Hydroacoustic mapping for native mussel and host fish habitats using Quadrula fragosa and Ictalurus punctatus
The St. Croix National Scenic Riverway (SACN) is one of the best remaining refuges for declining populations of native unionid mussels in the United States and supports the only known self-sustaining population of the federally endangered Winged Mapleleaf (Quadrula fragosa) in the Upper Mississippi River basin. Mussel fauna are important to the river ecosystem, providing important ecological services such as filtration, nutrient recycling, and food web modification. Because of their imperiled status and the ecological services they provide, Q. fragosa are the focus of conservation and restoration efforts for many agencies. The stretch of Riverway from Highway 8 to the High Bridge (Figure 1), approximately 36.5 kilometers, remains virtually unmapped in terms of habitat information such as hydrologic measures of high-resolution bathymetry and flow velocities. While some coarse resolution flow velocities exist, the transect data were collected approximately 1 kilometer apart and may miss some important flow refuges. Due to the nature of the habitat where Q. fragosa live, information on what constitutes suitable habitat is needed.
Many studies have been conducted on the life cycle of Q. fragosa, including the brooding, encystment, and juvenile release periods. A key discovery was made for Q. fragosa that the only known host for Q. fragosa in the SACN is the Channel Catfish (Ictalurus punctatus). Using acoustic telemetry, USGS and NPS were able to passively track I. punctatus captured in the vicinity of Q. fragosa beds (Figure 2) just prior to glochidia release to study their movement behavior in the SACN. Studies have shown movement and habitat use patterns for I. punctatus moving upstream into flowing areas during spring and summer, and downstream into impounded areas during winter (1). Understanding the seasonal movements and habitat use of I. punctatus in relation to glochidia released by Q. fragosa will be integral to identifying suitable reintroduction sites and help determine best management practices for Q. fragosa conservation.
Recent advances in hydroacoustic technology are proving valuable for mapping physical habitat for fisheries (2) and sedentary biota such as freshwater mussels (3). To broadly analyze river habitat, remote sensing technologies such as hydroacoustics (sonar) are a non-invasive way to collect information on hydraulic measures (i.e., depth and water flow velocities). While some depth information has been collected during monitoring and survey efforts, survey-grade bathymetry can be obtained using a multibeam or single-beam echosounder to map the depth and topography of the riverbed (Figure 3), providing valuable habitat information for resource management. Additionally, backscatter and sidescan imagery can provide more habitat information such as riverbed characteristics like wing dams, sand dunes, vegetated areas, and even bottom composition of sand vs gravel. While some habitat characteristics (i.e., bed composition) may not be provided as an outcome, the information remains within the raw sonar data, and can be derived later for additional information.
The goals for the project are to provide the information and tools needed to examine the habitat associations of I. punctatus and Q. fragosa using hydrologic variables of depth and water velocities. Objectives include the following tasks per fiscal year listed:
- FY2022: assess I. punctatus locational movement using existing telemetry data (2017 NRPP, funded)
- FY2023: collect high-resolution sonar data for the main stretch of Riverway (where depth allows) from Highway 8 to the High Bridge; collect river current velocities using an acoustic Doppler current profiler (ADCP) for select overwintering, deep areas of I. punctatus (determined by objective #1) and/or the length of Q. fragosa dense mussel beds
- FY2024: analyze bathymetry with existing I. punctatus telemetry data to determine preferred depth parameters
Hydraulic variables such as current velocity, shear stress, and relative substrate stability have shown promise in predicting the distribution of mussels (4) and identifying critical habitat (5). Depth and water flow velocities (Figure 4) can vary spatially within a river and can be combined to describe baseline habitat conditions needed to describe critical habitat information for where I. punctatus and Q. fragosa intersect.
Hydroacoustic surveys are needed for this stretch of river to provide baseline hydraulic measures for I. punctatus and Q. fragosa to help define preferred mussel or host fish habitat. Applying these hydraulic measures for known preferred habitat for overwintering I. punctatus can help identify key locations of the glochidia environment throughout its life stage and identify critical habitat information of the two species distributions and where they intersect. These measures, or habitat variables, have the analytic capabilities to be modeled and viewed in a digital environment, providing key locations for further investigation for restoring endangered and threatened species, and to better understand the distribution of mussels and host fish throughout the river corridors.
While the main objective for this project is to collect missing information of depth and water velocities for the SACN, there is a much broader application of these datasets. The data itself is recognized as a need by the NPS – there is currently little depth and river flow velocity information for this stretch of the SACN. These datasets are also valuable for habitat characterization of other host fish and native freshwater mussels, invasive species (zebra mussels) or other riverine species.
References:
- Butler, S. E. and Wahl, D. H. 2011. Distribution, movements, and habitat use of channel catfish in a river with multiple low-head dams. River and Research Applications, 27: 1182-1191.
- Delonay, A. J., McElroy, B. J., Jacobson, R. B., and Throsby, M. R. 2010. Determining Physical Fish Habitat in Large Rivers with Multibeam Sonar: An Example with Pallid Sturgeon in the Lower Missouri River, American Geophysical Union, Fall Meeting 2010, abstract id. OS13F-1309.
- Smit, R. and Kaeser, A. 2016. Defining freshwater mussel mesohabitat associations in an alluvial, Coastal Plain river. Freshwater Science. 35(4):1276 –1290.
- Morales, Y., Weber, L. J., Mynett, A. E., and Newton, T. J. 2006. Effects of substrate and hydrodynamic conditions on the formation of mussel beds in a large river. Journal of North American Benthological Society, 2006, 25(3):664-676.
- Zigler, S. J., Newton, T. J., Steuer, J. J., Bartsch, M. R. and Sauer, J. S. 2008. Importance of physical and hydraulic characteristics to unionid mussels: a retrospective analysis in a reach of large river. Hydrobiologia 598:343-36
The St. Croix National Scenic Riverway (SACN) is one of the best remaining refuges for declining populations of native unionid mussels in the United States and supports the only known self-sustaining population of the federally endangered Winged Mapleleaf (Quadrula fragosa) in the Upper Mississippi River basin. Mussel fauna are important to the river ecosystem, providing important ecological services such as filtration, nutrient recycling, and food web modification. Because of their imperiled status and the ecological services they provide, Q. fragosa are the focus of conservation and restoration efforts for many agencies. The stretch of Riverway from Highway 8 to the High Bridge (Figure 1), approximately 36.5 kilometers, remains virtually unmapped in terms of habitat information such as hydrologic measures of high-resolution bathymetry and flow velocities. While some coarse resolution flow velocities exist, the transect data were collected approximately 1 kilometer apart and may miss some important flow refuges. Due to the nature of the habitat where Q. fragosa live, information on what constitutes suitable habitat is needed.
Many studies have been conducted on the life cycle of Q. fragosa, including the brooding, encystment, and juvenile release periods. A key discovery was made for Q. fragosa that the only known host for Q. fragosa in the SACN is the Channel Catfish (Ictalurus punctatus). Using acoustic telemetry, USGS and NPS were able to passively track I. punctatus captured in the vicinity of Q. fragosa beds (Figure 2) just prior to glochidia release to study their movement behavior in the SACN. Studies have shown movement and habitat use patterns for I. punctatus moving upstream into flowing areas during spring and summer, and downstream into impounded areas during winter (1). Understanding the seasonal movements and habitat use of I. punctatus in relation to glochidia released by Q. fragosa will be integral to identifying suitable reintroduction sites and help determine best management practices for Q. fragosa conservation.
Recent advances in hydroacoustic technology are proving valuable for mapping physical habitat for fisheries (2) and sedentary biota such as freshwater mussels (3). To broadly analyze river habitat, remote sensing technologies such as hydroacoustics (sonar) are a non-invasive way to collect information on hydraulic measures (i.e., depth and water flow velocities). While some depth information has been collected during monitoring and survey efforts, survey-grade bathymetry can be obtained using a multibeam or single-beam echosounder to map the depth and topography of the riverbed (Figure 3), providing valuable habitat information for resource management. Additionally, backscatter and sidescan imagery can provide more habitat information such as riverbed characteristics like wing dams, sand dunes, vegetated areas, and even bottom composition of sand vs gravel. While some habitat characteristics (i.e., bed composition) may not be provided as an outcome, the information remains within the raw sonar data, and can be derived later for additional information.
The goals for the project are to provide the information and tools needed to examine the habitat associations of I. punctatus and Q. fragosa using hydrologic variables of depth and water velocities. Objectives include the following tasks per fiscal year listed:
- FY2022: assess I. punctatus locational movement using existing telemetry data (2017 NRPP, funded)
- FY2023: collect high-resolution sonar data for the main stretch of Riverway (where depth allows) from Highway 8 to the High Bridge; collect river current velocities using an acoustic Doppler current profiler (ADCP) for select overwintering, deep areas of I. punctatus (determined by objective #1) and/or the length of Q. fragosa dense mussel beds
- FY2024: analyze bathymetry with existing I. punctatus telemetry data to determine preferred depth parameters
Hydraulic variables such as current velocity, shear stress, and relative substrate stability have shown promise in predicting the distribution of mussels (4) and identifying critical habitat (5). Depth and water flow velocities (Figure 4) can vary spatially within a river and can be combined to describe baseline habitat conditions needed to describe critical habitat information for where I. punctatus and Q. fragosa intersect.
Hydroacoustic surveys are needed for this stretch of river to provide baseline hydraulic measures for I. punctatus and Q. fragosa to help define preferred mussel or host fish habitat. Applying these hydraulic measures for known preferred habitat for overwintering I. punctatus can help identify key locations of the glochidia environment throughout its life stage and identify critical habitat information of the two species distributions and where they intersect. These measures, or habitat variables, have the analytic capabilities to be modeled and viewed in a digital environment, providing key locations for further investigation for restoring endangered and threatened species, and to better understand the distribution of mussels and host fish throughout the river corridors.
While the main objective for this project is to collect missing information of depth and water velocities for the SACN, there is a much broader application of these datasets. The data itself is recognized as a need by the NPS – there is currently little depth and river flow velocity information for this stretch of the SACN. These datasets are also valuable for habitat characterization of other host fish and native freshwater mussels, invasive species (zebra mussels) or other riverine species.
References:
- Butler, S. E. and Wahl, D. H. 2011. Distribution, movements, and habitat use of channel catfish in a river with multiple low-head dams. River and Research Applications, 27: 1182-1191.
- Delonay, A. J., McElroy, B. J., Jacobson, R. B., and Throsby, M. R. 2010. Determining Physical Fish Habitat in Large Rivers with Multibeam Sonar: An Example with Pallid Sturgeon in the Lower Missouri River, American Geophysical Union, Fall Meeting 2010, abstract id. OS13F-1309.
- Smit, R. and Kaeser, A. 2016. Defining freshwater mussel mesohabitat associations in an alluvial, Coastal Plain river. Freshwater Science. 35(4):1276 –1290.
- Morales, Y., Weber, L. J., Mynett, A. E., and Newton, T. J. 2006. Effects of substrate and hydrodynamic conditions on the formation of mussel beds in a large river. Journal of North American Benthological Society, 2006, 25(3):664-676.
- Zigler, S. J., Newton, T. J., Steuer, J. J., Bartsch, M. R. and Sauer, J. S. 2008. Importance of physical and hydraulic characteristics to unionid mussels: a retrospective analysis in a reach of large river. Hydrobiologia 598:343-36