Aquatic Invasive Species

Transcription

1 Aquatic Invasive Species Redpath Museum McGill University This presentation was made possible with funding from the PromoScience programme of NSERC public domain or licensed under a Creative Commons Attribution Share-Alike 3.0 License

2 One of these things is not like the others licensed under a Creative Commons Attribution-Share Alike 3.0 Unported license. Public domain. licensed under a Creative Commons Attribution-Share Alike 3.0 Unported license. USDA, public domain

3 A very different beast Zebra mussels are not native to Canada: they are an invasive species licensed under a Creative Commons Attribution-Share Alike 3.0 Unported license.

4 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.

5 Aquatic invasives 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. Creative Commons Attribution-Share Alike 3.0 Unported license. Chinese mitten crab: an invasive species that can tolerate a range of salinities but needs salt water to reproduce

6 How do invasives harm the environment? (i) Without native predators and parasites to control them, invasive species often flourish. Zebra mussels covering a current meter. public domain

7 How do invasives harm the environment? (ii) In their new ecosystems, invasive species may become predators competitors parasites diseases Sea lampreys attached to a lake trout of our native and domesticated plants and animals. USGS, public domain.

8 Aquatic invasives: mussels (i) 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 native plankton-feeders (e.g., other invertebrates, fish), that now have to compete for food Public domain.

9 Aquatic invasives: mussels (ii) 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.) Public domain. Native mussel (Lampsilis sp.) covered with zebra mussels. Photo credit: A. Ricciardi.

10 Aquatic invasives: mussels (iii) 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. Public domain. Quagga mussel Zebra mussel

11 Aquatic invasives: fish Invasive species can prey on native species, including species at risk, and threaten their survival. This reduces biodiversity. For example, the round goby is a bottom-feeder that preys on local invertebrates that feed native fish species. The round goby also eats fish eggs. Round goby Public domain.

12 Aquatic invasives: shrimp Bloody red mysid shrimp (Hemimysis anomala) were found in the Great Lakes in 2006 and are spreading throughout the St. Lawrence river. There are no native freshwater shrimp 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. Public domain.

13 Invasives and disease (i) Viral Hemorrhagic Septicemia (VHS) virus is an invasive species that affects over 100 species of fish, including muskellunge, northern pike, yellow perch, walleye, and smallmouth bass. Photo credit: Dr. Mohamed Faisal, Michigan State University. Accessed at 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.

14 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.

15 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 1 Ricciardi, A Patterns of invasion in the Laurentian Great Lakes in relation to changes in vector activity. Diversity and Distributions 12:

16 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.

17 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.

18 How do aquatic invasive species get to Canada? In the ballast water of ships Snagged on recreational boats As live bait, aquarium fish, and exotic pets released into our water bodies Public domain or Creative Commons Attribution-Share Alike 3.0 Unported license..

19 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 into the Great Lakes as well. Creative Commons Attribution-Share Alike 3.0 Unported license..

20 The trouble with ballast (ii) Invasive species have been introduced to the Great Lakes by ballast water release since the early 20 th century. This trend increased greatly after the St. Lawrence Seaway opened in Many of the invasive species currently in the St. Lawrence River spread there following ballast water introductions in the Great Lakes. Creative Commons Attribution-Share Alike 3.0 Unported license..

21 Ballast water blacklisted In 1990, new guidelines from the Canadian government were put in place. These guidelines meant that ships were no longer allowed to exchange freshwater ballast in lakes, rivers, etc. Instead, ships had to release all of their ballast water in the ocean before entering the river. They would then take on salt water as ballast. In 2008, a loophole that still allowed certain ships to exchange 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 2 Ricciardi, A Patterns of invasion in the Laurentian Great Lakes in relation to changes in vector activity. Diversity and Distributions 12: Ricciardi, A. and MacIsaac, HJ Evaluating the effectiveness of ballast water exchange policy in the Great Lakes. Ecological Applications 18(5):

22 Everyone s problem Aquatic invasives affect everyone using our waters: fishing industries boaters anglers and harvesters divers cottage owners municipalities

23 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,

24 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

25 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