Sunday, July 3, 2011

Whale watching trip July 2

I first started working on whale watch boats during my masters and used the  chance to collect behavioural data on right whales.  Each year since, I have worked on a whale watch as a naturalist, and used that opportunity to collect data of whale, seabird and other large pelagic sightings, such as sharks and blue fin tuna.  The trips are all a bit different and some more memorable than others. 

July 2 we had an amazing day south east of White Head Island, part of the Grand Manan Archipelago and a tidal upwelled area that concentrates prey and attracts predators such as whales and seabirds.  There have been some fin whales in the area which we found easily but then groups of Atlantic white-sided dolphins arrived and the fin whales immediately changed their behaviour from 4 to 6 minute dives to 2 minute dives. The fin whales kept in a small area and the groups of dolphins associated with the fin whales, bow riding. The number of fin whales increased over the time we were with them with the whales keeping in a tight area with the dolphins.

Before we spotted the dolphins I was intrigued but the activity of some of the fin whales who were arching highly but not going for long dives. Some also seemed to be charging (swimming quickly to the surface throwing a large bow wave) and then the dolphins showed up. The dolphin vocalizations can be heard underwater for several kilometres. Perhaps the fin whales were anticipating their arrival or the dolphins were attracted to the activity of the fin whales.

There was great excitement on board but it seemed like there was great excitement with the fin whales, some of whom were vocalizing at the surface (low rumbling calls) which we could hear. Fin whales have deep voices and usually their calls need to be speeded up for us to hear them. For fin whales this was like us talking several octaves above our normal range in a high shrill. I heard more fin whale calls during this whale watch than I have ever heard at one time.

The dolphins were mostly juveniles and adults with no calves and stayed in three groups of about 10-12 individuals each, associating only with the fin whales who were in groups from two to six or seven. Normally dolphins will come over to a boat and check it out but they completely ignored us and stayed with the whales.

The fog moved in on us but not before we counted 23 fin whales and about 35 dolphins. As we left the area but could still hear the activity through the fog.

A humpback whale, named Tornado, on the northern edge of the whale distribution rounded out the trip.  I also recorded eleven species of seabirds (great and sooty shearwaters, Wilson's storm petrels, northern gannet, northern fulmar, common eider, herring gulls, greater black-backed gulls,  razorbill, common murre, black guillemot) and a bald eagle and an osprey.  There were also a couple of blue fin tuna that we could see pushing at the surface - this is swimming just below the surface and leaving a visible wake.

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