Tisbury town employees will have to restrict their use of Facebook and Twitter while at work from now on.

The selectmen voted this week to approve a social media policy for municipal workers, becoming the first town on the Island to do so.

The policy allows town departments to use social media sites for public communication only, and sets guidelines for public records law, copyright laws, confidential information protection and defamation. The policy will be sent out to all departments for signing within the next two weeks.

“Responsible use of social media in government is a big issue,” said selectman and board chairman Tristan Israel following the meeting. “I don’t think it’s a matter of trying to censor, it’s a matter of productivity. There are issues that involve the public that should not be on Facebook. It’s just to make sure that employees of the town use social media in a responsible way.”

Chilmark has a social media policy for the tri-town ambulance and police departments.

“[For the rest of the town departments] we have longstanding policies that we feel address everything from a typewriter to a text messaging device for appropriate behavior of our employees,” executive secretary Tim Carroll said. “We keep in mind every record we produce is a public record, and try to balance transparency with people’s legitimate rights to privacy.”

Oak Bluffs, Edgartown, West Tisbury and Aquinnah have not adopted social media policies.

In other business the selectmen held a public hearing on a plan to convert the former department of public works garage property site on Spring street into a parking lot for teachers at the Tisbury school. Voters approved $50,000 at the annual town meeting in April for the parking lot construction. On Nov. 19 selectmen signed a memorandum of understanding with school officials stating that the town will maintain the lot and review terms of use annually.

Plans prepared by DPW director Fred LaPiana include an asphalt parking area, a stockade fence around the lot, street lights, and trees. Abutters Eric and Karen Medeiros asked that no lights be installed, especially since the parking lot would only be used in the daytime, and also requested a taller fence.

Emergency services building chairman Joe Tierney agreed, saying “after dealing with abutters at the fire station, we should have a minimum of a six-foot fence.”

Selectmen agreed that street lights were unnecessary and expensive with a cost estimate of $12,000, and said instead the money could be put toward a better fence. Work will begin next spring.

Selectmen also introduced full-time emergency medical technician Tracey Jones as the new ambulance coordinator effective Jan. 2, 2013. She will replace longtime coordinator Jeff Pratt, who is retiring.

Shellfish committee chairman James Tilton reported that at the request of the selectmen his committee had discussed clarifying language and definitions in the town shellfish regulations. Mr. Tilton said a standard bushel box will measure 18 by 10.5 by 12.25 inches, plus or minus a quarter inch; a wire bushel basket can hold one bushel, or 32 quarts, and will be approved by shellfish constable Danielle Ewart. He said a gang dredge will be defined as two or more dredges fastened together side by side. A public hearing on the regulations is set for Dec. 11 at 6 p.m.

Mr. Tilton also reported that Tashmoo will be open to dip netting only for recreational and commercial scallopers starting Dec. 1. Commercial fisherman Thomas Searle said he would like to see Tashmoo open to dredging for both family and commercial fishermen, because parts of the pond are too deep to reach by wading. Mr. Israel referred the question to the shellfish committee; Mr. Tilton said it could be discussed at the next committee meeting on Dec. 20.