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AquaticInvasive Species
Redpath MuseumMcGill University
©McGill University 2011
www.wikipedia.org: public domain or licensed under a Creative Commons Attribution Share-Alike 3.0 License
This presentation was made possible with funding from the PromoScience programme of NSERC
One of these things is not like the others…
www.wikipedia.org: licensed under aCreative Commons Attribution-Share Alike 3.0 Unported license.
www.wikipedia.org: licensed under aCreative Commons Attribution-Share Alike 3.0 Unported license.
www.wikipedia.org: USDA, public domain©McGill University 2011
www.wikipedia.org. Public domain.
A very different beast• Zebra mussels are not native to Canada: they
are an invasive species
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©McGill University 2011
What is an invasive species?
• An invasive species is a species that:– is not originally from an area (i.e., it is not a
species native to that area)
– may threaten the environment, the economy, or society ̶ including human health ̶ in the new area to which it is introduced or spreads.
• An invasive species can be an animal, plant, fungus, bacteria, or virus.
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Aquatic invasives
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Chinese mitten crab:an invasive species that can tolerate a range of salinities but needs salt water to reproduce
• Aquatic invasives live in aquatic environments.
• Some species live only in fresh water, others live only in salt water, and some species can tolerate both fresh and salt water, enabling them to spread throughout many different ecosystems.
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How do invasives harm the environment? (i)
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• Without native predatorsand parasites to controlthem, invasive speciesoften flourish.
Zebra mussels covering a current meter.
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How do invasives harm the environment? (ii)
www.wikipediia.org: USGS, public domain.
• In their new ecosystems, invasive species may become• predators• competitors• parasites• diseases of our native and domesticated plants and
animals.
Sea lampreys attached to a lake trout
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Aquatic invasives: mussels (i)
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• Invasive species can change habitat and make it inhospitable for some native species.
• E.g., Zebra mussels in the Great Lakes filter tremendous amounts of plankton out of the water:• The water is clearer• Sunlight penetrates deeper • There can be overgrowth of
vegetation and toxic algal blooms• There can be less
plankton available for nativeplankton-feeders (e.g., other invertebrates,fish), that now have to competefor food
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Aquatic invasives: mussels (ii)
www.wikipedia.org. Public domain.
• Zebra mussels and one of the newer invaders, the quagga mussel, have wiped out most of the native mussel populations in the Saint-Lawrence River, changing the invertebrate populations in ways that scientists are still studying.
Native mussels (Lampsilis sp.) Native mussel (Lampsilis sp.) covered with zebra mussels.Photo credit: A. Ricciardi. ©McGill University 2011
Aquatic invasives: mussels (iii)
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• In a strange twist that pits invasive vs. invasive, the quagga mussel may now be out-competing the zebra mussel!
• In some areas of the St. Lawrence and most of the Great Lakes, the quagga mussel has replaced the zebra mussel as the dominant bivalve.
Quagga mussel Zebra mussel©McGill University 2011
Aquatic invasives: fish
www.wikipedia.org. Public domain.
• Invasive species can prey on native species, including species at risk, and threaten their survival. This reduces biodiversity.
• For example, the roundgoby is a bottom-feederthat preys on local invertebrates that feednative fish species. Theround goby also eatsfish eggs.
Round goby
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Aquatic invasives: shrimp
• Bloody red mysid shrimp(Hemimysis anomala) werefound in the Great Lakes in 2006and are spreading throughoutthe St. Lawrence river.
• There are no native freshwatershrimp in North American rivers. When an invasive has no equivalent in the environment it is invading, the impact it has is more likely to be an important one.
NOAA, Great Lakes Environmental Research Laboratory. www.wikipedia.org. Public domain.
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Invasives and disease (i)• Viral Hemorrhagic Septicemia (VHS)
virus is an invasive species thataffects over 100 species of fish,including muskellunge, northern pike,yellow perch, walleye, and smallmouthbass.
• VHS has been present in the Great Lakes-St. Lawrence system since 2003 or earlier, and it has caused several fish die-offs in the Great Lakes and upper St. Lawrence River. Die-offs have not yet been recorded in Quebec waters.
Photo credit: Dr. Mohamed Faisal, Michigan State University. Accessed at http://www.nps.gov/piro/naturescience/vhs.htm
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Invasives and disease (ii)• VHS was probably introduced to the Great Lakes-
St. Lawrence system from the Atlantic coast of North America, but it is not known how it was introduced.
• For more information, please see this VHS factsheet.
Photo credit: Dr. Mohamed Faisal, Michigan State University. Wikipedia.org. Public domain.
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Invasives and biodiversity• In freshwater systems, invasive species
are the second most significant threat to biodiversity, after habitat loss!
• On average, a new invasive species is discovered in the Great Lakes every 28 weeks. That suggests the highest rate of invasion known for any freshwater system.1
1Ricciardi, A. 2006. Patterns of invasion in the Laurentian Great Lakes in relation to changes in vector activity. Diversity and Distributions 12: 425-433
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Do invasive species have only negative effects? (i)
• Nearly all invaders have both positive and negative effects.
• Even those invasive species that produce strong negative impacts can also produce strong positive ones, depending on the ecosystem component you are considering.
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Do invasive species have only negative effects? (ii)
• For example, the increased water clarity generated by zebra mussels benefits submerged aquatic plants, the invertebrates that live on them, and the fish that use weedy habitats.
• However, because we do not know what impact any invader will have, it is best to prevent the entry and spread of invasive species right from the start.
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How do aquatic invasive species get to Canada?
• In the ballast waterof ships
• Snagged onrecreational boats
• As live bait, aquarium fish, and exotic pets releasedinto our water bodies
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The trouble with ballast (i)
• Large ships coming from freshwater ports in Europe and Asia used to release ballast water they picked up at home into the Great Lakes.
• This meant that any species present in that water could have been released intothe Great Lakes as well.
www.wikipedia.org. Creative Commons Attribution-Share Alike 3.0 Unported license. .©McGill University 2011
The trouble with ballast (ii)
• Invasive species have beenintroduced to the Great Lakesby ballast water release sincethe early 20th century. Thistrend increased greatly afterthe St. Lawrence Seaway opened in 1959.
Many of the invasive species currently in the St. Lawrence River spread there following ballast water introductions in the Great Lakes.www.wikipedia.org. Creative Commons Attribution-Share Alike 3.0 Unported license. .
©McGill University 2011
Ballast water blacklisted• In 1990, new guidelines from the Canadian
government were put in place. Theseguidelines meant that ships were nolonger allowed to exchange freshwaterballast in lakes, rivers, etc.Instead, ships had to release all of theirballast water in the ocean before enteringthe river. They would then take on salt water as ballast.
• In 2008, a loophole that still allowed certain ships toexchange ballast water in freshwater lakes, rivers, etc. was closed. Since then, scientists have not been able to attribute any new invaders to ballast water.2, 3
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2 Ricciardi, A. 2006. Patterns of invasion in the Laurentian Great Lakes in relation to changes in vector activity. Diversity and Distributions 12: 425-4333 Ricciardi, A. and MacIsaac, HJ. 2008. Evaluating the effectiveness of ballast water exchange policy in the Great Lakes. Ecological Applications 18(5): 1321–1323
Everyone’s problem
• Aquatic invasives affect everyone using our waters:– fishing industries– boaters– anglers and harvesters– divers– cottage owners– municipalities
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How you can help
• Thoroughly wash your boat and all gear, including waders, after use
• Remove all aquatic plants and animals from boats and gear
• Drain water from your boat, trailer, tackle, and gear before leaving an area
• Do not release aquarium pets, plants, or live bait into aquatic environments
• Do not move live fish and other aquatic organisms from one body of water to another.
From: Fisheries and Oceans Canada, www.dfo-mpo.gc.ca©McGill University 2011
More information
• Aquatic invasive species: Fisheries and Oceans Canada
• Aquatic Invasive Species Identification Booklet: Fisheries and Oceans Canada
• Battle for the Riverbed: Montreal Gazette• Invasive Species Fact Sheets: Dr. A.
Ricciardi, Redpath Museum, McGill University
©McGill University 2011
Acknowledgements
• Scientific consultation: Dr. Anthony Ricciardi, Redpath Museum
• Concept, design, and production: Jacky Farrell, Redpath Museum
This presentation was made possible with funding from the PromoScience programme of NSERC
©McGill University 2011