AP Environmental Science Unit 5 Notes: Resource Extraction, Land/Water Use, and Sustainability

Overfishing

Harvesting fish or other aquatic organisms faster than their populations can replace themselves through reproduction and growth (a problem of harvest rate exceeding replenishment).

Fishery Collapse

A dramatic drop in catch because the population becomes too small to support continued harvesting, often occurring long before a species goes extinct.

Sustainable Yield

The amount of a renewable resource (e.g., a fish population) that can be harvested without reducing its long-term availability; harvest stays at or below the population’s net growth over time.

Bycatch

Unintentional capture of non-target species (e.g., sea turtles, dolphins, seabirds, juvenile fish) in fishing gear, wasting life and disrupting food webs.

Trophic Cascade

A chain reaction in a food web caused by removing a predator (or key consumer), leading to changes in prey populations and then organisms lower in the food chain (often altering algae levels, water quality, and habitat).

Bottom Trawling

A fishing method that drags heavy nets along the seafloor, which can destroy benthic habitats and juvenile “nursery” areas, reducing ecosystem capacity to support fish populations.

Fishing Down the Food Web

A shift in harvesting from large, high-trophic-level species to smaller, lower-trophic-level species as top species decline, often simplifying the ecosystem and reducing resilience.

Marine Protected Area (MPA)

An ocean zone where fishing is restricted or prohibited to allow populations to recover through higher survival and reproduction.

Spillover (from an MPA)

Movement of adult fish and/or larvae from a protected area into nearby waters, which can help replenish and support adjacent fisheries.

Catch Limits (Quotas)

A cap on total allowable catch designed to prevent overharvest; most effective when science-based and strongly enforced.

Individual Transferable Quotas (ITQs)

A management system that assigns individuals/companies shares of the total allowable catch to reduce the “race to fish,” but can raise equity concerns about who receives fishing rights.

Aquaculture

Fish farming that can reduce pressure on wild fisheries but may create pollution, habitat conversion, and disease/parasite spread if poorly managed; sustainability depends on species, feed, waste handling, and siting.

Mining

Extraction of geologic resources (metals, nonmetal minerals, fossil fuels) that reshapes landscapes and generates pollution and long-term waste (e.g., tailings).

Surface Mining

Mining that removes overburden to access near-surface deposits; commonly causes large land disturbance, erosion, and runoff.

Subsurface Mining

Mining that uses tunnels/shafts to reach deep deposits; can cause subsidence, acid mine drainage, and worker hazards.

Mountaintop Removal

A surface mining method that blasts off mountaintops and places waste in valleys, leading to forest loss, stream burial, and increased sedimentation.

Acid Mine Drainage (AMD)

Acidic runoff formed when sulfide minerals exposed by mining react with oxygen and water to produce sulfuric acid, which can mobilize toxic metals and persist long after mine closure.

Tailings

Crushed rock and leftover materials after resource extraction, often stored in piles or behind dams; may contain processing chemicals, sulfides that generate AMD, and fine particles that spread in wind/water.

Reclamation

Restoring mined land by reshaping terrain, replacing topsoil, and replanting vegetation; reduces hazards but may not fully restore original habitat complexity, soils, or water quality.

Urbanization

Growth of cities and the increasing proportion of people living in urban areas; a land-use change that alters water flow, heat storage, and ecosystem function while increasing resource demand.

Impervious Surfaces

Surfaces (roads, roofs, parking lots) that prevent water from infiltrating soil, increasing stormwater runoff and peak stream flow and reducing groundwater recharge.

Groundwater Recharge

Process by which water infiltrates into the ground to replenish aquifers; typically decreases when impervious cover increases.

Combined Sewer Overflow (CSO)

Release of untreated or partially treated sewage when stormwater and sewage share pipes and heavy rain overwhelms capacity, harming water quality (pathogens, nutrients, low dissolved oxygen).

Urban Heat Island Effect

The tendency for cities to be warmer than surrounding rural areas due to heat-absorbing surfaces, reduced evapotranspiration from vegetation loss, and added waste heat from buildings/vehicles.

Green Infrastructure

Design approaches (e.g., rain gardens, permeable pavement, bioswales) that slow, store, and infiltrate stormwater, reducing runoff volume/peak flow, filtering pollutants, and improving groundwater recharge.