Field expedition

Sampling at Myravatn

Some additional samples from Lake Myravatn were needed, and Ingrid Wathne and her colleagues went once again to the lake, this time in beautiful (but rainy) autumn setting.

Two persons sampling with a plankton net from a boat on a rainy autumn day

Hauling in the plankton net at Lake Myravatn

Photo:

Mikko Heino

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By Mikko HeinoPublished: 27.10.2014

Only one of two large daphnid species, Daphnia longispina, has survived the invasion by perch. However, there is suspicion that hybridization between D. longispina and Daphnia galeata may have occured. To figure whether this is the case, some fresh material for genetic analysis is needed.

There is only one option - off to the lake. Autumn colours were pretty but rain started soon after we began to row towards the sampling station in the deep part of the lake. Of course, rain is no obstacle, and sampling went as planned.

Back in the lab, Daphnia were sorted out from the samples. Luckily, the catch was big enough, although another autumn day at Lake Myravatn would not be that bad either!

Lake Myravatn is a small lake in Bergen. After perch was illegally introduced there in 2006, the zooplankton community has undergone dramatic changes.

Two people with microscopes in a lab working with plankton samples

Ingrid Wathne and Petter Larsson sorting the plankton samples in the relative comfort of plankton lab

Photo:

Mikko Heino

Trees with yellow leaves reflect on lake surface

Autumn landscape at Lake Myravatn

Photo:

Mikko Heino

Picking Daphnia out under the microscope

Picking out Daphnia in the lab

Photo:

Mikko Heino

How to survive an alien invasion?

Sometimes fish can be just as scary as aliens – especially if you are a tiny Daphnia looking into the mouth of a big perch. Until 2006 daphnids in Lake Myravatn were unaware of the vertebrates living in neighbouring lakes. That year perch was illegally introduced and the daphnids had to face a novel...