Why Are Alaskan Snow Crabs Disappearing?

This year, the state of Alaska had to cancel its annual Bering Sea snow crab harvest for the first time in history. The state’s most profitable harvest will not happen because the snow crabs are disappearing. Scientists estimate that the state’s snow crab population has declined by almost 90%, going from 8 billion in 2018 to a billion last year.

The reason for this? There are many theories, some more far-fetched than others. In fact, some people think the crabs were abducted by aliens. The much more likely causes of the disappearance are rooted in climate change. The water is warming faster in the Bering Sea than anywhere else. Alaska is the fastest warming state in the U.S. Crabs require cold water – in warmer waters their metabolism increases, they expend more energy, and need more food to survive. Which resulted in a consequence that scientists did not foresee – mass cannibalization. When there was no longer other food available for these omnivores, the crabs began eating each other. Now there are hardly any crabs left to harvest.

Human-Made Global Warming and Our Ocean

The cancellation of the Alaskan snow crab harvest is one of many early signs that Mother Nature has been sending us about the potential collapse of our ocean’s ecosystems. According to the United Nations (UN) Climate Action group, the ocean has absorbed about 90 percent of the heat generated by the rising greenhouse gases trapped in the Earth’s system. As the ocean heats up, the consequences can be seen in many ways.
We see ice caps melting, rising sea-levels, heat waves that kill marine life, and the continuing acidification of our ocean water. When sea levels rise, this leads to the more frequent devastating storm events we’ve seen. Events that used to occur once a century are now occurring yearly. Communities and governments cannot keep up with the damage to homes and businesses and the rising costs for recovery. All of the major coastal areas of the world will continue to see rising sea levels, including many areas in the U.S., such as Miami, New Orleans, and the Pacific Northwest. These places will become uninhabitable, and millions of people will be displaced.

Marine heatwaves have also become more frequent and long-lasting. Coral reefs have been devastated by the heating waters, leading to coral bleaching. Without coral reefs, scientists estimate that up to 25% of marine life would lose their food source, shelter, and spawning grounds. Warming waters also leads to a loss of marine biodiversity, which is critical to the ocean ecosystems. The UN Educational, Scientific and Cultural Organization warns that the Earth could lose more than half of its marine species through extinction by 2100.

“At a 1.1°C increase in temperature today, an estimated 60 percent of the world’s marine ecosystems have already been degraded or are being used unsustainably. A warming of 1.5°C threatens to destroy 70 to 90 percent of coral reefs, and a 2°C increase means a nearly 100 percent loss – a point of no return”

– UN Educational, Scientific and Cultural Organization

The Vanishing Ocean Wilderness

What is a wilderness? A place that is uninhabited or undeveloped by human beings. These are the places where you see the most biodiversity in the animal world. Places that thrive without pollution, resource decimation, or encroachment of natural habitats. There are still places in the ocean that are considered wilderness – but those spaces are becoming smaller and smaller. 

A study published four years ago in the journal Current Biology found that only 13% of our ocean is considered marine wilderness. The ocean covers 70% of Earth, but only a tiny fraction of that has been left untouched by us. Vast amounts are considered overfished or “dead” – which means that the amount of marine biodiversity is so low that it cannot sustain the ecosystems. 

Continued warming of the ocean and further loss of ice cover will only make this problem worse. If we do not place limits on fishing, these areas eventually will be affected. Without human intervention, we will continue to see pollution grow. Or is it too late? 

The future does not look bright for the Alaskan snow crab. Recovery from this most recent loss will take years – and only if the waters in the Bering Sea remain cold enough for them to thrive. That doesn’t look likely given the trends in climate change. What does this mean for us? It’s not just that a food source is no longer available for people who are privileged enough to buy the expensive crab. It also means that the people who rely on this industry to feed their families will have to find another way to survive. The loss to the economy will have consequences for everyone. And the biggest loss is to the ocean’s ecosystem – on which we all rely.