WK 1: Geography

Aquatic Biological Invasions FW 421/521

Introduction to Invasive Species: Geography

Overview of This Week's Topics
  • Geography
    • 1. Where most invasions occur
    • 2. General patterns of invasions
    • 3. Origins of most invasions
    • 4. Habitat comparisons for invasive species
Where?
Invasive Marine Species Hotspots
  • Widespread Presence: Certain regions have a high incidence of invasive marine species
  • Medium Presence: Other regions show moderate levels of invasive species occurrences
The Columbian Exchange: "Ecological Imperialism"
  • Historical context of invasive species movement:
    • Key figures and dates:
    • John Cabot (1610, English explorer)
    • Hernán Cortés (1519, Spain, noted for his expedition to Mexico)
    • Giovanni da Verrazzano (1524, France)
    • Christopher Columbus (1492, Spain)
  • Major geographic regions involved: North America, Europe, Africa, and various islands in the Caribbean and Pacific.
  • Introduced Species Examples from the Columbian Exchange:
    • Comb jelly, zebra mussel, cholera, rhododendron shrub, etc.
Number of Introduced Species
Overview of Introduction Patterns
  • The study by Jeschke & Strayer (2005) indicates:
    • From Europe to North America: 67 species introduced
    • From North America to Europe: 72 species introduced
  • Breakdown of introduced vertebrate species over centuries:
    • Fish, Birds, and Mammals represent significant numbers
Graphical Data Summary
  • Introduction over centuries:
    • 15th – 20th Century trends depicted; various classes of introduced species categorized:
    • Birds
    • Fish
    • Mammals
    • Notable patterns of introductions over these centuries (represented visually)
Numbers of Known Harmful Alien Species
Mapping Alien Species Data
  • Number of alien species reported varies significantly.
  • Classification of alien species range:
    • No Data, 1-2, 3-7, 8-15, 16-30, 31-56.
Locations of Seaweed Invasions
Where Do Most Invasions of Seaweed Occur?
  • Identified regions of introductions:
    • E Pacific, N Atlantic, W Atlantic, Black Sea, S Pacific, etc.
  • Expression of invasions visually represented in a geographical mapping format.
Invasive Species in North America
Total Number of Established Nonindigenous Species
  • Study by Ruiz et al. (2000) outlines:
    • Total number of established species in U.S. coastal areas: 225 invasive invertebrates/algae.
    • Breakdown of unique and repeat invasions:
    • Unique: 298 species
    • Repeat: 76 invasion events
Distribution of Invasive Fish
Freshwater States Overview
  • Number of fish species introduced per state (Fuller et al. 1999).
  • Categories:
    • Established vs. Not Established species in various states
    • Visual data representation indicating numbers of introductions in states such as Florida, Georgia, Alabama, etc.
Homogenization of Fish Fauna Across the United States
  • Representation of geographical distribution of introduced species and impact on local biodiversity:
    • Percentages of states’ fish fauna consisting of introduced species illustrated.
Geographic Distribution of Invasive Species by Latitude
Latitudinal Gradient Analysis
  • Analysis of invasive species along latitudinal lines:
    • Northern America exhibiting distinct profiles for birds and mammals.
  • Data implies:
    • Variability in introduction attempts and ecological processes
    • Associated factors such as sampling efforts.
Origins of Introduced Species
Major Source Regions
  • Common origins for introduced species:
    • Notable source regions include:
    • Asia, North America, Africa, and various other regions noted for significant contributions to the species observed in new habitats.
  • Map representation shows the connections between origin points and invasion areas.
Conclusion
  • Spread trends indicate that invasive species introduction is often linked to human activity and trade.
  • Consideration of geographical regions and specific historical exchanges is crucial in understanding the patterns of aquatic biological invasions.