It’s easy to sympathize with the fishermen who dock at piers in Portland who are concerned over a proposal to let more pleasure vessels use those docks. However, a campaign by some of them to keep current limits in place may be harmful to their interests rather than beneficial to them.

Right now, thanks to a referendum that passed in 1988 limiting development on the water side of Commercial Street to marine-related commercial uses only, berthing space at the docks is primarily limited to commercial fishing vessels, tour boats and ferries. Piers can only allocate 50 feet of docking space for noncommercial vessels.

These days, with the huge decline of the groundfishing industry in Maine due to federal restrictions on the allowable catch of major commercial species, most of the fishing boats using Portland’s waterfront are run by lobster fishermen. The well-regulated lobster fishery has its ups and downs, but it is far healthier at present than the groundfishery.

Overall, however, the waterfront is suffering. Although later changes to the 1988 zoning opened up space above street level to nonmarine uses such as offices and studios, residential uses are still banned.

However, the departure of their major clients has left pier owners with insufficient resources to maintain the docks that the boats are using.

Now, the City Council is taking up a package of zoning changes that would expand the uses permitted on the waterfront to give pier owners more resources to meet their needs.

One of those changes met with resistance this week. A lobsterman named Willis Spear took Monday off from fishing to circulate a petition opposed to doubling the berthing space for rental by recreational boaters from 50 feet to 100 feet on each pier. Pier owners said last fall they had a total of about 700 feet of unclaimed space to rent.

Spear says the 50-foot-per-pier increase, though small, will still raise his industry’s costs. Fishing vessels pay less than pleasure craft for berthing space, because competition has driven the fee for pleasure boats far above the commercial rate.

But that means providing more space for pleasure craft also could increase the income of the pier owners, who can use the money to improve maintenance and stay in business.

It only took a few hours for Spear to gather 70 signatures, and his petition has been submitted for councilors’ consideration when they take up the zoning changes Monday night.

Councilors certainly should consider the petition, but they should also remember they have the health of the entire waterfront to consider.

As long as vacant space is available, a 50-foot increase seems appropriate.