A new Maine law bans lead fishing tackle in hopes of protecting loons.

The Department of Inland Fisheries and Wildlife says keeping lead fishing weights out of Maine waters will better the birds’ survival and spur population growth across the Northeast.

Ingesting lead fishing tackle is the leading cause of death for the birds.

A law effective in September bans the use of lead fishing sinkers that measure less than 2.5 inches long or weigh less than 1 ounce. The state says too-small sinkers that contain any amount of lead will be considered illegal.

The department estimates there are around 4,500 adult common loons across the state.