Maine oyster farmer stares down climate change, learns to adapt - Part 3

Mook Sea Farm, on the Damariscotta River in mid-coast Maine, is adapting to risks associated with climate change. Photo courtesy of Mook Sea Farm.

The waters ahead?

Presumably, the global ocean will only become more acidic since the carbon dioxide emissions that caused the problem are still rising.

Scientists estimate that in the last two centuries, ocean water has become 30 percent more acidic, changing at a rate faster than any other change in ocean chemistry in the past 50 million years, according to the Smithsonian’s Ocean Portal.

The ocean is absorbing about 22 million tons of carbon dioxide per day, and has absorbed an estimated 525 billion tons of carbon dioxide from the atmosphere since the beginning of the Industrial Age.

The Global Carbon Project in mid-November published emissions estimates in three major scientific journals (Nature Climate Change, Environmental Research Letters and Earth System Science and Data Discussions; https://phys.org/news/2017-11-global-carbon-dioxide-emissions-stable.html).  Researchers estimated 2017 global carbon dioxide emissions from human activities would reach 41 billion tons, a 2 percent increase after a three-year period of almost no annual growth.

In U.S. coastal regions like the Gulf of Maine and the Pacific Northwest, acidification is “regionally greater than the global average” according to the Climate Science Special Report.

Freshwater inputs into the Gulf of Maine cause acidification to be greater there than the global average, the scientists reported with medium confidence.

Warming waters have led to increased concern over Vibrio parahaemolyticus – a bacteria that includes strains that can sicken people after eating raw oysters. Not all strains of Vibrio parahaemolyticus cause illness.

There have been outbreaks in southern New England states, and some evidence of a particularly virulent strain of Vibrio parahaemolyticus – but not in Maine waters.

The bacteria have always been there. But it’s reportable now. And there is concern that warmer waters will lead to higher risk of outbreak. From 2004 to 2013, the Gulf of Maine warmed faster than any other marine ecosystem in a 10-year period, according to work by Andrew Pershing of the Gulf of Maine Research Institute.

The problem, explained Kohl Kanwit, director of the Bureau of Public Health in Maine’s Department of Marine Resources, is that a harvested oyster is no longer filtering out the bacteria, and at a warm temperature bacteria inside a closed oyster can quickly multiply. Protocols now call for chilling oysters to 50 degrees-F within 15 minutes of harvest.

Mook and other industry leaders were proactive in working with the state on new, mandated shellfish protocols to reduce the risk.

Mook Sea Farm has also been conducting experimental trials that hold the oysters in post-harvest tanks so they can filter out the vibrio. They’re looking for the food level in the water that leads to maximum filtration rates by the oysters.

“We have a lot of work to do to figure this out so that it brings the levels down,” said Mook.

New facility built for adaptation

This month, Mook plans to open part of a new, 9,000-square-foot building designed to accommodate the business’ expansion and adaptation.

It includes an area with four tanks. Each one holds 26,000 gallons of filtered, UV-treated seawater, and together with bins placed over the tanks, they are designed to let Mook Sea Farm harvest and hold oysters ahead of a rainfall so it can keep shipping.

There, they can also keep testing whether feeding levels can be manipulated so that oysters purge any vibrio bacteria on their own.

The new building includes a new room for packing and shipping, including a new walk-in cooler and adjacent to loading docks, to accommodate increased volume.

It also includes a “clean” room where Mook employees mix the algae culture medium and grow a proprietary microalgae Mook developed as food for the hatchery production.

The new building also lets Mook grow oyster seed to a larger size. Typically, oyster seed is set out in the spring when rainfalls and acidity are at their highest. Recent summers have brought drought and lower acidity.

The thing that gives me confidence is that eventually Maine people will do the right thing – or at least I hope they do.

The company is also growing its seed oysters to a larger size, “so that hopefully they are a little more resilient when they go into the natural environment,” said Mook.

Combined, there are many fronts and projects for Mook to keep track of these days. He knows there could be more ahead.

“There are a lot of things that aren’t even on our radar and when you start messing with a complex ecosystem it’s tough to predict all the things that might follow,” said Mook.

And trying to get action from national political leaders on the root of the problem – carbon pollution – has been frustrating, so he’s focused his efforts at the state and local level.

He’s encouraged by two things: As the company develops solutions, it tends to be healthier and find new opportunities for revenue, and Mook recalls the effects of a polluting neighbor who nearly put him out of business. Mook’s oysters were sick and dying and in 1998 he could not get a cohort of oysters to survive. Then he realized a neighbor had a business pumping out raw sewage and was dumping it into a creek that fed the Damariscotta upstream from his leases.

The pollution almost put Mook Sea Farm out of business. But he took the neighbor to court and prevailed.

“The thing that gives me confidence is that eventually Maine people will do the right thing – or at least I hope they do. I was really taken aback by how outraged people were that this guy would just be dumping into the Damariscotta River,” said Mook.He plans to keep telling his story and informing people in hope that they will be outraged by the carbon pollution on a global scale. Meanwhile, he’ll keep adapting.