Operative word: Envisioned.

Scientists at Michigan State University (MSU), University of Waterloo, and University of Alaska Fairbanks report in Climatic Change where vessels are traveling in the ice-covered waters of the Arctic between Alaska and Russia, and what those reports may mean for important wildlife and communities in the region.

“Even with climate change, sea ice is still a substantial barrier to Arctic vessel traffic,” said Kelly Kapsar, a research associate at MSU’s Center for Systems Integration and Sustainability (CSIS). “Sea ice also provides critical habitat for many endemic Arctic species and a hunting platform for Indigenous subsistence hunters. Understanding when and where ships are entering areas of sea ice can help us to better understand potential impacts of vessel traffic in the region.”

Whether its fishing vessels seeking better catches over a longer season, or Russian shipping companies eager for better ways to deliver oil and gas to Chinese customers, increased marine traffic is a given. Whether this traffic occurs only in the open water season, or also in times of ice cover is not.

But the researchers point out the difference between what ships could do as ice changes, and what they will do can be vastly different.

“Up until now projections have been about theoretical ships, such as noting certain vessel types can travel through up to 2 meters of ice,” Kapsar said. “But that’s like saying a car can drive up to 200 mph — just because it can doesn’t mean it will.”

Combining satellite pictures of ice cover with GPS vessel tracking data the team was able to analyze how the ships have been behaving as the shipping passages change. What they’ve found is that many ships are following the ice, fishing close to the edge of ice packs. The researchers also found marked overlap between areas with vessels traveling in sea ice and the overwintering areas for bowhead whales.

Previous research by another group has demonstrated that between 1990 and 2012, some 12% of bowhead whales harvested by Alaska Native subsistence hunters showed signs they had been tangled in fishing gear, and 2% had scars from being struck by vessels. The new analysis points to a growing threat to wildlife which also are using the receding ice as they travel and breed.

Noise from large boats also can disrupt marine mammals. Ships equipped to break ice potentially could strand both animals and people traveling across the frozen expanses. Increased traffic also raises fear of accidents and oil spills. The new pathways are far away from rescue or clean-up crews.

So far, Kapsar said, their work indicates ship travel reflects a certain caution, offering indications that capability is balanced by practical and economic realities. For now.

Kapsar and co-author Jianguo “Jack” Liu are members of MSU’s Ecology, Evolution, and Behavior Program. “Mapping vessel traffic patterns in the ice-covered waters of the Pacific Arctic” also was written by Lawson Brigham and Grant Gunn. The work is funded by the National Science Foundation.

“Prevention strategies for Alzheimer’s and related dementias are urgently needed,” said study author Suzette J. Bielinski, PhD, of the Mayo Clinic in Rochester, Minnesota. “Routine screenings for cholesterol and triglyceride levels are commonly done as part of standard medical care. Fluctuations in these results over time could potentially help us identify who is at greater risk for dementia, help us understand mechanisms for the development of dementia and ultimately determine whether leveling out these fluctuations could play a role in reducing dementia risk.”

Researchers used health care data to identify 11,571 people age 60 or older who did not have a prior diagnosis of Alzheimer’s disease or dementia. Researchers looked at participants’ measurements of total cholesterol, triglycerides, low-density lipoprotein cholesterol (LDL) and high-density lipoprotein cholesterol (HDL) on at least three different days in the five years before the start of the study.

Then researchers divided participants into five equal groups based on how much the measurements fluctuated. The lowest group had the least variation over time and the highest group had the most variation.

Participants were followed for an average of 13 years. During that time, 2,473 people developed Alzheimer’s disease or another form of dementia.

After adjusting for variables that could affect risk of dementia including sex, race, education and lipid-lowering treatments, researchers found for total cholesterol, participants in the highest group had a 19% increased risk of dementia compared to those in the lowest group. Of the 2,311 people in the highest group, 515 developed dementia compared to 483 of the 2,311 people in the lowest group. For triglycerides, those in highest group had a 23% increased risk.

Researchers did not find a link between variations in LDL and HDL and an increased risk of dementia.

“It remains unclear why and how fluctuating levels of cholesterol and triglycerides are related to the risk of Alzheimer’s disease,” said Bielinski. “Further studies looking at the changes over time for this relationship are needed in order to confirm our results and potentially consider preventative strategies.”

A limitation of the study was researchers looked at Alzheimer’s disease and related dementias as a whole and did not differentiate between the types of dementia.

The study was supported by the National Heart, Lung and Blood Institute.

“Tooth loss and gum disease, which is inflammation of the tissue around the teeth that can cause shrinkage of the gums and loosening of the teeth, are very common, so evaluating a potential link with dementia is incredibly important,” said study author Satoshi Yamaguchi, PhD, DDS, of Tohoku University in Sendai, Japan. “Our study found that these conditions may play a role in the health of the brain area that controls thinking and memory, giving people another reason to take better care of their teeth.”

The study involved 172 people with an average age of 67 who did not have memory problems at the beginning of the study.

Participants had dental exams and took memory tests at the beginning of the study. They also had brain scans to measure volume of the hippocampus at the beginning of the study and again four years later.

For each participant, researchers counted the number of teeth and checked for gum disease by looking at periodontal probing depth, a measurement of the gum tissue. Healthy readings are from one to three millimeters.

Mild gum disease involves probing depths of three or four millimeters in several areas, while severe gum disease involves probing depths of five or six millimeters in several areas as well as more bone loss and can cause teeth to become loose and eventually fall out.

Researchers found that the number of teeth and amount of gum disease was linked to changes in the left hippocampus of the brain.

For people with mild gum disease having fewer teeth was associated with a faster rate of brain shrinkage in the left hippocampus.

However, for people with severe gum disease having more teeth was associated with a faster rate of brain shrinkage in the same area of the brain.

After adjusting for age, researchers found that for people with mild gum disease, the increase in the rate of brain shrinkage due to one less tooth was equivalent to nearly one year of brain aging. Conversely, for people with severe gum disease the increase in brain shrinkage due to one more tooth was equivalent to 1.3 years of brain aging.

“These results highlight the importance of preserving the health of the teeth and not just retaining the teeth,” Yamaguchi said. “The findings suggest that retaining teeth with severe gum disease is associated with brain atrophy. Controlling the progression of gum disease through regular dental visits is crucial, and teeth with severe gum disease may need to be extracted and replaced with appropriate prosthetic devices.”

Yamaguchi said future studies are needed with larger groups of people. Another limitation of the study is that it was conducted in one region of Japan, so the results may not be generalizable to other locations.

The study was supported by the Japanese Ministry of Education, Culture, Sports, Science and Technology; Keio University; Japan Arteriosclerosis Prevention Fund; Japanese Ministry of Health, Labor, and Welfare; Teikyo University; Pfizer Japan; Bayer Yakuhin; Chugai Pharmaceutical; Daiichi Sankyo; Astellas Pharma; Takeda Pharmaceutical; Health Care Science Institute; Health Science Center; and Takeda Science Foundation.

This is the first time that tracking data for so many seabird species has been combined and overlaid onto global maps of plastic distribution in the oceans.

The results show that plastic pollution threatens marine life on a scale that transcends national boundaries: a quarter of all plastic exposure risk occurs in the high seas. This is largely linked to gyres — large systems of rotating ocean currents — where vast accumulations of plastics form, fed by waste entering the sea from boats, and from many different countries.

Seabirds often mistake small plastic fragments for food, or ingest plastic that has already been eaten by their prey. This can lead to injury, poisoning and starvation, and petrels are particularly vulnerable because they can’t easily regurgitate the plastic. In the breeding season they often inadvertently feed plastic to their chicks.

Plastics can also contain toxic chemicals that can be harmful to seabirds.

Petrels are an understudied but vulnerable group of marine species, which play a key role in oceanic food webs. The breadth of their distribution across the whole ocean makes them important ‘sentinel species’ when assessing the risks of plastic pollution in the marine environment.

“Ocean currents cause big swirling collections of plastic rubbish to accumulate far from land, way out of sight and beyond the jurisdiction of any one country. We found that many species of petrel spend considerable amounts of time feeding around these mid-ocean gyres, which puts them at high risk of ingesting plastic debris,” said Lizzie Pearmain, a PhD student at the University of Cambridge’s Department of Zoology and the British Antarctic Survey, and joint corresponding author of the study.

She added: “When petrels eat plastic, it can get stuck in their stomachs and be fed to their chicks. This leaves less space for food, and can cause internal injuries or release toxins.”

Petrels and other species are already threatened with extinction due to climate change, bycatch, competition with fisheries, and invasive species such as mice and rats on their breeding colonies. The researchers say exposure to plastics may reduce the birds’ resilience to these other threats.

The north-east Pacific, South Atlantic, and the south-west Indian oceans have mid-ocean gyres full of plastic waste, where many species of threatened seabird forage.

“Even species with low exposure risk have been found to eat plastic. This shows that plastic levels in the ocean are a problem for seabirds worldwide, even outside of these high exposure areas,” said Dr Bethany Clark, Seabird Science Officer at BirdLife International and joint corresponding author of the study.

She added: “Many petrel species risk exposure to plastic in the waters of several countries and the high seas during their migrations. Due to ocean currents, this plastic debris often ends up far away from its original source. This highlights the need for international cooperation to tackle plastic pollution in the world’s oceans.”

The study also found that the Mediterranean Sea and the Black Sea together account for over half of petrels’ global plastic exposure risk. However, only four species of petrel forage in these enclosed, busy areas.

The study was led by a partnership between the University of Cambridge, BirdLife International and the British Antarctic Survey, in collaboration with Fauna & Flora International, the 5 Gyres Institute, and over 200 seabird researchers in 27 countries.

It is published today in the journal Nature Communications.

To get their results, the researchers overlaid global location data, taken from tracking devices attached to the birds, onto pre-existing maps of marine plastic distribution. This allowed them to identify the areas on the birds’ migration and foraging journeys where they are most likely to encounter plastics.

Species were given an ‘exposure risk score’ to indicate their risk of encountering plastic during their time at sea. A number of already threatened species scored highly, including the Critically Endangered Balearic Shearwater, which breeds in the Mediterranean, and Newell’s Shearwater, endemic to Hawaii.

Another Endangered species, the Hawaiian Petrel also scored high for plastic exposure risk, as did three species classified by the IUCN as Vulnerable: the Yelkouan Shearwater, which breeds in the Mediterranean; Cook’s Petrel,which breeds in New Zealand, and the Spectacled Petrel, which only breeds on an extinct volcano called Inaccessible Island, part of the Tristan da Cunha archipelago, a UK Overseas Territory.

“While the population-level effects of plastic exposure are not yet known for most species, many petrels and other marine species are already in a precarious situation. Continued exposure to potentially dangerous plastics adds to the pressures,” said Professor Andrea Manica at the University of Cambridge’s Department of Zoology, a co-author of the study.

He added: “This study is a big leap forward in understanding the situation, and our results will feed into conservation work to try and address the threats to birds at sea.”

This research was funded by the Cambridge Conservation Initiative’s Collaborative Fund for Conservation, sponsored by the Prince Albert II of Monaco Foundation, and the Natural Environment Research Council.