Ten scientists with Fisheries and Oceans Canada headed out from the dock at the Bedford Institute of Oceanography on Monday for a three-week research trip to conduct a so-called sea census.

The goal is to determine the health of Canada's East Coast fish populations and check on the state of the water they live in.

Don Clark, a biologist and the lead scientist on the project, said the sampling happens twice a year.

"We'll cover areas all the way from the Bay of Fundy up to Cape Breton and we'll be towing this net at each station and doing water sampling, plankton sampling," he said.

"The information is fed to fisheries management and the fishing industry and it's the major source of information they use in deciding how to set quotas."

Scientists from the United States will be conducting similar research this summer.

The work involves using two laboratories on the Canadian Coast Guard ship Alfred Needler as it tows a large sea trawl that scoops up almost all the sea life in its path.

Clark expects most of the catch will be haddock, dogfish, silver hake and lobster as well as less common creatures including sculpins, sea ravens and blennies.

Water sampling tool

This water sampling device is lowered to different depths and scientists are able to open and close the bottles remotely to take samples. (Jean Laroche/CBC)

He said the net used in the survey is tightly woven.

"The net we use has a mesh that's about ¾ of an inch at the back so we catch almost all the fish that we run into," Clark said.

The scientists do most of their work in the fish lab and water sampling lab. The wet lab is where fish from the trawl are counted, measured or dissected. They work in rubber boots and wear plastic aprons and are often sloshing around in ankle-deep sea water.

The adjacent dry lab is reserved for the computer equipment and the detailed recording work.

It's the job of Harris Johnson, the fishing mate, to work the net. He's been with Fisheries and Oceans Canada for decades and before that he worked on a commercial fishing trawler owned by National Sea.

He's anxious to head to sea again.

"I love this job. Done it all my life. Wouldn't want to change it for anything," he said.

During this trip, Johnson said he'll be setting nets between six to 10 times during every 12-hour shift.

"It's busy," he said.