Beginning this year, under a new federal law, recreational saltwater fishermen are required either to have a saltwater license or to have registered with their state. In Massachusetts, where a law requiring a license will take effect next year, fishermen are supposed to register.

But very few have.

A check with three tackle shop owners on the Vineyard early this week revealed that two of the three owners had not registered. The president of the Martha’s Vineyard Striped Bass and Bluefish Derby, Ed Jerome, hasn’t registered either. But because he is over 60, Mr. Jerome didn’t think he was required to register.

In fact there is much confusion among local fishermen about the new law and what they are supposed to do. And some don’t agree with the law, so they are not going along with it for that reason.

It seems as if everybody’s got an angle.

“It is tough. People have a lot of questions,” said Vineyard state environmental police sergeant Matthew Bass. “Anytime I step into a tackle shop or talk to a fisherman, they’ve got questions.”

Mr. Bass said he is not enforcing the law, although he said he is spending a lot of time explaining it.

When Congress adopted the Magnuson-Stevens Act reauthorization of 2006, the National Marine Fisheries Service was required to establish a registry for recreational saltwater anglers.

The federal requirement was proposed for last year, but was postponed until this year. Within the federal law, states could adopt their own fishing license, as long as it included data needed for fisheries management.

Last November Gov. Deval Patrick signed legislation establishing a Massachusetts saltwater recreational fishing permit. Registration is required this year with no fee; next year a fee will be put in place, expected to be set at $10.

Steve Morris of Dick’s Bait and Tackle Shop has not yet registered. Interviewed this week, he said he is not required to register because he has a commercial fishing license. Cooper A. Gilkes 3rd, who owns Coop’s Bait and Tackle in Edgartown, also has not registered yet; Mr. Gilkes said he believes anyone over 60 is not required to register. Mr. Jerome, a retired school principal and charter fishing captain, is of the same opinion.

But Steve Purcell, owner of Larry’s Tackle Shop in Edgartown and a charter fishing captain, registered months ago. So far Mr. Purcell said he has helped over 50 fishermen register in his shop. “A lot of people aren’t computer literate. So if I’ve got the time, and the store is empty, I help them,” he said. A computer with Internet access sits near his cash register. “I registered months ago. I always wait for the last minute for anything. I just didn’t want to get into trouble, so I did it,” Mr. Purcell said. He said it takes about a minute to register on the Internet.

Gordon Colvin, a biologist with NOAA’s Fisheries Service and interim senior policy advisor on recreational fishing, said the confusion is understandable. But he said anyone who 16 or over and fishes recreationally in Massachusetts should register. Fishermen who hold commercial fishing licenses are fine, but if they fish recreationally they too should register, he said.

That includes a commercial striped bass fisherman who goes out to catch a fluke for his dinner. And it includes fishermen who are over 60, Mr. Colvin said.

The only people who don’t need to register are:

• Those who fish on a licensed charter, party or guide boat;

• Those who already hold a highly migratory species angling permit or subsistence fishing permit;

• Those who fish only commercially under a valid fishing license.

The Web site for registering is Registration is free.

Next year, the Massachusetts state saltwater fishing license will kick in, at an expected fee of $10. Fishermen over 60 will pay no fee.

Most coastal states require a recreational fishing license. “There are four states that don’t have anything; two are New Jersey and Hawaii. Puerto Rico and the Virgin Islands don’t have one,” Mr. Colvin said. “This is a transition period for Maine and New Hampshire, which are both preparing a new state program for next year. Rhode Island is bringing along their own license this year,” he added.

The license rquirement is aimed at improving fisheries data.

Commercial fishermen are licensed and often file catch reports. Seafood dealers file landing reports. But data for recreational fishing catch is based largely on a system of random interviews with fishermen, conducted by telephone and in person.

The federal government estimates there are 12 million recreational fishermen in the U.S.. “You’ve got to imagine the past,” Mr. Colvin said. “Our contact with fishermen was something like selecting names from the Manhattan phonebook.” With the registry, he said, “In the future we’ll be able to select people from the list that actually go fishing. Which do you think works better? Once you explain that to the fishermen, they understand it. There is already a lot of skepticism about the current data collection, so people, most people understand what is being done.” He continued:

“If you think about it, we are estimating the number of fish caught. If we overestimate the number of fish being caught, we may end up imposing fishing restrictions that aren’t warranted.

“If we go the other way, and we underestimate the amount of fish being caught, and we enable the overfishing, the resource and the fishermen suffer. We need to be on the mark to make sure that fishing is sustainable.”

Mr. Gilkes has another point of view. “I refuse. I am 60 years old and to be perfectly honest, I am really confused about the whole thing,” he said, adding:

“It all started out to be a federal license. Then all of a sudden the state of Massachusetts wanted to do it because the feds wanted it all to go to the states. Now the state is going to do it, but the state isn’t ready yet. So this year we are doing it with the feds, which isn’t going to cost anything.”

Mr. Gilkes said he thinks states should offer reciprocal licenses, so a fisherman in Florida doesn’t need to register in Massachusetts.

But Mr. Colvin said states may not want to be reciprocate, because the license fees represent revenue in these cash-strapped times.

Dan McKiernan, a deputy director with the state Division of Marine Fisheries, said the registry is important. “The fact is there are 750,000 recreational fishermen in this state and a third of them don’t live in Massachusetts. It is real important,” he said.

For an explanation about the saltwater registry go to