Jun13

Where have the whales gone?

Categories // Bay of Biscay Wildlife Officer

Where have the whales gone?

Dolphin's came out to play for the Wildlife Officers and passengers on board the Cap Finistère.

Hello there, Laura again, and I can’t believe that we are already at the end of the 11th week of our Wildlife Officer season. Soon we will be welcoming our first summer intern placement on board! The daily motions of life at sea have become second nature to us, so much so that I wonder how I will readapt to a full-time life on land.

But before I digress too much into the semantics of my sea-faring life, I should probably give you an update as to the goings-on on board the Cap Finistère. My last two weeks on board have been a little different to what I had become accustomed too, and I feel like change is in the air in the Bay of Biscay. Only a few weeks ago, large whales (in particular fin and sei whales), dominated our sightings records, whilst dolphins presented themselves to us far less frequently. However, over the past fortnight I have been treated to numerous sightings of common dolphins, striped dolphins, pilot whales, bottlenose dolphins and harbour porpoises, but only a handful of large whales. It would seem that the dolphins very much want me to think that they are ruling the seas once again! And whilst I greatly enjoyed my numerous dolphin sightings, I found I couldn’t help but ask myself “Where have all the whales gone?”

However, it turns out, I am not the first Wildlife Officer to ask this question. After chatting to Heather (a returning Wildlife Officer from 2017), and some of the ORCA staff I have learnt that this dip in large whale (especially fin whale) sightings is not too unusual. As the fin whales we often spot in the Bay of Biscay aren’t actually part of a resident population, their presence in the Bay is widely believed to be linked to food availability, and the greatest number of individuals tend to be recorded in summer where the phytoplankton blooms are largest. But it’s not quite as simple as that; the masses of plankton and krill that attract our fin whales are largely dependent on environmental variables, such as weather and sea surface temperature, meaning that sudden changes in environmental conditions could lead to a perceived sudden change in large whale distributions. As, on the ship, our field of view is limited to just 16km into the distance (the distance to the horizon), it would only take a small shift in food availability, and subsequent whale distribution, for our sightings numbers to decline.

So there you go, that’s one theory as to where our large whales might be; just a smidge out of sight. Hopefully we might get a more detailed indication as to the cycle of fin whale presence and absence in our surveys once our ship-strike work is analysed further, however, having trawled through Wildlife Officer blogs for the past few years; it seems highly likely that our fin whales will return soon! I’ve got my fingers crossed that they put on a show for Sam and Heather next week!

Until next time!

Laura

ORCA Wildlife Officer, Bay of Biscay