A.M. Scheuhammer1 1 A review of the environmental S.L. Norris impacts of lead shotshell ammunition and lead fishing weights in Canada Occasional Paper Number 88 Canadian Wildlife Service Aussi disponible en français 1 Environment Canada, Canadian Wildlife Service, National Wildlife Research Centre, Hull, Quebec, K1A 0H3. A member of the Environmental Conservation family Cover photos (left to right): Common Loon (David Pond), Mallard (G.W. Beyersbergen), and Bald Eagle (Richard Fyfe) Published by Authority of the The Canadian Wildlife Service Minister of Environment Canadian Wildlife Service The Canadian Wildlife Service of Environment Canada handles wildlife matters that are the responsibility of the Canadian government. These include protection and ©Minister of Supply and Services Canada, 1995 management of migratory birds as well as nationally Catalogue No. CW69-1/88E significant wildlife habitat. Other responsibilities are ISBN 0-662-23633-5 endangered species, control of international trade in ISSN 0576-6370 endangered species, and research on wildlife issues of national importance. The service cooperates with the provinces, territories, Parks Canada, and other federal agencies in wildlife research and management. The Occasional Papers series Canadian Cataloguing in Publication Data Occasional Papers report the results of original research carried out by members of the Canadian Wildlife Scheuhammer, Anton Michael, 1952– Service or supported by the Canadian Wildlife Service. Occasional Papers have been subjected to external peer A review of the environmental impacts of lead shotshell review. ammunition and lead fishing weights in Canada For more information about the Canadian Wildlife Service or its other publications, please contact: (Occasional paper, ISSN 0576-6370; no. 88) Issued also in French under title: Examen des impacts Publications environnementaux de la grenaille et des plombs de pêche Canadian Wildlife Service en plomb au Canada. Environment Canada Includes bibliographical references. Ottawa, Ontario ISBN 0-662-23633-5 K1A 0H3 Cat. no. CW69-1/88E (819) 997-1095 1. Lead — Environmental aspects — Canada. Aussi disponible en français sous le titre Examen des 2. Fishing tackle — Environmental aspects — Canada. impacts environnementaux de la grenaille et des plombs 3. Hunting — Equipment and supplies — Environmental de pêche au Canada. aspects — Canada I. Norris, S.L. II. Canadian Wildlife Service. III. Series: Occasional paper (Canadian Wildlife Service); no. 88. TD196.L4S33 1995 363.17é91 C95-980208-8 95-08 2 Abstract This report reviews the available information, from lead concentrations in soils or sediments associated with Canada and elsewhere, on the use, environmental fate, and clay target shooting ranges are often sufficiently high as to toxicity of spent lead shot and lost lead fishing weights exceed lead criteria for hazardous waste. Molecular lead and discusses options for managing the negative impacts from the breakdown of spent shot can be transferred to of these products. biota, especially soil and sediment invertebrates and Lead shot ammunition and fishing sinkers worth an terrestrial and aquatic plants, and thence to higher trophic estimated $25–$35 million are purchased annually in levels. Canada. For lead shot, more product is imported Lead shot ingestion is probably the primary source (primarily from the United States) than is manufactured in of elevated lead exposure and poisoning in Canadian Canada; for lead sinkers, more product is produced waterfowl and most other bird species. For some species domestically than is imported. A major proportion of (e.g., Common Loons), lead sinker ingestion is a more Canadian lead sinker production is probably attributable to frequent cause of lead poisoning. Based on gizzard and individuals and very small local companies. Between 1988 wing bone surveys of the species of ducks most commonly and 1993, the total deposition of lead shot and sinkers into hunted and extrapolation from U.S. estimates, up to the Canadian environment by hunters, clay target shooters, 6 million of the approximately 50–60 million game ducks and sport anglers averaged about 2400–2700 t/yr. About migrating from Canada every fall may ingest one or more 70–80% of the total deposition was lead shot from hunters. spent lead shotgun pellets while in Canada. These Most of the deposition of shot and sinkers occurs in individuals suffer either mortality (~200 000–360 000) or Ontario and Quebec, but some deposition occurs in all sublethal lead poisoning (several million). Because the provinces and territories. Local deposition rates vary from United States has banned the use of lead shot for almost nil to very high in some locations (certain rivers, waterfowl hunting nationwide since 1991, Canada is now lakes, marshes, target shooting clubs) where shooting or responsible for an increasingly large proportion of the lead angling pressure has traditionally been high. Where they poisoning problem in North America and may be the have been measured, shot pellet densities at waterfowl major continental source of migrating waterfowl that carry hunting sites in Canada are comparable to those measured embedded lead shot. Lead shot ingestion also occurs in a in the United States and elsewhere. wide variety of non-waterfowl species, including upland Metallic lead pellets deposited onto soils and game birds, shorebirds, raptors, and scavengers. Where it aquatic sediments are not chemically or environmentally has been explicitly studied in Canada and the United inert, although tens or hundreds of years may be required States, lead poisoning mortality of Bald and Golden eagles for total breakdown and dissolution of pellets. The rates of from eating prey animals with lead shot embedded in their erosion, oxidation, and dissolution of metallic lead pellets tissues or the gizzards of birds with ingested lead shot in the environment depend on various physical and accounts for an estimated 10–15% of the recorded chemical factors. Aerobic, acidic conditions enhance the post-fledging mortality in these raptorial species. Several rate of pellet breakdown, whereas anaerobic, alkaline studies have demonstrated that the incidence of embedded conditions decrease it. Physical factors such as high water shot in apparently healthy, free-flying waterfowl flow rates, soils or sediments dominated by the presence frequently exceeds 20%, indicating that millions of of coarse sand or gravel, and frequent disturbance of migrating ducks and geese carry embedded shot. A contaminated soils all serve to enhance the rate of lead significant proportion of heavily hunted upland species pellet breakdown. Lead concentrations in soils and and small game mammals, and even some nonhunted sediments of shotfall zones of clay target shooting ranges species, also carry embedded shot. can exceed the Canadian Environmental Quality Clay target shooting ranges, especially those in (Remediation) Criteria for lead in soils. This may also be which the shotfall zones include ponds, marshes, lakes, true for sites experiencing heavy hunting pressure, but rivers, beaches, or other aquatic-type environments, create data from such sites are generally lacking. The leachable 3 a significant risk of shot ingestion and poisoning for Neither the federal government nor the waterfowl. provincial/territorial governments have the resources to In North American freshwater environments where comprehensively assess all areas for which nontoxic shot sport angling activity and loon populations co-occur, lead zoning or use of nontoxic sinkers may be appropriate, nor poisoning from ingestion of small (<50 g) lead sinkers or do they have the capability to effectively enforce bans on jigs can account for 10–50% of recorded adult loon the use of lead shot or sinkers in numerous local “hot mortality, depending on the location studied. spot” areas. From the point of view of hunter and angler Good-quality, nontoxic alternatives to lead shot and compliance, effective enforcement, efficient and sinkers are currently being produced, and additional such predictable retail availability of nontoxic products, and the products are being developed. Nontoxic alternatives now protection of wildlife and ecosystem health, partial bans available are more expensive than lead shot or sinkers but on lead shot or small lead sinkers/jigs are less than ideal would increase the average hunter’s total yearly expenses solutions to the lead poisoning problem and cause their by only about 1–2% (based on the use of steel shot) and own additional problems. Other countries have those of the average angler by <1–2%. There will probably successfully banned the use of small lead sinkers and of be a marginal market for and incomplete availability of lead shot for waterfowl and other hunting and are in the nontoxic shot and sinkers until lead shot and sinkers are process of banning the use of lead shot for clay target made unavailable. shooting, using a phasing-out process that gives Modern steel and bismuth/tin shotshell ammunition manufacturers, sellers, and users adequate time to adjust are both effective for bagging waterfowl and other game to the regulations. animals over accepted shotgun shooting ranges (up to In Canada, several provinces and territories are about 45 m for waterfowl). Crippling of game animals is committed to phasing out the use of lead shot for much more a function of the skill of the shooter than of the waterfowl hunting throughout their jurisdictions, and there type of ammunition (lead,