frequently, and by mid-century these events are projected to occur annually, especially if current trends in greenhouse gas emissions continue. Bleaching and acidification will result in loss of reefs, leading to lower fisheries yields and loss of coastal protection and habitat.

These changes imperil Indigenous peoples’ health and well-being and their relationships with lands, territories, and cultural resources.

Climate change reduces the ability of habitats to support protected plant and animal species. Changes promote the spread of invasive species, threatening biodiversity, important to island people and a source of economic revenue. Some species are expected to become extinct and others to decline to the point of requiring costly protection.

“This Assessment puts out a red alert to island communities like Oʻahu and shows just how vulnerable we are at a local level to climate change,” Stanbro said.

©Jan TenBruggencate 2018

Tuesday, November 13, 2018

Do humans always wipe out the big animals, or can they sometimes coexist? Evidence from Madagascar.



Scientists generally accept the theory that once humans arrive at an isolated landscape, they quickly destroy the big animals there.


Some call it the blitzkrieg hypothesis. But there's new evidence that, at a minimum, raises questions about this theory.

(Image: Bones with tool cut marks of the Madagascar Aepyornis, the giant elephant bird. Credit:  V. Pérez, Science Advances, 5:9 (2018))

In the Hawaiian Islands, the big flightless ducks that have been called moa nalo were in the islands when the first Polynesians arrived, but were gone soon thereafter. Smithsonian researcher Storrs Olson reported that the moa nalo—which represents a class of extinct big birdsdisappeared during the early human occupation of the Islands.

Fossils of numerous such species are "contemporaneous with Polynesian culture. The loss of species of birds appears to be due to predation and destruction of lowland habitats by humans before the arrival of Europeans," Olson wrote. 

In New Zealand, the class of giant moa birds (Dinornis sp.) also disappeared with the arrival of the humans. New Zealand Geographic has a piece on that loss. 

In Madagascar, the arrival of humans has been linked to the loss of the giant elephant birds, Aepyornis maximus and other species.

But recently, researchers in Madagascar found Aepyornis bones more than 10,000 years old with human tool marks on them. Until now, humans were not believed to have been in Madagascar until 2,500 years ago or at most 4,000 years ago. Some came from Polynesian origin societies to the east and some from Africa to the west.

And Aepyornis are believed to only have gone extinct in the last couple of thousand years.

So, 10,500 years ago?

"Our evidence for anthropogenic perimortem modification of directly dated bones represents the earliest indication of humans in Madagascar, predating all other archaeological and genetic evidence by >6000 years and changing our understanding of the history of human colonization of Madagascar," write the authors of this paper, Early Holocene humanpresence in Madagascar evidenced by exploitation of avian megafauna


An article in Science reviews the issue. 

In it, paleoecologist David Burney says it's a big deal: The findings"fly in the face of all that we thought we knew about human arrival in Madagascar." Burney has worked extensively with the Kaua`i-based National Tropical Botanical Garden, and has also done considerable work in Madagascar.

If humans were there that early, why didn’t they earlier wipe out the big birds and big mammals as the theory suggests they do? And if humans were there that early, why haven't archaeologists found evidence of the human presence?

For now, two theories arise.

1) It was perhaps a small, temporary human presence—maybe a visiting group of people that killed and ate some creatures and then left, or died out.

2) Maybe they haven't found evidence because they haven’t been looking for archaeological sites that early.
That said, scientists for four decades have understood that when humans arrive, they conduct a "blitzkrieg" that wipes out many big animals. Is it possible that in Madagascar, humans were able to coexist, to survive for thousands of years without wiping out megafauna?

Depending on what researcghers uncover next, it is at least possible.

Well, and then there's the question of how humans were voyaging across oceans as early as 10,500 years ago. That's more than 5,000 years before Polynesians began plying the Pacific in their voyaging canoes.

© Jan TenBruggencate 2018

Thursday, November 8, 2018

Climate forecast: 2019 to be an El Nino year


It's been a while coming, but federal climate researchers say there's now robust evidence that the Pacific is moving into a new El Nino cycle.

For our Islands, that means a possibly dry winter, and the potential of a higher hurricane count than normal in 2019.

The Climate Prediction Center issued its new outlook today (Nov. 8, 2018), and you can look at it here

It concludes that there is now an 80 percent chance that an El Nino will form, and will stay in place right through next winter—meaning it's there during the entire 2019 hurricane season.

There are now warmer-than-normal water temperatures across the equatorial Pacific, although right now the assessment is that conditions are still neutral.

Climate forecasters' best guess is that the 2019 El Nino will not be a strong one, giving those concerned about hurricane patterns a little good news.

The International Research Institute for Climate and Society at Columbia University publishes lots of detailed information on climate forecasts, and if you're interested in a whole lot of colorful spaghetti charts summarizing different climate models, look here

© Jan TenBruggencate 2018