Identifying extinction debt in Great Lakes wetland fishes

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

Fielding Montgomery, University of Toronto, [email protected]
Nicholas Mandrak, Biological Sciences, University of Toronto Scarborough, [email protected]
Scott Reid, Ontario Ministry of Natural Resources, [email protected]

Abstract

Extinction debt is the number, or proportion, of species expected to go extinct without any further habitat modification, following a perturbation. Following the observed loss and fragmentation of wetland habitat in southwestern (SW) Ontario historically, one would expect a net loss of species richness in the remaining patches. Yet, SW Ontario appears to maintain a high diversity of wetland fishes and numerous at-risk fishes, whose populations are low. Using fish data collected with fyke and seine nets from 40 wetlands in 2016 and 2017, and previously collected data, we will test the hypothesis that wetland fishes in SW Ontario are in extinction debt. Species richness estimates for each wetland were calculated using EstimateS (to account for imperfect detection) and wetland area was calculated through ArcGIS. The sampled wetlands were classified as either control or degraded and species-area (S-A) curves were generated separately for each class. We considered extinction debt to be present if the S-A curve of the degraded wetlands was steeper than the S-A curve of the control wetlands. These results can be used to determine whether urgent restoration and/or offsetting is needed to reduce the risk of eventual extinction. 

1. Keyword
conservation

2. Keyword
wetlands

3. Keyword
fish

4. Additional Keyword
extinction