Resurrection ecology is an evolutionary biology research approach that allows observation of evolutionary change over long periods of time. Researchers use this with aquatic organisms that produce dormant eggs (ephippia) which are buried and deposited in sediments regularly. By extracting ephippia and inducing hatching, researchers can study the organisms as they existed decades ago and evaluate the population for changes over time. Stocking fish (e.g. rainbow trout) in lakes can potentially induce trophic cascades that impact the zooplankton community’s composition. As visually-orientated, size-selective predators, rainbow trout (RBT) prey on large-bodied zooplankton grazers (Daphnia pulicaria) instead of the smaller-bodied zooplankton (Daphnia mendotae). In 1981, an annual RBT stocking program was initiated in Square Lake. Through comparing zooplankton exoskeletal remains in the sediment records of Square Lake and non-stocked Big Carnelian Lake, researchers found that mean body size of D. pulicaria decreased significantly in Square Lake during stocking moratoriums, while D. mendotae remained unchanged. This implies D. pulicaria body size decreased after the RBT stocking program began, however, it’s unknown whether the change occured due to evolution or as an induced response with phenotypic plasticity. We used resurrection ecology to evaluate whether the Square Lake Daphnia population evolved to become smaller in response to RBT predation over 35 years. Hatchlings produced from ephippia extracted from sediments of different depths in lake core samples were cultured to produce clonal offspring able to be observed for life history traits including somatic growth rate, total reproduction rate, and size and age at first reproduction. We expect the D. pulicaria population in Square Lake is showing life history traits consistent with selective pressure from visually-orientating predators, such as earlier reproduction, reproduction at a smaller size, and overall smaller body size. Final results are anticipated to be found by summer 2022 as this research is ongoing.