January 20, 2013

Hoping 'to turn the tide' on Atlantic salmon

Biologists are optimistic that an improved hydraulic egg-planting method will yield more adult fish.

By PAUL KOENIG Kennebec Journal

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

Atlantic salmon eggs are ready to be planted by Maine Department of Marine Resources biologists Jan. 15 in the Sheepscot River in Palermo.

Photos by Andy Molloy/Kennebec Journal

click image to enlarge

Maine Department of Marine Resources biologist Jason Overlock, right, drills a nest, or redd, as Jason Bartlett, center, places a funnel for Paul Christman, left, to insert Atlantic salmon eggs into last week in the bed of the Sheepscot River in Palermo.

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

Near a site along the eastern branch of the Sheepscot River last week, 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 to create a hole for the eggs. After reaching the desired depth, 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 not buoyant, so they fall gently to the bottom of the hole, Christman said. After the eggs settled, He 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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