What can mackerel and a volcano say about climate change?

PORTLAND — What could an Indonesian volcanic eruption, a 200-year-old climate disaster and a surge in the consumption of mackerel tell us about today's era of global warming?

Quite a bit, researchers say.

A group of scientists and academics with the University of Massachusetts and other institutions made that assessment while conducting research about a long-ago calamity in New England that was caused by the eruption of Mount Tambora half a world away in 1815.

A cooled climate led to deaths of livestock and changed fish patterns in New England, leaving many people dependent on the mackerel, an edible fish that was less affected than many animals. The researchers assert that bit of history gives clues about what food security could be like in the modern era of climate change.

"How we respond to these events is going to be critically important for how we come out of this in the long term," said Karen Alexander, the lead author of the study and a research fellow in environmental conservation. "We can learn from the past how people dealt with the unanticipated."

The research group's findings were published this month in the journal Science Advances . They looked at what the catastrophic Tambora eruption meant for the Gulf of Maine and nearby human food systems.

The eruption was one of the most powerful in recorded history and was followed by a short time of climate change — specifically, global cooling — and severe weather. Its impact on weather, food availability and human and animals deaths worldwide has been studied extensively. The year that followed the eruption, 1816, is often described as the "Year Without a Summer."

The researchers behind the Science Advances article found that alewives, a fish used for everything from fertilizer to food by 19th-century New Englanders, did not fare well. But mackerel had better survival rates and became a critical source of protein and jobs, Alexander said.

As crops failed and famine began to spread, the little fish emerged as a staff of life, the report states. The shift marked the beginning of the mackerel fishery as a critical piece of New England's marine economy, and it remains active today; Maine and Massachusetts fishermen caught more than 8 million pounds of Atlantic mackerel in 2015.

It's a scenario similar to what parts of the developing world are experiencing today as climate change affects food security.

The study states there is a parallel between the need for immediate adaptation after Tambora and the challenges in coping with the climate-driven devastation caused by storms, floods and droughts today. It notes that the loss of food staples due to climate change caused people in the northeastern states to move — something seen today in places such as Pakistan and Syria.

"Understanding how adaptive responses to extreme events can trigger unintended consequences may advance long-term planning for resilience in an uncertain future," the report states.

How fisheries in the developing world will adapt to future climate change is an important contemporary food security issue, because fish are a vitally important protein resource worldwide. More than a billion of the world's poor obtain most of their animal protein from fish, and 800 million depend on fisheries and aquaculture for livelihoods, according to the nonprofit research group WorldFish.

The report illustrates how abrupt changes in climate can have unexpected consequences long after conditions moderate, said Andy Pershing, chief scientific officer and ecosystem modeler for the Gulf of Maine Research Institute in Portland.

"Good stewardship of our natural resources can help buffer against some climate impacts. Unlike the people in 1815, we have an idea of what's coming, and we need to make sure we are prepared," he said.