BIOLOGICAL POLLUTION: THE NONINDIGENOUS AQUATIC SPECIES PROBLEM By Bob McMahon Professor of Biology Dean of the Honors College The University of Texas at Arlington

The University of Texas at Arlington Great Minds, Great Futures The Honors College The University of Texas at Arlington Great Minds, Great Futures

The Honors College Program Advanced academic programming for exceptional students 3.2 GPA required, average GPA of 3.5 among our 700 students Honors degree awarded in addition to degree in major Renewable scholarships ranging from $500 – 12,000 per year Small classes taught by award-winning faculty Final year thesis based on research supervised by faculty Subsidized study abroad (individual and group) Service learning Summer stipends to assist faculty members with research Bridge to Graduate School fellowship program Honors Academy dual credit program Advanced Placement Summer Institute

What is a Nonindigenous Species? A ‘nonindigenous species’ (NIS) is one which has been introduced to areas outside of its native (natural) distribution range Dispersal into nonnative habitats may be by natural or human mediated vectors

Types of Nonindigenous Species Terrestrial and Aquatic Plants & Algae Terrestrial Vertebrates Amphibians, Reptiles, Birds, Mammals Terrestrial Invertebrates Mollusks, Insects Aquatic Vertebrates Fishes, Amphibians, Mammals Aquatic Invertebrates Mollusks, Crustaceans Animal Pathogens Plant Pathogens

Impacts of Nonindigenous Species (NIS) Benefits of NIS Harmful Impacts of NIS Agricultural Crops Negative Economic Impacts Livestock Agricultural Pests Pet Industry Forestry Pests Nursery Industry Macrofouling Pests Fish and Wildlife Management Aquaculture Pests Biological Control Negative Human Health Impacts Ornamental Plants - Gardening Negative Environmental Impacts Ecosystem Alteration Extinction of Indigenous Species Reduction in Biodiversity Environmental Degradation

Vectors for NIS Introduction and Dispersal

Basic Difference between Chemical/Particulate Pollution and Biological Pollution The technology for mitigating and controlling chemical and particulate pollution is available and readily applied - release of chemical and particulate pollutants is readily abated Once established, NIS are almost impossible to remove from the environment NIS disperse to new habitats after establishment by natural and human mediated means Control of NIS is often equally or more harmful to nontarget, indigenous species Once the genie of a nonindigenous species is let out of its box, it is almost impossible to put it back again

Some Aquatic Nonindigenous Species Impacting or Potentially Impacting Northeast Texas Aquatic Habitats

Golden Algae Prymnesium parvum Esturaine crysophyte alga introduced to brackish lakes in Texas river drainages. Toxic blooms cause massive fish kills.

Eurasian Water Milfoil

Hydrilla verticillata

Water Hyacinth

Asian Clam

Nutria

Some Aquatic Nonindigenous Species potentially Impacting Northeast Texas Aquatic Habitats If Introduced

Giant Salvinia

Purple Loosestrife

Tamarisk (Salt Cedar)

Zebra Mussel

Limnoperna (Golden Mussel)

Asian Swamp Eel

Northern Snakehead Fish

Asian Carp Bighead Carp Silver Carp

Why Should We Worry About Nonindigenous Species Introductions?

Cumulative Numbers of Nonindigenous Species of Foreign Origin in the United States 200 Plant Pathogens 100 180 Molluscs Terrestrial Vertebrates 90 160 80 Fish 140 70 120 60 Cumulative Number of Species 100 Cumulative Number of Species 50 80 40 60 30 40 20 20 10 1790 1830 1870 1910 1950 1990 1790 1830 1870 1910 1950 1990 Year 2000 Year 1800 Plants 1600 Insects 1400 1200 1000 Cumulative Number of Species 800 600 400 200 1790 1830 1870 1910 1950 1990 Year

Reported Effects of Nonindigenous Species in the United States Terrestrial Vertebrates (n = 125) Insects (n = 1,059) Harmful Effects Benefits 32% 31.3% Benefits Harmful Effects 8% 35.4% Bene/Harmful 24% 36% 33.3% Neutral Neutral Fishes (n = 111) Molluscs (n = 88) Harmful Effects Benefits Harmful Effects 43.4% 28% Bene/Harmful 30% 3.0% 25% 17% 53.5% Neutral Bene/Harmful Neutral

U.S. Congress Office of Technology NIS Report Recommendations More effective screening of imported fish, wildlife and their diseases More stringent evaluations of new plant introductions for their potential as harmful weeds Better rapid response to emergencies and better means of setting priorities

Approaches to NIS Species Regulation Dirty or Black Lists: NIS listed as harmful cannot be imported or released Found to be harmful only after introduction and establishment Regulator determines if NIS is harmful Reactive - Poor! Does not prevent new NIS Clean or White Lists: All NIS are prohibited unless determined to be acceptable prior to release Places burden of proof on the importer to demonstrate that a species is not harmful Proactive - Good! Gray List: Combination of Black and White list approaches Best!

Many Thanks for Your Attention