title: Assessing historical fish community composition using surveys, historical collection data, and species distribution models.
abstract: Accurate establishment of baseline conditions is critical to successful management and habitat restoration. We demonstrate the ability to robustly estimate historical fish community composition and assess the current status of the urbanized Barton Creek watershed in central Texas, U.S.A. Fish species were surveyed in 2008 and the resulting data compared to three sources of fish occurrence information: (i) historical records from a museum specimen database and literature searches; (ii) a nearly identical survey conducted 15 years earlier; and (iii) a modeled historical community constructed with species distribution models (SDMs). This holistic approach, and especially the application of SDMs, allowed us to discover that the fish community in Barton Creek was more diverse than the historical data and survey methods alone indicated. Sixteen native species with high modeled probability of occurrence within the watershed were not found in the 2008 survey, seven of these were not found in either survey or in any of the historical collection records. Our approach allowed us to more rigorously establish the true baseline for the pre-development fish fauna and then to more accurately assess trends and develop hypotheses regarding factors driving current fish community composition to better inform management decisions and future restoration efforts. Smaller, urbanized freshwater systems, like Barton Creek, typically have a relatively poor historical biodiversity inventory coupled with long histories of alteration, and thus there is a propensity for land managers and researchers to apply inaccurate baseline standards. Our methods provide a way around that limitation by using SDMs derived from larger and richer biodiversity databases of a broader geographic scope. Broadly applied, we propose that this technique has potential to overcome limitations of popular bioassessment metrics (e.g., IBI) to become a versatile and robust management tool for determining status of freshwater biotic communities.
authors.affiliation: Texas Natural History Collections, University of Texas, Austin, Texas, United States of America. benlabay@mail.utexas.edu
authors.forename: Ben
authors.initials: B
authors.lastname: Labay
authors.forename: Adam E
authors.initials: AE
authors.lastname: Cohen
authors.forename: Blake
authors.initials: B
authors.lastname: Sissel
authors.forename: Dean A
authors.initials: DA
authors.lastname: Hendrickson
authors.forename: F Douglas
authors.initials: FD
authors.lastname: Martin
authors.forename: Sahotra
authors.initials: S
authors.lastname: Sarkar
mesh_terms: D000818:Animals; D017753:Ecosystem; D004784:Environmental Monitoring; D005399:Fishes; D005618:Fresh Water; D013781:Texas