Produced by: Christopher Intagliata
Guest Speaker: David Lodge of Environmental Change Initiative at the University of Notre Dame
South Bend, Indiana
Date: October 17, 2014
Link to podcast: http://www.sciencefriday.com/playlist/#play/segment/9568 Link to podcast:
Summary:
This podcast is about how scientists are now able to track invasive species using a technique called "environmental DNA." The guest speaker, David Lodge, talks about how there are a large number of invasive species in the Great Lakes and it is extremely hard to track them all, especially underwater. The environmental DNA technique allows scientists who track invasive species to get a time sensitive-fingerprint of which species are living where. This means that when invasive species trackers take a sample of lake water, they can identify through the genetic information (DNA) which of the organisms of which species are living in that vicinity. This includes the invasives they are after. The DNA traces of organisms that the scientists find in the sample of water is usually of organisms that are living nearby. Through experiments and observations, scientists have concluded that after an organism is removed from an aquatic ecosystem, their DNA is barely traceable because it degrades in a matter of hours to days. Now, this tool is used to look for invasive species all over the world.
Relevance:
This podcast is relevant to what we are learning about in class because it focuses on the investigation of invasive species. In the first unit of the year, we talked about what invasive species are, examples of invasive species, and the impacts of them. This podcast talks about how invasives are coming into the Great Lakes by boat because the aquatic plants get stuck onto ships and are carried across the world. Many of the invasive species are from Asia, and they impact the environments of the Great Lakes region drastically. David Lodge speaks about ways to track invasive species to eventually get rid of the most harmful ones to the environment. Another way this connects to what we are learning is through the discussion of DNA. We have learned briefly about how DNA is the genetic coding of our cells, it is made in the nucleus of cells, and it makes up nucleic acids. Scientists use DNA of aquatic organisms to figure out if invasive species are living in a particular ecosystem.
Summary:
This podcast is about how scientists are now able to track invasive species using a technique called "environmental DNA." The guest speaker, David Lodge, talks about how there are a large number of invasive species in the Great Lakes and it is extremely hard to track them all, especially underwater. The environmental DNA technique allows scientists who track invasive species to get a time sensitive-fingerprint of which species are living where. This means that when invasive species trackers take a sample of lake water, they can identify through the genetic information (DNA) which of the organisms of which species are living in that vicinity. This includes the invasives they are after. The DNA traces of organisms that the scientists find in the sample of water is usually of organisms that are living nearby. Through experiments and observations, scientists have concluded that after an organism is removed from an aquatic ecosystem, their DNA is barely traceable because it degrades in a matter of hours to days. Now, this tool is used to look for invasive species all over the world.
Relevance:
This podcast is relevant to what we are learning about in class because it focuses on the investigation of invasive species. In the first unit of the year, we talked about what invasive species are, examples of invasive species, and the impacts of them. This podcast talks about how invasives are coming into the Great Lakes by boat because the aquatic plants get stuck onto ships and are carried across the world. Many of the invasive species are from Asia, and they impact the environments of the Great Lakes region drastically. David Lodge speaks about ways to track invasive species to eventually get rid of the most harmful ones to the environment. Another way this connects to what we are learning is through the discussion of DNA. We have learned briefly about how DNA is the genetic coding of our cells, it is made in the nucleus of cells, and it makes up nucleic acids. Scientists use DNA of aquatic organisms to figure out if invasive species are living in a particular ecosystem.
What invasive species are currently living in the Great Lakes and how do they affect that environment? What technology did they use to get the "environmental DNA"?
ReplyDeleteSome invasive animal species in the Great Lakes region are zebra mussels and round goby, and some invasive plant species are purple loosestrife and common reed. The round goby impacts the food web in that region by competing with native fish for food and environment. Zebra mussels have nearly eliminated the native clam population. The invasive plants are able to spread their seeds very quickly, and because of that they have displaced the native plant populations that prevent erosion. Scientists apply DNA technology to non-native species, and they are subsequently treated with piscicide. The proportion of water samples showing positive detections increased with relative abundance of the species, as indicated by the number of carcasses recovered after poisoning. New markers for for different species of fish are reported and details of the marker testing to ensure specificity are provided.
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