Endemic Whitefishes of Bear Lake, Utah-Idaho: A Problem in Systematics

The systematic status of whitefishes endemic to Bear lake, Utah-Idaho, has remained tenuous since their original description. Clarification of this problem was the major objective of the present study. The general approach was an integrated one, including examination of morphological, biochemical and ecological parameters; artificial hybrids were produced and compared with questionable groups from the natural population. Morphological analysis revealed five forms of Bear Lake whitefishes Prosopium gemmiferum (Bonneville cisco) and P. abyssicola (Bear lake whitefish) were well differentiated from other forms and were treated as originally described. The P. spilonotus (Bonneville whitefish) group, however, was found to be made up of two morphologically distinct populations, referred to as P. spilonotus (small form) and P. spilonotus (large form). The fifth group referred to as P. gemmiferum-like (represented by only five specimens) was intermediate between P. gemmiferum and either P. spilonotus (small form) or P. abyssicola and was hypothesized to be of hybrid origin. Multiple discriminant function analysis of the four major groups and P. williamsoni (mountain whitefish) (Logan River) confirmed morphological differentiation between forms. Hybridization studies among Bear Lake Prosopium and P. williamsoni involved 50 homo - and heterospecific crosses (17 combinations). Of 12 experimental hybrid combinations attempted, all those involving simultaneously ripe specimens of two groups (five crosses) showed maximum fertilization success equalling that of pure crosses. no evidence that interspecific crosses are less successful than conspecific crosses, with the possible exception of P. williamsoni ♀ x P. gemmiferum ♂ (W x G), was obtained. Culture methods were developed and morphological comparisons made. Origin of P. gemmiferum-like hybrids in the lake population was not consistently explained by morphological comparison of known P. spilonotus (small form) ♀ x P. gemmiferum ♂ (S x G) hybrids or P abyssicola ♀ x P. gemmiferum ♂ (A x G) hybrids; morphometric characters were more like S x G hybrids while meristic characters were more closely associated with A x G hybrids. Based on evidence available, no definitive statement could be made concerning the origin of P. gemmiferum-like hybrids except that they are hybrids among combinations of P. gemmiferum and either P. spilonotus (small form) or P. abyssicola. no known hybrid explained the origin of either group of P. spilonotus. Electrophoretic analysis of general proteins and several enzyme systems of various tissues showed much similarity among Bear Lake Prosopium; only P. williamsoni was totally unique. Biochemical evidence did not support or refute separate consideration of the two forms of P. spilonotus but did establish that neither were phenotypic variants of P. williamsoni. Ecological characteristics of Bear Lake Prosopium revealed important distinctions between forms. Growth histories of P. abyssicola, P. spilonotus (small form) and P. spilonotus (large form) showed pronounced differences. Distinct differences in growth and in age and size at maturity of forms of P.. spilonotus provided further evidence supporting their separate consideration. Spatial overlap of spawning activities was marked between forms of P. spilonotus and P. gemmiferum; P. abyssicola was well separated spatially. Temporally, slight overlap was observed between ripe females of one group and ripe males of the succeeding group to spawn. the only observation of the simultaneous occurrence of ripe females of two forms was between P. spilonotus (large form) and P. spilonotus (small form); in this instance, the number of ripe females of each form was extremely small. No evidence of mass hybridization among forms was observed. A combination of temporal, spatial and ethological premating isolating mechanisms are thought to be important in reproductive isolation of Bear lake whitefishes while postmating mechanisms are nonfunctional with the possible exception of hybrid sterility. Morphological and ecological analyses, combined with results of experimental hybridization, provided abundant evidence supporting separate recognition of the two forms of P,. spilonotus. Karyotypes of P. gemmiferum, P abyssicola and P. spilonotus (small form) have been determined (Booke, 1974) and are unique for each species. If the karyotype of P. spilonotus (large form) is found to also be unique, there should be no question that the two forms of P. spilonotus represent distinct species. Final clarification of the taxanomic status of these forms will not come until karyotype data is available; however, based upon present evidence, tentative recognition of a new species is recommended

The impacts of agricultural chemicals and temperature on the physiological stress response in fish

ix, 137 leaves : ill. ; 29 cm.Fish are exposed to multiple stressors in their environment. The interactive effects of pesticide exposure and increased temperature on the physiological stress response were investigated in a comparative field study with cold-water (whitefish, Prosopium williamsoni) and cool-water (sucker, Catostomus) fish from the Oldman River, Alberta, Canada, and in a laboratory study with rainbow trout, Oncorhynchus mykiss. Physiogical stress indicators were measured, and exposure to pesticides was estimated using acetylcholinesterase (AChE) inhibition. Species-specific differences in AChE activities and responses of the physiological stress axis were detected in whitefish and suckers, suggesting that whitefish are a more sensitive species to temperature and pesticide stress. In vivo Dimethoate exposure inhibited AChE activity in various tissues and disrupted the physiogical stress response. Commercial Dimethoate, in vitro, caused a decrease in viability and cortisol secretion while pure grade Dimethoate did not. The results from this study can be used in predictions of fish vulnerability to stress

Response of riparian cottonwoods to experimental flows along the lower Bridge River, British Columbia

xii, 89 leaves : ill. (some col.) ; 29 cmThe Bridge River drains the east slope of the Coast Mountain Range and is a major tributary of the Fraser River in southwestern British Columbia. The lower Bridge River has been regulated since the installation of Terzaghi Dam in 1948, which left a section of dry riverbed for an interval of 52 years prior to 2000. An out-of-court settlement between BC Hydro and Federal and Provincial Fisheries regulatory agencies resulted in the required experimental discharge of 3 m3/s below Terzaghi Dam in 2000. This study investigated growth of black cottonwood (Populus trichocarpa) trees in response to the experimental discharges. Mature trees did not show a significant response in radial trunk growth or branch elongation. In contrast, the juvenile trees displayed an increased growth response, and the successful establishment of saplings provided a dramatic response to the new flow regime. Thus, I conclude that cottonwoods have benefited from the experimental flow regime of the lower Bridge River

Mitigating human impacts including climate change on proliferative kidney disease in salmonids of running waters.

Over the last two decades, an increasing number of reports have identified a decline in salmonid populations, possibly linked to infection with the parasite Tetracapsuloides bryosalmonae and the corresponding disease, that is, proliferative kidney disease (PKD). The life cycle of this myxozoan parasite includes sessile bryozoan species as invertebrate host, which facilitates the distribution of the parasite in running waters. As the disease outcome is temperature dependent, the impact of the disease on salmonid populations is increasing with global warming due to climate change. The goal of this review is to provide a detailed overview of measures to mitigate the effects of PKD on salmonid populations. It first summarizes the parasite life cycle, temperature-driven disease dynamics and new immunological and molecular research into disease resistance and, based on this, discusses management possibilities. Sophisticated management actions focusing on local adaptation of salmonid populations, restoration of the riverine ecosystem and keeping water temperatures cool are necessary to reduce the negative effects of PKD. Such actions include temporary stocking with PKD-resistant salmonids, as this may assist in conserving current populations that fail to reproduce

Effects of hydropeaking and refuge configurations on the behaviour of cyprinids in experimental flume conditions

Doutoramento em Restauro e Gestão Fluviais (FLUVIO) - Instituto Superior de Agronomia / Faculdade de Arquitetura / Instituto Superior TécnicoFlow regime regulates the ecological integrity of river ecosystems, shaping the structure and function of fish communities. The discharge fluctuations in hydropower plants in response to peak electricity demand (i.e. hydropeaking) result in rapid flow changes in tailwaters. The continued hydropower operations produced morphological, hydraulic and water quality alterations, affecting downstream fish. Fish responses to hydropeaking range from organism to life-cycle event changes. It is challenging to establish a cause-effect relationship between flow variability and a fish response, and to propose adequate mitigation measures. In the first part of this research, a literature review was conducted to find evidence for that relationship. The review showed that flow variability can represent a stressor for fish. However, it remained unclear if the responses were maladaptive. In the second part, the effects of hydropeaking and refuges were assessed for L. bocagei in an indoor flume. A multidisciplinary approach was adopted, where fish responses were combined with a hydraulic characterization. Peak events were tested by manipulating magnitude, peak frequency and duration. The refuges were lateral (meandering and one-sided deflectors) and instream (triangular pyramids and v-shaped) structures, tested along three experimental campaigns. Glucose and lactate (secondary responses), and movement behaviour (whole-animal responses) were assessed. The flow field and fluid-body interactions were characterized by using acoustic Doppler velocimetry and an artificial lateral line probe respectively. The movement patterns of L. bocagei were diverse and not always proportional to the severity of the flow event. Lateral deflectors and v-shaped structures provided low velocity areas. However, the created flow complexity represented an additional constraint for fish, reducing their ability to find them. Flow thresholds that represented the resting state of L. bocagei were identified, and specific movement patterns were related with hydrodynamic changes. Practical recommendations for operational schemes and for the implementation of mitigation measures to hydropeaking were proposedN/

Population Structure in the Roundtail Chub (Gila robusta Complex) of the Gila River Basin as Determined by Microsatellites: Evolutionary and Conservation Implications

abstract: Ten microsatellite loci were characterized for 34 locations from roundtail chub (Gila robusta complex) to better resolve patterns of genetic variation among local populations in the lower Colorado River basin. This group has had a complex taxonomic history and previous molecular analyses failed to identify species diagnostic molecular markers. Our results supported previous molecular studies based on allozymes and DNA sequences, which found that most genetic variance was explained by differences among local populations. Samples from most localities were so divergent species-level diagnostic markers were not found. Some geographic samples were discordant with current taxonomy due to admixture or misidentification; therefore, additional morphological studies are necessary. Differences in spatial genetic structure were consistent with differences in connectivity of stream habitats, with the typically mainstem species, G. robusta, exhibiting greater genetic connectedness within the Gila River drainage. No species exhibited strong isolation by distance over the entire stream network, but the two species typically found in headwaters, G. nigra and G. intermedia, exhibited greater than expected genetic similarity between geographically proximate populations, and usually clustered with individuals from the same geographic location and/or sub-basin. These results highlight the significance of microevolutionary processes and importance of maintaining local populations to maximize evolutionary potential for this complex. Augmentation stocking as a conservation management strategy should only occur under extreme circumstances, and potential source populations should be geographically proximate stocks of the same species, especially for the headwater forms.The article is published at http://journals.plos.org/plosone/article?id=10.1371/journal.pone.013983

Spatiotemporal Distribution of Ceratonova shasta and its Genotypes in the Deschutes River Basin

The waterborne, myxozoan parasite Ceratonova shasta is endemic to the Pacific Northwest and can be lethal to its secondary salmonid host, including the culturally, economically, and recreationally important spring Chinook salmon (Oncorhynchus tshawytscha) of the Deschutes River, OR. Previously described genotypes of C. shasta exhibit specificity with their salmonid hosts. As a first step toward managing C. shasta in the Deschutes River, the spatial and temporal distribution of this pathogen and its genotypes needed to be described. Historically, parasite prevalence was quantified by fish mortalities from sentinel surveys at 2-3 sites at different times of year on the Deschutes River mainstem. Herein I used water sampling and qPCR to provide a method for determining detailed spatiotemporal information about waterborne parasite distribution both within (Chapter 4) and between (Chapter 2) sites of the river. Ceratonova shasta was detected throughout the upper and lower Deschutes River basins at variable positions within sites. Though there was variation between years (average spores/L 81.0, 11.2, 46.4 in 2016, 2017, 2018, respectively), C. shasta density was 1.5x higher between rkm 48-82 than the average of all other spatial survey sites. Additionally, sites such as DRR (rkm 116) and DWS (rkm 155) had higher than average C. shasta abundance for 63% (5/8) of the surveys. Only low densities (< 1.5 spores/L) of C. shasta were detected in the Warm Springs River, an important spawning tributary for spring Chinook salmon. Using linear mixed effect models (LMEMs), parasite abundance at temporal monitoring sites in the lower basin appears to be positively related to water temperature but has an inverse relationship with river discharge, supporting previously described observations in the Klamath River, CA/OR. The upper Deschutes basin exhibited different temporal dynamics than the lower basin with variable peaks in July or August. In Chapter 3, I determined that C. shasta genotype I dominated the lower Deschutes River basin below Round Butte Dam, type II was the main genotype present in the upper basin above Round Butte Dam, and type O was detected throughout the system at lower proportions than I or II. Type II was also identified in the lower basin, but only during August. Genotype I was not detected in the upper basin, despite the passage of spring Chinook salmon above the Round Butte Dam for over a decade. I identified that peak C. shasta abundance and the Chinook salmon host-specific genotype I coincide with spring Chinook adult returns and juvenile spring Chinook releases, although spring Chinook salmon are one of the least abundant salmonid species. Genotype O is associated with Steelhead trout, the most abundant species of salmonid in the upper and lower basins of the Deschutes River. However, although genotype O was found throughout both basins, supporting earlier hypotheses that the spatial and temporal patterns of genotypes may be explained by host distribution, our hypothesis that the density of genotypes in water samples would be related to salmonid abundance was not supported. Despite the high densities of C. shasta genotype I in water samples of the lower Deschutes, only mild to moderate pathology was observed in juvenile and adult tissue samples (Appendix A). Although C. shasta was the most common pathogen that we detected and caused enteronecrosis, pathology associated with Renibacterium salmoninarum and Parvicapsula minibicornis was observed also in juvenile and adult spring Chinook salmon, respectively. Therefore, while C. shasta may be contributing to low survival of spring Chinook salmon in the lower Deschutes River basin, it does not appear to be the sole cause

2019 Annual Meeting

The Montana Academy of Sciences (MAS) was incorporated on the 20th day of March, 1961, as a non-profit, educational organization. The objectives of the Montana Academy of Sciences are to encourage interest and participation in the sciences and to promote public understanding of science and its contribution to society. The Academy accomplishes its objectives by conducting meetings of those interested in sciences and the education of scientists, by publishing contributions to scientific knowledge, by supporting research, by making awards to recognize accomplishments in science, by administering gifts and contributions to accomplish these aims, by assigning and cooperating with affiliated and other organizations with similar objectives, and by engaging in such other activities as deemed necessary to accomplish its objectives. We held our 2019 Annual Meeting at Montana Tech in Butte, MT. on April 5 and 6. Over 90 registrants participated, viewing 24 contributed oral presentations and 27 poster presentations over the day and a half meeting. We present the abstracts from our meeting here so that the readers of the Intermountain Journal of Sciences can see the quality and types of science supported by MAS