How to decide what fish you should eat and what you shouldn't

Haddock in the North Sea are among the climate change "losers" as a result of warming ocean temperatures.

Credit: NEFSC/NOAA

From Forbes by Margot Wilsterman

When I explain my fish-based research to folks, the question that pops up the most is: “What kind of seafood is ok to eat?”
My answer is always, “How much time do you have?”
Unfortunately, there is no quick and easy way to handle this inquiry.
A truly good answer involves peeling back the layers of the massive onion that is global fish production.

Let’s say we start with individual fish species, where you might decide to avoid fish with low population levels, like bluefin tuna for example.
But what if we eat the smaller fish that the tuna needs to survive?
And what about the ecosystem as a whole, which allows the tuna (and its food) to live and thrive?
And what about the working conditions for the fishermen who catch the tuna?
And what about the conditions the tuna is processed in?
See what I mean?
Five layers into the onion, and my questioner probably feels like it was a mistake to ask me, Debbie Downer, what kind of fish she should buy for dinner tonight.

A popular follow-up question I get is: “Well, is it better for the ocean if I eat farmed fish?”
Again, strap in, because the answer is not cut and dry.
Back when fish farming, or aquaculture, was in its infancy, it seemed like the perfect answer for the seafood consumer concerned with sustainability.
Here we had a new industry that was rearing aquatic animals for the sole purpose of food production, more in line with the poultry or cattle farms.
These aquatic farms were, and still are, located in ocean pens or cages, or on land in large tanks or pools.
This newer industry is soaring: Aquaculture is now a $180.2 billion global industry, as estimated by Technavio, and is expected to grow to $224.2 billion by 2022.

Just 2% of the food eaten around the world comes from the ocean.
And global agribusiness players like Cargill are betting that consumers will increasingly gravitate towards fish by the time global demand for protein grows 70% by 2050.
It’s also a more strategic bet when considering how climate change will impact traditional farming.
Fish are far more sustainable to farm—it generally takes about one pound of feed to grow one pound of seafood, compared to two for chicken, three for pork and six for beef.
But it’s still not that simple.

Let’s start with the shellfish farming industry.
Farmed filter feeders, or bivalves, like oysters and mussels are beloved by Americans, in part because many consumers are aware of their environmental benefits.
Oysters and other bivalves eat plankton and microscopic particles in the water, and in doing so they remove excess nitrogen, which pollutes the ocean.
Oysters don’t mess around when it comes to feeding.
They are able to filter up to 50 gallons of sea water per day, and their impact on water quality can be incredible.

See for yourself in this video posted by the Florida Oceanographic Society:

Time-lapse video demonstrating oyster filtration.

An adult oyster is capable of filtering 20 to 50 gallons of water per day.

It is estimated that historic populations of oyster in the Chesapeake Bay were capable of filtering the entire volume of the bay in less than 5 days!

Through the Florida Oceanographic Oyster Restoration program (FL.O.O.R.) we are building oyster reefs so that this incredible filtering capability can be restored to our local estuaries.

Unlike shellfish farming, finfish aquaculture brings with it many environmental risks.
Reports of increased pollution, habitat destruction, use of wild fish feed, farmed fish escapes, the spread of disease and the use of antibiotics have seafood consumers confused and worried.
Finfish aquaculture is often advertised as a way to take pressure off wild fish populations that may be in decline.
However, a recent study has concluded that aquaculture does not significantly displace fisheries capture.
Instead, it supplements it.
So, are farmed fish off the table?

Many aquaculture operations have taken leaps to reduce their environmental impacts, including moving operations on land to reduce pollution, disease, and escapes.
A plethora of farmed species are certified by eco-labels or ranked as “green” on seafood guides, but public opinion of fish farming remains low.
Some in the industry feel that aquaculture is being “unfairly demonized.”
This negative consensus could create problems, as global demand for seafood is not slowing, and aquaculture already makes up the majority of the seafood eaten globally.
A report by the FAO on perceptions and misconceptions of aquaculture highlights this issue:

With a growing world population, annual supply needed from the aquaculture sector must further surpass that from capture fisheries, reaching 62 percent in 2030, to maintain current consumption levels per capita.
This presents tremendous challenges to the sector, to policy-makers and to the aquaculture community at large.
Improving perceptions of the sector will be instrumental if the goal is to be achieved.

A fish farm off the coast of Greece.

(Photo CC-licensed by Artur Rydzewski)

Additionally, aquaculture industry leaders and a growing field of investors are pushing for the passage of a new bill that would open more avenues for aquaculture in offshore waters.
Stronger America Through Seafood, a group advocating for “legislation establishing a workable framework for all U.S.
Aquaculture production,” wrote a letter to congress, urging them to “reintroduce an updated version of the “Advancing the Quality and Understanding of American Aquaculture Act” this Congress.
The bill would clarify a process for permitting aquaculture in federal waters that preserves existing environmental safeguards and minimizes impacts to existing ocean-based industries.”

There is wide support for this bill from the aquaculture community, but fierce opposition from wild fish harvesters.
Large-scale fish farming in offshore waters could be in direct conflict with commercial fishing operators.
This is one of America’s oldest industries and a group that has already been hindered by population declines and reduced quotas.
In their letter to congress, a collection of commercial fishermen and suppliers argue, “This emerging industrial practice is incompatible with the sustainable commercial fishing practices embraced by our nation for generations and contravenes our vision for environmentally sound management of our oceans.”
They raise concerns of increased economic burdens, pollution, and farmed fish escapes.
In bold text, they write: “American commercial fishing and marine finfish aquaculture cannot coexist.”
At this writing, the bill has passed through the house and is being considered in the senate.
The landscape of U.S. fish production will be changed if the bill is passed.
If that occurs, I’ll have to add a few more layer to the onion when asked “Which seafood is ok to eat?”

In the meantime, what can you do to be a conscientious consumer of seafood?
My advice comes from seafood writer Paul Greenberg, who was inspired by Michael Pollan when he said, “Eat American seafood, a wider variety of it, and mostly farmed filter feeders.”
The latter include mussels, clams, oysters, scallops, and any other bivalve you can get your hands on.

Links :

• ScienceMag : Warming oceans are hurting seafood supply—and things are getting worse
• NYTimes : The World Is Losing Fish to Eat as Oceans Warm, Study Finds
• CNN : Earth's fish are disappearing because of climate change, study says
• The Guardian : Fish stocks continuing to fall as oceans warm, study finds
• Phys :  Climate change shrinks many fisheries globally, study finds
• BlueOcean : The Future of Aquaculture, Two Sides of the Story