Ecologist

Imagine standing knee-deep in a fast-moving, frigid creek 20 metres from where it runs into a spectacular alpine lake. In front of you is a large fishing net strung between the creek's banks in which five enormous bull trout have been caught.

You are an ecologist and you've been here for two weeks gathering data on the endangered bull trout population.

Two decades ago, the province wanted to encourage sport fishing and tourism in the area, so it introduced rainbow and brown trout to the lake. These new species became direct competitors with the bull trout for food and habitat, sending the bull trout population into sharp decline.

Years of study and work have been dedicated to reviving the bull trout population by removing the introduced fish. You are here to see if these measures are working.

Several times a day, you wade out nets to grab the fish that have been caught and bring them to your mobile station on the bank. One at a time, you put the bull trout in a basin of water with a bit of anaesthetic that temporarily sedates the fish so you can work with each one for about 10 minutes.

When the fish is sufficiently calm, you take it out of the basin and check for an identification chip implanted just under the skin. Once you have identified the fish, you measure its length and weigh it. You then put the fish in another tank, where you will keep it until the anaesthetic's effects have worn off and the fish can be safely returned to the creek.

Then, you will compare the data from this year to years previous. The ID chip lets you track each fish individually so you can check if it is growing longer and gaining weight, indications of an abundant food supply.

The ID chip also lets you measure recruitment rates by counting how many new juveniles are caught without chips, as well as death rates by counting how many fish from last year didn't return to the creek. These factors will allow you to evaluate the recovery of the lake's bull trout population.

After a couple long weeks in the field, you will return to your office and begin analyzing all the data using statistical software to indicate the size and growth of the bull trout population and whether it is going to survive in the lake.