Burgeoning salmon farming industry sparks controversy over pollution and sustainability

There has been a growing appetite around the world for fish. But that growth in demand is raising all kinds of questions and concerns for the industry about sustainability and impact. Science correspondent Miles O'Brien has the first of a two-part look at what's known as "aquaculture."

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  • Amna Nawaz:

    Around the world, there has been a growing appetite for fish, but that demand is raising questions and concerns about sustainability and impact.

    Science correspondent Miles O'Brien has the first of a two-part look at what's known as aquaculture.

  • Miles O’Brien:

    It was a perfect summer day when we steamed out of Southwest Harbor, Maine, on a different kind of fishing vehicle.

    Is this a particularly good place to raise salmon?

  • Andrew Lively, Cooke Aquaculture:

    Certain places in Maine are ideal for salmon farming.

  • Miles O’Brien:

    Our guide was Andrew Lively with a Canadian company called Cooke Aquaculture.

  • Andrew Lively:

    This is where these fish have been living for thousands of years. This is an environment that they are well adapted to.

  • Miles O’Brien:

    And yet pollution, dams and fishing rendered Atlantic salmon and endangered species in the U.S. Cooke farms them at 120 leases here and in Canada.

    The company raises all sorts of fish all over the planet, 18 countries in all. Business is booming. With wild fisheries maxed out and the global appetite for seafood rapidly increasing, aquaculture is now the fastest growing form of food production in the world.

  • Andrew Lively:

    There's no question there is a very good strong demand for a product.

  • Miles O’Brien:

    Off of Swan's Island, we boarded the ship where they monitor and feed their crop of nearly a half-million salmon. They're kept in 16 flexible floating nets made with stainless steel fiber to guard against escapes.

    We watched as they fed some of the fish using a network of submerged cameras.

  • Andrew Lively:

    He's seeing the fish, and there's no feed coming down through the water column.

  • Miles O’Brien:

    The trick is releasing the feed at just the right rate. Too fast, and it falls to the bottom of the sea, impacting the bottom line. But it also can cause an environmental problem. As the feed decomposes, it generates nitrogen, as does the fish poop.

    High nitrogen levels are a persistent problem for salmon farmers.

    Do you feel like you have met those challenges?

  • Andrew Lively:

    One of the big way to deal with that challenge is proper site location and proper density. We're in an area that gets about a 12-foot rise and fall of water twice today, so lots of current, lots of freshwater going through here.

  • Miles O’Brien:

    Even at the perfect location, fish farmers must closely monitor a myriad of factors to keep their crops healthy.

    Farmed salmon are frequently beset with serious infestations of sea lice. To combat the problem, Cooke deploys custom designed boats equipped with warm freshwater showers to clean the fish. It's an expensive solution that might soon have an unlikely replacement.

    Steve Eddy, Director, Center for Cooperative Aquaculture Research: All right.

  • Miles O’Brien:

    Marine biologist Steve Eddy is director of the Center for Cooperative Aquaculture Research at the University of Maine.

    These fish are lumpfish. Tell me about them.

  • Steve Eddy:

    So these are used as a cleaner fish to remove sea lice off of farmed salmon, a form of biological control.

  • Miles O’Brien:

    Norwegian salmon farmers, the pioneers and juggernauts of the industry, developed the technique. Researchers here believe one or two lumpfish per 10 salmon in a pen should be enough to delouse the whole school.

  • Steve Eddy:

    And then, as the salmon swim by and the sea lice start becoming a problem, they will dart out and pluck that sea louse right off of the salmon's back and eat it.

  • Miles O’Brien:

    Cooke makes its own feed. It is a mix of plant and Marine life, like these Peruvian anchovies.

    The company claims each pound of salmon sold at market requires six-tenths of a pound of fish meal and fish oil. In the early days of the industry 30 years ago, it required almost seven times as much.

  • Deborah Bouchard, Director, Aquaculture Research Institute:

    These fish are 6-month-old Atlantic salmon.

  • Miles O’Brien:


    Microbiologist Deborah Bouchard is director of the University of Maine Aquaculture Research Institute. She and her team are looking at alternatives to make salmon aquaculture more sustainable, including insects.

  • Deborah Bouchard:

    Fish meal is more complicated than just the protein you're putting in it. As long as they're getting the omega-3s and the other fish oil and the other oils that they need — and we have come a long way and still having them tastes really good, like an Atlantic salmon.

  • Miles O’Brien:

    It takes about three years for a salmon to grow from egg to market. As complex and resource-intensive as aquaculture is, its sustainability compares favorably to some land-based agriculture.

    Author and journalist Paul Greenberg has spent much of his career focused on the fishing industry.

    Paul Greenberg, Author, "Four Fish": We have already halved the feed inputs and doubled the growth rate. So that's pretty — if you're a scientist, you're like, wow, that's amazing. Could we go further?

    So I can understand them being excited about that momentum. But then if you kind of stop drinking the Kool-Aid for a moment and look at the other options on the table, like things that are already extremely efficient, then you sort of like, well, come on, let's just put it in perspective now.

  • Miles O’Brien:

    The other options? Aquatic farms that produce crops further down the food chain. And, in fact, mussel and oyster farms here in Maine are also doing well.

    These crops require no inputs, filter the water and capture carbon, sustainable sources of protein for a planet on its way to a population of nine billion.

  • Paul Greenberg:

    I think the oceans actually have a really important role in feeding both the present and the future of humanity.

  • Miles O’Brien:

    Between 70 and 85 percent of the seafood Americans eat is imported. And the U.S. is 18th on the list of aquaculture producers. With its long, sparsely populated coastline, Maine may be an ideal place for aquaculture to grow.

    But a coalition of lobster fishers and summer residents are opposed.

    Jeri Bowers is a ninth-generation Mainer who lives near Frenchman Bay, where a company called American Aquafarms seeks to build a 120-acre salmon farm and hatchery.

  • Jeri Bowers, Frenchman Bay Unite:

    To see this proposal right here in the heart of Acadia National Park really, I think, rang some alarm bells for all of us.

  • Miles O’Brien:

    The project is mired in opposition, but she says the state is too eager to approve aquaculture leases.

  • Jeri Bowers:

    It's the equivalent of setting up a farm on the town green. That's really what it's like. These are public waters. And so while I'm really supportive of making a living on the water, I want it done in a balanced way.

  • Miles O’Brien:

    Jeri Bowers believes land-based aquaculture is a better idea. That seeming contradiction in terms is gaining momentum, as consumers demand, technology permits, and the oceans reach their limits.

    We will visit a fish farm in the middle of some cornfields in Indiana in our next installment.

    For the "PBS NewsHour," I'm Miles O'Brien in Downeast Maine.

  • Amna Nawaz:

    Thank you, Miles, for that report.

    And stay tuned for part two coming soon.

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