Lake Erie Larval Yellow Perch Predation: a Molecular Genetic Approach

Variation in recruitment of Yellow perch (Perca flavescens) (YP) is not yet fully understood. The western basin of Lake Erie is an important rearing habitat for YP larvae. The western basin of Lake Erie receives input from two main tributaries (Maumee and Detroit River), that differ greatly in their nutrient and sediment loading. Turbidity and nutrient levels are elevated in the Maumee River plume, and YP recruitment has previously been correlated with Maumee River discharge. Higher turbidity in the Maumee River plume could avert predation on larvae and early juvenile yellow perch. Predation during early life stages is often a major factor limiting recruitment success in many fish species. Identification of soft body prey (e.g. larval fish) in stomach contents using traditional methods is very challenging due to rapid digestion rates. However, molecular genetic techniques allow accurate identification of highly digested prey to species level. The objective of this project was to investigate predation levels on YP larvae and early juveniles in the Maumee and Detroit River plumes using a yellow perch species-specific single nucleotide polymorphism (SNP) assay. Predator fish white bass, white perch and walleye were collected from late April- to early June in Detroit and Maumee River plumes in the western basin of Lake Erie in 2006, 2007 and 2008. DNA was extracted from stomach contents of these piscivorous fish and assayed with the SNP species specific probe. Patterns of predation based on capture time, collection site and predator size will be compared. The development of genetic tools in Fisheries research can aid in understanding underlying mechanisms controlling recruitment success in commercially important fish species.