Visions from nature

In the field —

Trout tagging in the sub-Antarctic

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– a research expedition to Kerguelen, part 1

At the end of November I had an early Christmas celebration with my family before I packed by bags and headed south. After several long flights, I finally arrived on Reunion Island, where I would meet staff from the French National Institute for Agricultural Research (INRA) and the French Polar Institute (IPEV) to join on a research expedition to the second most isolated group of islands in the world.

Text: Sindre Eldøy, NTNU University Museum

Translation: Anders L. Kolstad, NTNU University Museum

Forskningsfartøyet Marion Dufresne forberedes for seilasen til Kerguelen. (Foto: Sindre Eldøy, CC BY-SA 4.0)
The research vessel Marion Dufresne is being prepared for the voyage to Kerguelen. Photo: Sindre Eldøy, NTNU University Museum, CC BY-SA 4.0.

The destination for this expedition is Kerguelen, a French territory in sub-Antarctic waters in the south Indian sea. Sea trout and seven other species of salmonids were released into rivers and lakes on the island in the 50s in order to have food for the people at the research station, and as an attempt at commercial aquaculture. The sea trout is the only species that really went out and colonized new watercourses, and it did this via the sea. There are now several sea trout populations on Kerguelen, but the colonization seems to have slowed down towards the northeast of the island group. We want to find out why.

På vei sørover mot Kerguelen stoppet forskningsfartøyet ved Crozet Island i to dager for å levere forsyninger og skifte ut mannskap på øyas forskningsstasjon. (Foto: Sindre Eldøy, CC BY-SA 4.0)
On the way south towards Kerguelen our ship stopped by Crozet Island for two days in order to deliver supplies and change crew. (Photo: Sindre Eldøy, CC BY-SA 4.0)

 

Tagging trout

The winter of 2017-2018 we put electronic tags into 50 adult sea trout. These tags omit signals that are read by 52 receivers that were placed in the rivers and lakes, and in the sea, at the same time. This method is called acoustic telemetry. By doing this we get information about where the trout is moving, as well as at what temperatures and salinity the water is. My main objective on this expedition is to make sure we find and retrieve these receivers, and to download and secure the data that they have been collecting over the last year. The project is a collaboration between IPEV, INRA, Ocean Tracking Network (OTN), Dalhousie University, and the NTNU University Museum.

«It’s hard not to get distracted from the work by the

king penguins and elephant seals along the rivers edge»

Christmas Eve in a tent

As a PhD student at the NTNU University Museum I routinely work with similar types of data from projects in central and northern Norway. Even though I’m used to field work in great scenery from places around the Trøndelag region, and the Tosenfjord and Skjerstadfjord in Nordland region, it’s hard not to get distracted from the work by the king penguins and elephant seals along the rivers edge.

Vi benyttet stoppet ved Crozet til å gjøre fiskebiologiske undersøkelser i bekken som renner gjennom øyas største koloni med kongepingvin. Her finnes det både ørret og bekkerøye. (Foto: Sindre Eldøy, CC BY-SA 4.0)
We made use of the stopover on Crozet to do fish biological studies in the stream that runs through the islands’ biggest colony of king penguins. Here there are both arctic char and sea trout. (Photo: Sindre Eldøy, CC BY-SA 4.0)
Kongepingviner. (Foto: Sindre Eldøy, CC BY-SA 4.0)
King penguins. (Foto: Sindre Eldøy, CC BY-SA 4.0)

Whilst I’m here, I also participate in fieldwork studying other salmonid fish species and I get to know so many interesting people and make new connections for potential future work collaborations. What better way to get to know each other than spending Christmas together in a tent camp and enjoing a nice meal on freshly caught trout and French wine?

After five weeks of travelling, waiting around at the Port Frances research station, and doing fieldwork for other projects than my own, I now can’t wait to start hunting down these receivers.

Etter tolv dager seilas nådde vi endelig nordspissen av Kerguelen. Her ved de karakteristiske fjellformasjonene Arc des Kerguelen.
After twelve days on the sea, we finally reached the north point of Kerguelen. Here you can see the characteristic mountain formations Arc des Kerguelen. (Photo: Sindre Eldøy, CC BY-SA 4.0)
Jula ble tilbrakt i telt ved sjøørretvassdraget Aceana en tre timers båttur unna forskningsstasjonen Port Frances.
Christmas Eve was spent in a tent by the trout containing river Aceana, a three hour boat ride from the research station Port Frances. (Photo: Sindre Eldøy, CC BY-SA 4.0).
Siden sjøørret er introdusert og svartelistet på øygruppen, er det fritt fiske i vassdragene. Med få kast i en av elvas større kulper var julemiddagen sikret. (Foto: Sindre Eldøy, CC BY-SA 4.0)
Since sea trout is an introduced and black listed species at Kerguelen, there is no regulations on the fishing. A few casts into some of the bigger pools of the river was enough to secure our Christmas dinner. (Photo: Sindre Eldøy, CC BY-SA 4.0)

 

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