Sampling Effort Required to Detect Rare Fishes

Session: 09. - Modeling, Detecting, and Managing Rarity

Alan Dextrase, Ontario Ministry of Natural Resources and Forestry, [email protected]
Nicholas Mandrak, Biological Sciences, University of Toronto Scarborough, [email protected]
Jason Barnucz, Department of Fisheries and Oceans, [email protected]
Lynn Bouvier, Department of Fisheries and Oceans, [email protected]
Robin Gaspardy, Department of Fisheries and Oceans, [email protected]
Scott Reid, Ontario Ministry of Natural Resources, [email protected]

Abstract

Many development activities have the potential to affect aquatic species at risk and their habitats. Determining whether species at risk are present within an activity’s projected zone of influence is an important first step in assessing and mitigating impacts. We developed species-specific guidance to complement existing general guidance on sampling effort to detect Ontario fish species at risk. Thirty-six occupancy model candidate sets were analyzed for six fish species at risk (Silver Shiner, Pugnose Shiner, Lake Chubsucker, Northern Madtom, Eastern Sand Darter, and Channel Darter) detected using a variety of sampling gears and protocols in 10 southern Ontario waterbodies. Estimates of detection probability were used to identify the sampling effort required to detect species at the site and reach scales. Estimated detection probability ranged from 0.06 to 0.89 and varied between and within species. Effort required to detect fishes at risk is similarly variable and is quite high for some species and gears. Within-species detection probability differed between watersheds and was positively correlated with relative abundance. Guidance on required sampling effort can be used to help design detection sampling for fishes at risk within a defined area using specific gears.

1. Keyword
fish

2. Keyword
monitoring

3. Keyword
modeling

4. Additional Keyword
Species at Risk

5. Additional Keyword
detection probability

6. Additional Keyword
sampling effort