Longitude: 37.38 West/Oeste
(A Beleza da Antárctica numa perspectiva Belga| Foto de Anton Van de Putte)
O cientista Belga Anton Van de Putte é daqueles jovens cientistas que quando se começa a falar com ele, nota-se que ele gosta do que faz e é orgulhoso do seu país e das suas origens....os famosos ciclistas Belgas, a cerveja, as ligações fortes com a Holand... Como ele está a estudar a genética de várias espécies de peixes (os peixes lanterna ou cientificamente, os peixes mictófideos) que fazem parte da dieta dos pinguins e das albatrosses que estudo, e como estamos no mesmo grupo de investigação a bordo (o grupo que estuda os peixes, as lulas e os crustáceos usando as maiores redes, RMT 25 (Rede de arrasto pelágico que tem 25 metros quadrados, ou sjea, uma rede que captura os animais na coluna de água e que tem uma boca de 25 metros quadrados)), estamos sempre à conversa.
Pedi-lhe para falar-nos do que faz....
(O Belga Anton Van de Putte, com barba ao melhor estilo de explorador polar)
As you may have noticed from the contribution from José I’m also working on the RMT 25 catches. This is because my interest is fish. I study the ecology and genetics of various fishes in the Southern Ocean. During this campaign my main interest lies with a fish called Electrona antarctica and other myctophid fish. I’ try to explain what I’m doing without getting to technical about it.
Myctophids are also called lanternfish because of the photophores, small light emitting organs, that cover their body and are meso-pelagic fish occurring between depths of 1000 m and the surface. They should not be confused with angler fish which are the scary deep sea fish that lure their prey by dangling a light organ in front of their mouth. Myctophids are a very species rich family that occurs in high numbers in all of the oceans and of which by comparison very little is known.
(Electrona antarctica|Anton Van de Putte)
In the Southern Ocean these lanternfish seem to play a key role in the ecosystem. The will consume mesozooplankton like copepods but also the occasional krill. Their importance in the diet of top predators such as seals and birds is indicated by the presence of otholiths and the isotopic signal. The latter is the field of expertise of Gabrielle Stowasser and Yves Cherel, the other two scientists that work with the net RMT 25.
(E. antarctica lives in such marine environment | Foto de Anton de Van de Putte)
So what has this to do with genetics and ecology? Well for me both go hand in hand with one giving valuable information for the other. The ecology will learn us about the current distribution of the species and can provide insight how this distribution could be affected by things such as climate chance. For E .antarctica it seems that this species has a very broad distribution from southern pars of the Southern Ocean up to the Northern parts at the Antarctic Polar Front. With the genetic tools I’m trying to understand the population structure of E. antarctica. Is their one big population of E. antarctica that goes all the way around the Antarctic or are there several more or less separate units? Also by analyzing the genetic structure in time we can learn if the population structure is stable or declining or expanding. Such knowledge is important for the management of this resource.
(Black browed albatross is one of the predators that feed on Electrona antarctica)
But this trip I’m also collecting samples to look at a broader picture. At the Antarctic Polar Front I hope to collect a larger diversity of myctophids. For these species I’ll try to read of a piece of DNA called COI. This is called DNA barcoding and this piece of DNA should be different between species but not within species. This will allow identifying species based on their genetic barcode but also it allows to compare these barcodes and to build a family three of these different species. With this we hope to investigate the relationships between lanternfish of the Atlantic Ocean and to see how closely related lanternfish in the North and South Polar Regions are. Thanks!!!!