Fishing is a kind of directed randomness. You never know what you might catch, but you usually have some idea of what you're trying to land.

It is with that same directed randomness that a team of UNH researchers has spent the last year trolling for information about the fishing industry itself. While they didn't know exactly what sources were available when they cast their nets, they had some idea of what they wanted: documents from the 18th and 19th centuries that would give them a look at the affect of humans on the ecology of underwater species.

What the researchers in the History of Marine Animal Populations (HMAP) project have found has actually crossed over the line of historical research into the intersection of history and the science of marine evolution.

Their primary source documents, a previously unexplored treasure trove of captain's logs and customs documents regulating the codfish industry, have enabled the group to illustrate the connections between fishing methods and the depletion of fish populations in the Gulf of Maine. This information will expand scientists' understanding of the effects of fishing on marine populations far beyond the 20th century, the era of most existing research.

"We hope our work is going to be able to establish baselines for certain fishing grounds in the 1850s, at a time when most people had considered the commercial fisheries not technologically sophisticated enough or not aggressive enough to really affect fishing populations," says Karen Alexander '92G, a graduate student who coordinates the project. "One of the things we're finding is that these guys fished really hard and they were affecting fishing populations at the time."

That sort of determination is the key to the success of the HMAP project, which is headed by Andrew Rosenberg, dean of the College of Life Sciences and Agriculture. Rosenberg is a former administrator with the National Marine Fisheries Service and a veteran of courtroom battles over modern-day catch limits. The information HMAP provides about what cod and other marine animal populations looked like 200 years ago will assist industry representatives, politicians and others who are discussing what the population should look like now, he says.

The ongoing—and at times contentious—debates over catch limits won't be settled just by finding out how fish populations have changed from the 1850s, Rosenberg says. But fishermen who need to pull their bounty from the water to survive and those who have argued for catch limits as a way to allow the marine populations to recharge themselves might be able to use the information to reframe what has become a litigious impasse.

The researchers are also discovering where the boats fished, the technology they employed and how the fishing industry evolved in the 19th century. That sort of historical detail, according to Matthew McKenzie '98G, '03G, another Ph.D. candidate, can help them retell the story of New England fisheries.

During the four-month fishing season, for example,a sense of community often developed between the boat crews. Anchors and supplies were traded back and forth, and on Sundays the trading included stories and tobacco, according to the records.

"These guys would hail each other every day, talk to each other, trade gossip. They wouldn't fish on Sunday. They would smoke a pipe, have a 'gam,'" or conversation, says Alexander.

The researchers have also leafed through hundreds of maps, some dating back to the 18th century, that show the location of favored fishing grounds. By combining data from the logs with inferences drawn from the maps, they can postulate what those map locations looked like, what kind of birds and sea life could be found there and where boats might have gone down.

From the records, they have been able to infer changes in the industry itself, particularly after large French tub trawlers appeared on the scene in the 1850s.

"It became more of a merchant controlled industry," says Bill Leavenworth '90G, '99G, who works as a document researcher on the project. "Shareholders in the boats might not have been just locals or local merchants, but people from out of town. As the technology became more expensive, the cost grew beyond the assets of a local capital market. It shifted to an industry requiring much larger dories, tub trawls and boats that had to be equipped to stay out for much longer, and carry more stores and more people, and required more capital."

A particularly revelatory intersection between history and science comes from logbooks documenting catch sizes during the Civil War. As crewmen went to fight in the Union army, fish stocks bounced back, again proving that fishermen were depleting marine populations.

Some of the finds have even been intriguing in a gruesome fashion. In what Leavenworth calls the project's "slasher story," the captain of one boat arrived at a fishing ground in 1866 to find the crews of other boats had been washed overboard by a storm. He indicated in his log that the catch was very good, but his crew "took a man's leg out of a large cod."

See? You never know what you might find.