Geology topics

Roger J. Haro

Publications and source records attributed to Roger J. Haro.

10 recordsLinked to original sources

USGS2024

The where and why of large wood occurrence in the Upper Mississippi and Illinois Rivers

Large wood (LW) plays important geomorphic and ecological roles in rivers and is widely used as a restoration tool. Changes to floodplain land use and historical removal have altered wood dynamics in fluvial systems globally. We know little about the distribution and dynamics of LW in great rivers (approximately >10 5 km 2 ) like the Upper Mississippi and Illinois Rivers despite its ecosystem importance and use in restoration projects. We assessed LW occurrence data collected by the fisheries component of the Upper Mississippi River Restoration Program's Long Term Resource Monitoring element. We analysed 25 years of data collected across six reaches of the Upper Mississippi and Illinois Rivers that represented contrasting physiographic settings, and across four aquatic area types comprising gradients of hydrology, connectivity and geomorphology. We tested hypotheses on drivers of LW occurrence using generalised linear mixed effects models, where occurrence was predicted by reach- and local-scale environmental variables. Occurrence varied significantly across reaches and aquatic area types. In general, wood occurred more frequently upriver and in side channels compared to other aquatic areas. Large wood was most strongly predicted systemically by reach identity but not local-scale variables, underscoring the importance of broad-scale physiographic gradients in defining hydrogeomorphic processes. Floodplain forests and shoreline revetment were consistently important predictors across reaches. Our findings show that the spatial variability of LW occurrence reflects the physical variability of the Upper Mississippi and Illinois Rivers. They also reveal the value in using geomorphic classifications as frameworks for understanding physical processes like LW dynamics because of their ability to contextualise site-scale conditions. The baseline understanding of LW abundance across different hydrogeomorphic gradients and scales presented here can give insight into how to more effectively target restoration efforts in great rivers and contribute to a broader understanding of LW dynamics where such studies have been lacking.

Illinois, Iowa, Minnesota, Missouri, Wisconsin↗

USGS2023

Bridging the gap between mathematical biology and undergraduate education using applicable natural resource modeling

Mathematical biology is a wide field of study with many venues that undergraduate students can access through research. However, the topics of study for these students can be overwhelming, and many topics of study yield either only trivial results or abstract outcomes that are nonintuitive and diffcult to understand. We have used natural resource modeling, and more specifically, a partnership between academic researchers and federal scientists, as a bridge between undergraduate research and mathematical biology. Our collaboration is an interdisciplinary team that combines biology, mathematics, and statistics professors with government research scientists. As a team, we have mentored students through opportunities such as a Research Experiences for Undergraduates and other projects. In this article, we provide an overview of how we develop questions for undergraduates and outline two case studies, both of which resulted in peer reviewed journal articles. Last, we describe how we also transfer the results from these undergraduate projects to resource managers so the results may be applied to real world problems.

Letters in Biomathematics↗

USGS2021

Spatial and temporal dynamics of phytoplankton assemblages in the upper Mississippi River

Phytoplankton provide large quantities of organic carbon and biomolecules that support large river ecosystems. However, when certain groups become overabundant (e.g., cyanobacteria), they can pose a risk to human health and river biota. The purpose of this study was to examine the spatial and temporal dynamics of phytoplankton community composition within the upper Mississippi River. More specifically, we analyzed samples from main channel, impounded, and backwater areas of Navigation Pools 8 and 13 to examine lateral variability within each of these pools. We analyzed samples from the main channel of Pool 26 to examine longitudinal variation among Pools 8, 13, and 26. Phytoplankton and water quality samples were collected during the summer months of 2006–2009. The main channels of Pool 8 and Pool 13 were generally dominated by diatoms, although cyanobacteria were (at times) more abundant. The backwaters were generally dominated by cyanobacteria and typified by flagellated species (e.g., cryptomonads and euglenoids). The main channel of Pool 26 was always dominated by diatoms. Discharge influenced phytoplankton community composition. In Pool 26, taxonomic richness tended to increase with increasing discharge. There were no linear correlations between cyanobacteria total or proportional biovolume and nutrient concentrations, indicating that nutrient limitation was not common. Differences in phytoplankton communities were generally associated with physical factors such as discharge, turbidity, and residence time.

River Research and Applications↗

USGS2020

Using Markov chains to quantitatively assess movement patterns of invasive fishes impacted by a carbon dioxide barrier in outdoor ponds

Natural resource managers use barriers to deter the movement of aquatic invasive species. Research and development of new invasive species barriers is often evaluated in pond and field scales using high‐resolution telemetry data. Telemetry data sets can be a rich source of data about fish movement and behavior but can be difficult to analyze due to the size of these data sets as well as their irregular sampling intervals. Due to the challenges, most barrier studies only use summary endpoints, such as barrier passage counts or average (e.g., mean or median) fish distance from the barrier, to describe the data. To examine more fine‐scale fish movement patterns, we developed a first‐order Markov chain. We then used this model to help understand the impacts of a barrier on fish behavior. For our study system, we used data from a previous study examining how bighead and silver carp (two invasive fish species in the United States) responded to a carbon dioxide (CO 2 ) barrier in a pond.

Natural Resource Modeling↗

USGS2017

Spatial and temporal relationships between the invasive snail Bithynia tentaculata and submersed aquatic vegetation in Pool 8 of the Upper Mississippi River

Bithynia tentaculata is an invasive snail that was first reported in Lake Michigan in 1871 and has since spread throughout a number of freshwater systems of the USA. This invasion has been extremely problematic in the Upper Mississippi River as the snails serve as intermediate hosts for several trematode parasites that have been associated with waterfowl mortality in the region. This study was designed to assess the abundance and distribution of B . tentaculata relative to submersed aquatic vegetation as macrophytes provide important nesting and food resources for migrating waterfowl. Temporal changes in both vegetation and snail densities were compared between 2007 and 2015. Between these years, B . tentaculata densities have nearly quadrupled despite minor changes in vegetation abundance, distribution and composition. Understanding the spatial distribution of B . tentaculata in relation to other habitat features, including submersed vegetation, and quantifying any further changes in the abundance and distribution of B . tentaculata over time will be important for better identifying areas of risk for disease transmission to waterfowl.

River Research and Applications↗

USGS2016

Digestive physiology comparisons of aquatic invertebrates in the Upper Mississippi River Basin

Limited information is available on the composition of digestive enzymes present in unionid mussels and the zebra mussel, Dreissena polymorpha . Available information is nearly exclusive to species used for culture purposes. A commercially available enzyme assay kit was used to examine the effect of habitat within an ecosystem, season, and species on the activities of several digestive enzymes. We used Amblema plicata to represent native unionids, D. polymorpha , and also Hydropsyche orris as an outgroup to compare differences between mussels and other macroinvertebrates. The data indicated that neither location nor time affect the activities of the digestive enzymes tested; species was the only factor to affect the activity. Differences were found mostly between four enzymes: naphthol-AS-BI-phosphohydrolase, acid phosphatase, alkaline phosphatase, and β-galactosidase.

Upper Mississippi River Basin↗

USGS2015

Annual variation in recruitment of freshwater mussels and its relationship with river discharge

Vital rates such as mortality, growth, and recruitment are important tools to evaluate the status of threatened populations and identify their vulnerabilities, leading to enhanced conservation strategies. Native freshwater mussels are a guild of largely sedentary, filter-feeding bivalves currently facing worldwide declines. Lack of recruitment has been identified as a major threat to mussel populations. A mussel bed in the Upper Mississippi River was sampled for 5 years (2008–2012). A trend analysis showed a significant decline in the percentage of species with juvenile representatives. Species were grouped into equilibrium and periodic life history strategies to assess past recruitment. Residuals from catch-curve regressions quantified past year-class strength of both strategists and Amblema plicata over a 13-year period (1994–2006), and identified strong and weak year-classes. Generalized linear regression models containing July maximum discharge and April minimum discharge explained 64% of the variation in recruitment strength of A. plicata . The best model for the equilibrium strategists explained 86% of the variation in recruitment and contained the same variables as A. plicata, but also incorporated the 7-day minimum discharge. For the periodic strategists, the model containing the number of low-flow pulses and the mean duration of high-flow pulses explained 56% of the variation in recruitment strength. Understanding variation in recruitment dynamics of native mussels and its relationship to river discharge will be useful in designing effective management strategies to enhance conservation of this imperilled fauna.

Minnesota↗

USGS2015

Effects of elevated water temperature on physiological responses in adult freshwater mussels

Freshwater mussels (order Unionoida) face multiple environmental stressors, which pose serious conservation challenges to this diverse assemblage of aquatic invertebrates. Of these stressors, elevated water temperature from global climate change and other anthropogenic sources may be the most ubiquitous and could be placing many mussel populations dangerously close to their thermal maxima. We tested the hypothesis that elevated water temperatures (20, 25, 30 and 35 °C) adversely affected physiological responses in adults of four North American species of mussels ( Amblema plicata , Elliptio complanata, Fusconaia flava and Lampsilis cardium) in 21-d laboratory tests. Oxygen consumption rates were directly affected by temperature in E. complanata and L. cardium , and indirectly affected by temperature in A. plicata and F. flava . Rates of O 2 consumption were generally positively correlated with water temperature. Ammonium excretion rates varied significantly with temperature in E. complanata and generally increased with temperature. The amount of O 2 consumed relative to nitrogen excreted (O : N ratio), varied significantly with temperature in A. plicata , E. complanata and F. flava . The tissue condition index varied among temperatures and species. These data suggest that elevated temperatures can alter metabolic rates in native mussels and may decrease the amount of energy that is available for key biological processes, such as survival, growth and reproduction.

Freshwater Biology↗

USGS2015

Preliminary characterization of digestive enzymes in freshwater mussels

Resource managers lack an effective chemical tool to control the invasive zebra mussel Dreissena polymorpha . Zebra mussels clog water intakes for hydroelectric companies, harm unionid mussel species, and are believed to be a reservoir of avian botulism. Little is known about the digestive physiology of zebra mussels and unionid mussels. The enzymatic profile of the digestive glands of zebra mussels and native threeridge ( Amblema plicata ) and plain pocketbook mussels ( Lampsilis cardium ) are characterized using a commercial enzyme kit, api ZYM, and validated the kit with reagent-grade enzymes. A linear correlation was shown for only one of nineteen enzymes, tested between the api ZYM kit and a specific enzyme kit. Thus, the api ZYM kit should only be used to make general comparisons of enzyme presence and to observe trends in enzyme activities. Enzymatic trends were seen in the unionid mussel species, but not in zebra mussels sampled 32 days apart from the same location. Enzymatic classes, based on substrate, showed different trends, with proteolytic and phospholytic enzymes having the most change in relative enzyme activity.

Journal of Shellfish Research↗

USGS2013

The effects of elevated water temperature on native juvenile mussels: implications for climate change

Native freshwater mussels are a diverse but imperiled fauna and may be especially sensitive to increasing water temperatures because many species already may be living near their upper thermal limits. We tested the hypothesis that elevated water temperatures (20, 25, 30, and 35°C) adversely affected the survival and physiology of 2-mo-old juvenile mussels ( Lampsilis abrupta , Lampsilis siliquoidea , and Megalonaias nervosa ) in 28-d laboratory experiments. The 28-d LT50s (lethal temperature affecting 50% of the population) ranged from 25.3 to 30.3°C across species, and were lowest for L. abrupta and L. siliquoidea . Heart rate of L. siliquoidea was not affected by temperature, but heart rate declined at higher temperatures in L. abrupta and M. nervosa . However, for both of these species, heart rate also declined steadily during the experiment and a strong temperature × time interaction was detected. Juvenile growth was low for all species in all treatments and did not respond directly to temperature, but growth of some species responded to a temperature × time interaction. Responses to thermal stress differed among species, but potential laboratory artifacts may limit applicability of these results to real-world situations. Environmentally relevant estimates of upper thermal tolerances in native mussels are urgently needed to assess the extent of assemblage changes that can be expected in response to global climate change.

Freshwater Science↗