Five Thousand Fish: Citizen Science on Lake Huron

We conducted a study in which volunteer anglers collected predators for a diet study that evaluated how changes in the Lake Huron forage base had affected both native and stocked piscivores. At inception, the study had only a small number of participants, but within the first month participation likely grew exponentially, and volunteers collected over 2000 predator stomachs during the first year. The study continued an additional two years, and was largely driven by stakeholder requests that it continue. Volunteer anglers provided over 5000 predator stomachs over three years. Data quality was high, and nearly all data were collected according to established protocols. Several factors likely contributed to success and high levels of participation: 1) we had a prior strong and positive relationship with many organized angling groups, 2) we were able to communicate with volunteers via email, 3) anglers encouraged peers to participate, 4) creel clerks from management agencies recruited many anglers or made collections, and 4) we provided feedback via email communication and presentation of results each year. While not quantifiable, we received unsolicited comments from many anglers expressing satisfaction with being able to assist with resolution of difficult management issues, and there was strong belief that they viewed themselves as equal partners in an important undertaking. The greatest problem we encountered was that the volume of stomachs collected exceeded our ability to process them, and we did not anticipate the need for centralized collection locations. Again, management agencies assisted in sample curation. Data from the study document how predators had responded to changes in the forage base, and diets suggested that piscivores responded to apparent prey shortage by switching to non-traditional prey, particularly invasive round gobies and invertebrates. We also found heavy predation by adult piscivores on recently stocked salmonids. Data from the study are being used in several important management decisions,  and as inputs for modeling approaches.