Population genetics of estuarine fish of Acadia National Park: connectedness among estuaries in Downeast Maine

Petersen, Chris; Wray, Charles

“Executive Summary: ·Small tissue samples (fin clips) were collected from two species of estuarine fish, Fundulus heteroclitus (mummichogs) and Menidia menidia (Atlantic Silverside) from four estuaries within or adjacent to Acadia National Park. ·Individuals from both species and the sites were genotyped at multiple microsatellite loci to determine the genetic diversity within the species and the genetic variability among site. ·Both species showed high levels of genetic diversity overall, and large amounts of diversity within each estuary. ·Estuaries were quite similar from a genetic standpoint, showing that both species had an extensive gene flow among locations. ·Atlantic silverside had both higher overall diversity and lower genetic divergence among sites, consistent with its life-history where adults are more mobile in marine waters away from estuaries with more gene flow and a more homogeneous genetic structure over the areas studied compared with mummichogs. ·The fishes in the estuaries within Acadia National Park appear to be well connected genetically, so although there are small differences among estuaries, estuarine populations have strong ties to each other. (Research recommendations:) Determine why the Schoodic Peninsula sample of Mummichogs was genetically different from estuarine populations on Mount Desert Island. Suggest adding the estuary at Sand Beach and improving resolution to the connectedness of ANP estuarine populations with those outside of the park. Appendix 1 contain a list of collections made (species, location, date, and number of individuals). /STUDY LOCATIONS:/ /MOUNT DESERT ISLAND/Bass Harbor/Babson Creek/Northeast Creek/ /SCHOODIC PENINSULA/Mosquito Cove/