PP 14: Invasive Species

Invasive species

-what are they?  

-why should we care?  

• ecological concerns 

• Human, plant, and animal health 

• economic concerns  

What prevents species from dispersing globally?

-Geographic barriers:  

• Oceans 

• Mountains 

• Deserts 

• large lakes  

-barriers are in the eye of the beholder: what is a barrier for one species is not a barrier to another  

• e.g. mountains may restrict plant distributions, but not birds  

Limits to dispersal

• Wallace identified 6 global biodiversity realms, each different from the other  

• ! know his name

• Neotropical, Nearctic, Palearctic, Ethiopian, Oriental, Australasian 

What are invasive species?

-Invasive species  

•  to be invasine you have to be damaging to the ecosystem

• likely to cause harm to the envrionment or human health

-Exotic species 

•  just means from another part of the world

-introduced species 

•  physically, intentionally, introduced

• not necessarily capable of reproduction

-alien species 

• implies introduction to a particulat ecosystem

• capable of reproduction in the new envrionment

• not often used

Classical model of invasion

• what prevents species from dispersing globally? 

• Establishment requires dispersal across barriers, colonization in acceptable number, and successful reproduction 

Natural colonization and human-mediated invasion

-humans allow them to get through the biogeographic filter

What allows invaders to invade

• Only some novel species will survive and establish self-sustaining population in the novel habitat 

• a subset of these species may not only survive, but become invasive, dominating the new community and even causing the extinction of natives 

• but, what allows a species to become invasive? 

  • no checks and balances, they can just take off

What allows invaders to invade, establish, and thrive

-Broad environmental tolerance  

• posses life history traits that confer superior colonizing ability or ability to acclimated to a wide range of habitats 

-Local adaptation 

• Readily adapt to local selective pressures 

-Life history traits  

• lack of predators in invaded habitat, high reproductive capacity, non-pocky eaters, wide ecological niche  

Drivers of species change

aquatic systems are impacted more by invasive species

Negative impacts of invasive species

-Ecosystem level impacts 

• disturbance regimes 

• hydrology: alternations of water regimes 

  • phragmites is doing this

• geomorphological processes (erosion, sedimentation) 

-Community or population level impacts 

• habitat structure 

• community composition 

• resource competition 

• population reductions, eliminations 

• genetic impacts  

Hydrology: alteration of water regimes

Salt cedar (Tamarisk): absorbs large quantities of water along riverbanks in arid regions, and excretes salt into soils; forms monocultures 

Homogenization of flora and fauna

• more species change due to introduction of nonindigenous fishes than to loss of native fishes 

• this pattern may not be general- may vary from system to system

Predation

-Lake Victoria, Africa 

• introduced nile perch drove hundreds of cichlid fishes extinct 

• current problem with introduced water hyacinth (plant) from S. America  

Economic impacts

-along with irreplicable losses to biodiversity- billions per year from 

• lost agriculture productivity  

• lost forest productivity 

• lost recreational opportunity 

The invasion curve

-prevention is key, how do we prevent organisms from coming in

• boat wash station

-Eradication: do whatever you can do to stop it immediately. if its a small lake, just kill the entire lake

-containment: gets very hard in the great lakes

-assest based prodction and long-term management: figure out hot to handle it longterm

graph

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Public and wildlife health impacts

-vector borne diseases  

-dreissenid mussel beds are hot spots for bacteria  

• avian botulism 

-poisonous and venomous plant and animal introduction  

-alter food webs which may cause population boom of detrimental organisms  

• dreissenid mussels and cyanobacteria blooms  

  • suck up algae. they will keep in the algae and spit out the cyanobacteria, giving it a competitive advantage

• white nose syndrome in bats and mosquitoes 

Aquatic invasive species (AIS) in the great lakes

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Invasion history in great lakes

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Our lakes are vulnerable

-Asian carp are poised to enter the great lakes  

• 1. bigheaded carp 

  • 3 found in Lake Erie in 2000 

  • sold live in Asian food markets in Toronto 

• 2. Silver carp  

-Asian carp reproduce in great lakes watershed (grass carp) 

Opening of the St. Lawrence seaway

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Welland Canal

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Nonindigenous animals in the great lakes

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Zebra mussels

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Mussel species change

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Invaders use corridors to the great lakes

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How can we determine where invasive species originated?

• 1. Track the vector: look at import- export records  

• 2. look at pathways that airlines and ships utilize 

• 3. assess at genetic composition of the population in introduced areas and source areas  

Eurasian distribution of the fishhook flea

• native to Aral and Caspian Lakes, Azoz and Black Seas 

• introduced to several rivers and baltic sea 

• discovered in lake ontario in 1998

Cercopagis invasion genetics

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animal and protist NIS hotspots in the great lakes

-a lot of these are salt water ports 

-a lot of ships will discharge in lake superior because its colder there and the species wont survive

Invasion causes a decline in zooplankton diversity in Harp Lake, Ontario

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Pathways of introduction pt. 1

-attached to ships’ hulls  

• Underwater view of a highly fouled ship hull showing attached fouling organisms  

-dumping of live bait  containers and packing materials (overland transport) 

• Attached to fishing gear, anchors, lines 

Pathways of introduction: Overland transport mechanisms

-Bythotrephes: 

• fishing/downrigger lines 

• bait buckets 

• live well water 

• bilge water 

• Macrophytes attached to boat 

Pathways of introduction: Overland transport mechanisms pt. 2

-Boats and trailers  

• recreational boats and trailers are frequently and rapidly transported over significant distances  

• litter regulation regarding cleaning boats, trailers, other exposed equipment 

Pathways of introduction: Overland transport mechanisms pt. 3

-Live bait 

• non-native species of fishes and many species of invertebrates are sold live as bait 

• bait boxes (worms) also contain up to two dozen species 

• poorly regulated, little inspection capacity 

Pathways of introduction: Overland transport mechanisms pt. 4

-Ballast water 

• the most well-known pathway 

• More than 2 million gallons of ballast water are dumped in U.S. harbors every hour  

• up to three hundred species have been identified in ballast of single ship 

• Uncertainty about viability of organisms 

• high quantity but low quality  

Pathways of introduction: Overland transport mechanisms pt. 5

-Aquarium introductions  

• many non-native species of fish, invertebrates and algae sold in U.S. 

• in CA, there are 900 non0native species of fish for sale in aquarium stores 

• pets commonly ”released" when get too big  

• many species could potentially become establish  

• transfers of aquaculture products or fish stocks 

• intentional introductions to establish new fisheries  

• escape from backyard ornamental ponds 

Pathways of introduction: Overland transport mechanisms pt. 5

-Backyard ponds 

• fastest growing segment of horticulture industry 

• 16 million backyard ponds  

• little regulation regarding placement near waterways or strom security 

• ex. Hydrilla, water hyacinth, Eurasian watermilfoil 

Pathways of introduction: Overland transport mechanisms pt. 6

-live seafood

• many species of non-native fish and invertebrates (oysters, mussels, clams, crayfish) are sold on live seafood market 

• Potential for release during storage or after sale 

Failed biological control

-asian carp were introduced in Arkansas in the 1960s and 70s by and for fish farmers to control vegetation, plankton, and most recently snails in catfish rearing ponds  

• escape or released and some intentional stocking occurred after that  

Early detection rapid response (EDRR)

• Most cost-effective investment is to fund a regular survey of high priority sites of introduction 

• early detection of an invasion can allow eradication just after the species has become established 

Prevention, prevention, prevention  

-Keep them out! 

• tighten important and interstate transport regulations 

• maintain clean species list 

• educate the public on the risk of releasing new species 

• increase fines and penalties for intentional illegal releases 

• if still in captivity, destroy all existing stocks  

• close all avenues of escape 

  • install organisms barriers  

  • improve water and waste treatment 

  • modify the navigation system  

Prevention, prevention, prevention pt 2.

-Barriers

Prevention, prevention, prevention, pt 3

-Hydraulic separation 

• “replumb” or hydraulically separate the Great Lakes and Mississippi River basin watersheds, essentially reversing or amending the engineering feats of the past (ex. Like the re-engineering project of the Kissimmee River in Florida) 

Control methods

• Kill them  

• sterilize 

10 nasty invasive species in the US exported to Europe

• Red-eared slider turtle 

• American lobster 

• Bullfrogs 

• Gray squirrels 

• Raccoons 

• American mink 

• Crayfish 

• Largemouth bass 

• rosy wolf snail  

• Colorado potato beetle 

Impact on environmental justice

• How do invasive species impact tribal fishing and hunting right? Traditional food (ex. Wilf rice) growth and acquirement?  

• How do invasive species impact sustenance fishing? 

• As vectors of disease and who is impacted? 

Solutions? What can I do?

• Individual level 

• Community level 

• State government level 

• federal government level 

• Global level  

Invasive species management and prevention resources: 

• RIPPLE (reduce invasive pet and plant escape) 

• USGS non-indigenous aquatic species list 

• Ontario’s invading species awareness program 

• Invasive species centre- Canada 

• Great Lakes non-indigenous aquatic species information system 

• UK guidance on control and management of ballast water 

• National exotic marine and estuarine species information system 

• University of Florida center for aquatic and invasive plants 

• Michigan.gov/invasives 

• Minnesota Aquatic invasive species research center 

• Midwest invasive plant network 

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