Monday, November 2, 2015

A 20-Step Guide to Tagging Giant Atlantic bluefin

There’s a long list of things that have to go right to tag a giant bluefin tuna.  Here’s an abbreviated version.

To tag a giant bluefin tuna you have to:
1.) Obtain research permits, program and prepare the electronic tags, and pack a lot of gear (don't forget anything!!!).

2.) Travel to a remote corner of Nova Scotia.

Autumn colors on Cape Breton Island, Nova Scotia. photo: E. Estess
3.) Wait, and wait, and wait for the weather to clear up. We were only able to fish 7 days out of 3 weeks this October due to weather!

4.)  Make sure your tagging boat motor is working.

5.) Find and catch large mackerel for bait.

6.) Search for a school of bluefin tuna (this can take hours/days).

Diving gannets and busting bluefin. photo: E. Estess
7.) Get a bluefin to bite the bait. Bluefin are notoriously picky about what they will bite. Last week we had a school of giant bluefin jumping through our mackerel baits without a single hookup!

A bluefin nails the bait! photo: E. Estess
8.)  Make sure the circle hook sets in the corner of the tuna’s mouth.

9.) Fight the fish to the stern without pulling so hard that you break the straining monofilament or bend the small metal hook.

Lloyd MacInnes and Dennis Cameron work together to angle in a
large bluefin for the tagging team. photo: E. Estess
10.) Guide the head of the tuna to the back door of the tagging boat. This is one of the hardest steps as the tuna can easily shake its head and pull the hook, particularly when the seas are rough.

11.) Use 5 people to pull the (up to 1,600lb) animal through the back door of the tagging boat onto a padded surgical mat.

12.) Place a hose into the tuna’s mouth to irrigate the gills with oxygen rich seawater and place fabric over the animal’s eye to reduce stress.

An eye cover and irrigation hose help keep the bluefin calm
and safe on deck.  Photo: R. Schallert
13.)  Remove the hook from the corner of the mouth.

14.)  Measure the length of the fish. This length measurement can be converted to an estimate of the fish’s weight at a later time.

15.)  Insert sterilized titanium darts into precise locations along the tuna’s back to anchor acoustic and satellite tags securely to the fish.  If done correctly, the acoustic tags will last for up to 5 years and the satellite tags will automatically detach from the animal after 1 year. Note: All tagging and handling procedures are conducted under the strictest animal care protocols.

Dr. Steve Wilson places a satellite tag into the dorsal muscle of a
large Atlantic bluefin. Photo: E. Estess
16.)  Insert a conventional/spaghetti tag with the phone numbers to call in case the fish is recaptured by a commercial fisherman.

17.)  Take a small (pencil eraser-sized) clip of the tuna’s fin to use for DNA sequencing.  This will allow us to understand if the animal is from the eastern or western Atlantic population of bluefin.

18.)  Lift and rotate the surgical mat to point the tuna’s head out the door (easier said than done!).

The Tag-A-Giant team lifts a giant bluefin to release it back into
the Gulf of St. Lawrence. Photo: R. Schallert
19.)  Guide the tuna out the door and watch it kick away into the deep blue of the Gulf of St. Lawrence.

20.)  Exchange high 5’s with the team!

The weeks of preparation and decades of expertise between the fishermen and researchers paid off and we were able to tag and release two giant bluefin on this trip. Our past results have shown that a majority of these tunas swim south from the foraging grounds in Nova Scotia to the Gulf of Mexico to spawn, and a small percentage swim across the Atlantic into the Mediterranean Sea for lesser-known reasons.  Only through long-term tagging studies like this will we be able to understand tuna migration and life history in order to effectively model population sizes for stock assessment and sustainable management of this species. 

Follow this link to the recent publication of our 8-years of tagging effort in Nova Scotia:

Saturday, October 17, 2015

Tag-A-Giant Nova Scotia 2015: First Bite

It’s 6am and the floodlights cast their rays on the back deck of the f/v Bay Queen IV in Murphy’s Pond, Port Hood’s small commercial fishing port on the west coast of Cape Breton Island, Nova Scotia.  Captain Dennis Cameron and mate Lloyd MacInnes move around the deck coiling lines and crimping monofilament, bantering over the low rumble of the inboard.

Murphy's Pond in Port Hood, Nova Scotia
photo credit: R. Schallert
We approach the dock in our minivan loaded with crates of scientific gear and snacks for our day on the water. Dr. Steve Wilson and Robbie Schallert of Stanford University and the Tag-A-Giant Foundation lift a heavy silver crate and shuffle towards the Bay Queen IV, greeting the crews of the various vessels staging their gear in the grey light.  The crate is full of acoustic and satellite tags that, with luck, will be deployed on some of the largest tunas in the world.

The TAG team has been coming up to Nova Scotia every fall for the past 8 years and it shows.  Robbie cracks jokes with Melvin, Troy, Carl and more as we make our way down the floating dock. TAG has fostered lifelong relationships within the Port Hood community to create a collaborative environment; we couldn’t tag without their ocean expertise, and our research contributes to the sustainable management of their local bluefin fishery.
Loading the bait well with mackerel in the morning light
photo credit: E. Estess
We shove off as the clouds turn a light pink hue. The first order of business, as with all fishing, is bait.  Dennis eyes the echo sounder and quickly shifts out of gear when he spots a school of mackerel.  We keep the biggest mackerel in the live-well and motor off towards the tuna grounds.  Once we’re in the zone Lloyd rigs up two of the thick rods with live mackerel and pink balloons as surface floats, and the third rod is connected to a kite line to dangle a live mackerel at the surface.  And now we wait.

Radio calls come in from across the Gulf of St. Lawrence.  “Congratulations Bill, glad to hear you got your fish.”  “We’re marking lots of fish over here boys.”  Again, I take note of the friendly, collaborative nature of the fishery. Canadians really are as nice as people say!  After hours of silence we decide to pick up our lines and try another spot. More silence and no tuna marks on the echo sounder.

Searching the Gulf of St. Lawrence for giant bluefin
photo credit: R. Schallert
This is our second day on the water and the fishing has been silent.  Not to mention the weather has been on the rough side of the spectrum.  Part of me accepts that this is the nature of fishing- the bite is always hotter the week before. It’s fishing, not catching. Am I wearing my lucky tuna belt? I didn’t even bring any bananas on board.  These old catchphrases and superstitions drift through my mind as the hours flow on.

Deep down I know I’m paying a karmic penance after my last trip up to Port Hood in 2013, when we tagged up to 9 giant bluefin in a day and fished for 5 days straight in sunny, flat calm conditions.  I knew I was going to have to pay some dues, and bouncing around in the cabin with my hands shoved deep into my foul weather jacket to keep warm in the Arctic breeze, I accepted my fate with a meditative mantra, “It’s fishing, not tagging.”

Wind on the water. Waiting for action.
photo credit: E. Estess
At that moment, I watched the monofilament pull tight and the pink balloon float disappear. SNAP! The rubber band holding the Teflon leader guard broke and it rocketed down the line to protect the mono leader from the glass-sharp teeth of the giant tuna below.  BZZZZZZZZZZZ the line screamed off the reel as Lloyd rocketed across the deck and started cranking away.  Dennis began maneuvering the vessel, backing down on the fish to gain slack in the 300lb test line like a boxer circling their opponent in the ring.  The rod bent with strain as the fish made a run and Lloyd waited patiently for his chance to gain line.
But as quickly as it had come, the tuna jerked the hook from its mouth and was gone.  Lloyd silently reeled in the slack line, pausing to look at the bent hook.  Strike one, but after days of no action the reminder of the power of these animals was enough inspiration.  The fish are around. They’re always on the move throughout the gulf waters as they hunt for herring and mackerel, and it takes skill and decent dose of luck to line up on them.  Weather permitting, we will be putting in our time these next weeks to tag and release these beautiful giants, unlocking the secrets of their life history and migratory routes to inform the sustainable management of the tuna fishery.

Hoping for an evening bite.
photo credit: E. Estess