Chapter 5 Threats
legislators to support use of nontoxic rifle ammunition may be based on perceptions about availability, price, and effectiveness of substitute ammunition (such as steel, copper, or copper- zinc alloy shot). However, it was reported there are as many as 48 different hunting rifle cartridges manufactured in the United States that contain lead-free ammunition, and they are readily available from national retailers (Thomas 2013) . There are recent concerns for the persistence of plastics in the environment, primarily from a variety of microplastics. Plastic ingestion can lead to physiological impacts to wildlife by facilitating the transfer of chemicals associated with plastics or the accumulation of other environmental pollutants on their surface (Mejia et al. 2024) . Toxic chemicals (i.e., polychlorinated biphenyls, organochlorine pesticides, and heavy metals) have been associated with mutagenic and carcinogenic effects (Mejia et al. 2024) . Seabirds are known to ingest marine debris, often mistaking debris for food, making seabirds a bioindicator for heavy metal and organochemical marine pollution (Mejia et al. 2024) . 5.11.3 Airborne Pollutants – Anticipated Impacts Animals are exposed to air pollutants through breathing, ingestion, or absorption through the skin (in the case of amphibians). The response of an organism depends on many factors, including the type of pollutant and the magnitude and duration of exposure. There are three general pollutant types: gases (e.g., ozone), non-acidic chemicals (e.g., metals, dioxins), and acidic chemicals (e.g., nitrates and sulfates). The burning of fossil fuels releases sulfur dioxide and nitrogen oxides, which are transformed in the atmosphere and returned as acid precipitation. Gases generally affect animal respiratory systems. Metals may affect their circulatory, respiratory, gastrointestinal, and central nervous systems, particularly the kidney, liver, and brain. Dioxins bioaccumulate, or build up in the body by concentrating in body fat, and are resistant to biological breakdown. A study of earthworms showed they accumulated dioxins up to five times the concentration found in the soil. While not lethal to the worms, it could affect many bird and small mammal species that rely on them as a food source. Acid rain reduces soil buffering capacity and eventually results in changes to vegetation and acidification of streams and surface waters. Many studies have shown that aquatic invertebrates, fish, and other organisms are greatly affected by low pH conditions, with species composition declining as pH drops. Acid rain impacts on fish are occurring in many countries, including the United States, but evidence in North Carolina is limited. Acid deposition is a possible cause of declines in amphibian populations, particularly those that use ephemeral waterbodies that are susceptible to precipitation events. Reproduction is most vulnerable because early life stages are more sensitive to changes in water chemistry.
Air pollutants also affect wildlife indirectly by causing changes in the ecosystem. Vegetation provides cover for protection from predators and weather, provides breeding and nesting
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2025 NC Wildlife Action Plan
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