The Wrinkled Snail, Xeroplexa intersecta, has been introduced and has spread in the Pacific Northwest of North America, with established populations now documented in Oregon, Washington, and British Columbia.

Severe storms have the potential to disperse land snails carried by strong winds between islands and archipelagos or to drown endemic fauna in storm surges. We compared land snail assemblages collected from Ngcheangel atoll (Kayangel State, Republic of Palau, Oceania) before and after the passage of Typhoon Haiyan in 2013. Most land snail species, including two species endemic to the atoll, remained present after the storm. Three species were not recovered post-Haiyan, and three species were reported for the first time after the storm. We conclude that the atoll's land snail fauna is fairly resilient to the impacts of severe storms. This finding raises the hope that at least one harbinger of climate change – increased prevalence and severity of storms – may pose minimal risk to certain imperiled and endemic Pacific Island land snails.

The next century will be a time of rapid change for freshwater mussel populations, which will be threatened by climate change, biological invasions, new pollutants, land-use change, habitat fragmentation, and many other causes. At the same time, habitat restoration and mussel propagation will offer opportunities to improve the size and viability of mussel populations. Mussel conservationists will be challenged to document, understand, and manage these changes to mussel populations and their habitats. Here, I focus on two scientific problems central to future mussel conservation: population monitoring and dynamic lags that affect mussel populations. Although mussel population monitoring has advanced greatly in recent decades, existing programs have important shortcomings: data are hard to find, data from different monitoring programs often are incompatible, many data sets are subject to permanent loss, and monitoring programs may be ill–suited to answer the questions facing us in coming decades. Monitoring programs can be improved by posting more data in public repositories, better coordinating existing monitoring programs, designing monitoring programs to answer specific questions, and better integrating monitoring into broader programs of research and management. Many drivers that affect mussel populations take decades to play out, so that mussel populations often are not in equilibrium with their current environments, leading to extinction debts and colonization credits. Delayed inputs of sediments, nutrients, and pollutants from the catchment, long intervals between extreme events, delays in biological invasions, and the demographic structure of the mussel population itself all may cause dynamic lags. Lagged systems can be difficult to understand and manage. Increased awareness of lags, model building, model application and testing, and adaptive monitoring and management may help mussel conservationists deal with lags.

Population genetics research is often a foundation of effective conservation efforts. Yet, such research is often missing for critically imperiled freshwater gastropods. Recently, several population genomic studies revealed that populations of Pleuroceridae species often harbor high amounts of genomic diversity, even when the species has undergone severe range contraction. To test for this pattern in additional species, we generated genomic data for Elimia crenatella (Lea, 1860) and Elimia capillaris (Lea, 1861). Both species have undergone greater than 95% range reduction and only one population of each species remains. We found that both species harbor relatively high amounts of genetic diversity in their remaining populations. Furthermore, genomic data do not indicate that remaining populations have undergone severe bottlenecks as might be expected given such drastic species-wide range contraction. By comparing these data to past studies, we developed a broad hypothesis to explain how pleurocerid species respond to habitat degradation: The Rapid Localized Extirpation Hypothesis. This hypothesis postulates that pleurocerid populations will persist without showing evidence of decline until a critical threshold in habitat quality is met. Crossing the threshold then results in rapid and complete extirpation. Future work should test and possibly expand on this hypothesis, which will likely include examining habitat requirements for pleurocerids, as basic toxicology and critical thermal limits are unknown for most species. Conservation efforts for pleurocerids should prepare for rapid extirpation of populations if habitat degradation occurs. However, high genetic diversity of remaining populations offers promise for management actions like captive propagation and reintroduction.

The Wichita Mountains pillsnail, Euchemotrema wichitorum (Branson, 1972), was originally described in 1972, when it was reported in two counties in southwest Oklahoma. All that was previously known about this species was from this one publication, which included no information on the species' ecology or distribution. The goal of this study was to investigate this snail's range, habitat use, and aspects of its natural history so that we may better understand and conserve this restricted-range endemic species. We located E. wichitorum in 68 of 114 survey sites across six of the sixteen counties surveyed in western Oklahoma and expanded the species' known range to approximately 4400 km² and a total of eight counties. General Additive Models of multiple microhabitat conditions explained up to 55.6% of the variation in live snail abundance and indicated that this species is positively associated with the number of available shelter logs and canopy density, while being negatively associated with the number of boulders at a site. Interestingly, E. wichitorum also had positive associations with fire; survey sites with recent fire evidence had significantly more live snails than did unburned sites, and charred logs harbored significantly more live snails than unburned logs. Fire may increase E. wichitorum abundance through a combination of increased soil pH and nutrient bioavailability (particularly of calcium) in charred or burned plant matter. However, surveys of recently burned sites also revealed that fire can lead to significant mortality in local snail populations when fire severity was high and sheltering logs burned. We also observed that E. wichitorum breeds readily and successfully in captivity. Given our findings, E. wichitorum's conservation outlook is promising.

It came as a surprise when I realized I have been working with freshwater bivalves for 50 years. This work has spanned the transition from analyses focused initially on shells, both modern and archaeological, to collaborations using an integrative approach. These 50 years have been broken into four separate periods, each focused on different aspects of freshwater bivalves: Graduate School, University of Tennessee, Knoxville [1973–1980]; Academy of Natural Sciences of Philadelphia [1980–1992]; Consultant [1992–1996]; and North Carolina Museum of Natural Sciences [1996–present]. Starting out, historical literature forced me to pay closer attention to basic taxonomy of the families Unionidae Rafinesque, 1820 and Margaritiferidae Henderson, 1929. When I began, freshwater bivalve research was focused primarily on shell morphology, and with time more comparative anatomy was added along with host fish and behavior to form an integrative approach. The next major shift was the use of starch gel electrophoresis, followed by Sanger sequencing of mitochondrial and nuclear DNA. The introduction of anchored hybrid enrichment using nuclear DNA with an integrative approach is the latest major step forward in the understanding of unionoid evolution. Intensive fieldwork and applying modern techniques in Asia and Southeast Asia has allowed the development of a more robust phylogenetic understanding of the Unionida Rafinesque, 1820. This is a tour of my development as a malacologist and the changing technology applied to taxonomy and systematics, data management, museum collections, and tools to understand this very imperiled group of animals.

Freshwater mussels are declining globally, experiencing both species losses and declines in the abundance of common species. Because mussels often have strong effects on ecosystem processes, these declines may lead to losses in mussel-generated ecosystem functions such as biofiltration and nutrient recycling and storage. Our understanding of mussel declines, the causes underlying declines, and the consequences of decline for species success and ecosystem health are limited by the lack of long-term data. We used long-term data from the Kiamichi River, Oklahoma to examine changes in abundance, species composition, and nitrogen and phosphorus nutrient recycling over a 30-year period that included two multi-year severe droughts. Overall mussel abundance declined during drought periods, and the relative abundance of drought-tolerant mussel species increased in proportion to drought sensitive species. Since 2016, mussel populations have begun to recover, and drought-sensitive species are increasing in relative abundance. Mussel declines led to large decreases in areal nitrogen and phosphorus excretion, however these rates are increasing as mussel abundance rebounds. Long-term monitoring is often essential for documenting the response of biodiversity and key ecological processes to environmental change.

The Wichita Mountains pillsnail, Euchemotrema wichitorum (Branson, 1972), was originally described in 1972, when it was reported in two counties in southwest Oklahoma. All that was previously known about this species was from this one publication, which included no information on the species' ecology or distribution. The goal of this study was to investigate this snail's range, habitat use, and aspects of its natural history so that we may better understand and conserve this restricted-range endemic species. We located E. wichitorum in 68 of 114 survey sites across six of the sixteen counties surveyed in western Oklahoma and expanded the species' known range to approximately 4400 km² and a total of eight counties. General Additive Models of multiple microhabitat conditions explained up to 55.6% of the variation in live snail abundance and indicated that this species is positively associated with the number of available shelter logs and canopy density, while being negatively associated with the number of boulders at a site. Interestingly, E. wichitorum also had positive associations with fire; survey sites with recent fire evidence had significantly more live snails than did unburned sites, and charred logs harbored significantly more live snails than unburned logs. Fire may increase E. wichitorum abundance through a combination of increased soil pH and nutrient bioavailability (particularly of calcium) in charred or burned plant matter. However, surveys of recently burned sites also revealed that fire can lead to significant mortality in local snail populations when fire severity was high and sheltering logs burned. We also observed that E. wichitorum breeds readily and successfully in captivity. Given our findings, E. wichitorum's conservation outlook is promising.