Monday, 29 August 2011

The calm before the storm - "Come in number 755 it's time to be tagged!"

Sunday promised much and didn't let us down. Equipment and personnel took a battering on our way west to Point Ouest and Banc Parent, and accumulated tiredness and frustration (AKA Field Lag) crept to the surface when a 12 volt battery powering the nerve centre of our operations (my trusty laptop) gave up the ghost 2 hours into the trip. Sometimes it is useful being able to swear in many different languages. Undeterred by our minor setback and resorting to pencil and paper, hey if it was good enough for the Russian Space program, we continued south and west. The wind and tide abated, the sun came out, and we hit a purple patch, porpoises and Atlantic white-sided dolphins. Then came the call we had been waiting for "Sirocco, Sirocco pour Rafale"......... "We are with 3 MN, and our position is 7miles due north of you........ ". Christian opened up the throttle and soon we were skimming north and seeing spouts. 

Following two spouts we came upon a female humpback (Stalagmite) being escorted by a male (Tmain). Stalagmite was happy to approach the boat and we were treated to a display of pectoral slaps and spy hops; however there was little time for me to enjoy the show as the pressure was now on to prepare a tag while Stalagmite was still interested in us. Cue more blue language as cable ties broke and Tygon tubing decided that today was the day it didn't want to be bent. Finally the tag was ready and the rest as they say should have been easy; place tag in the TAD (tag attachment device), tie myself in, raise the tag pole, wait for Stalagmite to swim by and deploy the tag. Like I said it should have been easy, but I like a challenge and it was going to be one of those days. The tag bounced off and our chance with Stalagmite was gone.

Cue another 2 humpback whales; number 755 (a small male), and close associate 708 (another male), perhaps it was going to be our day after all. An easy life is just not my way, and so it proved with tagging 755. Pole fully extended, 755 sinking below the boat, a quick prod some way down from the dorsal fin on the right hand side, tag floating back to the surface............... Hang on!..... No tag in the TAD, no tag at the surface, in fact the tag was defying the laws of buoyancy and heading down into the depths below............................compute brain, compute brain..... whir, click, click, whir........"TAG ON!". "Time ........12:12:22, way-point 7". Somehow we had successfully attached a tag to humpback 755, now we waited to see if it would stay on. Shortly after tagging there was a lot of surface interaction between our whale, its close associate 708 and another humpback, miraculously the tag stuck and somehow migrated up the flank to sit in a perfect position just below the dorsal fin.

The waiting game over we followed at a respectful distance, listening to our VHF for the tags beacon and scanning the horizon trying to catch each surfacing, religiously noting down the time and position of every dive. As the minutes ticked by we nervously watched the horizon for signs of tropical storm Irene and listened intently to each new weather forecast. Would the tag release at it's allotted time (1500 hours) or were we going to be in for a long anxious wait? "Blow, fluke, blow, dive, blow, logging.........." so the hours passed.

From Rafale, Alain biopsied our whale as our hands were all tied up with tracking. The blubber sample that Alain collected will be used to assess stress levels by measuring cortisol concentrations, measure toxic loading and to determine at what level in the food chain our whale was feeding at.

The designated hour arrived and we waited with fingers crossed for continuous beeping from the tags VHF beacon, which would signal that it was back at the surface and had released successfully. Our whale surfaced and dove at 15:01 and the tag was still clearly attached.. "Beep, beep, beep, beep, beep, beep, beep, beep....." the tag was off, and the time was 15:07, seven minutes from release to the suction cup filling up and falling off. Time to find the tag and collect our valuable data, while saying thank you to 755 for sharing this brief glimpse into his life. Within a minute we had retrieved the tag, and within 5 we had packed up and were heading back to base at 26 knots ahead of the advancing Irene.

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