3.26.2009

The Local Food Report: bluefin tuna, part 2

Have you ever seen anything like this?


It's an aerial picture of a school of giant bluefin tuna, swimming around the Gulf of Maine. The Large Pelagics Research Center let me borrow it, since I talked with a research director there, Molly Lutcavage, for the radio today.

It's really a pretty amazing idea, that the tuna are so big, and stand out from the ocean so clearly, that someone flying around in a plane could just snap! take a picture and there they are. Like little tadpole-Cheerios, swimming around in the big blue, milky sea.

Lutcavage, along with the New England Aquarium and her group of researchers, studied tuna this way for three years, using spotter pilots from the fishing industry. The spotter pilots' job was to fly around looking for big schools of tuna, and then call the boat captains so they could rev up their engines, grab their nets or harpoons, and head out.


It used to be that only harpoon boats and purse seiners used pilots, but when they started flying for boats with general category licenses, for example rod and reel, whoever got to the fish first could catch most of the quota. In other words, it was first come first serve, and some boats lost out. As you might imagine, this didn't go over very well with a lot of fishermen, and the spotter pilots became so controversial in the late 90s that Lutcavage had to stop using them. Instead, she started tracking giant bluefin with tags.

When she did, she noticed the same thing the fishermen have been noticing: there are a lot fewer big fish around these days, and a lot more juveniles in Cape Cod Bay. The giants are out there, she says, it's just that they're bypassing the whole Gulf of Maine, heading up to Canada or hanging out places like Georges Banks instead.

To try and figure out why, Lutcavage is looking into all kinds of things. Their reproductive cycles, where they spawn, how they interact with their prey. The Center even has a program called Tag a Tiny, aimed at studying the juveniles themselves. The tags track the little tunas' geographic locations, and what the depth and temperature of the water they're swimming in is like. Every little bit of information helps.

If you're interested in knowing more, it's well worth checking out all of the links (in purple) above. Because even though we have a long way to go when it comes to understanding and managing tuna, Lutcavage and her team are learning more by the day.

I, for one, am hoping we understand enough soon enough that tuna sashimi will never be a distant dream. That's one treat I'd rather not do without.

P.S. All photos here are courtesy of the Large Pelagics Research Center in Durham, New Hampshire. Thank you so, so much!

11 comments :

Craig Caldwell said...

Elspeth - I love your shows and learn so much of our local life here on the Cape and Islands.

I would like to talk with you about a very important food source here, striped bass, and the various health warnings issued from every east coast state except MA on eating these fish. These fish are far more important as a recreational driver of the local economy for guiding, fishing and recreation (we have possibly the world's best) and simply catching and eating all of the large (all striped bass over 28" are female) over 34" fish that the commercial fishermen can keep are destroying the entire species' ability to sustain current levels of these fish.

If you are interested in this topic I would love to talk with you and share the science involved to protect these fish which ME, NH, CT, NJ have all enacted and which we are trying to enact here in MA. As an aside, over 60% of all striped bass eaten are farm raised and are much more healthful for consumption.

In any event I would love to hear from you and wish you the best with your fantastic show.

Anonymous said...

Craig - why don't you identify yourself as policy coordinator for Stripers Forever, a group that pushes for eradication of commercial bass fishing? Wouldn't that be more honest?

Craig Caldwell said...

No problem - I'm not trying to be dishonest. I have helped to get the Striped Bass Conservation Bill into the legislature. This bill is geared for the long term viability of these fish that are currently in decline and are being managed by DMF who has not shown a record of saving any fish. Quite the opposite.

My reason for commenting here is for health concerns that are posted on every state's (with a commercial fishery) web site except here in MA?. Why not? Why do we harvest a fish for market (90% of our fish go straight to New York anyways) that is unhealthy to consume more than once a month and not at all for mom's or children?

As a locovore we need to be aware of the health concerns for this food source and learn about other choices.

Most of these fish are also infected with Mycobacteriosis which is very contagious for the commercial fishermen who catch them.

Anonymous said...

MOST striped bass harbor infectious bacteria? Shouldn't that make recreational bass fishing dangerous?

I understand your concern Craig, which raises one question... are YOU a locavore?

Craig Caldwell said...

As much as I can be - I hit the local farm markets and shop at the Health Food stores as well as grow my own garden.

As for the mycobacteriosis - yes, recreational anglers need to be careful and indeed DMF needs to start educating them. The main problem is for the guys (and gals) that catch a lot and work on them at the fish markets as they come in to contact with far more of the infected fish.

The real problem is that up to 70% of the large females are infected and do not show any external lesions (and it is expected that fully 90% will expire from the stress of the disease). They tend to get the disease after spawning when they have been weakened. Therefore, most of the larger fish are the ones to watch out for, not the schoolies, per se.

You can look at this information at the Virginia Institute of Marine Studies. If you need the link let me know.

Anonymous said...

Thanks for looking out for the fish-cutters, Craig, and keep up the good fight. Just watch your backcast, and remember, circle hooks save lives.

Anonymous said...

There is a good deal of science out there now on this topic as well as a deep tradition of harvesting bass.

There needs to be more communication between the two groups so each side can understand the other.

The striped bass stock recovery of the 80's and 90's was a monumental achievement for fisheries management. There is no reason why we can't move on to the next phase of a sustainable harvest program. -FM

Elspeth said...

Craig:

Thank you for your kind words about the show.

It's great to see a lively conversation on this site—these are important issues and I think it's good to raise awareness on all sides.

I am planning to look into our bass fishery for a show this summer—I'll keep everyone posted once I have a date.

All the best,

Elspeth

Anonymous said...

Hiya, Elspeth. I've really enjoyed the ongoing tuna entries... neat to see old pictures of Pop in there in part one.

Also, I'd like to direct any of your readers who are interested in bluefin tuna issues to visit the Tag A Giant foundation website.

http://tagagiant.org/

There are many interesting points about tuna biology, behavior and policy.

Keep up the good work!

- Josiah

Elspeth said...

Josiah:

So good to see you here. Aren't the pictures a hoot!? We had so much fun digging them up.

Hope you're doing well...sure I'll see you more once summer rolls around.

Best,
Elspeth

norm6969@verizon.net said...

I have heard that the disaster in the Gulf of Mexico so close to spawning season may wipe out this entire year class. Any ideas/comments? Norman Floyd

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