With the pandemic encouraging many of us to put off large Thanksgiving gatherings this year, and foregoing the annual insanity of “Black Friday” (an event I honestly have never understood), there remains the opportunity to explore the outdoors.
The current situation is what it is, and we are stuck with it. For the moment, at least. Now, more than ever, why not opt to head outside? Social distancing is a lot easier to accomplish, and it’s good from time to time to remind ourselves that we are still a part of the natural world.
So try to spend some time outside this weekend, but remember to keep your proper wildlife distance.
Salmon is a vital resource in the state, so it should come as no surprise that Alaska has been studying salmon since before statehood. For over 60 years, the Alaska Department of Fish and Game has kept detailed records of length, weight, age and escapement for four species of Pacific salmon that spawn here.
The salmon that return to Alaska from their time in the ocean, are now smaller than they have been historically. The reason: They are returning to spawn at a younger age.
The Chinook, Alaska’s state fish, has been the hardest hit. King salmon are, on average, coming in at 8% smaller than in the 1980’s. The coho, or silver salmon is 3.3% smaller, chum is at 2.4%, and the sockeye 2.1. The decrease in size has accelerated since 2010 for all four species.
At first glance, what is 8% really? Well, the ramifications are large and far reaching. The Yukon-Kuskokwim River system is the largest subsistence area in the entire country. It takes more fish to feed a family. Commercial fishermen also must catch more fish to make the same amount of money.
Environmentally, the entire ecosystem relies on the salmon returning to spawn. Just the reduction in chinook salmon size alone means a reduction of 16% in egg production, i.e. future salmon populations; and a 28% reduction in nutrients going back into the river systems. For the pocket book issues: the reduction in king salmon means a 26% reduction as a food source, and a 21% reduction in the value of the fishery.
There does not appear to be one smoking gun for the change in Alaska’s salmon population, but a series of events that effect each species differently. Warming ocean temperatures are partly to blame, but so is competition between wild and hatchery populations. Size-selective fishing seems to also be a part of the equation, especially with the mighty chinook.
Wild salmon can stay out in the ocean for up to 7 years, but now they are often returning to fresh water to spawn at 4 years.
Sources: University of Alaska – Fairbanks; Alaska Dept of Fish & Game; Alaska Public Media; Fairbanks Daily News-Miner
The sea otter is the largest of the weasel family; it is also the smallest marine mammal. Adult males average five feet in length and ninety pounds. Females are about the same length, but run about thirty pounds lighter.
Life span is between 15-20 years in the wild. Sexual maturity happens at 2-3 years for females, and 4-5 years for males. It should be noted, it may take several more years for a male to breed, until one holds a breeding territory. Breeding can happen at any time of the year, and young can be born during any and all seasons, but in Alaska, birth usually occurs in the spring. The female raises one pup per year.
In order to maintain body weight, a sea otter must eat 25% of its mass, every day. They have the densest fur of any mammal, with between 800,000 – 1 million hairs per square inch.
Alaska has three distinct populations of sea otter: The Southwest, South-central and Southeast. Alaska is home to 90% of the world sea otter population.
The Southeast and Southcentral population is stable, but the Southwestern population has been listed as threatened since 2005. This population, which runs from Kodiak Island west throughout the Aleutian Chain, has lost roughly 65% of its numbers since the 1980’s.
Sea otters are considered a keystone species in the Alaska coastal environment. Now, they are proving to be the protectors of the underwater kelp forests. As the sea otter population plummeted in the Aleutians, the sea urchin population exploded. The sea otter is the number one predator of the sea urchin; sea otters will eat them like popcorn.
The number one predator of the kelp forest, is the sea urchin. Without the sea otters to keep the sea urchin population under control, the urchins have decimated the kelp forest along the Aleutian Chain. Now, the sea urchins are destroying the reefs along the Chain. With the drop in kelp, the sea urchins are eating the algae that creates the reef. These reefs are disappearing right before researchers eyes.
The kelp forest are now gone from the central and western Aleutians. In their place are often 400 sea urchins per square meter. The loss of the kelp is huge on several fronts. It is a home and safety zone to numerous fish species, cod among them. The 1200 mile Aleutian Chain supports two multi-million dollar fisheries: Bristol Bay and the Bering Sea.
Kelp is also an extremely efficient absorber and holder of CO2. Like all land plants, kelp forests take CO2 out of the air during photosynthesis. Without kelp, the oceans lose a tool in lowering carbon in the atmosphere. Kelp forests also help reduce the force of storm surges, which Alaska is facing more and more.
According to the Alaska Department of Fish & Game, there are several potential drivers for the western sea otter population drop. Overharvest, disease and predation. The new predator on the block in the Aleutians is the killer whale. Prior to 1991, there was not a documented case of an orca singling out sea otters for a food source. Now, it seems to be common. What changed? Something else changed in the diet of orcas that now makes the sea otter worthwhile. There are several theories, but no definitive answer.
Currently, sea otters are protected under the Marine Mammal Protection Act.
Sources: University of Alaska – Fairbanks; Alaska Department of Fish & Game; Fairbanks Daily-News Miner; Alaska SeaLife Center; Ocean Conservancy.
A large glacial dam gave way in Southeast Alaska this summer. Known by its Icelandic term: jökulhlaup, the power of this sudden release of pent up water can be incredibly destructive.
Desolation Lake, which sits above the Lituya Glacier in Desolation Valley, collects meltwater from both the Desolation and Fairweather Glaciers. That meltwater is normally blocked by the Lituya Glacier, forming the roughly four square mile lake.
The water level suddenly dropped 200 feet.
A commercial fisherman, Jim Moore, along with his two grandsons, tried to enter Lituya Bay to fish for Chinooks in August. They should have been riding the tide into the bay, but the unusually muddy water was moving outward, and it was filled with trees and other debris. The bay was also filled with small icebergs. Moore managed to bring some of the ancient ice onboard for his coolers, then left the bay, instead of fighting the dangerous current.
It is one of the largest jökulhlaups known to have occurred in Alaska. The water found a path under the Lituya Glacier, causing a rush that would have rivaled the hourly discharge of the Amazon River. It would have lasted for several days.*
Lituya Bay has a history. In 1958, an earthquake triggered a landslide that started one of the largest known tsunamis at over 1700 feet.
Part III: “We didn’t have a lot of money, but we had a lot of food.”
This is the third part of the After the Ice series. The video is less than 6 minutes long. Part III delves a bit into the Arctic Report Card, which is an annual assessment, and how our local Arctic population is finally getting a seat at the climate table.