In an effort to reintroduce a fish that was one prevalent in most New England rivers and ponds, the Darien Land Trust has been restocking Olson Pond with blueback herring.

Denis Frelinghuysen, steward for the Darien Land Trust, said the restocking process began two years ago.

"We've had this [Olson Pond] property for a long time," Frelinghuysen said. "The idea was to be a proactive steward."

The Darien Land Trust began restocking Olson Pond two years ago and this past spring they released 200 pregnant blueback herring into the pond. Frelinghuysen said the Land Trust will continue to restock the pond until the first group of herring returns to the pond.

After getting in touch with the state about possibly restocking the pond with fish, the Land Trust decided on the blueback herring over bass or trout because they were once a native fish that was unable to return to the rivers and ponds after the construction of the I-95 culvert, Frelinghuysen said. Frelinghuysen said bass and trout could have been stocked in the pond at some point in the past as well.

"Herring are a migrating species and they will go out to sea and feed and grow before returning to the place where they were born," says Frelinghuysen.

Besides reintroducing a species that is no longer prevalent in local waterways, Frelinghuysen said the land Trusts's efforts will help sport fishing, birds who eat fish and other aspects of life in the Long Island Sound. Along with enhancing the value of the habitat within the Olson Woods property, Frelinghuysen said the herring would help to enhance the food chain within the Long Island Sound.

The native herring were unable to return to the rivers and ponds in Darien and other towns because of the lip on the bridge in the I-95 culvert, Frelinghuysen said. The lip, which he described as being only about 18 inches off the water, was enough to prevent the fish from migrating upstream.

Frelinghuysen said the efforts to restock Olson Pond also help to establish a link between all of the Land Trust's properties. He added that once a fish ladder is constructed, the herring could travel as far north as New Canaan.

"The real problem was I-95," Frelinghuysen said. "But both of our properties above I-95 and below would be enhanced by restocking."

Currently, the Darien Land Trust is in the process of getting grants in order to construct a fish ladder in the culvert that would allow the herring to migrate.

"There is money for this stuff," Frelinghuysen said in regards to receiving grants for building a fish ladder.

The fish that the land trust has been using to restock Olson Pond come from Rye Brook, N.Y., where there is strong migration for herring, Frelinghuysen said.

Once the fish ladder is constructed, Frelinghuysen said traps would be place in the river to see if the herring are migrating.

Frelinghuysen said the project to construct a fish ladder is on target at the moment, but he did caution that the timeline for construction is dependent on other groups like the Connecticut Fun for the Environment which are applying for grants.

"We could be in business for 2012,but if it doesn't happen until 2013, it will happen then," Frelinghuysen said.

To prepare for the future construction of a fish ladder, Frelinghuysen said the Land Trust has been taken water level readings with the help of an environmental group from the high school at the culvert.

"By having local support and volunteers, it has enabled us to jump-start the project," Frelinghuysen said.

The Darien Land Trust is working to expand more into the community in their efforts to improve the property they own because, as Frelinghuysen said, "When you know about places you relate to them, and when you relate to them, you care about them."

On Oct. 16, the Darien Land Trust asks volunteers to help pick up trash and collect data at Olson Woods, Nearwater Lane and Weed Beach. To join the cleanup efforts, contact Shirley Nichols or Denis Frelinghuysen at the Darien Land Trust at 203-655-4148.