Environmental Science and Ecology Faculty Received Provost’s Post-Tenure Fellowship Award
Dr. Jacques Rinchard received a $3,500 Provost’s Post-Tenure Fellowship Award to assess diet of Lake Champlain lake trout using fatty acid signatures.
Lake trout were extirpated from Lake Champlain by 1900 and lake trout restoration efforts started by the early 1970s. Despite widespread stocking, lake trout recruitment was not observed until 2015, but has been sustained since then. Alewife a preferred food prey of salmonine species as been linked to lake trout recruitment failure because they prey on lake trout free embryos and contain the enzyme thiaminase that breaks down thiamine. Thus, predators consuming alewife allocate insufficient thiamine to their eggs, resulting in mortality of free embryos due to thiamine deficiency. Therefore, assessing the diet of lake trout in Lake Champlain is of primary importance. Stomach content analysis is a conventional technique used to investigate food web linkages. Although this method provides valuable information, it has limitations and biases, which include differential digestion, loss of both hard and soft parts, representation of only the last meal eaten, and often empty stomachs. Thus, we will use fatty acid signature to decipher lake trout diet. This approach is based on the concept that fatty acids are conservatively transferred from prey to predator and therefore infer diet in accordance to the principle “you are what you eat”. The fatty acid method integrates not only spatial and temporal variations, but is also reliable in rapid detection of diet shifts in fish, because the time needed to influence fatty acid signature is relatively short. Our data will be instrumental for the restoration effort of lake trout in Lake Champlain.