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Millions of pounds of lead used in hunting, fishing, and shooting sports wind up in the environment each year and can threaten or kill wildlife, according to a new scientific report. Sarah Gerould, head of the USGS's Contaminant Biology Program, talks with Dr. Barnett Ratter, a USGS scientist at the Patuxent Wildlife Research Center and a co-author of the new report, about the ways lead is affecting wildlife and their habitats. This episode includes images and video. Play Video: (downloading may take some time due to file sizes) 
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File Size: 65292475 bytes Duration: 11:25 Released: Fri, 11 Jul 2008 15:34:33 UTC |
Transcript:
Sarah Gerould: Hello and welcome to the U.S. Geological Survey's Core Cast on lead in shot and sinkers. I'm Sarah Gerould, the Program Coordinator for Contaminant Biology at the USGS.
The Wildlife Society and American Fisheries Society recently compiled a technical review on the effects of lead and ammunition and fishing tackle on natural resources. This review will help shape position statements of those societies on the continued use of lead for hunting, shooting sports, and fishing.
USGS has done a lot of research in the area of lead. I'm talking today with Dr. Barnett Rattner of the U.S. Geological Survey's Patuxent Wildlife Research Center in Laurel, Maryland. Barnett was one of the co-authors of the report, and he's been doing research on this issue for many years. Welcome Barnett.
Barnett Rattner: Sarah, it's great to be here.
Sarah Gerould: How long have hunters and fishermen been using lead shot and sinkers?
Barnett Rattner: Well, the use of lead ammunition dates back to the 14th century and parallels development of gunpowder, while lead fishing weights and hooks date back even further, perhaps to the Bronze Age. In the 1870s we began to realize that ingestion of spent lead shot by ducks could poison and kill them.
About a hundred years later, we realized that fishing tackle could also pose a serious hazard when ingested by some species of water birds like loons.
Sarah Gerould: Perhaps you could give us some background about the current production of lead ammunition and lead sinkers.
Barnett Rattner: Well, a number of studies tried to get a handle on this issue. Global estimates of ammunition production in the year 2000 were about 195,000 metric tons. As you can see from the graph, the USGS estimates that lead use in ammunition has fluctuated between about 45,000 metric tons and 70,000 metric tons per year since 1975.
This number includes types of ammunition other than shot. The U.S. EPA believes that about 72,000 metric tons of lead shot and bullets were deposited in outdoor shooting ranges annually, which seems to be relatively high compared to production estimates. Needless to say, a great deal of lead ammunition is produced and used.
As far as fishing tackle goes, in Europe, annual estimates are somewhere between 2,000 and 4,000 metric tons being sold. And in the U.S., a similar amount is sold each year.
Sarah Gerould: What about the annual lost rates for fishing tackle?
Barnett Rattner: These estimates are highly variable. For example, in the Netherlands it's thought that about 28 tons are lost annually, while in Poland the estimates are 1,000 to 1,500 tons annually. In Canada, one author published that 559 tons are purchased each year so a similar amount must be lost.
Sarah Gerould: I understand the use of lead shot for hunting waterfowl in the U.S. and Canada was phased out in 1986 to 1990. So why is the American Fisheries Society and the Wildlife Society interested in this analysis?
Barnett Rattner: Well since then, additional evidence has documented significant exposure to spent ammunition by upland game birds species like doves, quail, raptors, hawks, eagles, and scavenging birds like the California condor. The use of lead ammunition in the range of the condor was recently restricted in California. There are also other examples, including lead poisoning of white-tailed sea eagles that fed upon hunter-killed sika deer in Japan.
From a fishing standpoint, in the past 20 years, many studies have been documenting that lead fishing tackle is ingested by some fish-eating birds, and in some instances, local populations of these birds, like common loons, appeared to be adversely affected in heavily fished sites.
Sarah Gerould: So where do all the lead sinkers go?
Barnett Rattner: Well Sarah, accurate information on the density of lost fishing tackle is difficult to obtain. You know, it depends on things like angler skill, shoreline conditions, and the nature of the bottom of the water body being fished.
In areas of low angling pressure, one might find 1 lost fishing sinker in 100 square meters. But in areas where fishing pressures are great, for example, the Thames River in England, where there was historic fishing, estimates range up to 1,600 sinkers per 100 square meters. So that's a really big difference.
Sarah Gerould: Gives you a sinking feeling doesn't it?
Barnett Rattner: It does.
Sarah Gerould: [Laughs]
Barnett Rattner: Lead ammunition and fishing tackle slowly dissolve. You know, it might take decades or centuries or even millennia. And it depends very much on the soil and sediment conditions. When the lead dissolves, it doesn't disappear. It just moves with the water, so that when contaminated water moves in the ground water, the dissolve lead with it ends up in ground water. When the contaminated water is pumped out of the water supply well, the lead ends up in that water supply being provided.
Sarah Gerould: So, where has this been found to be a problem?
Barnett Rattner: In some instances, ground water near shooting ranges has been affected by the dissolution of lead shot and ammunition. As a matter of fact, there has been a recent USGS survey in Delaware at a shooting range that has demonstrated this. And in some instances, surface water in ponds and wetlands near shooting ranges and heavily hunted sites have been reported to have elevated lead concentrations.
Sarah Gerould: So what's the effect on fish and wildlife?
Barnett Rattner: Well, lead is one of the most highly studied toxic chemicals. As this video shows, it can even affect behavior in birds; their ability to fly and avoid predation. Lead has no known beneficial effect on biological systems. Ingested shot, bullets, and fragments inhibit the enzymes involved in making the part of blood that moves oxygen around the body.
Lead can cause anemia and even disrupt the passage of food. Prior to restrictions on the use of lead shot for hunting waterfowl in North America, literally millions of birds died each year from lead poisoning.
Sarah Gerould: So how much can kill a bird?
Barnett Rattner: As little as one BB ingested by a bird can be a lethal dose.
Sarah Gerould: What about fishing tackle? Is fishing tackle as much of a problem?
Barnett Rattner: Well, the effects of ingested fishing tackle to fish-eating birds is similar to that of lead ammunition, although as one would expect, the incidence of exposure seems to be far less. There are a few instances now when fishing tackle might even be affecting reptiles.
Sarah Gerould: What about in fish?
Barnett Rattner: Well, fish don't die from lead poisoning from ingesting tackle. They succumb from the injury, trauma, and blood loss associated with being captured.
Sarah Gerould: We talked about where lead sinkers go, but what about lead ammunition?
Barnett Rattner: Well, in shooting ranges, spent lead ammunition is often concentrated in one area. It might be at the target, or fall zone for trap and skeet. In hunting, lead can be concentrated in an often-used field and wetland. You know, prior to the ban of lead shot for hunting waterfowl, it's concentration in an average hunted field was about 69,000 shot per hectare. And in some heavily hunted sites, it was up to 5 million shot per hectare.
Sarah Gerould: No wonder the birds are picking it up. In this picture of a shooting range, the soil is completely covered with lead. That's that gray soil there, and it has caused stunting of the plants.
That same shooting range was cleaned up by the Fish and Wildlife Service and remediated. And the next picture shows what happened afterwards. So is cleaning up shooting ranges like this an option?
Barnett Rattner: Some shooting ranges have been cleaned up under the direction of State and Federal agencies and even others. And it's certainly an option, it works, but it's very expensive to do.
Sarah Gerould: Lead has certainly received a lot of attention from researchers, but what are the scientific unknowns?
Barnett Rattner: Well, we feel there are data needed on exposure and toxicity and species like amphibians, reptiles, and even some species of birds like passerines. It would be good if we had some additional information on the weathering, dissolution, and fate of lead from shot and sinkers in aquatic and terrestrial ecosystems.
And it would also be worthwhile to really assess and demonstrate the beneficial effects of using new alternative materials and how it in fact, it lowers lead in the environment related to fishing and hunting activities. And when I'm talking about the beneficial effects, I'm talking about the beneficial effects for the environment.
Sarah Gerould: So why do hunters and anglers continue to use lead?
Barnett Rattner: Part of it's tradition. Lead shot and sinkers are readily available and their cost is certainly much lower than the alternatives that are available. Hunters of upland game and anglers have been using them for many years so they're really accustomed to how traditional materials perform. They're accustomed to the ballistics of the ammunition and the performance of the fishing tackle.
So for these reasons, some hunters are a little bit reluctant to make the switch.
Sarah Gerould: So what are the alternatives?
Barnett Rattner: Well, for ammunition, there are several. These include steel, bismuth, tungsten, tin, nickel, polymers, and even combinations of these materials. For fishing tackle, similar types of metals are used as well as plastics, ceramics, glass, and even brass.
Sarah Gerould: It sounds like a careful look is needed. Who is involved in evaluating this issue?
Barnett Rattner: Currently, it's being evaluated by the American Fisheries Society, by the Wildlife Society, and the Association of Fish and Wildlife Agencies. But they don't have regulatory authority. They do have, though, a large constituency that they can influence.
Sarah Gerould: What government agencies regulate the use of lead ammunition and fishing tackle?
Barnett Rattner: Well, regulation is currently a patchwork. It involves Federal agencies and State governments. The Fish and Wildlife Service and the National Park Service have banned the use of lead fishing tackle on some of their management units.
Many States, including California, Illinois, Iowa, Minnesota, and Missouri have restrictions on the use of lead shot that extend far beyond waterfowl to include upland game birds.
Sarah Gerould: What about in other countries?
Barnett Rattner: Well, some countries have been far more aggressive in banning and restricting the use of lead and fishing activities. There was an international survey conducted in 2000, and 82 percent of the countries that responded indicated that they had some regulations in place to limit the use of lead in hunting waterfowl. Statutory bans were actually in effect on the use of lead for hunting any water bird species in places like Canada, Finland, Denmark, and the Netherlands.
Sarah Gerould: What about for fishing?
Barnett Rattner: Sometimes the regulations can be simple and allow flexibility. For example, in Canada, the size of lead fishing sinkers that can be used must be greater than 50 grams because they aren't ingested by water birds.
Sarah Gerould: That's about all the time we have. Thank you, Barnett, for talking with me today about lead and shot and sinkers.
Barnett Rattner: Thanks, and I'm glad to help out.
Sarah Gerould: We've been visiting with Dr. Barnett Rattner of the U.S. Geological Survey's Patuxent Wildlife Research Center.
I am Sarah Gerould, the Program Coordinator for the Contaminant Biology Program here at the USGS. CoreCast is a product of the U.S. Geological Survey, Department of the Interior. Thank you for joining us.
Resources related to this episode:
- Press release on the report
- Wildlife Society (report available to members)
- American Fisheries Society article on the known and potential impacts of lead in shooting and fishing
- USGS Contaminant Biology Program
- U.S. Fish & Wildlife Service
- What elements are harmful to living organisms and how do they get into our environment?
