January 19, 2013

Egg by egg, Department of Marine Resources restoring Atlantic salmon to Maine rivers

Effort to introduce Atlantic salmon roe to Sheepscot River in Palermo uses innovative technique

By Paul Koenig pkoenig@centralmaine.com
Staff Writer

PALERMO -- State biologists working in shallow river tributaries reachable by dirt roads and snowmobile trails are on the front line of the battle against extinction of the Atlantic salmon.

click image to enlarge

Department of Marine Resources biologist Jason Overlock, right, drills a redd for salmon roe Tuesday, as his colleague, Jason Bartlett, center, places a funnel for biologist Paul Christman, left, to insert Atlantic salmon eggs into the bed of the Sheepscot River in Palermo. DMR is using a novel technique, of blasting the bottom of the river with a high-pressure hose, to create the proper environment for inseminated eggs to hatch.

Staff photo by Andy Molloy

click image to enlarge

Atlantic salmon roe is ready to be planted by Department of Marine Resources biologists Tuesday into the bed of the Sheepscot River in Palermo.

Staff photo by Andy Molloy

Additional Photos Below

They visit the waterways in January and February, sometimes dragging their equipment on a plastic sled more than a mile to the sites, to mimic wild salmon spawning. They're planting thousands of eggs in the gravel of riverbeds, an effort mostly funded through a federal grant.

Near a site along the Sheepscot River on Tuesday, Maine Department of Marine Resources biologist Paul Christman prepared the salmon eggs, carefully lifting the tiny, pinkish-orange orbs wrapped in damp cheesecloth and placing them into a wide-mouthed beverage cooler.

The eggs, fertilized last fall at Green Lake National Fish Hatchery in Ellsworth, have developed small black specks for eyes and are no larger than the tip of a child's pinkie finger. They're stronger than recently fertilized eggs, Christman said.

While Christman fetched the eggs, Jason Overlock and Jason Bartlett, two other biologists for the department, worked in icy, foot-deep water to prepare the nests.

They pressed a long metal funnel into the ground with a cross-shaped pipe connected to a water pump, mounted on a backpack frame, with plastic tubing.

Overlock swung the standing pipe back and forth, digging the metal funnel into the ground, as the blue tubing behind him followed the movement. The gas-powered pump blasted water into the ground through the pipe, allowing the funnel to be pushed into the riverbed and create a hole for the eggs. After reaching the desired depth in the ground, Overlock lifted the pipe out of the funnel, which was now stuck in the gravel.

Christman scooped a cupful of about 500 eggs and lowered his arm into the cone to release the eggs.

The eggs are negatively buoyant, so they fall gently to the bottom of the hole, Christman said.

After the eggs settled, Christman rotated the cone slightly as he pulled it out of the gravel bottom.

If all goes well, Atlantic salmon will hatch from the man-made nest, also known as a redd, by the end of May. After living in freshwater for two years, they'll swim downstream to the Atlantic Ocean before returning to the river to spawn in 2017.

Christman and the other biologists at the Marine Resources department first experimented with hydraulic salmon egg planting methods in 2007 after Christman heard about biologists in Alaska doing it.

The original design had eggs being dropped from the top of the pipe, instead of the more gentle funnel method. Christman said they altered the design in 2009 with the separate funnel piece to protect the eggs better.

They first started large-scale planting in 2010 in the Sandy River, a tributary of the Kennebec River. This is the second year they've conducted large-scale planting in the Sheepscot River in Palermo.

Salmon from the first large-scale planting would be returning to spawn in 2014.

"The real test will be when, and if, adults show up," Christman said.

Last year, Christman and his team planted around 1.3 million eggs in Sandy River, the Penobscot River and its Cove Brook tributary, and the Sheepscot River, he said.

Christman said he's optimistic about the groundbreaking new egg-planting method.

"We're really hopeful that we're going to be able to turn the tide and actually increase the number of adults coming back," he said. "If we can do that, it will, to a certain degree, make some of our other supplementations obsolete."

Fishing for solutions

Christman said their other methods have never been able to increase the number of wild spawners and fish permanently.

(Continued on page 2)

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Additional Photos

click image to enlarge

Department of Marine Resources biologists place fertilized Atlantic salmon eggs into a standpipe Tuesday, which was inserted into the bottom of the Sheepscot River in Palermo with a hydraulic planter.

Staff photo by Andy Molloy


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