The Minnesota Department of Natural Resources (MNDNR) has been quantitatively sampling a mussel bed in West Newton Chute (a side channel in Navigation Pool 5 of the Upper Mississippi River, UMR) annually since 2008. Briefly, ~200 systematically-placed 0.25 m2 quads are sampled annually; divers excavate substrates to a depth of ~15 cm and place material into a 6 mm mesh bag. Mussels are identified to species, aged via external annuli, measured for shell length, and sexed. From 2008-2016, this mussel bed contained 12-16 live species, had densities that ranged from 4-10/m2, and juveniles (≤ 5 years old) comprised 3-18% of the assemblage. Because this assemblage was well characterized, it represented an excellent location to estimate vital rates (i.e., survival and growth) in mussels. Our objectives were to estimate patterns in survival and growth across four species of mussels and over time within a mussel bed, and to assess if these patterns changed across patches with varying mussel densities. The counts of live mussels in quadrats sampled by the MNDNR during surveys from 2008-2011 was compiled and interpolated using an inverse distance weighted (IDW) algorithm in ArcGIS. The IDW surface of mussel density was classified by quartiles and the highest quartile was delineated as the core areas of the bed and the lowest quartile was delineated as the peripheral areas of the bed. This resulted in four polygons—two with relatively high mussel densities (core, labelled A1-A5 and B1-B5) and two with relatively low mussel densities (periphery, labelled C1-C5 and D1-D5). Five study plots (5 m x 5 m) were randomly selected within each polygon. Plot C5 was inaccessible, so we used plot C5a. Plots were aligned with the direction of river flow and demarcated into four quarters by driving nine pieces of PVC pipe into the substrate in a 3 x 3 array. To obtain mussels to PIT tag, we haphazardly searched West Newton Chute in August 2012 and obtained 578 mussels, including both common (Amblema plicata, Obliquaria reflexa) and less common (Cyclonaias pustulosa, Pleurobema sintoxia) species. Shells were scrubbed to remove existing zebra mussels. A 20- or 23-mm PIT tag was attached near the umbo of each mussel with cyanoacrylate glue to enable recovery of individual mussels in subsequent years. One end of a 36-cm piece of buoyant fishing line (color coded by species) was glued near the posterior edge of each shell to facilitate recovery. We randomly allocated 9-10 A. plicata and O. reflexa and 4-5 C. pustulosa and P. sintoxia into each plot. Mussels were placed into a randomly chosen quarter of each plot. The age, shell length, and PIT tag identification number of each mussel was recorded prior to placement within a plot. We returned to WNC to recover tagged mussels in August 2013, August 2014, July 2015, and July 2016. Once each plot was found, a diver placed a 2.5 m x 2.5 m PVC frame over each plot quarter to facilitate a thorough search. The diver systematically searched each plot quarter using an 18-cm loop antenna that was connected, via a 15.2 m cord, to a PIT-tag reader located in an attending boat. Surface to diver communication was used to notify the diver when a marked mussel had been found. During recovery efforts, divers searched within each plot and then searched the periphery of each plot (~1-2 m outside each plot) for any marked mussels that might have moved out of the plot. All recovered mussels were identified by PIT tag, recorded as alive or dead, measured for age and shell length, and any attached zebra mussels were removed and counted. If the PIT tag was damaged or missing, we replaced it with a new one and recorded the new PIT tag ID number.

This data release includes the data associated with the manuscript "Freshwater mussel distribution and catchment prioritization for mussel conservation in the Northeastern United States." It describes native freshwater mussel distribution data for Maine, New Hampshire, Vermont, Massachusetts, Rhode Island, and Connecticut as well as catchment priority scores for different conservation activities. The data release also includes some data to enable better understanding of the models used in the associated manuscript such as model standard deviations and model parameter permutation importance values.

Data is included for two types of field surveys conducted for freshwater mussels in the mainstem of the middle and upper Delaware River in the Mid-Atlantic region of the United States from 2000-2002. Timed search (qualitative) surveys were conducted during 2000-2001 from a point at the confluence of the East and West Branches of the Delaware River near Hancock, NY continuously downstream to a point at the mouth of the Paulins Kill River near Columbia, NJ. In this qualitative survey, mussel species and counts were collected in the field catch-per-unit-effort (CPUE) data was determined for all mussel species within each of 1,095 consecutive stream sections ~200 m in length. Subsequent quantitative surveys were conducted in select 200-m sections of river using quadrats during 2002 in order to estimate abundance and density of mussel present in these sections. One Excel file contains data from qualitative surveys, and a second excel file contains data from quantitative quadrat surveys.

Data is included for two types of field surveys conducted for freshwater mussels in the mainstem of the middle and upper Delaware River in the Mid-Atlantic region of the United States from 2000-2002. Timed search (qualitative) surveys were conducted during 2000-2001 from a point at the confluence of the East and West Branches of the Delaware River near Hancock, NY continuously downstream to a point at the mouth of the Paulins Kill River near Columbia, NJ. In this qualitative survey, mussel species and counts were collected in the field catch-per-unit-effort (CPUE) data was determined for all mussel species within each of 1,095 consecutive stream sections ~200 m in length. Subsequent quantitative surveys were conducted in select 200-m sections of river using quadrats during 2002 in order to estimate abundance and density of mussel present in these sections. One Excel file contains data from qualitative surveys, and a second excel file contains data from quantitative quadrat surveys.

We conducted large-scale systematic surveys for native mussels across six reaches of the upper Mississippi River. In each reach, divers placed two 0.25 square meter quadrat frames on the river bottom. The duplicate quadrats, which were placed 10 m apart in an upstream to downstream direction, were used to increase the area sampled at each site and increase the effectiveness of this cluster design. Divers excavated substrates to a depth of about 15 cm and placed material into a 6 mm mesh bag. Mussels were identified to species, aged via external annuli, measured for shell length, and sexed (in species with external sexual dimorphism).

A systematic sampling design was developed to sample mussels in Upper Mississippi River navigation Pools 3, 5, 6, 8, 13 and 18. Hydrologically-enforced buffers were created at a hierarchy of scales to better determine the extent of influence on mussel population assemblages. Buffers were generated using a radii of 1000 meters from the quadrat site point. Several landcape metrics related to the buffer shape, underlying water depth at several modeled river discharges, aquatic vegetation presence, river training structure presence, topographic position, aquatic area classification, adjacent land use types, and wind fetch magnitude were then calculated to help assess which of these metrics/indices are predictive of the distribution, abundance, diversity, and recruitment of native mussels across these six pools in the Upper Mississippi River.

A systematic sampling design was developed to sample mussels in Upper Mississippi River navigation Pools 3, 5, 6, 8, 13 and 18. Hydrologically-enforced buffers were created at a hierarchy of scales to better determine the extent of influence on mussel population assemblages. Buffers were generated using a radii of 500 meters from the quadrat site point. Several landcape metrics related to the buffer shape, underlying water depth at several modeled river discharges, aquatic vegetation presence, river training structure presence, topographic position, aquatic area classification, adjacent land use types, and wind fetch magnitude were then calculated to help assess which of these metrics/indices are predictive of the distribution, abundance, diversity, and recruitment of native mussels across these six pools in the Upper Mississippi River.

A systematic sampling design was developed to sample mussels in Upper Mississippi River navigation Pools 3, 5, 6, 8, 13 and 18. Hydrologically-enforced buffers were created at a hierarchy of scales to better determine the extent of influence on mussel population assemblages. Buffers were generated using a radii of 100 meters from the quadrat site point. Several landcape metrics related to the buffer shape, underlying water depth at several modeled river discharges, aquatic vegetation presence, river training structure presence, topographic position, aquatic area classification, adjacent land use types, and wind fetch magnitude were then calculated to help assess which of these metrics/indices are predictive of the distribution, abundance, diversity, and recruitment of native mussels across these six pools in the Upper Mississippi River.

A systematic sampling design was developed to sample mussels in Upper Mississippi River navigation Pools 3, 5, 6, 8, 13 and 18. Hydrologically-enforced buffers were created at a hierarchy of scales to better determine the extent of influence on mussel population assemblages. Buffers were generated using a radii of 10 meters from the quadrat site point. Several landscape metrics related to the buffer shape, underlying water depth at several modeled river discharges, aquatic vegetation presence, river training structure presence, topographic position, aquatic area classification, adjacent land use types, and wind fetch magnitude were then calculated to help assess which of these metrics/indices are predictive of the distribution, abundance, diversity, and recruitment of native mussels across these six pools in the Upper Mississippi River.

This layer represents fundamentally suitable and unsuitable habitat for freshwater mussels in the Meramec Basin as modeled by these authors on May 17, 2017 based on spatial data ranging from 1990 to 2014. Identification of habitat characteristics associated with the presence of freshwater mussels is challenging but crucial for the conservation of this declining fauna. Most mussel species are found in multi-species assemblages suggesting that physical factors influence presence similarly across species. In lotic environments, geomorphic and hydraulic characteristics appear to be important factors for predicting mussel presence. We used maximum entropy (MaxEnt) modeling to evaluate hydrogeomorphic variables associated with mussel presence at a riverscape-scale along 530 river km of the Meramec River basin, USA. Mussel locations were obtained from an existing multi-year dataset, and hydrogeographic variables were derived using high-resolution, open-source datasets of aerial imagery and topography. The following hydrogeomorphic variables were associated with mussel presence: lateral channel stability, low-flow surface water availability, presence of gravel bars, and stream power, but presence of gravel bars appeared to be the most important variable. Identification of suitable habitat was strongly influenced by the distance to gravel bars, suggesting mussels are found near gravel bars. A subset of the data not used in model development was used to validate the final model. The validation locations fell almost exclusively and disproportionately in habitats that the model identified as suitable, suggesting that we identified common habitat requirements for multiple mussel species. These findings can inform how resource managers allocate survey, monitoring, and conservation efforts.