With the fall fishing season about to begin, there is a renewed warning out to shore fishermen to be careful not to litter the landscape. Spent fish line left on the ground can be a killer to wildlife.

In July an osprey chick was killed when it got entangled in a monofilament fish line.

David Nash of Edgartown, a recreational flyfisherman and naturalist, saw the dead osprey chick. “This was my third time to the nest. When I arrived at the nest I saw a deceased chick hanging off the nest, wrapped up in fish line,” Mr. Nash said. The chick had only just recently died.

Mr. Nash is one of a number of volunteers this summer who monitor the well being of young osprey chicks. He was charged with monitoring nests near the Edgartown Great Pond. The nest with the dead bird was off Oyster Watcha Road on private property. He said there was a similar incident this summer at Woods Hole.

Ospreys build their nests from branches and naturally occurring debris. But they also will grab spent pieces of rope, plastic, fishnet and cloth. After finding the dead bird, Mr. Nash passed the news on to scientists gathering data on the success of juvenile ospreys. But an even more important message arose from the incident: fishermen should not discard their spent fish lines in the wild.

Fishermen with the Martha’s Vineyard Surfcasters Association, a nonprofit organization, have been campaigning for years to try to educate fishermen not to discard their line. Almost since the organization was formed in 1989, the volunteers within the group have posted collection boxes for unwanted fish line.

The little white boxes — there are at least six of them — stand at the entrances to popular beaches. There is one at the entrance to Wasque on Chappaquiddick and another at the Dike Bridge, nearby. There is another at Eastville Beach in Oak Bluffs.

The boxes are intended to raise public awareness about the hazards of thoughtless discarding of waste, especially by recreational fishermen. A fundamental mission within the association is to promote thoughtful respect for the environment. The association has provided volunteers to help in annual beach cleanups that have been held through the years. Late last year the association came out against the use of lead weights in the fishing gear used in yo-yoing, a striped bass fishing technique that often leaves lead in the bellies of fish that get away and in the environment.

Chris Kennedy, the Island’s regional director for The Trustees of Reservations, oversees a lot of conservation land that is visited by both ospreys and fishermen, and wildlife and beach users. He had high praise for the efforts of the Martha’s Vineyard Surfcasters Association over the years to maintain the boxes for fishermen to discard their line. The box isn’t just a place to put spent fish line, it is a working sign to remind anglers to keep the environment clean.

“What they do is a wonderful service. They took the initiative,” Mr. Kennedy said. He said he looks inside occasionally, and he confirms the “old fish line” boxes do get used.

How the fish line gets into the environment is a familiar tale. An angler will have a line get fouled in his reel. A bad cast, a bad rig and the reel gets covered in a small tangle. The angler will remove the tangle to get his rod and reel ready to fish again. Tangled line happens. Mr. Kennedy said he knows of some anglers who will change the line on their rod right there on the beach. They’ll take the whole line off the reel and put on fresh line.

There is nothing wrong with changing line, it is just what the fisherman does afterwards.

“Fishermen should never throw monofilament into the wild. It never degrades,” Mr. Nash said.

Mr. Nash said ospreys are notorious for using trash in the building of their nests. “Chicks start to get active before they fledge.” That is probably when this chick got into trouble, Mr. Nash said.

Mr. Nash was a volunteer for Richard O. (Rob) Bierregaard, Jr. a scientist at the University of North Carolina at Charlotte who studies osprey. Over the years he has monitored the seasonal migration of the birds with transmitters mounted on their backs.

Mr. Nash and Dick Jennings of Oak Bluffs were among those who provided data for Mr. Bierregaard’s work.

Mr. Nash said they monitored 70 osprey nests. This year was a good year for fledged ospreys. A total of 122 birds fledged. “It could have been 123,” Mr. Nash said.