Environmental 2025

Chapter 9: Sustaining Biodiversity: Endangered Species

Endangered Species Act

• Determination of Status:

  • Endangered Species: Species in danger of extinction throughout all or a significant portion of its range.

    • Significantly low numbers

    • Very significant habitat loss

    • Loss of breeding, nesting, and reproductive habitat

  • Threatened Species: Any species likely to become endangered within the foreseeable future throughout all or a significant portion of its range.

    • prognosis is to become endangered without help/intervention

Criteria for Listing Species

• A species is added to the list based on several factors:

  • Destruction, modification, or curtailment of habitat or range.

  • Overutilization for commercial, recreational, scientific, or educational purposes.

  • Disease or predation.

  • Inadequacy of existing regulatory mechanisms.

  • Other natural or manmade factors affecting survival.

Provisions of the Endangered Species Act

• US Fish and Wildlife Service Responsibilities:

  • Maintains a list of endangered or threatened species.

  • Species may not be killed or caught.

  • Plants may not be disturbed.

  • Sale or purchase of threatened or endangered species/products is prohibited.

  • Federal projects cannot jeopardize endangered species.

  • A species recovery plan must be prepared for each species on the list.

Characteristics of Endangered Species

• Examples of Characteristics:

  • Low Reproductive Rate:

    • Examples: Blue whale, giant panda, rhinoceros.

  • Specialized Niche:

    • Examples: Blue whale, Everglades kite.

  • Narrow Distribution:

    • Examples: Elephant seal, desert pupfish.

  • High Trophic Levels:

    • Examples: Bengal tiger, bald eagle, grizzly bear.

  • Fixed Patterns:

    • Examples: Migratory whooping crane, sea turtle.

  • Rare Species:

    • Examples: African violet, some orchids.

  • Large Territories Required:

    • Examples: Grizzly bear, Florida panther.

Threats to Endangered Species

• Natural Threats:

  • Competition with other species.

  • Disease.

  • Weather-related catastrophes.

  • Natural predators.

• Human-caused Threats:

  • Hunting/poaching.

  • Habitat destruction.

  • Pollution.

  • Competition for habitats.

Human Impact on Species Extinction

• Current Extinction Rates:

  • Species are disappearing at 30 to 75 species a day, primarily due to human activity.

• Primary Causes of Extinction:

  • HIPPO:

    • H: Habitat alteration.

    • I: Invasive species.

    • P: Pollution.

    • P: Population growth.

    • O: Overconsumption.

Major Threats to Biodiversity

• H.I.P.P.C.O. Framework:

  • H: Habitat destruction, degradation, fragmentation.

  • I: Invasive (nonnative) species.

  • P: Population and resource use growth.

  • P: Pollution.

  • C: Climate change.

  • O: Overexploitation.

Critically Endangered Animals Worldwide

• Highlight of Endangered Species:

  • Amur Leopard, Black Rhino, Cross River Gorilla, Hawksbill Turtle, Javan Rhino, Leatherback Turtle, Mountain Gorilla, Pangolin, Saola, South China Tiger, Sumatran Elephant, Sumatran Orangutan, Sumatran Rhino, Sumatran Tiger, Vaquita, Western Lowland Gorilla, Yangtze Finless Porpoise.

Top 10 Most Endangered Animals

1. Mountain Gorilla

2. Javan Rhinoceros

3. Komodo Dragon

4. Koala Bear

5. Giant Panda

6. Kagu

7. Snow Leopard

8. Siberian Tiger

9. African Wild Dog

10. California Condor

Causes of Depletion and Premature Extinction

• Underlying Causes:

  • Population growth.

  • Rising resource use.

  • Undervaluing natural capital.

  • Poverty.

• Direct Causes:

  • Habitat loss.

  • Pollution.

  • Commercial hunting and poaching.

  • Habitat degradation and fragmentation.

  • Climate change.

  • Sale of exotic pets and plants.

  • Introduction of nonnative species.

  • Overfishing.

  • Predator and pest control.

Chapter 6 Population Growth

• Patterns of population

  • exponential growth, usually “new” species or invasive species

  • carrying capacity

    • species growth is limited by resources (food (predators/prey))

• Rates

  • birth rates and death rates are usually calculated per 1,000 people

  • total fertility rate

    • total number of children a woman gives birth to

• Replacement fertility rate

  • how many offspring are needed to replace the parents

  • low= lower infant mortality (2.1)

  • higher = higher infant mortality (3)

water table

• depth at which water should always be available

Aquifers

• rock or sediment that stores water

  • water still moves downhill

• Recharge zones: Areas where water infiltrates the ground to replenish aquifers.

• unconfined aquifers

  • usually is open at the top

  • water can infiltrate into the aquifer from the surface

• Confined aquifers: These are trapped between layers of impermeable rock or clay, which prevents water from easily entering or exiting the aquifer.

  • Might have different recharge areas

• Ogallala Aquifer

  • huge, old, aquifer in the N American prairie reagion

  • huge Impact on agriculture and human life in the surrounding states

Chapter 13: Water

Dynamic and Complex: The Global Water Cycle

• The global water cycle comprises various processes that facilitate water movement and storage.

• Key Processes:

  • Sublimation: Transition from solid to vapor.

  • Condensation: Vapor cooling to form liquid (clouds).

  • Precipitation: Rain or snow falling to Earth.

  • Evaporation: Liquid water turning into vapor.

  • Transpiration: Water released from plants into the atmosphere.

  • Infiltration: Water soaking into the ground.

  • Snowmelt Runoff: Water from melted snow flowing into streams.

  • Surface Runoff: Water flowing over land into rivers and lakes.

  • Groundwater Storage and Discharge: The storage of water underground and its eventual return to surface water.

Where is Earth's Water?

• Distribution of Earth's Water:

  • Freshwater: 2.5%

    • Groundwater: 30.1%

    • Glaciers and ice caps: 68.7%

    • Surface freshwater: 1.2%

    • Lakes: 20.9%

    • Rivers: 0.49%

    • Swamps and marshes: 2.6%

  • Saltwater: 97.5%

    • Oceans hold the majority of saltwater (1,365,000,000 km³).

Water Storage Mechanisms

• Infiltration and Aquifers:

  • Water accumulates underground in cracks and pores of soil and rock, referred to as aquifers.

  • The water table indicates the upper level of groundwater, which can be unconfined or confined by impermeable layers.

Pumped Well Systems

• Types of Aquifers:

  • Unconfined Aquifer: Directly available to recharge from the surface.

  • Confined Aquifer: Isolate from surface influence by a confining layer.

  • Recharge areas: Areas where water seeps into aquifers, ensuring the sustainability of groundwater.

  • Water withdrawals can be measured over time to monitor aquifer health.

Aquifers and Wells

• Definition and Types of Wells:

  • Flowing Artesian Well: Water rises to the surface due to pressure in confined aquifers.

  • Water Table Well: Taps into unconfined aquifers; water level fluctuates with the water table.

  • Extensive networks of aquifers used in the U.S.; Ogallala Aquifer is significant.

Sources of Water

• Types:

  • Surface Water: Lakes, streams, rivers.

  • Groundwater: Wells, aquifers, springs.

  • Water collected and stored in reservoirs for future use.

Water Use Across Sectors

• Global Water Consumption:

  • Largest Use: 70% for agriculture.

  • Industry: 20% of freshwater is used in manufacturing and processing.

  • Domestic Use: Approximately 10%.

  • Examples:

    • 4,650 liters of water to produce 300g of meat.

    • 4,100 liters to produce a cotton T-shirt.

Water Treatment Processes

• Key Components of Water Treatment:

  • Preliminary Treatment: Screening and sedimentation to remove large debris.

  • Coagulation and Flocculation: Chemicals added to form larger particles that trap contaminants.

  • Filtration: Sand and granular media filter out smaller particles.

  • Disinfection: Treatments such as chlorination and UV to make water safe for drinking.

Desalination Process (Tampa Bay Example)

• Processes to remove salt from seawater include:

  • Initial Particle Settlement: Heavier solids removed by gravity.

  • Filtration Methods: Sand filters and diatomaceous earth filters eliminate microscopic materials.

  • Reverse Osmosis: High-pressure pumps push water through semipermeable membranes to remove salt.

  • Post Treatment: Blending the desalinated water with treated surface water before distribution.

Regional Water Projects

• California Water Project: Complex system of reservoirs and aqueducts to supply water across regions.

• Significant infrastructures like dams and aqueducts play crucial roles in managing water supplies efficiently.

Maple Syrup Unit

• xylem

  • system of tubes that transports water to leaves up from the roots.

• Phloem

  • system of tubes that transports dissolved biomolecules (sugar) up and down plants.

  • “tap” or drill into phloem tubes to get sap

Water treatment

• Drinking water/ Municipal water

  • steps/general

    • large screens and filters

      • remove the large materials “fish” trees/branches, weeds, human materials

    • Pre-disinfection

      • chlorine, UV light, or ozone to kill the bacteria

    • Coagulations and Flocculation

      • bind with biomolecules microorganisms/ to form “clumps”

      • coagulants in the water are mixed

      • remove the floc

    • Post Chlorination

      • chlorine added to kill bacteria/microorganisms in pipes between the water treatment plant and taps

Damns and Reservoirs

• Generate electricity (hydroelectric)

• water storage/control

• flood control

• negatives

  • destroys or alter habitat

  • flood