Tuesday 17 September 2019

As summer 2019 saw Alaska bake, more birds seals and other marine life continue to die in unprecedented numbers and the "Pacific Blob" has returned

Credit NOAA. The Pacific Blob has returned and is causing havoc for marine life. Click on image to enlarge.

2019 will go down as Alaska’s hottest summer on record, the latest benchmark in a long-term warming trend with ominous repercussions ranging from rapidly vanishing summer sea ice and melting glaciers to raging wildfires and deadly death and chaos for marine life.
According to Reuters, July’s statewide average temperature rose to 58.1 degrees Fahrenheit (14.5 degrees Celsius), a level that for denizens of the Lower 48 states might seem cool enough but is 5.4 degrees above normal and nearly a full degree higher than Alaska’s previous record.

More significantly, July was the 12th consecutive month in which average temperatures were above normal nearly every day, said Brian Brettschneider, a scientist with the Alaska Center for Climate Assessment and Policy (ACCAP) at the University of Alaska Fairbanks.
Of Alaska’s 10 warmest months on record, seven have now occurred since 2004.

Alaska waters were completely clear of sea ice as the last ice in the Beaufort Sea melted away by Aug the 4th this year.
"The closest ice to Alaska is now about 150 miles (240km) northeast of Kaktovik." As Mashable pointed out, this is not the first time Alaska's waters have been completely free of ice - in fact, just two years ago, in the summer of 2017, the same thing happened.
But what's notable is that during the 2017 melt season, the ice melted much later in the summer.

Region 11 reported earlier this month:

2019 Alaska Seabird Die-off

Date: September 9, 2019

ANCHORAGE, Alaska—In May 2019, the U.S. Fish and Wildlife Service (USFWS) and the National Park Service (NPS) began receiving reports of dead and dying seabirds from the northern Bering and Chukchi seas, including near Bering Land Bridge National Preserve.

From late June to early August, thousands of Short-tailed Shearwaters were reported dead and washing up on beaches in the Bristol Bay region, or observed weak and attempting to feed on salmon gillnets in inland waters. By mid-August, the shearwater die-off had extended north, in smaller numbers but widespread locations, into the northern Bering and Chukchi seas along the coasts of Alaska and the Chukotka Peninsula of Russia. Puffins, murres, and auklets are also being reported, but at much lower numbers than shearwaters. Additionally, live Short-tailed Shearwaters have been observed in large numbers this August in the Gulf of Alaska, along the coasts of Glacier Bay and Kenai Fjords national parks, and bays of Kodiak Island. It is unusual to see this species in high abundance in these areas, as it is typically offshore and comes from the southern hemisphere to forage in the Bering and Chukchi seas during the summer and fall.

Photo credit adn.com
Historically, seabird die-offs have occurred occasionally in Alaska; however, large die-off events have occurred each year since 2015. (TBW Quote: millions of small dead sea birds have been reported dead annually since 2015, this year it's Short-tailed Shearwaters but recent years have seen puffins, murres, and auklets dying thought to be due to starvation).  Consistently, dead birds examined from the Bering and Chukchi seas during these recent die-offs were determined to have died due to starvation. Seabird carcasses from the 2019 die-off events were collected from multiple locations and sent to the U.S. Geological Survey (USGS) National Wildlife Health Center for examination and testing. Initial results indicate starvation as the cause of death for most locations. However, in southeast Alaska, exposure to saxitoxin (a biotoxin associated with paralytic shellfish poisoning) was linked in June to a localized die-off of breeding Arctic Terns. 

Unusual mortality event: Hundreds of seals found dead on Alaskan beaches, hundreds more thought to have died at sea.

ANCHORAGE, Alaska, (Reuters) - U.S. government biologists are investigating the deaths of nearly 300 Arctic ice seals found on Alaska beaches since the end of last summer, federal officials said on Thursday.
The National Oceanic and Atmospheric Administration on Thursday declared the seal die-off an “unusual mortality event,” a designation that allows extra resources to be used to determine the cause.

So far, 282 seal carcasses have been discovered since June 2018. Fewer than half - 119 - were found last year, NOAA said. That is five times the normal mortality rate for such seals, according to NOAA.
The carcasses likely account for a small fraction of the total number of dead seals, as scientists assume the majority of stricken animals would sink after dying or otherwise never make it to shore, said Julie Speegle, an Alaska spokeswoman for NOAA’s Fisheries Service.
The die-off comes as Arctic Alaska sea ice is scarce and sea temperatures are unusually high - conditions most scientists attribute to global warming brought on by human-caused increases of heat-trapping greenhouse gases in Earth’s atmosphere.

Earlier this month AP reported, (AP) — Federal scientists are monitoring a new ocean heat wave off the U.S. West Coast, a development that could badly disrupt marine life including salmon, whales and sea lions.
The expanse of unusually warm water stretches from Alaska to California, researchers with the National Oceanic and Atmospheric Administration said Thursday. It resembles a similar heatwave about five years ago that was blamed for poorer survival rates for young salmon, more humpback whales becoming entangled in fishing gear as they hunted closer to shore, and algae bloom that shutdown crabbing and clamming.
“Given the magnitude of what we saw last time, we want to know if this evolves on a similar path,” said Chris Harvey, a research scientist at the Northwest Fisheries Science Center.
NOAA Fisheries said the water has reached temperatures more than 5 degrees Fahrenheit above average. It remains to be seen whether this heat wave dissipates more quickly than the last one, the agency said.
If it lingers, it could be disastrous for the Pacific Northwest’s endangered orcas, which largely depend on chinook salmon. The warmer waters can weaken the food web that sustains the salmon and brings predators of young salmon, including seabirds, closer to shore, further reducing their abundance. Chinook returns have been extremely low in recent years following the last heatwave, which scientists dubbed “the blob.”
The new heatwave has emerged over the last few months, growing in a similar pattern in the same area. After “the blob,” it’s the second-most widespread heatwave in the northern Pacific Ocean in the last 40 years — as far back as the relevant data goes.
“It’s on a trajectory to be as strong as the prior event,” said Andrew Leising, a research scientist at NOAA Fisheries’ Southwest Fisheries Science Center in La Jolla, California, who developed a way to use satellite data to track marine heatwaves in the Pacific.

Unusually warm temperatures across Alaska this summer led to die-offs of massive amounts of unspawned chum, sockeye, and pink salmon.

From the Koyukuk River to the Kuskokwim, to Norton Sound, to Bristol Bay's Igushik River, unusually warm temperatures across Alaska this summer led to die-offs of unspawned chum, sockeye, and pink salmon. Warm waters also sometimes this summer acted as a "thermal block" - essentially a wall of heat salmon don't swim past, delaying upriver migration. Stephanie Quinn Davidson, the Director of the Yukon Inter-Tribal Fish Commission, took a team of scientists along 200 miles of the Koyukuk River to investigate a die-off of chum salmon at the end of July. The team counted 850 dead, unspawned chum - and that, she said, was a minimum count. "We were boating, going about 35 or 40 miles per hour, and we know we missed a lot," she said. "On a boat going by relatively fast, we were probably getting at most half the fish and at the least about ten per cent of the fish." Locals to the area said this same thing happened four or five years, ago, she said, but not to the scale it did this year. She attributes the deaths to heat stress. "We cut open the fish, looked for any size of disease, infections, parasites... By all indications, these fish looked healthy," she said. "They didn't have any marks on them, or any sign of disease or stress otherwise. And the die-off event coincides with the week of heat we had."

The total run was more than 1.4 million chum, she said, with some arriving before the warm weather event. "We definitely had chum salmon spawn," she said. "And have chum salmon continue to make it to spawning grounds. There are salmon that made it through. Hopefully, they'll pass those genes on that allowed them to persist." In the Kuskokwim, according to KYUK, there was a die-off of salmon having "heart attacks" due to the warmer than usual water along the ocean. In Norton Sound, large numbers of pink salmon were observed dead before spawning, according to KNOM. Full story

For more information please see the 2019 Alaska Seabird Die-off fact sheet:  https://www.nps.gov/subjects/aknatureandscience/upload/9Sep2019-Die-Off-USFWS-Factsheet-508C-revised-29Aug.pdf