Monday, May 14, 2018

Fin whales sightings are increasing year by year!!!

A month ago three biologists from Futurismo were in the 32nd European Cetacean Society conference, forging effective strategic partnerships for marine conservation. 

One of these biologists, Víctor Ojeda, presented a poster where the temporal distribution of the fin whale around São Miguel was analyzed using data collected since 2009. This study was carried on by Víctor Ojeda, Cristina Montoya, Miranda van der Linde and Laura González. 

In this poster it is shown that fin whales are mainly sighted in São Miguel during spring time. This supports the general migration theory: baleen whales spend winters in lower latitudes to mate and give birth, then in spring they start the migration to high latitudes, and spend summers feeding in the rich Arctic waters.  
Halfway in this migration are the Azores, where  the “spring bloom” triggers every year the enhancement of primary production (phytoplankton), favouring the development of upper trophic levels such as zooplankton (including krill) or small fish in our waters. This way, plenty of potential preys become available in the Azores for the starving whales coming from the south.

Sightings of fin whales have increased in the last years. It is noteworthy how they concentrate in spring, agreeing with the previously explained whale migration theory; but they are sighted as well in the other seasons. 

You can have a look at the graphic below where is shown in X axis the days of the year (366 days) and in Y axis the last 9 years, with number of tours with fin whales presence in each year between brackets. 
Every point is a day with a fin whale sighting. The reason of this temporal pattern is still unknown, but it suggests that the distribution of this whale species in the North Atlantic is more complex than previously thought. 
Different hypothesis arise from those results: maybe different whale stocks can choose different migration strategies, e.g. depending on their reproductive stage or on food availability; or perhaps some fin whales do not undertake extensive latitudinal migrations, remaining around the same area for longer time In spite of being the second largest animal in the world, categorized as Endangered by the UICN, fin whales are still quite unknown. 

This encourages us to keep on studying them even more, making the most of the data collected in our whale watching trips. Right now, Laura González, one of our biologists, is analyzing as part of her PhD fin whales distribution and habitat preferences in relation to environmental variables such as depth, water temperature, chlorophyll or ocean dynamics. 

Our work, together with the studies of other researchers, provides essential information for species conservation, improving the understanding of cetaceans distribution and its relation with the environment.

Daily temporal distribution of fin whales from 2009 to 2017. Between brackets number of tours with fin whales sightings

                A huge fin whale breathes from its two blowholes

Our Biologist Victor Ojeda explaining the increase of fin whales sighting during the European Cetacean Society conference.

Written by Victor Ojeda and Laura González

No comments:

Related Posts Plugin for WordPress, Blogger...