Timed Search Technique Used to Evlauate Freshwater Mussel (Bivalvia: Unionidae) Species Richness in Headwater Streams: Is a Single One-Hour Visit Enough?

Abstract

Freshwater mussels were sampled in the upper Mackinaw River basin, Illinois, for five years to determine if a single, one-hour visit was enough to adequately characterize the species richness at a headwater stream site when using the timed search technique. Eight sites were each handpicked for one person-hour every year, and species richness was calculated to determine if it varied by year for five years. During 39 person-hours, 2,692 live individuals of 14 species were collected. Species accumulation curves and Spearman's correlation analysis suggested that a single, one-hour visit was not adequate when using the timed search technique to determine species richness in headwater streams of the Mackinaw River basin and might not be sufficient in other basins.

How a Statewide Stream Survey Can Aid in Understanding Freshwater Mussel (Bivalvia: Unionidae) Ecology: Examples of Utility and Limitations from Maryland

“…Although not indicated in this study's data, we have recently encountered these species through stream assessments in large river and tidal-fresh habitats as part of other studies while using the same informal visual search. Nonetheless, we realize the current methods may be insufficient to detect and characterize the true mussel richness in some habitats where species with cryptic life history traits reside (Metcalfe-Smith et al, 2001;Tiemann et al, 2009). However, a cursory comparison of our mussel richness data to that collected by the Maryland Natural Heritage Program using timed-snorkel surveys has shown good agreement between most small to medium sized streams and watersheds.…”

Microhabitat and Landscape Drivers of Richness and Abundance of Freshwater Mussels (Unionida: Unionidae) in a Coastal Plain River

“…All collected mussels were placed in mesh bags until survey completion, at which time identifiable mussels were returned to the stream, and unidentified taxa were placed on ice and returned to the lab for identification [57,61,62]. These data allowed for calculation of catch per unit effort and relative abundance for each species, as well as assemblage richness and evenness at each study site ( [63]; but acknowledging concerns in [64]).…”

Establishing minimum counts for semiquantitative bank‐to‐bank river transect mussel studies in species‐poor rivers

“…Some research has been conducted regarding the requirements for the various sampling methods. For example, 1 hour has been deemed insufficient in species‐rich (14 species) headwater sites (Tiemann, Cummings, & Mayer, ). As for the area search methods, the bank‐to‐bank method has been suggested to be slightly more efficient (Dickson, ) than the quadrat method (for description of the sampling methods, see Strayer & Smith, ).…”