Threats to Biodiversity: Pollution

Flashcards about threats to biodiversity from pollution, covering types of pollution, their effects, and sources of air pollution including acid deposition and mercury.

What is a pollutant?

A substance introduced into the environment that has undesired effects, potentially harming wildlife, humans, and entire ecosystems due to toxicity or altered chemical balance.

What is point source pollution?

Pollution discharged from a single identifiable source, such as a pipe, ditch, ship, or smokestack.

What is nonpoint source pollution?

Pollution originating from broad areas, such as sediments, pesticides, and fertilizers carried by runoff from agricultural fields, lawns, and streets; considered the leading threat to endangered freshwater species in the US.

What are acute effects of pollution?

Direct mortality or impairment of reproduction; severe and visible impacts (e.g., oil spills).

What are chronic effects of pollution?

Persistent exposure to sublethal levels of toxins, leading to altered sexual, neurological, and behavioral development, impaired health, growth, or reproduction, compromised immune systems, and chemical transfer from parent to offspring.

What are major sources of air pollution?

Transportation, fuel combustion from power plants, space heating of buildings, industrial processes, solid waste disposal, and burning of forests and agricultural lands.

What is acid deposition?

Primarily nitrogen oxides and sulfur dioxides from power plants burning fossil fuels that transform into nitric and sulfuric acids in the atmosphere, settling as acid rain, snow, or dry particulates.

What are the effects of acid deposition on animals?

Low pH levels can kill adult fish, inhibit fish egg hatching, cause thinner egg shells in birds, and damage frogs, toads, and reptiles in aquatic ecosystems; aluminum leached from soils causes problems for aquatic life.

What are the effects of acid deposition on plants?

Lowers soil pH, changes soil chemistry, leaches minerals and nutrients, and directly damages plants when acid rain falls on leaves.

What is the primary source of mercury (Hg) contamination in the US?

Coal-fired power plants release Hg into the atmosphere as a byproduct.

What is methylmercury?

A highly toxic form of Hg that accumulates in animal tissues, acting as a potent neurotoxin impacting the central nervous system.

Why is methylmercury dangerous?

It increases in concentration with each step up the food chain and poses serious health risks to people and wildlife who consume contaminated fish or other species.