Population biology in the Great Lakes

The subject of todays blog is population biology in the great lakes.  In todays blog, we will go over the basics of what population biology is, what it means in regards to the great lakes, and how invasive species effect it.  Now let us begin with a description of what population biology is.  Population biology, according to Environmental Science A Global Concern's authors William P. Cunningham and Mary Ann Cunningham, "is the science of modeling changes in species abundance."  (Environmental Science A Global Concern p.117).

So what does Population biology have to do with the great lakes?  Overfishing and loss of biodiversity are major controversial issues in the world, and the fact is that we are having an impact on the world.  Humans are exploiting the limited resources offered up by our planet, and consuming them at an alarming rate.  It has been said many times that fish stocks are being depleted, but what does this mean?  When a fish stock reaches a certain level and human consumption exceeds the fishes ability to replace the individuals that are caught for human consumption, the stock depletes growing smaller and smaller until it is wiped out or a new fish is chosen.  All over the world this is happening, but what is happening in the Great Lakes?  Sadly, fish stocks in the great lakes are being depleted, fishing, pollution, and invasive species are taking their toll on the native fish that inhabit our Lakes.  According to www.rff.org, the sea lamprey alone crushed the populations of lake trout.  It is likely other fish were effected similarly.  One invasive species managed to bring a local population to its knees.  This coupled with fishing, pollution, and the combined pressure of invasive species could spell doom for local fish stocks.

So the final question his how do invasive species effect population biology in the great lakes.  The fact is that invasive species such as Asian Carp breed at a rapid rate and consume the food other fish need to survive.  Zebra mussels filter out the smallest particles of food leaving behind sterile water incapable of supporting life.  Sea Lampreys are wiping out the populations of larger fish further disrupting the natural balance of the great lakes.  All these invasive species are causing Native populations to plummet.  The Great Lakes themselves are in shock.  If things continue as they are, they will flat line, and there may be no reviving our Lakes.  The flip side of the coin here is although Native species are on the decline, these successful invasive species are breeding quite fast and replacing the old fish stock in a sense.  According to www.npr.org, the asian carp could be used as a potential food source and are even now being harvested.  Unlike traditional fish stocks, this invasive species will not likely have limitations to stock as the breed quite rapidly and have the advantage of a lack of predators.  While this is good news for depleted fish stocks, it is also bad news as the asian carp are replacing our Native fish populations.  Only time will tell what will happen, but at present things are looking grim for the Great Lakes.

Resources:

Environmental Science A Global Concern by William P. Cunningham and Mary Ann Cunningham

 http://www.rff.org/Publications/WPC/Pages/03_23_09_RestoringGreatLakesEcosystemsWorththeCost.aspx

http://www.npr.org/templates/story/story.php?storyId=5542199