ELLSWORTH, Maine — Maine fishermen landed 276.6 million pounds of seafood and bait worth more than $425 million in 2011 thanks, in part, to a record lobster haul, state fisheries officials announced Thursday.

According to preliminary figures, last year’s total catch was 21 million pounds larger than in 2010 and represented the biggest haul since at least 2006. But despite the increase in total pounds, the estimated value of Maine’s 2011 catch declined by roughly $30 million due to a smaller harvest of pen-raised Atlantic salmon, the Department of Marine Resources said.

Once again, the lobster fishery continued to dominate Maine’s commercial fishing industry, especially in terms of the monetary value of the catch.

For the first time in history, the lobster catch broke the 100 million-pound mark in 2011, with the 103.9 million pounds representing nearly 38 percent of the total landings in Maine last year. Financially speaking, those lobsters were worth an estimated $331.4 million to fishermen — or nearly 78 percent of the total “boat price” value of all species caught in Maine in 2011.

Ten years ago, Maine fishermen landed just 49 million pounds of lobster. Fisheries officials and researchers attribute the dramatic increase to a number of factors, including a decline in fishing for other species such as groundfish and urchins as well as the health of lobster populations. Maine’s aggressive policies requiring fishermen to mark and toss back egg-bearing females and a lack of predators are often credited with helping the local lobster population to grow.

The record catch has not coincided with record profits for lobstermen, however.

Fishermen received, on average, $3.19 a pound for lobster last year, down from $3.31 a pound in 2010 and prices that exceeded $4 a pound from 2004 to 2007. Additionally, higher prices for fuel and bait have eaten into any profits in recent years.

The amount of Atlantic herring, which is a major source of bait for lobstermen, landed in Maine also jumped by nearly 18 million pounds. Landings of groundfish also increased from 4 million to 5.1 million pounds.

But total harvests for many other species declined from 2010 to 2011, according to the preliminary figures. Maine’s shellfish industry reported the most declines.

For instance, the mahogany quahog catch dropped from 4.7 million pounds in 2010 to 2.2 million pounds last year. Likewise, landings of hard clams fell from 1.8 million pounds to 429,000 pounds although soft clams increased from 10.2 million to 11.1 million pounds.

The Department of Marine Resources did not release the 2011 landings for farm- or pen-raised Atlantic salmon. However, the department said in a press release that lower salmon harvests were responsible for much of the $30 million decline in the total value of Maine landings last year. Aquaculture operations harvested 24.5 million pounds of salmon in 2010 worth an estimated $77 million, which represented the second most valuable fishery in the state last year.

Breaking down the catch by region, more lobster were landed in Hancock County than any other county in Maine, with fishermen reportedly landing 33.4 million pounds of the crustaceans worth an estimated $106 million. Hancock was followed by Knox and Washington counties, with 29.7 million pounds and 16.6 million pounds, respectively.