By Heather W. Barron, DVM, DABVP
Hospital Director, CROW
The Clinic for the Rehabilitation of Wildlife (CROW) recognizes that lead is a potent toxin to humans and wildlife (especially birds) that can have individual and population-level effects. Lead is a toxic metal, yet tons of lead are deposited into our environment annually through hunting, fishing, and recreational shooting.
Lead deposited in the environment will persist indefinitely and will not break down over time into less-toxic compounds. Mortality due to lead poisoning has been documented in humans, birds, and a variety of other wildlife for over 2,000 years. Lead toxicity can also have sub-lethal consequences that can compromise both survival and reproductive success in a wide variety of species.
In the early 90s, concern grew that millions of waterfowl were dying each year from lead poisoning in North America. After years of debate, the federal government finally enacted a ban on the use of lead shot for most waterfowl hunting; however, it has remained legal for many other species.
Lead is also often being ingested by waterfowl mistaking fishing tackle for grit. Raptors (like eagles or osprey) and other wildlife that prey upon wounded animals that have been shot, eat fish that have ingested lead tackle, or scavenge dead fish or game can also ingest significant amounts of lead. Lead remains a primary cause of death in bald eagles and loons.
Recently, there has also been compelling evidence to suggest that humans may develop high lead levels from inhalation of lead dust when firing guns using lead ammunition. The more a person fires guns loaded with lead shot, the higher the risk. Firing ranges can be particularly hazardous environments due to the amount of lead in the air.
The consensus among medical researchers is that there is no safe level of lead exposure in young children. Even very low levels of lead exposure can decrease IQ and cause learning disabilities and behavioral problems in children or increase the probability of dying from a heart attack or stroke in adults. Many state health and wildlife agencies recommend that women and children not consume any game killed with lead shot. So, there are many reasons to consider the use of non-lead alternatives, even if not motivated by a concern for wildlife.
What can you do to help? Suspected cases of lead poisoning in wildlife should be reported to a local licensed wildlife rehabilitator, such as CROW (call 239-472-3644), or to FL Fish and Wildlife Conservation Commission. Advocate the use fishing sinkers and jigs made from nontoxic materials such as tin, bismuth, stainless steel, ceramic, and tungsten-nickel alloy. Encourage the use of nontoxic rifle and shotgun ammunition. Nontoxic ammunition is increasingly available online and at many locations where lead ammunition is sold. Ask your local bait and tackle shop and your ammunition dealer to carry a variety of non-lead products if they do not already carry them. Non-lead ammunition outperforms lead in many cases and has become increasingly affordable.
CROW advocates for greater public awareness and understanding of the consequences of lead exposure to human and wildlife populations, and emphasizes the potential gains for wildlife and environmental quality from use of non-toxic ammunition and fishing tackle. CROW encourages and participates in research and education aimed at understanding the extent of the problem of lead poisoning in humans, the environment, and wildlife in Southwest Florida. As a 501(c)(3) nonprofit, CROW is funded through memberships and donations. For more information on how to support CROW through membership, please visit www.crowclinic.org/donate/become-a-member.