alaska – BioQuakes

Have you ever indulged in the scrumptious cuisine that is Alaskan Snow Crab? Any such meal is one to remember. However, there is a threat to this dish, and to the Chionoecetes opilio species as a whole: the crabs are cannibalizing each other. Or so, scientists think.

The snow crab population was once rapidly expanding in the eastern Bering Sea, reaching its highest recorded abundance in 2018 at 11.7 billion. The population then rapidly declined to an all-time low of 940 million in 2021. At least 10.76 billion crabs disappeared within the course of 3 years. But where did they go?

Researchers have proposed various theories to account for the decline in population. The first obstacle was determining whether the crabs had died off, or merely relocated. After surveying the surrounding habitats and observing no significant influx of snow crabs, the researchers were able to conclude that the crabs had indeed passed on.

With the cause of the crab disappearance isolated, theories were proposed for the cause of death. Temperature, predation, fishery, disease, and cannibalism were all considered. As far as temperature, snow crabs typically exist in cold environments—hence their name. An increase of temperature in their habitats could potentially have accelerated the crabs’ metabolic rates, and consequently expended calories at a rapid rate. With regard to predation, snow crabs are a component of the Pacific cod diet. Relative changes in abundance and distribution of the cod species could have affected the rate of snow crab death. Fisheries provided yet another possibility, as trawling rates are dependent on consumer demand. Disease was also a consideration. Snow crabs are susceptible to Bitter Crab Syndrome, a disease caused by the dinoflagellate parasite Hematodinium perezi, a single-celled eukaryote. Single-celled eukaryotes are organisms comprised of a single cell, as discussed in class. Finally, cannibalism could have been at play. Large snow crabs have been observed to cannibalize smaller snow crabs as a source of food.

Researchers were able to rule out predation and fishery as potential causes of the snow crab population decline. Disease and cannibalism were also eliminated. Through the use of various models, researchers determined that environmental temperature and population density correlated positively with crab mortality, particularly in mature crabs. Therefore, increased caloric expenditure as a result of increased environmental temperature was identified as the likely culprit of the crabs’ disappearance. Accordingly, a clear link exists between declines in snow crab population and climate change. Further work is necessary to clarify the exact association between the two phenomena.

I invite comments and potential solutions to this serious challenge.

Glaciers Hold Less Water than Previously Thought. Is this Good?

By sukrose

On February 16, 2022

In Student Post

Last summer in Alaska, I was kayaking up to the Holgate Glacier when I noticed the water getting colder. I began to feel the katabatic winds as I got even closer to the massive wall of ice. Small ice chunks began to surround the kayak, and I could see the fast moving silt deposits flowing beneath me. I then heard a noise which boomed and echoed off of the surrounding mountains, and I saw a massive chunk of ice break off (“calve”) from the glacier and plummet into the sea. I’ve always known that climate change was happening, but seeing it before my eyes reaffirmed my fears.

Holgate Glacier, Aialik Bay, Kenai Fjords National Park, Seward, Alaska

I’m not here to talk about my fantastic trip to Alaska, but rather to talk about the new scientific findings which will further predict the climate change battle. Previously, scientists believed that warmer-than-average temperatures can begin to melt glaciers, causing the sea levels to rise and cause disastrous flooding. Just recently, satellite image glacier research spearheaded by Romain Millan of Grenoble Alpes University in France has determined that glaciers hold 20% less water than previously thought. This means that, if all of the glacier ice were to melt, that the seas are predicted to rise 10 inches instead of 13 inches.

This is great news, right? Well, some could argue that less flooding means less disaster (landslides, wipe out infrastructure, etc), and that it’s good news. But it’s not, because even if the sea levels were to rise just a few inches lower, still 29% of the entire world’s population would be predicted to be immediately affected by flooding, and within a few days, 99.9% of the entire world’s population would feel the indirect effects through shortages or outages. In addition, less water quite literally means “less water.” 2 billion people currently rely on glaciers as their primary source of water, so “less water” would effect them through a drought. As

Glacier at Chugach State Park, Alaska (which I too visited)

we’ve learned in AP Biology, water is one of the most, if not the most, important molecules to biological existence. A drought can affect human life from hundreds of angles, such as famine, or more immediately, dehydration. Water is extremely crucial to performing catabolic reactions such as hydrolysis, which we learned in AP Biology.

Factoring in mountaintop glaciers and their water content, Millan is able to determine the rate at which communities will run out of water. But for the non-alpine communities, these mountaintop glaciers are only a tiny drop in a large bucket. Millan’s research lacks one major component: the antarctic and arctic glaciers. If these unbelievably large ice fields continue to melt at the current pace, 90% of the United States is predicted to be underwater by 2050. To be honest, I believed this statistic was exaggerating until just recently. In Alaska, one of the glaciers named “Exit Glacier” had markers at the glacier’s terminus for each year. As I got closer to the glacier, I noticed the markers getting further and further away, signaling that the glacier was melting quicker and quicker. Take a look at the graph below, specifically how the year intervals begin to get smaller, and let me know how it makes you feel in the comments. Although it does not take a trip to Alaska to realize that climate change is really happening, new and emerging headline-worthy research like Millan’s is truly highlighting the immediate issue we all could face soon.

Exit Glacier Terminus Position From 1950-2020

Tiny Devils Take Down Gentle Giants all due to Climate Change!

By theroid

On January 14, 2019

In Student Post

A innocent female moose, about to be attacked by an onset of terrible parasite in Northeast Canada.

Winter Ticks, not containing Lyme Disease or other Human-harming diseases, are rising exponentially in population throughout New England and Canada, all due to increasingly warmer and snow-free springs and later winters everywhere. As a result, an unlikely species in this region is being targeted by these tick epizootics, Moose, because ticks search for hosts in the fall and other warmer temperatures and stop once freezing weather and snow befalls the land. Yet, when these conditions occur much later, it gives these ticks more time to feast on peaceful animals, and also giving more time for female ticks to fall off its host and create tons more larvae, not making this issue any better. As these raisin sized parasites latch onto to these large creatures, draining so much blood at a time that they simply are unable to function anymore and weakly fall, succumbing to the environment, other predators, or even more ticks. But it’s not simply a few ticks, no, these moose can carry up to around 90,000 ticks! Because of this, there has been “an unprecedented 70 percent death rate of calves over a three-year period” according to a similar source from the University of New Hampshire. Plus, this problem has gotten so bad that now a threatened species in this region of British Columbia, the boreal Caribou, are being eaten alive as well!” If blood loss from heavy tick loads does not directly kill animals, it can make them susceptible to other health risks, Schwantje adds in the original source. “They have spent so much time scratching and chewing on themselves that they haven’t been feeding, so they are in poor body condition,” she says, even with tremendous hair loss that they become basically unrecognizable.

An example of one of these detrimental winter ticks, a female engorged in size with blood and larvae, ready to reproduce .

But How Can This Be Stopped?

Currently, researchers are offering a multitude of solutions to help save these wonderful species from these terrifying parasites, as Swantje says that “They have huge cultural and nutritional value to our First Nations, And when moose forage in wetlands, they help release nutrients into the environment and make them available to other plants and organisms, studies have shown”, one solution can even be seen here. One possibility is to continuously treat half of the moose with anti-parasite gel and pills that make attached ticks drop from their bodies in order to isolate specifically what the ticks do and don’t do to harm these moose. The other possibility is a highly unlikely one, hunt the moose. Researcher Peter Pekins suggests that “issuing more moose-hunting permits in strategically selected areas” could essentially starve out the ticks in certain areas, yet it is argued that this would only benefit the environment short term, as the climate will continue to warm leading to the growth of more and more ticks.

Who know, if this isn’t stopped soon, ticks will continue to grow in population and maybe even take down us humans! Save the moose (and the caribou)!

BioQuakes

AP Biology class blog for discussing current research in Biology

Tag: alaska

The Great Disappearance of the Alaskan Snow Crab

Glaciers Hold Less Water than Previously Thought. Is this Good?

Tiny Devils Take Down Gentle Giants all due to Climate Change!

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