Movements of brook trout, Salvelinus fontinalis, at Hunter's Brook, Acadia National Park, Maine

Le, Jon

Marked and recaptured brook trout in Hunter's Brook, Acadia National Park, to determine movements. Correlated results with water temperature, diversityof benthic macroinvertebrates, habitat and productivity. From abstract: 'Movements of brook trout, Salvelinus fontinalis, were examined at Hunter's Brook, Acadia National Park, Maine, using mark-recapture. Five fin-clip combinations were used to identify fish caught in five separate marking sections. Recapture periods consisted of sampling all marking sections and randomly chosen sections by backpack electrofishing. Water temperature, species diversity, habitat, and productivity were measured to further examine factors that may influence movements. Except for habitat, parameters measured were relatively homogenous throughout the study reach. Recaptures of marked fish outside their sections of original capture were low. Although proportions of unmarked to marked fish in the marking sections were high (35-60%) in the first recapture period, summer recapture periods had lower proportions of unmarked to marked fish (less than 30%) in marking sections. However, there was an increase in unmarked fish during the last recapture period. These proportions of unmarked fish are most likely the result of immigration. Seasonality and spawning movements may explain increases in immigration percentage in the first and last recaptures, respectively. Overall, brook trout movement was observed and detected by both recaptures and marked, mobile fish and immigration of unmarked fish into marking sections. An interesting observation was that large proportions of immigrants were 1 and 2-year-old fish. This is contrary with previous literature on the size of mobile salmonids.' Appendix 2 gives habitat measurements (wetted width, bankfull width, depth, and grade) for each transect at Hunters Brook; Appendix 3 gives substrate data at all transects; Appendix 8 gives the size and age of all brook trout captured. /STUDY LOCATIONS:/ /MOUNT DESERT ISLAND/Hunter's Brook/