Riverscape-scale modeling of fundamentally suitable habitat for mussel assemblages in an Ozark River system, Missouri

Freshwater Mollusk Biology and Conservation
By: , and 

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Abstract

Identifying the physical habitat characteristics associated with riverine freshwater mussel assemblages is challenging but crucial for understanding the causes of mussel declines. The occurrence of mussels in multispecies beds suggests that common physical factors influence or limit their occurrence. Fine-scale geomorphic and hydraulic factors (e.g., scour, bed stability) are predictive of mussel-bed occurrence, but they are computationally challenging to represent at intermediate or riverscape scales. We used maximum entropy (MaxEnt) modeling to evaluate associations between riverscape-scale hydrogeomorphic variables and mussel-bed presence along 530 river km of the Meramec River basin, USA, to identify river reaches that are fundamentally suitable for mussels as well as those that are not. We obtained the locations of mussel beds from an existing, multiyear dataset, and we derived river variables from high-resolution, open-source datasets of aerial imagery and topography. Mussel beds occurred almost exclusively in reaches identified by our model as suitable; these were characterized by laterally stable channels, absence of adjacent bluffs, proximity to gravel bars, higher stream power, and larger areas of contiguous water (a proxy for drought vulnerability). We validated our model findings based on model sensitivity using a set of mussel-bed locations not used in model development. These findings can inform how resource managers allocate survey, monitoring, and conservation efforts.

Study Area

Publication type Article
Publication Subtype Journal Article
Title Riverscape-scale modeling of fundamentally suitable habitat for mussel assemblages in an Ozark River system, Missouri
Series title Freshwater Mollusk Biology and Conservation
DOI 10.31931/fmbc-d-20-00002
Volume 24
Issue 2
Year Published 2021
Language English
Publisher Freshwater Mollusk Conservation Society
Contributing office(s) Coop Res Unit Atlanta
Description 16 p.
First page 43
Last page 58
Country United States
State Missouri
Other Geospatial Meramec River basin
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