Fish community response to in-channel woody debris in a channelized river system

Additions of large wood (LW) have become a go-to technique for recovering altered river ecosystems. However, successful applications of this technique are generally limited to unchannelized rivers and headwater streams. Channelization of rivers, that is, engineering river channels to reduce recruitment and retention of in-channel structure, may, by definition, limit success of this restoration technique. Moreover, sufficient time has passed (a century or more) since initial channelization of many large rivers that portions of the fish community associated with LW may have become extirpated. Thus, the maxim that LW leads to a positive fish community response may not hold true. We examined fish community associations in habitats with and without LW in the channelized Missouri River to gain an understanding of the role of LW in large, channelized rivers. There were some differences between habitats with wood present compared to those without, but the differences were not evident once year, season and channel modifications intended to create aquatic habitat were taken into account. We assert that careful planning is necessary to ensure that additions of LW in channelized rivers are made to appropriate locations such that it will be retained in-channel for use as fish habitat and that LW-associated species are found in the system

A Synopsis of Global Mapping of Freshwater Habitats and Biodiversity: Implications for Conservation

Accurately mapping freshwater habitats and biodiversity at high-resolutions across the globe is essential for assessing the vulnerability and threats to freshwater organisms and prioritizing conservation efforts. Since the 2000s, extensive efforts have been devoted to mapping global freshwater habitats (rivers, lakes, and wetlands), the spatial representation of which has changed dramatically over time with new geospatial data products and improved remote sensing technologies. Some of these mapping efforts, however, are still coarse representations of actual conditions. Likewise, the resolution and scope of global freshwater biodiversity compilation efforts have also increased, but are yet to mirror the spatial resolution and fidelity of mapped freshwater environments. In our synopsis, we find that efforts to map freshwater habitats have been conducted independently of those for freshwater biodiversity; subsequently, there is little congruence in the spatial representation and resolution of the two efforts. We suggest that global species distribution models are needed to fill this information gap; however, limiting data on habitat characteristics at scales that complement freshwater habitats has prohibited global high-resolution biogeography efforts. Emerging research trends, such as mapping habitat alteration in freshwater ecosystems and trait biogeography, show great promise in mechanistically linking global anthropogenic stressors to freshwater biodiversity decline and extinction risk

Session B2: A Quantitative, Traits-based Approach for Choosing and Prioritizing Study Species for Evaluating the Impacts of Turbine Passage

Abstract: The choice of study species when conducting environmental assessments of hydropower facilities is of great importance from a licensing and policy perspective. Power analyses are commonly used to provide quantitative backing for the numbers of study organisms and trials used, but there is not frequent use of quantitative methods for choosing appropriate study species. Species choice can be especially important when measuring the impacts of ecosystem alteration, such as in a hydropower system, when study species must be chosen that are both sensitive to the alteration and of sufficient abundance for study. In this study, we step through two examples using a combination of GIS, a fish traits database, and multivariate statistical analyses to present a quantitative, traits-based approach for designating study species. In our first example, we present a case study where we select broadly-representative fish species for understanding the effects of turbine passage on fishes based on traits that suggest sensitivity to turbine passage. In our second example, we build off of our first example and present a framework for selecting a surrogate species for an endangered species. We suggest that our traits-based framework can provide quantitative backing and added justification to selection of study species while also delineating the expanded inference space of study results

MULTI-SCALE PERSPECTIVES ON PADDLEFISH POPULATIONS: IMPLICATIONS FOR SPECIES CONSERVATION AND MANAGEMENT

The Order of fishes containing paddlefish and sturgeon has been named the most endangered group of organisms on the planet by the International Union of Conservation of Nature (IUCN). Population trajectories of paddlefish, whose native range is entirely encompassed within the United States of America, are currently unknown, although the IUCN has considered them to have a high extinction risk in the wild. The declaration of the vulnerability of paddlefish to extinction, coupled with the global plight of other sturgeon species create urgency to establish population and species-level population trajectories. Moreover, this declaration creates a great need for swift management and conservation plans to prevent further species decline and loss. In this dissertation, I use multi-scale analyses ranging from local (Nebraska and South Dakota) to nearly range-wide (all states except Montana and North Dakota) to examine paddlefish population dynamics, and movement

Metazoan Parasites of Young-of-the-Year Paddlefish from Lewis and Clark Lake, Nebraska, U.S.A.

Young-of-the-year paddlefish, Polyodon spathula (Polyodontidae), from Lewis and Clark Lake, an impoundment of the Missouri River in Nebraska, U.S.A., were surveyed for parasites. In 2001 and 2002, 28 and 48 fish were examined for parasites, respectively. Only the nematode Rhabdochona decaturensis infected fish collected in 2001, but 8 parasite taxa (R. decaturensis, Spinitectus sp., Camallanus sp., Contracaecum sp., Marsipometra sp., Diclybothrium hamulatum, Ergasilus elongatus, and 1 unidentified leech) infected fish collected in 2002. Rhabdochona decaturensis was the most common parasite, occurring in 21.4% of fish in 2001 and 79.2% of fish in 2002. Prevalence of other parasite species infecting fish from 2002 was 33% or less. The helminth community of young-of-the-year paddlefish in both years was dominated by nematodes. This study is the first report on parasites of young-of-the-year paddlefish and documents a new host record for R. decaturensis

Swimways: Protecting Paddlefish through Movement-centered Management

Attempts to mitigate lack of formal interjurisdictional paddlefish management have been made in the United States through the Mississippi River Interstate Cooperative Resource Association (MICRA). We used 1988–2009 data from the MICRA paddlefish (Polyodon spathula) stock assessment database—a database containing mark–recapture and biometric information on more than 30,000 individually marked wild paddlefish and more than 2 million hatchery-origin paddlefish—to estimate survival and movement across large and potentially biologically relevant spatial scales. Paddlefish frequently moved between political jurisdictions with differing conservation strategies and harvest regulations and showed differences in survival parameter estimates throughout their range. We argue that the degree of interjursidictional movements, spatially variant survival rates, and conservation concerns associated with paddlefish necessitate more cohesive interjurisdictional management. Based on criteria used to establish flyways for migratory bird management, we offer swimways as a potential spatial configuration for biologically relevant management units. Corredores de nado: protección del pez espátula mediante manejo centrado en su movimiento Resumen: La Asociación Interestatal de Recursos Cooperativos del Río Mississippi (AIRCRM) ha hecho intentos para mitigar la falta de manejo inter-jurisdiccional del pez espátula en los EEUU. Se utilizó información sobre evaluación de los stocks de pez espátula (Polyodon spathula) contenida en la base de datos de AIRCRM para el periodo 1995-2009, la cual contiene información biométrica y de marca-recaptura de \u3e30,000 peces espátula marcados individualmente y de \u3e2 milliones de especímenes provenientes de cultivo, con el fin de estimar la supervivencia y movimiento a escalas espaciales amplias y con potencial biológico relevante. El pez espátula frecuentemente se mueve entre jurisdicciones políticas que difieren en cuanto a sus estrategias de conservación y regulaciones de captura, y muestra diferencias en sus parámetros de supervivencia a lo largo de su ámbito geográfico. Se argumenta que el grado de movimiento inter-jurisdiccional, el cambio espacial en las tasas de supervivencia y las preocupaciones de conservación asociadas a esta especie, demandan de un manejo interjurisdiccional con mayor cohesión. Sobre la base de criterios usados para establecer corredores de vuelo para el manejo de aves migratorias, aquí se muestra un corredor de nado como una potencial configuración espacial para unidades de manejo biológicamente-relevantes

Fish community response to in-channel woody debris in a channelized river system

Additions of large wood (LW) have become a go-to technique for recovering altered river ecosystems. However, successful applications of this technique are generally limited to unchannelized rivers and headwater streams. Channelization of rivers, that is, engineering river channels to reduce recruitment and retention of in-channel structure, may, by definition, limit success of this restoration technique. Moreover, sufficient time has passed (a century or more) since initial channelization of many large rivers that portions of the fish community associated with LW may have become extirpated. Thus, the maxim that LW leads to a positive fish community response may not hold true. We examined fish community associations in habitats with and without LW in the channelized Missouri River to gain an understanding of the role of LW in large, channelized rivers. There were some differences between habitats with wood present compared to those without, but the differences were not evident once year, season and channel modifications intended to create aquatic habitat were taken into account. We assert that careful planning is necessary to ensure that additions of LW in channelized rivers are made to appropriate locations such that it will be retained in-channel for use as fish habitat and that LW-associated species are found in the system

Understanding the Environmental Study Life Cycle in the United States Hydropower Licensing and Federal Authorization Process

We analyzed United States Federal Energy Regulatory Commission (FERC) documents prepared for 29 recently licensed hydropower projects and created two novel datasets to improve understanding of the environmental study life cycle, defined here as the process that begins with an environmental study being requested by a hydropower stakeholder or regulator, and ends with the study either being rejected or approved/conducted. Our two datasets consisted of summaries of information taken from (1), study determination letters prepared by FERC for 23 projects that were using the integrated licensing process, and (2), environmental study submittals and issuances tracked and attributed to seven projects using the FERC record. Our objective was to use the two resulting environmental life cycle datasets to understand which types of environmental studies are approved, rejected, and implemented during FERC licensing, and how consistently those types of studies are required across multiple hydropower projects. We matched the requested studies to a set of 61 river function indicators in eight categories and found that studies related to the category of biota and biodiversity were requested most often across all 29 projects. Within that category, studies related to river function indicators of presence, absence, detection of species and habitat/critical habitat were the most important to stakeholders, based on the relative number of studies requested. The study approval, rejection, and request rates were similar within each dataset, although the 23 projects with study determination letters had many rejected studies, whereas the dataset created from the seven projects had very few rejected studies

Fish community response to in-channel woody debris in a channelized river system

Additions of large wood (LW) have become a go-to technique for recovering altered river ecosystems. However, successful applications of this technique are generally limited to unchannelized rivers and headwater streams. Channelization of rivers, that is, engineering river channels to reduce recruitment and retention of in-channel structure, may, by definition, limit success of this restoration technique. Moreover, sufficient time has passed (a century or more) since initial channelization of many large rivers that portions of the fish community associated with LW may have become extirpated. Thus, the maxim that LW leads to a positive fish community response may not hold true. We examined fish community associations in habitats with and without LW in the channelized Missouri River to gain an understanding of the role of LW in large, channelized rivers. There were some differences between habitats with wood present compared to those without, but the differences were not evident once year, season and channel modifications intended to create aquatic habitat were taken into account. We assert that careful planning is necessary to ensure that additions of LW in channelized rivers are made to appropriate locations such that it will be retained in-channel for use as fish habitat and that LW-associated species are found in the system