Tag A Tiny 2009 Update!

The end of tuna season is fast-approaching in the northwest Atlantic!

The Tag a Tiny program has had its most successful year to date, handing out 1520 tags! Thanks for the donations that keep this project going. About 200 tagging reports have been returned to the LPRC, with more coming in every day! If you have tagged a fish with one of our tags, it's not too late to send it in.

To date, we have given out almost 5000 conventional tags. We have received tagging reports for 850 tags. Keep your eyes out for these tuna. They provide valuable information on migration, management, and age and growth.

Every bit of information helps, we look forward to hearing from you! See our website for updates on our most exciting outreach program.

LPRC Research Cruise Bluefin tuna tagging, Nova Scotia, Canada 08-12 October, 2009

Bluefin tuna fishing in Canada has been great in the last few years. Canadian fishermen from Nova Scotia and Prince Edward Island are reporting large numbers of bluefin giants swimming near coastal waters allowing a great opportunity for the LPRC to tag some of the fish that skip the Gulf of Maine during their migration.
So, on a stormy day I found myself on a ferry on the way to Nova Scotia to meet some hard-core bluefin fishermen and LPRC collaborators, on a mission to tag these giants.
As soon as I landed in Yarmouth harbor the Jacquards, Erik and Joel, along with Floy picked me up and we drove strait to Port Mouton to join Chris Malone on his boat, the F/V Rumbunkshus. We steamed north along the coast and by 21:05 we had our first hook in the water. I had high hopes for this tagging trip, but what happened that night exceeded all of my expectations. The Canadian fishermen (and fish) lived up to their reputation, and five minutes after we started fishing, a fish was on! By sunrise we had tagged six giants, what a great night. We continued fishing for two more days, with a short break due to bad weather, and deployed all the tags I had brought with me (10). These tags are programmed to stay on the fish up to one year and record valuable information, including fish location and swimming patterns.
Tuna season is almost over in the Gulf of Maine and “laboratory time” is approaching. The long winter ahead will be used to analyze data of previously tagged fish as well as biological samples collected throughout the season.
Stay tuned for updates!
Best,
Gilad Heinisch

Bluefin sampling with the "Nantucket Tuna Blast"

On a rainy weekend, 12-13 September 09, the 2nd “Nantucket Tuna Blast” tournament took place on the beautiful island of Nantucket, MA. Twenty-nine captains and their crews were competing for the heaviest bluefin caught by trolling. Since these fish were to be brought to the weighing station round (not dressed), it gave us a great opportunity to maximize our sampling efforts.
During this year we have observed many bluefin in the size range of 60-65”. These fish, presumably of western Atlantic stock, are considered immature, and thus are important to our study on maturity schedules of west Atlantic bluefin tuna.

So, what exactly are we doing?
Atlantic bluefin tuna are managed as two separate stocks, east and west. Natal homing is assumed to be the predominant reproductive behavior, where fish return to spawn in their native waters, which so far have been documented in the Mediterranean Sea or the Gulf of Mexico and the Florida Straits. Mixing of eastern and western fish occurs on feeding grounds such as the Bay of Biscay and the Mid-Atlantic Bight.
The current theory is that the two stocks have different maturity schedules, or ages of sexual maturation. Mediterranean spawners mature between the ages of 3-5 years old, whereas western Atlantic spawners are believed by some to mature between the ages of 10-12 years. This great discrepancy might be a result of a sampling bias and not represent the actual age of maturity of all western origin bluefin. Over the last 30 years some bluefin fishermen and scientists have suggested that smaller fish are capable of spawning in areas of the west Atlantic Ocean other than the Gulf of Mexico or Florida Straits. Among these suggested alternative spawning grounds are the Gulf Stream edge, the Bahamas and the Caribbean Sea.
We are examining the possibility that the presence of primarily large spawners caught as bycatch in the Gulf of Mexico during the spawning season, does not exclude other spawning behaviors. Sampling of tissues involved in bluefin reproduction from various size classes of fish, during and outside of the reproduction season, is crucial for the understanding the specie’s reproductive physiology.

Sampling with the Nantucket tournament
Learning about the Nantucket tournament from our tagging partner, Capt. Eric Stewart of the FV Tammy Rose (and The Hookup, Inc), we knew that it would be a great opportunity to increase our sampling. Tournament director, Jonas Baker, immediately offered his help with obtaining the samples, and the Kaisers, Thea and Pete, a long time tuna fisherman and a charter captain, generously offered to host us. The captains and crews were all happy to help with our scientific effort and weighing station master, Dave Berard, graciously assisted throughout the tournament.
The tournament was a great success and we sampled eleven fish, seven females and four males, and obtained blood and reproductive tissues. All of the bluefin were between 88-162 lbs., measuring 53-65”.

Collaborating with fishermen in bluefin tuna research has been at the heart of our program. Such coordinative efforts are critical for obtaining more information on Atlantic bluefin tuna’s biology.
We’re grateful for the opportunity to obtain samples at the Nantucket Tuna Blast and to spread the word about our Tag a Tiny tagging program. We also want to send a big thank you for the assistance we received by all participants!
Gilad Heinisch

Sonar work a beaming success

Last week the Large Pelagics Research Center conducted a research project with the Center for Coastal Ocean Mapping. The project, funded through the Northeast Consortium, is a pilot project to determine the feasibility of estimating biomass of juvenile Atlantic bluefin schools in the Gulf of Maine using high frequency multibeam sonar. Captain Billy (Hollywood) Muniz along with spotter pilots Mark Brochu, Mark Avila and George Purmont were all involved in data collection. In total, we spent 5 days on Stellwagen Bank and in Cape Cod Bay imaging juvenile bluefin tuna.

Sam and Michelle setting up the sonar system

Sam and Tom lowering the sonar head

A major objecive is that in ABFT stock assessments, any estimate of recent recruitment is highly dependent upon assumptions or estimates of the selectivity of the five youngest age classes in the most recent year of the stock assessment . We hope to develop new approaches for developing indices of abundance, and/ or improve the understanding of population dynamics of juveniles. A direct assessment of juveniles with sonar techniques (and aerial reconnaissance) has the potential to provide critically needed information for stock assessments and managers.

Mark Brochu found the fish for us and took aerial images


Captain Muniz

Thanks to the presence of fish, the sonar work was a great success. The data collected (about 1MB/second of imaging!) will keep us busy this fall and winter!

Post and photos Ben Galuardi, Research Scientist, Large Pelagics Research Lab

A Tale of Two Leatherbacks

Leatherback turtle with pilot fish consort

The relentless rain, cold and fog of June hasn't deterred all Cape Cod visitors... leatherback turtles have returned and our first field day was a doozy! To set the scene: a rare day of light winds, calms seas, and plentiful sunshine on Nantucket Sound. The day began at 5 am and didn't end until nearly sunset as we worked with a leatherback off Harwich and then regrouped for a leatherback off Chatham. Biologists from New England Aquarium and Provincetown Center for Coastal Studies, including our turtle vet Dr. Charlie Innis, rounded out the LPRC field team. Thanks to the gracious assistance of our fishermen collaborators Ernie and Mark, we were able to successfully examine, sample and flipper tag both turtles, and satellite tag one turtle.

Our satellite tagged turtle "Ethan" (named after Ernie's grandson) just before release

Coming up for a breath

The turtle went that way...

At 131 and 126.5 cm curved carapace (shell) length and about 400 pounds each, these two subadult leatherbacks are some of the smallest we have handled during our three year research project! This may not sound small but it is for leatherbacks, the largest living sea turtle and the second-largest reptile in the world (second only to the saltwater crocodile). These turtles surprised us given the lack of jellyfish inshore right now: leatherbacks eat jellyfish and may follow jellies to within a few hundred yards of the beach. But local fishermen tell me that few jellyfish have been seen since April, a stark contrast to July of 2008 when jellies (and hungry leatherbacks) were in abundant supply. It's still early in the season, so it remains to be seen if these two turtles signal the start of another big leatherback summer here off Cape Cod. Stay tuned!

So ends another beautiful day in the field (Wychmere Harbor, Harwich, MA)

Kara Dodge, Large Pelagics Research Lab Ph.D. student
All photos © Kara Dodge, Large Pelagics Research Center

All research activities conducted under NMFS permit #1557-03

Collaboration with Norwegian Modelers....

I've arrived in Bergen, Norway for a 5-week stay to work with collaborators at the University of Bergen. It was an uneventful trip, which exceeded all my expectations for traveling with my kids, Reece (4) and Kira (2), across the Atlantic.


The business end of the trip is well underway.....I am working within the Modeling Group (http://bio.uib.no/modelling/) in the Department of Biology which has an impressive range of expertise. The goal for my stay is to collaborate primarily with Christian Jørgensen and Øyvind Fiksen to develop a model that explores the interaction between environmental variability and Atlantic bluefin tuna life history. Christian and Øyvind have published several papers addressing similar questions using simulations of a cod model. Their approach has many promising applications to Atlantic bluefin tuna research. I am clearly in the right place at this stage of model development. I'm extremely excited to be here and I'm optimistic that this will be a productive collaboration.....more soon!!!!!



Erik Chapman