Biodiversity and Change

The Changing Biodiversity of the Laurentian Great Lakes

You should be aware of the major causes of loss of biodiversity:

Environmental Change due to colonisation of North America - eg deforestation, impacts of logging, changes due to agriculture
Overfishing of Native species - starting with large species such as the Atlantic Salmon and the Lake Trout, moving on to intermediate species such as the Whitefish and Ciscos (General BIOL468 Pages on Overfishing )
Invasion of Alien species (General BIOL468 Pages on Invasive Fish )

You should be aware of some of the additional consequences such as the loss of genetic diversity in species such as the Lake Trout where there were many different strains breeding in different areas of the lakes and even in differing habitats such as rivers

Alien Species in The Great Lakes

There are very many species (>130, by no means all fish) that have managed to colonise the lakes to date. You should be particularly aware of two of long standing 'invasives':

Sea Lamprey
Alewife

Together with deliberate management introductions such as

And the Eurasian Ruffe which has invaded the Lakes since 1980

Details on Major Invasive Species in Laurentian Great Lakes:

The Sea Lamprey (Petromyzon marinus Linnaeus 1758)

Predation can result in rapid and drastic changes in a fish fauna when an exotic piscivore into a community of fishes not adapted to its style of predation. the Sea Lamprey was able to virtually wipe out the populations of large fishes in the upper Great Lakes in less than 20 years. Everything you ever wanted to know about the Sea Lamprey (Petromyzon marinus Linnaeus 1758) : http://nas.er.usgs.gov/queries/FactSheet.asp?speciesID=836

Sea Lamprey Control : http://www.glfc.org/lampcon.php

Additional notes on recent problems arising with the control of the Sea Lamprey in the St Marys River on the outflow from Lake Superior (+ overheads from the lecture )

Alewife (Alosa pseudoharengus)

Basic info on the Alewife on Liverpool Fishweb (now somewhat out of date)
Pretty pictures and basic info on the Alewife :
http://www.seagrant.wisc.edu/greatlakesfish/alewife.html
Info on Alewife dieoff : http://www.seagrant.wisc.edu/greatlakesfish/alewifenews.html

Everything you ever wanted to know about the ALEWIFE and its spread in North America,
http://nas.er.usgs.gov/queries/FactSheet.asp?speciesID=490

Ruffe (Gymnoceaphalus cernuua)

The Ruffe has invaded the Lakes quite recently, probably through the introduction of ballast water from ocean-going shipping. Everything you ever wanted to know about the Ruffe in the USA : http://nas.er.usgs.gov/queries/FactSheet.asp?speciesID=7

Summary Report on the status of Ruffe in the Great Lakes ca. 1990 (pdf format, 2.9MB) : http://www.glfc.org/pubs/SpecialPubs/RuffeReport.pdf

Map of distribution of Ruffe captures in the North American Great Lakes

Major database and bibliography on Ruffe
http://www.fw.umn.edu/research/ruffe/