Alex (at the right in the photo) is looking at the dietary habits of three types of fish in the Stanley River estuary system in PEI: mummichogs, fourspine sticklebacks, and the American eel. This involves examining gut contents, which he obtains by dissecting the stomachs of mummichogs and fourspines and through a non-lethal stomach pumping apparatus
for eel. The contents of the digestive system are identified by viewing them under a dissecting microscope. This project is being carried out in order to verify the results of a technique called stable isotope analysis, which was partially carried out last year. Stable Isotope analysis helps to rank organisms by their position in the food chain (e.g. predator vs herbivore) by measuring the relative amounts of certain naturally occurring forms of common elements like Carbon and Nitrogen, which increase in a predictable way based on food source or food chain level. Feeding information is especially important for the American eel, which is a declining and economically pertinent species. Monthly sampling has been ongoing since late April. So far, all of the fish have exhibited a wide diet, including clams, eggs, mussels, sea lettuce, shrimps, marine worms and even other fish.
Student Research