Continuing from last week’s series on the types of gear that local fishermen use to catch fish for CAFC, this week I will discuss draggers. Draggers are the predominate type of gear used to catch groundfish in New England. Draggers tow nets along the ocean floor (and sometimes in the mid-water column for fish such as herring). The nets are held open by metal ‘doors’ that help spread the mouth of the net open. A chain runs along the bottom often lined with ‘scrubers’ or ‘rollers’ which help the net to bounce over rocks and other impediments. The fish cannot outswim the net and are forced into it, ending up in the ‘codend’.

By the criteria we discussed last week: selectivity and ocean impact, draggers score low on both counts. They are indiscriminate fishers, however many modern draggers use large mesh, and sophisticaed electronics to reduce by-catch. And, they have arguably the greatest impact on the ocean bottom.

Some dragger fishermen argue that in some cases dragging is much like tilling the soil and may actually result in increased fecundity. There is some evidence for this in species like scallops and flounders.

Many CAFC folks ask whether dragging (sometimes also called trawling, which is not the same as trolling) is sustainable, andthe answer like most things in the fish business is a little yes and a little no. Small scale draggers are incredibly efficient fishers. When the fish are in close to Gloucester, a dragger can go out and back in less than twenty-four hours with a full hold of fish.

Further, Captains like Joe Orlando argue that he has been fishing the same grounds for thirty years and that if draggers were wiping out the habitat, they would not be abl to continue to fish over and over in the same spots. As with most things in life, it is really a question of moderation vs. excess. Small scale day-boat draggers while not the ideal gear type are relatively benign. The problem is when you have large vessels with nets the size of football fields systematically towing patterns over the bottom that large scale habitat destruction occurs.

Another huge problem is when draggers target spawning aggregations. As we’ve come to learn many of our local groundfish are a lot more like salmon than we ever thought in that they return to the same breeding grounds over and over. When a dragger (or a gillnetter) wipes out a spawning mass, that sub-population could be wiped out for decades or even as they are seeing in Atlantic Canada and Downeast Maine, populations just cannot rebuild despite the absence of fishing.

Seafood sustainability is such a difficult topic because ultimately it boils down to the idea that we humans have the ability to determine the exact right level of seafood we can take from a complex and not always well understood ocean that will allow seafood populations to not only maintain, but to function more or less as if we were not harvesting seafood.

Wait, does that make sense at all? Is there really some magical line in the ocean that allows us to have our cake and eat it too? What about complex highly interdependent ecosystems? What do we use as a baseline? Do we use historical abundance or recent abundance? How does the harvesting of one species like herring impact the health and abundance of other species that depend on it?

The “truth” if there is one is that sustainability is a “best guess” when it comes to seafood. If you Google “Sustainable Seafood” you’ll find a number of species specific seafood buying guides. There is some value to these guides. Most folks that want to do the right thing don’t necessarily want to spend their time reading some random blog about seafood sustainability and these guides can be a decent starting point for folks that want to do the right thing.

We think a better way to approach seafood is to have a set of principles.

But, to understand how seafood cards can get things wrong, we have to gain an understanding of how fisheries are determined to be sustainable. Usually this has to do with many sceintific assesments, but the two biggies are TAC (Total Allowable Catch) and MSY (Maximum Sustainable Yield).

TAC is a hard number that defines how much fish fishermen can catch. It is based on fish population assessments and is supposed to be scientifically vetted. MSY is a bit harder to understand, but it is essentially the amount of fish that can consitstently be taken from a population of a single species that will allow the population to maintain over the long term. In simple terms, it is usually around 30% of a “healthy” population of fish.

In some ways they define the same thing, however MSY is more like the speed limit, while the TAC is the actual speed that can get you a ticket. In other words, the numbers are not always the same and are subject to the discretion of the managers.

So, let’s get back to sustainable. In effect the TAC defines what fisheries managers think is sustainable. Fishermen have little to no impact on this number. It is defined, determined and vetted by the Science and Statistical Comittee (SSC) of the New England Fisheries Management Council (NEFMC) and accepted or rejected by the NEFMC. So in effect, how much fishermen will catch – whether or not that fishing is sustainable – is determined by managers not fishermen.

So, how can sustainable seafood cards put things like Atlantic Cod on a list of sea foods to avoid when managers, vetted by the best available science, are saying that Cod are no longer overfished? This article is a great exploration of the complexities in particular concerning our local codfish.

So, in sum, managers/regulators are defining sustainable ideally based on science that determines a level of seafood that can be caught indefinitely. As a principle, its a good place to begin to approach sustainability. But if you are like me, you have a healthy skepticism of the ability of scientists and managers to know the ocean well enough to consistently and impartially determine the magical number of fish we can eat without any impact. It just sounds silly to me and reminds me of one of my old friends’ skepticism of another magical animal.

Last week, I mentioned that the idea of Marine Spatial Planning (MSP) is becoming the next big thing in fisheries management. At the most basic level the idea is akin to zoning laws on land.

The ocean, of course exists in three dimensions and many of the creatures in the ocean migrate from and through zones. However, the idea is that by taking what we know about the ocean we can make plans that will balance the desires to maintain and improve the ocean environment, extract resources from the ocean etc.

A frequent example used to explain how the concept works is the recent change to the shipping lanes approaching Boston Harbor to protect marine mammals, specifically whales, and in this case even more specifically, the North Atlantic Right Whale which is an endangered species. You can see from the image below how moving the channel can reduce the likelihood of a ship striking a whale.

In the image above (Example of the Potential Benefits of CMSP: Stellwagen Bank National Marine Sanctuary (Photo Courtesy NOAA)) the dots represent Right Whales and the colors represent baleen whale densities.

Another example that can help explain MSP is how the Lobster Fishery is managed in Maine, where regional councils of fishermen set the rules for their “area”. In this case they are managing a single species in a specific area as opposed to an entire eco-system, but the idea is the similar. In the case of the Maine lobster fishery, it is and has been one of the few examples of a prolific fishery that fishermen voluntarily chose restrictions to their catch to ensure the species would be around for future generations.

Some people argue that catch shares serve the same purpose in that giving fishermen a share of the fishery will encourage stewardship over the resource. However, the reality is that fishermen become stewards of the economic value of their share rather than stewards of the resource itself. They only have incentive to care about the resource when it would negatively affect the value of their share. Think of it like the difference between leasing a car and owning a car.

In general MSP does have a lot of potential as a means to deal with the ocean resources and competing interests, and the science to effectively do it is improving all the time. I always suggest reading some of Ted Ames’ work on gaddiform populations in the Eastern Gulf of Maine as a way to understand how fish can fit into manageable areas.

Other News and Notes
I think it is about time to blow the lid off the cooking pot here at Cape Ann Fresh Catch blog. We started this blog because we want our members to be informed. Initially we felt that there were so many critical things happening in fisheries issues that we had a responsibility to inform and maybe educate a bit along the way.

However, most every time I talk to CAFCatchers (thats the new name I am giving to members, ) all we ever talk about is cooking fish and fish recipes. To that end, I would like to offer that anyone who would like to contribute an article, recipe, fish experience with the blog should please get in touch.

I am also in the process of trying to line up some guest columnists who can provide different takes on all things seafood.

Last but not least, remember to sign up for the spring season, and make sure to tell folks about CAFC!

One of the questions people often ask about CAFC is what do we mean by “sustainable”? “Sustainable” is defined as capable of being continued with minimal long-term effect on the environment. And by that definition, the fish we get are in fact sustainable. All of the stocks of fish that we purchase are not considered to be “overfished”. In addition according the best and latest science, the stocks of fish that CAFC delivers are all growing.

But, just because a population of fish is growing does not necessarily mean that the fishing is sustainable. Some would argue that the way fish are caught is an important consideration of sustainability. The concern is that some fishing methods may do long term damage to the environment. These concerns usually focus on draggers, by-catch and extreme overfishing.

The draggers we buy fish from are fishing with a 5 inch mesh size, which is one of the largest mandated mesh sizes in the world. The large size of the mesh allow smaller fish to escape the net. Additionally it is not always clear that draggers “damage” the seafloor. It is certainly true that they can damage the seafloor, but it is also possible that small draggers may enhance an ecosystem by in effect ’tilling’ the soil. More research needs to be done in this area, but as one fisherman said recently about the ecofriendliness of nets vs. hook and line, “There is no more indiscriminate killer in the ocean than a baited hook.”

Here’s a good take on how dragger fishing can be minimal impact.

One of the other key factors for sustainable harvesting of seafood really falls at the feet of the regulators who set the catch limits. Fishermen in the US fish under some of most restrictive rules in any fishery in the world. One of the things we can all agree on is that until the industry is rewarded for making changes to fish more sustainably, the status quo will prevail. So while we believe our program is sustainable, there is no question that making fishing more sustainable can happen if regulators create rules and laws that reward fishermen for fishing in area and with gear that results in decreasing long term negative impacts to ecosystems. We beleive that CAFC is a program that shows people care about sustainability, rewards sustainable fishing and encourages sustainable fishing. What do you think? Post a comment and let us know what you think about sustainability.