CAPTURE, ACCLIMATION CAPTURE, ACCLIMATION AND TRANSPORT OF AND TRANSPORT OF

ATLANTIC TUNASATLANTIC TUNAS

Ben Daughtry, and Forrest A. Young. June Ben Daughtry, and Forrest A. Young. June 20102010

CONTENTSCONTENTS Collection technique, Early captive husbandry,Collection technique, Early captive husbandry,Feeding and Acclimation of:Feeding and Acclimation of:

Blackfin Tuna (Blackfin Tuna (Thunnus atlanticusThunnus atlanticus))Skipjack Tuna (Skipjack Tuna (Euthynnus pelamisEuthynnus pelamis))Little Tunny (Little Tunny (Euthynnus alletteratusEuthynnus alletteratus))

Transport and Post Transport Husbandry of Transport and Post Transport Husbandry of Blackfin TunaBlackfin Tuna

ConclusionConclusionAcknowledgements Acknowledgements

Capture Capture TechniqueTechnique

Use of lures and live bait at seamounts more than 20 Use of lures and live bait at seamounts more than 20 nautical miles out to seanautical miles out to sea

Hook and line fishing using 20lb spin tackleHook and line fishing using 20lb spin tackle

Fish are lifted into live well while on line and released into Fish are lifted into live well while on line and released into tank with no contact to the fish’s skin by any foreign object tank with no contact to the fish’s skin by any foreign object (ie. Net or hands)(ie. Net or hands)

Transported 4 fish (3 Blackfin and 1 Skipjack) in for a Transported 4 fish (3 Blackfin and 1 Skipjack) in for a maximum time of 4.5 hours in 8’ (2.5 meter) wellmaximum time of 4.5 hours in 8’ (2.5 meter) well

Used 2 , 5’ (1.5 meter) wells to transport all fish from dock Used 2 , 5’ (1.5 meter) wells to transport all fish from dock to Dynasty Marine main holding facility (15 minutes)to Dynasty Marine main holding facility (15 minutes)

Used same technique to transport one Little tunny several Used same technique to transport one Little tunny several days after initial capturedays after initial capture

EARLY CAPTIVE HUSBANDRYEARLY CAPTIVE HUSBANDRY

All fish are very sensitive to handling and capture trauma, especially to All fish are very sensitive to handling and capture trauma, especially to the skinthe skin

Due to their other eccentricities they appear to require high water Due to their other eccentricities they appear to require high water quality standards and significant swim area. quality standards and significant swim area.

Tank size was 22’ Long X 18’ Wide X 5’ deep (15,000 Gallons)Tank size was 22’ Long X 18’ Wide X 5’ deep (15,000 Gallons)

All fish were feeding with in 2 week of capture. They appear to need to All fish were feeding with in 2 week of capture. They appear to need to feed multiple times daily and the Blackfin are finicky about their food.feed multiple times daily and the Blackfin are finicky about their food.

Smaller tuna (2-5 lbs) survive well in existing holding systems that we Smaller tuna (2-5 lbs) survive well in existing holding systems that we use for pelagic sharks and other pelagic fishes.use for pelagic sharks and other pelagic fishes.

Larger fish (6-8 lbs) had longer term issues. Larger fish (6-8 lbs) had longer term issues.

SHORT TERM CAPTIVE SHORT TERM CAPTIVE HUSBANDRYHUSBANDRY

Tunas can be challenging to Tunas can be challenging to acclimate to feeding in captivity. We acclimate to feeding in captivity. We have felt it best to acclimate them to have felt it best to acclimate them to feeding prior to any attempted feeding prior to any attempted transports. The Blackfins prefer transports. The Blackfins prefer eating small silvery fish and are fussy eating small silvery fish and are fussy about the size of food presented. about the size of food presented. Best results were achieved by Best results were achieved by feeding small/medium fish like feeding small/medium fish like pilchards and small scads. (1.5”-2”). pilchards and small scads. (1.5”-2”). The Skipjack tuna and Little tunny The Skipjack tuna and Little tunny fed more readily than Blackfin tuna. fed more readily than Blackfin tuna.

SHORT TERM CAPTIVE SHORT TERM CAPTIVE HUSBANDRYHUSBANDRY

We had good results from feeding to satiation on a daily We had good results from feeding to satiation on a daily basis, this meant 3-4 feeding times daily and offering a basis, this meant 3-4 feeding times daily and offering a variety of foods.variety of foods.

Small fishes were preferred in many cases, specifically Small fishes were preferred in many cases, specifically with the tunas.with the tunas.

Tunas appeared to be more temperamental feeders. Tunas appeared to be more temperamental feeders. They showed loss of weight and vitality quickly during They showed loss of weight and vitality quickly during fasting periods.fasting periods.

Based on their high energy budget we feel they would do poorly if Based on their high energy budget we feel they would do poorly if fasted prior to transportfasted prior to transport

Both the largest Tuna and the Skip jack had problems Both the largest Tuna and the Skip jack had problems with apparent self sustained injuries in the holding with apparent self sustained injuries in the holding tank after 3-4 weeks and eventually had to be tank after 3-4 weeks and eventually had to be euthanized. euthanized.

Tuna FeedTuna Feed

Skipjack and Tuna feedSkipjack and Tuna feed

TRANSPORT OF TUNASTRANSPORT OF TUNAS

On October 29th of 2009 we attempted a mock transport of the 2 smaller On October 29th of 2009 we attempted a mock transport of the 2 smaller tunas.tunas.

This was done at our facility in Marathon. This was a 24 hours, This was done at our facility in Marathon. This was a 24 hours, simulation of a 1500 mile road trip or cross Atlantic air transport. We simulation of a 1500 mile road trip or cross Atlantic air transport. We transported 2 Blackfin tuna, one 40 cm and the other 45 cm. (estimate) transported 2 Blackfin tuna, one 40 cm and the other 45 cm. (estimate)

We used plastic sheeting and bags to remove the tunas from their tank We used plastic sheeting and bags to remove the tunas from their tank without touching them.without touching them.

The mock transport was accomplished in a circular 2.5m (8’) diameter The mock transport was accomplished in a circular 2.5m (8’) diameter pelagic transport tanks, approx 3000L (750 gal).pelagic transport tanks, approx 3000L (750 gal).

Dissolved O2 was kept at 130%-150% of saturation at 27-28 C.Dissolved O2 was kept at 130%-150% of saturation at 27-28 C.

We did have some ammonia challenges due to feeding right up to the We did have some ammonia challenges due to feeding right up to the transport. This was handled with the addition of Amquel and bi-carb as transport. This was handled with the addition of Amquel and bi-carb as needed.needed.

Transport tankTransport tank

POST TRANSPORT CAPTIVE POST TRANSPORT CAPTIVE HUSBANDRYHUSBANDRY

The tunas both survived. Only one of the individuals began eating The tunas both survived. Only one of the individuals began eating immediately after the mock transport and this same one ate in the immediately after the mock transport and this same one ate in the transport tank while underway.transport tank while underway.

It took dedicated efforts to get both tuna feeding regularly post It took dedicated efforts to get both tuna feeding regularly post transport. transport.

Eight days after the mock transport one of the tunas hit the tank Eight days after the mock transport one of the tunas hit the tank wall and had to be euthanized due to excessive damage. wall and had to be euthanized due to excessive damage.

The second tuna lived for more than 2 ½ months after transport The second tuna lived for more than 2 ½ months after transport before a cold front dropped the water temperature to 15 C. At this before a cold front dropped the water temperature to 15 C. At this point the tuna began to swim erratically and rub the wall.point the tuna began to swim erratically and rub the wall.

The Little Tunny (Euthynnus alletteratus) was able to survive the The Little Tunny (Euthynnus alletteratus) was able to survive the cold temperatures , but succumbed some 4 months later to a cold temperatures , but succumbed some 4 months later to a Dylox treatment. Dylox treatment.

ConclusionConclusion

The Blackfin tuna, Skipjack tuna, and The Blackfin tuna, Skipjack tuna, and the Little tunny are all very the Little tunny are all very interesting potential display species. interesting potential display species. They do have certain eccentricities They do have certain eccentricities that will need to be overcome for that will need to be overcome for long term success, but with long term success, but with maximum sizes in the 20-25KG range maximum sizes in the 20-25KG range they hold a unique opportunity for they hold a unique opportunity for displaying truly pelagic fishes in displaying truly pelagic fishes in “smaller” tanks.“smaller” tanks.

AcknowledgmentsAcknowledgmentsYoshitaka Abe, Aquamarine Fukushima, Yoshitaka Abe, Aquamarine Fukushima,

Fukushima Prefecture JapanFukushima Prefecture JapanKenichi Fuji, Aquamarine Fukushima, Kenichi Fuji, Aquamarine Fukushima,

Fukushima prefecture JapanFukushima prefecture JapanToshiki Matsuyama, Tokyo Sealife Park, Tokyo Toshiki Matsuyama, Tokyo Sealife Park, Tokyo

JapanJapanManny Ezcurra, Monterey Bay Aquarium, CAManny Ezcurra, Monterey Bay Aquarium, CAJohn O’Sullivan, Monterey Bay Aquarium, CAJohn O’Sullivan, Monterey Bay Aquarium, CACollection staff, Husbandry staff at Dynasty Collection staff, Husbandry staff at Dynasty

Marine Associates, IncMarine Associates, IncJosh Moreira, Dynasty Marine Associates, Inc. Josh Moreira, Dynasty Marine Associates, Inc.

Marathon, FL USAMarathon, FL USA