It is definitely time to get the lead out. (Feel free to cue up the Zeppelin tunes!)

Lead is a naturally occurring element that can be toxic to human and animals, causing illness and even death with high exposures. Both people and animals can be at risk.

Great efforts have been made to reduce the risk of human lead poisoning, and work is ongoing to protect animals and the environment as evidence of lead’s damage grows.

Consider the loon. Nancy Weaver found a dead red-throated loon last week and asked if there was anything specific that might be causing loon mortality. Turns out that lead is a significant factor in loon deaths.

Research by the Biodiversity Research Institute and the Tufts Wildlife Clinic shows direct mortality effects on common loons from lead. Lead can found in the marine and freshwater environments naturally; however, increased amounts occur due to the use of lead fishing tackle.  This human-made addition to the ecosystem accumulates in both habitats and fish (the loon’s primary food source).

Loons ingest lead in two ways. The first is through consumption of fish that have lead in their bodies (the fish that got away with fishing jigs and sinkers in their bellies), and the second is by consuming small pieces of lead on the lake or sea bottom. And don’t assume they’re being dumb for swallowing bits of lead that obviously aren’t nutritious. Since loons lack teeth, they need to ingest stones or grit-type material to help them grind and digest their food. Shot and split shot can be just the right size.

In one study of common loon mortality in New Hampshire (between 1989 and 2012), lead toxicity was to blame for 49 per cent of bird deaths. Of the objects removed from the stomachs of loons, 53 per cent were fishing jigs and 39 per cent were sinkers. These are alarming statistics, given how long we’ve known about the dangers of lead poisoning.

There has been some progress in reducing the prevalence of lead sources from sporting activities. New Hampshire, Vermont, Massachusetts, New York and Maine have laws that limit or ban lead in fishing gear. These and other improvements over the last 30 years have led to decreased loon mortality. The results of another study show that lead poisoning in adult common loons has dipped from 30 per cent (1987-2001) to 20 per cent (2013 through 2016).

These numbers are good, however there have been setbacks. A U.S. Fish and Wildlife order issued under President Obama mandating the phasing out of lead in ammunition and tackle on National Wildlife Refuges by 2022 was revoked by current Secretary of the Interior Secretary Ryan Zinke last March.

Common loons are a species of special concern in Massachusetts under the Commonwealth’s Endangered Species Act, with only 40 pairs of these birds currently breeding in the state (though many fly through). Red-throated loons are a regular (but uncommon) species here in winter, and are observed in larger numbers during their spring and fall migrations to their breeding grounds to the north.

In the case of Nancy’s red-throated loon, it was unclear what caused its mortality. In addition to lead, loons can be killed as by-catch in commercial gillnet fisheries, by oil spills, and through diseases and conditions including botulism, avian influenza and red tide neurotoxins.

Continuing to work for a reduction in lead is in our interest as well as wildlife’s. Many fishing groups, as well as conservation organizations, have come out to support environmental protection and efforts to reduce lead pollution. Any other action should go over like — well, like a lead balloon.

Suzan Bellincampi is director of the Felix Neck Wildlife Sanctuary in Edgartown, and author of Martha’s Vineyard: A Field Guide to Island Nature.