Festival of marine visitors

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26 April 2011

Festival of marine visitors

Tara came across a few boats over the last few days, before arriving at Guayaquil, they were mainly fishing boats. Although on the surface people don’t have much of a presence here, below the ocean, readings and observations reveal that the marine world is full of inhabitants. Two hundred and twenty nautical miles from the Peruvian coast, the clear blue sea of the oceanic desert is now a distant memory. Here the blue, gray, opaque water betrays the large amount of plankton present. At the edge of the Peruvian upwelling (an oceanographic phenomenon which results in the rising to the surface of cold waters from nutrient-rich depths) micro-organisms and predators pour in: fish, sharks, fishermen and… scientists.

Our catch throughout this 102nd scientific station – the last one to take place between Easter Island and Guayaquil – has been fruitful and not just in terms of micro-organisms. While the rosette was performing a late night immersion, Sarah placed her angling jig starboard, a tool she carries with her on every oceanographic expedition. Suddenly a cry of joy pierced the starry night and a squid about 70cm long could be seen tickling the deck of the boat with its tentacles. Alerted by the noise, the crew were quick to come and observe the animal whose appearance on earth dates back nearly 200 million years. The birds also heard our oceanographer engineer’s cry of joy and within minutes these white birds had surrounded the schooner. Lit up by a red moon, the scene was like something straight out of the famous film by Alfred Hitchcock.

Equipped with their numerous nets, the researchers continued their night time sampling and managed to catch two silver hatchetfish. These silver coloured fish (as the name indicates) with their sharp teeth, had previously been spotted during the Atlantic Ocean crossing. Another prisoner of the nets to turn up was a scaly dragonfish, with teeth even more frightening than those of the silver hatchetfish. These spindle-shaped, copper coloured fish normally live at depths of over 1000 meters, but at night they rise to the surface to feed. ‘Hoisted by his own petard’, the scaly dragonfish (Stomias boa) got itself snared while trying to capture its own prey, using its natural lure, shaped like a copepod, a small crustacean.

With the first night of the station accomplished, the scientists rinsed their instruments in fresh water and returned to their bunks for a few hours of sleep. Two sailors remained on deck to keep watch on the drifting boat. All was calm onboard Tara, but within the ocean activity is always in full swing. As François Aurat, Deck Officer, was performing his nightly rounds, he was surprised by the sound of a blowhole spitting its wet breath. A whale was hunting in Tara’s surrounding area, no doubt it had also been informed of the presence of squid!

Second morning of the station. While the crew carries out an immersion, the tips of some sharks’ fins are peeping out on the horizon. According to Gabriella Gilkes, a scientist who specialises in these predators, this region of ​​the South Pacific is infested with blue sharks, mako sharks, black tip and white tip sharks… After the sharks, it was the turn of a fishing boat to visit the crew. Coming aboard Tara to ask for a little bread, these Peruvian fishermen confirm the words of our scientist: they themselves are criss crossing this area in their hunt for sharks.

On board the scientists continue their fishing, certainly less dangerous than that of the Peruvians, but just as exciting. Three Beroë are caught. These pink striped, transparent ctenophores are put in a jar, arousing the admiration of our chief scientist, Stéphane Pesant. However to reveal the beauty of this marine organism, we really need light. Thanks to the iridescence of their cilia, which enable them to move about, their ciliated combs become rainbows when lit up. And to conclude this festival of marine visitors, some tuna, escorted by dolphins, are putting on a show for us, not far from the boat.

After two days of station duty, Tara has resumed her journey and is heading for the Equator. With each nautical mile travelled, the schooner plunges into these fishy waters, while at the rear of the boat, the fishing lines relentlessly caress the sea trying to gently steal one of its inhabitants. On deck everyone is keen to get their hands on the binoculars. The crew are still hoping to see a few marine species before discovering those of the mangrove. After the sharks, it would be nice to come across some caimans. Now is definitely not the time to go swimming!

Anna Deniaud