Declining lake whitefish recruitment in lakes huron and michigan has been attributed to declines inice cover and increases in dreissenid mussels dreissena polymorpha, D bugensis that consume…

The Department of the Interior Fish and Wildlife Service Region 3 awarded a $261,273.81 Project Grant to Miami University under the Fish and Wildlife Management Assistance program (CFDA 15.608) for the period of July 1, 2022 through June 30, 2025.

The grant will support research examining the potential role of ultraviolet radiation exposure as a factor contributing to declining lake whitefish recruitment in Lakes Huron and Michigan. Specifically, the awardee will study the effects of UV exposure as a physical habitat feature and identify differences in UV tolerance across various lake whitefish stocks. Insights gained regarding whether and where UV contributes to recruitment bottlenecks could inform the development of alternative management strategies to protect lower productivity stocks from potential overexploitation. This work will enable more effective protection of suitable reproductive habitat and improve stock assessment models used to predict sustainable harvest levels in different management units.

Declining lake whitefish recruitment in lakes huron and michigan has been attributed to declines inice cover and increases in dreissenid mussels dreissena polymorpha, D bugensis that consume zooplankton preynecessary for the survival of first feeding larvae simultaneous strong trends of increasing watertransparency have also been observed in recent decades one potential consequence of increased transparency is increased exposure to ultra violet UV radiation, which is known to have lethal and sublethal effects on the early life stages of some fish species we propose to examine this previously unstudied mechanism UV effects on lake whitefish recruitment specifically, we will 1 elucidate the role of UV exposure as a physical habitat feature and 2 identify differences in UV tolerance of larvae across different stocks, and thus provide insights into whether and where UV contributes to recruitment bottlenecks if UV reduces larval survival, this information can be used to develop alternative management strategies to protect the correspondingly lower productivity stocks from potential overexploitation this will enable more effective protection of suitable reproductive habitat, an improvement of stock assessment, and will better inform stock assessment models that predict sustainable harvest levels in different management units