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Exotic SpeciesCauses and Consequences

1) How do exotic species impact native communities?

2) Why are exotic species so successful in their newhabitat?

3) What can be done about limiting the spreadof exotic species?

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Exotic species are a major cause of the decline of nativespecies

In the USA, exotics cause >$138 billion in lossesand environmental damage per year

In 1999, there were more than 50,000 non-indigenous(non-native) species in the USA

About 42% of T and E species are at riskbecause of exotics

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Exotic species are addedto new habitats throughboth intentional andaccidental introductions

http://biology.usgs.gov/s+t/imagefiles/x185f02.htm

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Ballast Tankshttp://biology.usgs.gov/s+t/imagefiles/x185f02.htm

www.glerl.noaa.gov/res/Task_rpts/ nsreid10-1.html

www.uscg.mil/hq/g-m/mso/ mso4/ansgal.html

http://www.glerl.noaa.gov/res/Task_rpts/nsreid10-1.htmlhttp://www.uscg.mil/hq/g-m/mso/mso4/ansgal.htmlhttp://www.uscg.mil/hq/g-m/mso/mso4/ansgal.htmlhttp://www.uscg.mil/hq/g-m/mso/mso4/ansgal.htmlhttp://www.uscg.mil/hq/g-m/mso/mso4/ansgal.htmlhttp://www.glerl.noaa.gov/res/Task_rpts/nsreid10-1.htmlhttp://www.glerl.noaa.gov/res/Task_rpts/nsreid10-1.htmlhttp://www.glerl.noaa.gov/res/Task_rpts/nsreid10-1.html

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Why are exotics so successful in their new habitat?

Exotics are released from their predators and diseases

High fecundity

The invaded habitat is altered or disturbed

Suggestions

Better competitors than the natives

Difficult to generalize. Still trying to make invasion

biology a predictive science.

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Lake Victoria

More than 30 million peopledepend on the lake forsurvival

zmax = 100m

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Lake Victoria Cichlidswww.reshafim.org.il/fishfarm/ lake_victoria.htm

Haplochromis obliquidens

Rock scraper

Plant scraper

Crab eater

Rock-reef low-foragingzooplanktivore

Parasite picker

Snail crusher Egg snatcher

Scale eater

Over 300 endemic speciesdescribed from Lake

Victoria (haplochromines andtilapiines)

http://www.reshafim.org.il/fishfarm/lake_victoria.htmhttp://www.reshafim.org.il/fishfarm/lake_victoria.htmhttp://www.animalnetwork.com/fish2/aqfm/2000/feb/features/2/photo9.asphttp://www.animalnetwork.com/fish2/aqfm/2000/feb/features/2/photo2.asp

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The traditional fisherywas dominated byhundreds of nativespecies, includingOreochromis esculentus (ngege)

But the introduction of

gill nets and other gearby the British in theearly 1900s resulted inover-fishing

www.miseagrant.org/nets/ largegill.html

www.animalnetwork.com/.../2000/ feb/features/2/default.asp

http://www.miseagrant.org/nets/largegill.htmlhttp://www.animalnetwork.com/fish2/aqfm/2000/feb/features/2/default.asphttp://www.animalnetwork.com/fish2/aqfm/2000/feb/features/2/default.asphttp://www.animalnetwork.com/fish2/aqfm/2000/feb/features/2/photo9.asphttp://www.animalnetwork.com/fish2/aqfm/2000/feb/features/2/photo2.asphttp://www.miseagrant.org/nets/largegill.htmlhttp://www.miseagrant.org/nets/images/gillnetlg.gif

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In the 1950s, several new species were introduced to LakeVictoria to compensate for the declining stock of nativespecies

Oreochromis niloticus Nile tilapiaplanktivore

Lates niloticus

Nile perchpiscivore

rps.uvi.edu/AES/Aquaculture/ brood.html

https://reader009.{domain}/reader009/html5/0427/5ae20b4a54

http://rps.uvi.edu/AES/Aquaculture/brood.htmlhttp://rps.uvi.edu/AES/Aquaculture/brood.html

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One major life-history difference between the native andexotic fish:

Many cichlids brood arelatively smallnumber (5 to 100) oflarge eggs

The exotics have much higher fecundity and no parental care

https://reader009.{domain}/reader009/html5/0427/5ae20b4a54ec4/5ae20b5

All cichlids provideparental care

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Before 1980, Haplocromines contributed about 80% of thebiomass and Nile perch less than 2%

Most rapidvertebratemassextinction inrecent history

Figure from Kaufman 1992

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What had been a fishery of > 400 species now wasdominated by three:

80% Nile perch 20% Nile tilapia and omena

As the native fish species declined, Nile perch shifted tofeeding on the native shrimp Cardina nilotica http://pub88.ezboard.com/fadelaidefishcentralforumsfrm4.showMessage?topicID=55.topic

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Other problems with Nile perch

Destroys gear

Cannot be sun-dried

Can be smoked, but smoking required wood

Favors large-scale fishing operations,which results in malnutrition,

unemployment and poverty

news.bbc.co.uk/.../business/ newsid_1778000/1778062.stm www.chinavista.com/travel/ yandang/enydz.html

http://news.bbc.co.uk/hi/english/business/newsid_1778000/1778062.stmhttp://news.bbc.co.uk/hi/english/business/newsid_1778000/1778062.stm

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St. Lawrence Seaway 19 locks, filled and emptied by gravityhttp://www.tc.gc.ca/pol/en/anre1999/graphics/chap10/99f10e08.GIF

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Welland Canal

http://www.seaway.ca/english/features/welland/history.html

Begun in 1829

Niagara Falls was the majorobstacle to an uninterruptedwaterway

www.ulrs.org/photo/01tonawanda/ 01tonawanda.htm

http://www.ulrs.org/photo/01tonawanda/01tonawanda.htmhttp://www.ulrs.org/photo/01tonawanda/01tonawanda.htm

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Sea Lamprey(Petromyzon marinus )

http://www.epa.gov/glnpo/image/viz_iss4.html

www.uscg.mil/hq/g-m/mso/ mso4/ansgal.html

Invaded the Great Lakes after the opening of theWelland Canal

Devastated native fish stocks, especially lake trout

h f h ( ) R d b (1990)

http://www.uscg.mil/hq/g-m/mso/mso4/ansgal.htmlhttp://www.uscg.mil/hq/g-m/mso/mso4/ansgal.htmlhttp://www.uscg.mil/hq/g-m/mso/mso4/ansgal.htmlhttp://www.uscg.mil/hq/g-m/mso/mso4/ansgal.html

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Other fish (>25 species)

Alewife (1873)(Alosa pseudoharengus )

Canals

Coho salmon (1933)(Oncorhynchus kisutch )

Deliberate release

Round goby (1990)(Neogobius melanostomus )Ballast water

Chinook salmon (1873)(Oncorhynchuys tshawytscha )Deliberate release

http://ww2.mcgill.ca/Redpath/ricciardi/goby.html

www.anr.state.vt.us/dec/waterq/ ans/ans-index.htm

www.zoology.ubc.ca/ ~keeley/coho.htm

www.hanford.gov/docs/annualrp00/ sumresearch.stm

k h d k h

http://www.anr.state.vt.us/dec/waterq/ans/ans-index.htmhttp://www.zoology.ubc.ca/~keeley/coho.htmhttp://www.hanford.gov/docs/annualrp00/sumresearch.stmhttp://www.hanford.gov/docs/annualrp00/sumresearch.stmhttp://www.zoology.ubc.ca/~keeley/coho.htmhttp://www.anr.state.vt.us/dec/waterq/ans/ans-index.htmhttp://www.anr.state.vt.us/dec/waterq/ans/ans-index.htmhttp://www.anr.state.vt.us/dec/waterq/ans/ans-index.htm

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Snakeheads in Lake Michigan?

http://ww2.mcgill.ca/Redpath/ricciardi/goby.html

One fish caught inBurnham Harbor

October 2004

Found in Maryland in 2002

(Channa sp.)

C i i (1998)

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Exotic Crustaceans (>6 species)

Bythotrephes cederstromi (1984)

Ballast water

Cercopagis pengoi (1998)Ballast water

http://invasions.bio.utk.edu/invaders/flea.html

Echinogammarus ischnus (1995) www.uni-konstanz.de/limnologie/ ags/straile/startpage.html

http://www.uni-konstanz.de/limnologie/ags/straile/startpage.htmlhttp://www.uni-konstanz.de/limnologie/ags/straile/startpage.htmlhttp://www.uni-konstanz.de/limnologie/ags/straile/startpage.htmlhttp://www.uni-konstanz.de/limnologie/ags/straile/startpage.html

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Exotic mollusks (> 14 species)Asiatic clam (1980)

(Corbicula fluminea )Aquarium releasewww.zoo.cam.ac.uk/zoostaff/ aldridge/corbicula.html

Quagga mussel (1990s)

(Dreissena bugensis )Ballast water

http://www.zoo.cam.ac.uk/zoostaff/aldridge/corbicula.htmlhttp://www.zoo.cam.ac.uk/zoostaff/aldridge/corbicula.html

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ZEBRA MUSSEL Dreissena polymorpha

Found in 1988 in Lake St. Clair (Lake between Huron andErie, just off of Detroit, MI).

Up to 70,000 individuals per m2

www.envirotacklebox.org/teacherguide/ module3/3nns.htm

http://www.michigan.gov/images/deq-water-greatlakes-zebra-mussel-on-stick_10596_7.jpg

http://www.envirotacklebox.org/teacherguide/module3/3nns.htmhttp://www.envirotacklebox.org/teacherguide/module3/3nns.htmhttp://www.envirotacklebox.org/teacherguide/module3/3nns.htm

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Also attaches to boat hulls, docks, locks, breakwaters andnavigation aids, increasing maintenance costs and impeding

waterborne transport.

One of the most expensive exotic species

Will biofoul and restrict the flow of water throughintake pipes (drinking, cooling, processing and irrigatingwater)

www.esemag.com/0596/ zebra.html sfbay.wr.usgs.gov/access/exotic-species/ zebramussel.html

http://www.esemag.com/0596/zebra.htmlhttp://sfbay.wr.usgs.gov/access/exotic-species/zebramussel.htmlhttp://sfbay.wr.usgs.gov/access/exotic-species/zebramussel.htmlhttp://sfbay.wr.usgs.gov/access/exotic-species/zebramussel.htmlhttp://sfbay.wr.usgs.gov/access/exotic-species/zebramussel.htmlhttp://www.esemag.com/0596/zebra.html

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They have a free-livingplanktonic larval stage veliger

Characteristics of zebra mussels:

Can attach to hardsubstrates with byssusthreads

Females can produce 40,000 veligers

These are typical characteristic of marine species

sfbay.wr.usgs.gov/access/exotic-species/ zebramussel.html http://campus.murraystate.edu/academic/faculty/jim.sickel/veliger1.jpg

http://sfbay.wr.usgs.gov/access/exotic-species/zebramussel.htmlhttp://campus.murraystate.edu/academic/faculty/jim.sickel/veliger1.jpghttp://campus.murraystate.edu/academic/faculty/jim.sickel/veliger1.jpghttp://sfbay.wr.usgs.gov/access/exotic-species/zebramussel.htmlhttp://sfbay.wr.usgs.gov/access/exotic-species/zebramussel.htmlhttp://sfbay.wr.usgs.gov/access/exotic-species/zebramussel.html

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Veligers are easily transported in bait buckets andlivewells and anywhere else water collects

Adults can attach to hulls and survive outside of waterfor several days.

Cover most

hard surfaces

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Negative effects onnative unionid clams

Zebra mussels coverthem and preventthem from feedingand moving

ww2.mcgill.ca/Redpath/ricciardi/ unionid.html

Ricciardi et al. 1996

http://ww2.mcgill.ca/Redpath/ricciardi/unionid.htmlhttp://ww2.mcgill.ca/Redpath/ricciardi/unionid.html

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Plants (> 59 species)

Eurasian Watermilfoil (1881)Myriophyllum spicatum

Purple Loosestrife (early 1800s)Lythrum salicaria

www.cce.cornell.edu/onondaga/ watersheds/Milfoil.htm

http://www.cce.cornell.edu/onondaga/watersheds/Milfoil.htmhttp://images.google.com/imgres?imgurl=www.funet.fi/pub/sci/bio/life/plants/magnoliophyta/magnoliophytina/magnoliopsida/lythraceae/lythrum/salicaria-2.jpg&imgrefurl=http://www.funet.fi/pub/sci/bio/life/warp/plants-2-English-Photolist.html&h=872&w=500&prev=/images%3Fq%3DLythrum%2Bsalicaria%26svnum%3D10%26hl%3Den%26lr%3D%26ie%3DUTF-8%26oe%3DUTF-8%26sa%3DNhttp://www.cce.cornell.edu/onondaga/watersheds/Milfoil.htm

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Prevention

Empty all water before leaving site

Never dump bait buckets

Before leaving site, inspect gear, boats and trailersfor exotics

Let equipment dry for several days (does not work for

species with resting eggs)

Rinse your boat and equipment with high pressure hotwater, especially if moored for more than a day

Wash your dog

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Concepts to Know

What are the ecological and economic consequences ofinvasive species?How are non-native species introduced to newecosystems?What happened in Lake Victoria?How did the St. Lawrence seaway impact theLaurentian Great Lakes?Why are zebra mussels such a nuisance?What can be done to prevent the spread of non-native

species?

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Practice QuestionMean Chlorophyll a concentrations in Western Lake ErieBetween April and September, 1976-1991

A common misconception that some membersof the public have is that zebra mussels aregood for lakes because they clean thewater.

Zebra mussels are effective filter feedersand their establishment in a particular lake isoften correlated with declines in Chl-a (e.g.,Figure 1).

Horgan and Mills (1999) investigated thepotential effects of a zebra mussel invasionon zooplankton (Figure 2), and used theirresults to speculate about what effects thisintroduction might have on higher trophiclevels.

Imagine that you belong to a lake-ownersassociation that is considering adding zebramussels to their lake in an effort to increasewater clarity. What would you say to them?

Figure 1