GLOBAL DILEMMAS

DILEMMA 1: INVASIVE SPECIES

• Notable Examples:
  • Tiger mosquito
  • Kudzu
  • Sea lamprey
  • Japanese knotweed
  • Wild boar
  • Phragmites
  • Wooly adelgid
  • Fire ant
  • Alewife

OVERVIEW OF INVASIVE SPECIES

• Video Reference: [Duration: 4:45]

ADDITIONAL VIDEOS

• Top 10 Invasive Species [Duration: 6 min]
• Lionfish & Robotic [Duration: 4 min]

A GROWING CONCERN: INVASIONS PER YEAR

• European settlers introduced hundreds of alien species.
• Steady increase in species invading the US: approximately 10 species/year (both plants and insects).

THE COST OF INVASIVE SPECIES

• Financial Impact:
  • Total cost to US: $138 Billion/year
  • Agricultural losses: $15 Billion/year
  • Control spending on aquatic plants: $100 Million/year
• Biodiversity Threat:
  • 33% of extinctions in last 500 years due to Invasive Alien Species (IAS).
  • 50,000 IAS and counting.

MANAGEMENT OF INVASIVE SPECIES

• Stages of Management:
  • Prevention
  • Eradication
  • Containment
  • Long-Term Control

MODES OF INTRODUCTION OF INVASIVE SPECIES

• Intentional Introductions:
  • Aquaculture (e.g., Asian carp)
  • Horticulture (e.g., water hyacinth)
• Unintentional Introductions:
  • Shipping (cargo containers, ballast, packaging)
  • Aquarium trade
  • Internet buying & trading

FEDERAL GOVERNMENT RESPONSE TO INVASIVE SPECIES

• Various policies handled by 20 federal agencies:
  • Lacey Act (1900): Prohibits trade in illegally sourced wildlife.
  • Non-native Aquatic Nuisance Prevention & Control Act (1990)
  • National Invasive Species Act (1996)
  • Plant Protection Act (2000)
  • Injurious Wildlife Provision of Lacey Act (2008)

BIOLOGICAL CONTROL OF INVADERS: A SUCCESS STORY

• Prickly Pear Cactus (Opuntia) in Australia:
  • Introduced in 1839 and became invasive due to lack of herbivores.
  • Introduced Cactoblastis moth in 1925 drastically reduced cactus population by 1931.

BIOLOGICAL CONTROL OF INVADERS: A CATASTROPHIC FAILURE

• Video Reference: [Duration: 3:30]

IMPACTS OF AQUATIC INVASIVE SPECIES

• Can clog waterways, intake pipes, and foul boats/docks.
• Lower water quality by changing productivity, turbidity, and toxicity.

ZEBRA MUSSEL INVASION TO THE UNITED STATES

• Introduction: Late 1980s in Lake St. Clair (freshwater mollusk native to Eastern Europe).
• Likely introduced via freshwater ship ballast.

IMPACT OF ZEBRA MUSSELS

• Restructure aquatic food webs by decreasing phytoplankton and zooplankton.
• Outcompete native species and decrease tourism.
• Clog hydroelectric pipes, causing industrial issues.

DILEMMA 2: WATER SECURITY

EUTROPHICATION: EXCESS NUTRIENTS

• Eutrophication refers to nutrient overload in aquatic systems, usually from land runoff.
• Causes dense plant growth and animal life deaths due to oxygen depletion.

DEAD ZONES: OXYGEN DEPLETION IN WATER

• Can be caused by:
  • Natural factors (coastal upwelling, wind changes)
  • Anthropogenic factors (chemical fertilizers, land usage changes, climate change).

HARMFUL ALGAL BLOOMS

• Overabundance of algae that produces toxins harmful to wildlife and humans.

SALINIZATION: INCREASING SALT CONCENTRATIONS

• Caused by pollution (road deicers, agricultural runoff), mining, and urbanization.

DILEMMA 3: GLOBAL CLIMATE CHANGE

A PRIMER ON CLIMATE CHANGE

• Oceans are the #1 victim of climate change.

EARLY DISCOVERY OF GREENHOUSE GAS EFFECT

• Svante Arrhenius proposed in 1900 that CO2 variations caused ice ages; he predicted a 6°C temperature increase with doubled CO2 levels.

GLOBAL WARMING: THE KEELING CURVE

• Continuous CO2 measurements began in 1958 showed consistent rise since pre-industrial levels of 280 ppm.

GREENHOUSE EFFECT

• A natural process warming Earth's surface through absorption and re-radiation of energy by greenhouse gases.

ECOLOGICAL IMPACTS OF GLOBAL WARMING

• Anthropogenic warming will lead to abrupt and irreversible ecological impacts, affecting nearly 90% of Earth's species.
• Increased extinction rates.

WORLD SCIENTISTS' WARNING TO HUMANITY

• 1992 & 2017 notices emphasize urgent need for sustainable practices to prevent ecological and societal catastrophe.

LAKE GEORGE AS A MODEL ECOSYSTEM

• Examples of managed invasive species include Eurasian water milfoil and zebra mussels.
• Eutrophication trends show a moderate increase in chlorophyll over time.

SALINIZATION TRENDS

• Road salt as a potential environmental threat.
• Increased chloride and sodium levels observed over recent decades in Lake George.