sexta-feira, 28 de maio de 2010

Once upon a blue!

The Azorean people since many years look at the sea searching for whales, in the beginning looking only for sperm whales witch they hunted, but since those times there are memories of bigger “fishes” with “blows like towers” that were sighted from land, but because they were not the sperm whales they were searching for, they were not of much interest.

When the Espaço Talassa team started going to the sea, 21 years ago the opportunity came to go sea closely one of those “big fishes” imagine the surprise on the discovery that was nothing more than a blue whale, the biggest animal ever to life on heart, and this was how the first sighting of a Blue whale ocorred on the Azores, by 29 may 1997.

After that, sightings of other baleen whales like the Fin, Sei, Bryde, Humpback and even the Minke occurred on this waters during the months of april and may, since there every season during this months we fulfil the dreams of many that want to sea the oceans biggest creatures life on their natural environment.

Every season during the months of April and May, the baleen whales are migrating from the warm waters in the south, were they mate and have their young’s, to the cold north waters were they feed. During this migration they pass in the Azores and that is when we get to see them here in south of Pico island.

Because there is some food availability in these waters, they tend to stay a few days around here. The 2010 season started with a month of April with a regular number of sightings of baleen whales, but then in May something extraordinary happened, we started seeing them almost everyday, and we were so surprised that we decided to make a small statistic analyses with the data that we collect every day.

The results are shown on the graphics below, one regarding the month of April and the other the month of may for the last 10 seasons (we collect this data since 1989, but only the last 10 years were analysed because before that the effort on this months was much smaller). The analyses consist on the number of times each species of baleen whales was sighted each year; also there is a line with the number of trips to the sea to give an idea on the effort.

Regarding the month of April we can see that we have been sighting baleen whales every season on the last ten years, doe the numbers of each species change a bit.

If we analyse species we can see that the 2006 season was the best regarding Blue and Fin whales sightings, 2001 was very strong on Humpback whales, 2004 on Sei whales and 2002 on Minke whales. And looking at the present season we can see that it’s a good season, but not that much different from other years like 2002, 2006, and 2007.

And we can see that this numbers are not dependent on the number of trips, since in some years with less trips we see more animals that in years with more trips (compare 2004 with 2006, for example).

But when we look at the month of May, we can see that specially regarding Blue and Fin whales this is definitely the best season of the last 10 years, and again it has not to due with the number of trips to sea. On 2004 we sighted more Humpback whales, in 2008 more Sei whales and in 2006 more Minke whales.
But the month of May is not over yet and we have no idea of what is still to happen on the months to come.

The reasons for this extraordinary amount of whales around are not fully understood by us, according to the knowledge we have on this animals we can infer that it is probably due to a higher amount of krill than usual, but because we do not develop dedicated research on the food availability here we can’t be sure.

On the year of 1998 Espaço Talassa started identifying Blue whales for Richard sears, and took the picture of the first Blue whale match from the Azores to Iceland, this season, Richard was here and during his stay, until the 15 of May, 15 different Blue whales were identified, at the moment this number is still increasing.

We keep in touch…

Sem comentários: