We’ve all heard of Invasive Species, but just in case, an invasive species is a non native species that is likely to cause economic harm. Today, we’re going to be focusing on just one invasive species. The species we will be focusing on is Alewife, and to be even more specific I will be talking about what they are doing to the Lake Trout population. The Lake Trout population has been descending for many year now, and Alewife have definitely not been of service in the situation.

Originally, Alewife would breed in freshwater and then they would carry out the rest of their lives in the ocean, they preferred depths of 150-350 ft. It seems that the Alewife entered the Great Lakes in the 19th century through the building of the Welland Canal. This introduced species has deserted the second part of their life cycle. They are now carrying out their entire lives in freshwater. Since the invasion of Alewife all Trophic Levels (Each of several hierarchical levels in an ecosystem, comprising organisms that share the same function in the food chain and the same nutritional relationship to the primary sources of energy.) have been afflicted by their vast predation of Zooplankton.

The Alewife population has been a major contributor in the inability to reproduce the Lake Trout population. Alewife eat Lake Trout fry and Lake Trout eggs which has lead to a major decrease in the Lake Trout population. Not only that but when the Lake Trout eat Alewife, most of them will obtain a Thiamin (vitamin) deficiency. This will cause a deficiency in the Lake Trout young, which will kill off most of the fry during the larva stage.  Some will survive the larva stage and will carry on with their life, while others will survive the larval stage but will be eaten before they are full grown. All of these reasons have caused a downfall in the population. Most of them being directly caused by Alewife but some indirectly caused by the Alewife species but still linked with the Alewife.

A good question to be asked about this is, what can we do to help? One study showed that without adding any additional factors such as pollution, Alewife are the main source to the loss of our Lake Trout. The study involved filling two large tanks with the necessary environment qualifications of Lake Trout fry. They then put a large amount of Lake Trout Fry into one of the Tanks, and Alewife and Lake Trout Fry in the other. After about a month they went back to the tanks and went through them sifting through the gravel and sand, making sure they didn’t miss a single Fry in either tank. The Lake Trout were counted up and to find the tank without Alewife had more surviving Lake Trout than the tank that contained Alewife. Scientists are thinking about making Lake Trout plants(Somewhere to breed and raise the Lake Trout and then release them.), but will that really help? Some scientists say that we might be able to create a chemical in order to get rid of the Invasive Alewife species. Another option that seems like it would be so much easier to follow through with would be to catch and eat the Alewife. It seems disgusting and weird but why not? I mean Michael Leviton is doing it and his restaurant is ranked in the top five by Zagat Boston.

Clearly Alewife are an issue, and we need to get their population under control in order to save the Lake Trout in our Great Lakes. There are many solutions, some you can even help out with. Now it’s your turn to decide, what's the best option? What are you going to do in order to save our Lake Trout species? Our Lakes would be so much safer for our Lake Trout species, and even other species affected by the Alewife.