Jennifer Bayer - Academia.edu (original) (raw)

Papers by Jennifer Bayer

Eos, Transactions American Geophysical Union, May 9, 2017

Developing Enterprise Tools and Capacities for Large-Scale Natural Resource Monitoring; Fort Coll... more Developing Enterprise Tools and Capacities for Large-Scale Natural Resource Monitoring; Fort Collins, Colorado, 12–13 October 2016

Fact sheet /, 2018

Natural resource managers who oversee the Nation's resources require data to support informed dec... more Natural resource managers who oversee the Nation's resources require data to support informed decision-making at a variety of spatial and temporal scales that often cross typical jurisdictional boundaries such as states, agency regions, and watersheds. These data come from multiple agencies, programs, and sources, often with their own methods and standards for data collection and organization. Coordinating standards and methods is often prohibitively time-intensive and expensive. MonitoringResources.org offers a suite of tools and resources that support coordination of monitoring efforts, cost-effective planning, and sharing of knowledge among organizations. The website was developed by the Pacific Northwest Aquatic Monitoring Partnershipa collaboration of Federal, state, tribal, local, and private monitoring programs-and the U.S. Geological Survey (USGS), with funding from the Bonneville Power Administration and USGS. It is a key component of a coordinated monitoring and information network. Screen shot of the Monitoring Explorer tool showing program sampling sites from six monitoring and assessment programs operating within the Pacific Northwest.

The use of data generated from long term monitoring efforts necessitates accurate authoritative s... more The use of data generated from long term monitoring efforts necessitates accurate authoritative source citations of those data to ensure credit for data collected, and accountability for the data quality to enable repeated retrieval of a given data set. Data sets used in published reports and articles are increasingly being considered objects that are required to be published and cited. Aggregating data into

ABSTRACT We documented changes in plasma levels of estradiol 17-beta (E2), progesterone (P), 15al... more ABSTRACT We documented changes in plasma levels of estradiol 17-beta (E2), progesterone (P), 15alpha-hydroxytestosterone (15alpha-T), thyroxine (T4), triiodothyronine (T3), protein, triglycerides (TGs), and glucose in adult Pacific lampreys (Entosphenus tridentatus) held in the laboratory in two different years. Levels of E2 in both sexes ranged from 0.5 to 2 ng/mL from September to March, peaked in late April (2-4 ng/mL), and decreased in May, with levels higher in males than in females. Levels of P were low from September through April, but then increased substantially during May (2-4 ng/mL), with levels again highest in males. Levels of 15alpha-T in males were around 0.75 ng/mL through the winter before exceeding 1 ng/mL in April and decreasing thereafter, whereas females showed a gradual increase from 0.25 ng/mL in November to 0.5 ng/mL in April before decreasing. Thyroxine concentrations differed between fish in each year, with most having levels ranging from 0.75 to 2.5 ng/mL in the fall and winter, and only fish in 2003 showing distinct peaks (3-4 ng/mL) in early April or May. Plasma T3 was undetectable from November through mid-March before surging dramatically in April (ca. 150 ng/mL) and decreasing thereafter. Levels of protein, TGs, and glucose decreased or were stable during the fall and winter with TGs and glucose surging in late April to early May for some fish. Our study is the first to document long-term physiological changes in Pacific lampreys during overwintering and sexual maturation and increases our understanding of the life history of this unique fish.

General and Comparative Endocrinology, Apr 1, 2006

Recent studies have provided evidence that 15-hydroxytestosterone (15-T) and 15-hydroxyprogestero... more Recent studies have provided evidence that 15-hydroxytestosterone (15-T) and 15-hydroxyprogesterone (15-P) are produced in vitro and in vivo in adult male sea lampreys (Petromyzon marinus), and that circulatory levels increase in response to injections with gonadotropin-releasing hormone (GnRH). We examined four species from the Petromyzontidae family including silver lampreys (Ichthyomyzon unicuspis), chestnut lampreys (I. castaneus), American brook lampreys (Lethenteron appendix), and PaciWc lampreys (Entosphenus tridentatus) to determine if these unusual steroids were unique to sea lampreys or a common feature in lamprey species. In vitro production was examined through incubations of testis with tritiated precursors, and 15-T and 15-P production was conWrmed in all species through co-elution with standards on both high performance liquid chromatography (HPLC) and thin layer chromatography. In vivo production was proven by demonstrating that HPLC-fractionated plasma had peaks of immunoreactive 15-T and 15-P that co-eluted with standards through using previously developed radioimmunoassays for 15-T and 15-P. The possible functionality of 15-T and 15-P was further examined in silver and PaciWc lampreys by investigating the eVect of injection of either type of lamprey GnRH on plasma concentrations of 15-T and 15-P. Injections with exogenous GnRH did not aVect circulatory levels of either steroid in silver lampreys, and only GnRH III elicited higher levels of both steroids in PaciWc lampreys. The 15-hydroxylase enzyme(s) for steroids appeared to present in adult males of all species examined, but the question of whether 15-hydroxylated steroids are functional in these lamprey species, and the signiWcance of the 15-hydroxyl group, requires further research.

Transactions of The American Fisheries Society, 2009

Pacific lampreys Lampetra tridentata are in decline throughout much of their historical range in ... more Pacific lampreys Lampetra tridentata are in decline throughout much of their historical range in the Columbia River basin. In support of restoration efforts, we tested whether larval and adult lamprey bile acids serve as migratory and spawning pheromones in adult Pacific lampreys, as they do in sea lampreys Petromyzon marinus. The olfactory sensitivity of adult Pacific lampreys to lamprey bile acids was measured by electro‐olfactogram recording from the time of their capture in the spring until their spawning in June of the following year. As controls, we tested L‐arginine and a non‐lamprey bile acid, taurolithocholic acid 3‐sulfate (TLS). Migrating adult Pacific lampreys were highly sensitive to petromyzonol sulfate (a component of the sea lamprey migratory pheromone) and 3‐keto petromyzonol sulfate (a component of the sea lamprey sex pheromone) when first captured. This sensitivity persisted throughout their long migratory and overwinter holding period before declining to nearly unmeasurable levels by the time of spawning. The absolute magnitudes of adult Pacific lamprey responses to lamprey bile acids were smaller than those of the sea lamprey, and unlike the sea lamprey, the Pacific lamprey did not appear to detect TLS. No sexual dimorphism was noted in olfactory sensitivity. Thus, Pacific lampreys are broadly similar to sea lampreys in showing sensitivity to the major lamprey bile acids but apparently differ in having a longer period of sensitivity to those acids. The potential utility of bile acid‐like pheromones in the restoration of Pacific lampreys warrants their further investigation in this species.

Journal of Morphology, 2006

The effectiveness of morphometric and meristic characteristics for taxonomic discrimination of La... more The effectiveness of morphometric and meristic characteristics for taxonomic discrimination of Lampetra tridentata and L. richardsoni (Petromyzonidae) during embryological, prolarval, and early larval stages (i.e., age class 1) were examined. Mean chorion diameter increased with time from fertilization to hatch and was significantly greater for L. tridentata than for L. richardsoni at 1, 8, and 15 days postfertilization. Lampetra tridentata larvae had significantly more trunk myomeres than L. richardsoni; however, trunk myomere numbers were highly variable within species and deviated from previously published data. Multivariate examinations of prolarval and larval L. tridentata (7.2-11.0 mm; standard length) and L. richardsoni (6.6-10.8 mm) were conducted based on standard length and truss element lengths established from eight homologous landmarks. Principal components analysis indicated allometric relationships among the morphometric characteristics examined. Changes in body shape were indicated by groupings of morphometric characteristics associated with body regions (e.g., oral hood, branchial region, trunk region, and tail region). Discriminant function analysis using morphometric characteristics was successful in classifying a large proportion (Ͼ94.7%) of the lampreys sampled.

North American Journal of Fisheries Management, Feb 1, 2007

We examined the survival, tag retention, and growth of Pacific lamprey Lampetra tridentata larvae... more We examined the survival, tag retention, and growth of Pacific lamprey Lampetra tridentata larvae and macrophthalmia marked with standard‐length decimal coded wire tags and exposed to two levels of handling stress. The survival of marked individuals did not differ from that of unmarked individuals at either life stage for the duration of the experiment (56 d). Tag retention was 100% for all treatment combinations except larvae that were handled frequently (93 ± 3%). The majority of tag loss occurred within 28 d of marking, and no tag loss was observed between 42 and 56 d after marking. The individuals that lost tags were among the smallest marked, and a logistic regression model indicated a relationship between larva length and the probability of tag retention. Size of larvae (length and mass) and macrophthalmia (mass) decreased over the duration of the experiment; however, changes in size were systematic among treatment combinations, indicating that factors other than tagging or handling affected growth. These data indicate that coded wire tags may be useful for field‐based studies of Pacific lamprey larvae and macrophthalmia.

Transactions of The American Fisheries Society, May 1, 2003

Populations of Pacific lamprey Lampetra tridentata have declined in the Columbia River basin. One... more Populations of Pacific lamprey Lampetra tridentata have declined in the Columbia River basin. One factor that may have contributed to this reduction in population size is an excessive use of energy by adult lampreys as they negotiate fishways at dams during spawning migrations. To gain an understanding of the performance capacity of Pacific lampreys, we estimated the critical swimming speed (U crit) and documented physiological responses of radio-tagged and untagged adult lampreys exercised to exhaustion. The mean (ϮSD) U crit of untagged lampreys was 86.2 Ϯ 7.5 cm/s at 15ЊC, whereas the U crit for radio-tagged lampreys was 81.5 Ϯ 7.0 cm/s, a speed that was significantly lower than that of untagged fish. The physiological responses of tagged and untagged lampreys subjected to exhaustive exercise included decreases in blood pH of 0.3-0.5 units, a 40% decrease in muscle glycogen levels, a 22% increase in hematocrit for untagged fish only, and a 4-to 5-fold increase in muscle and a 40-to 100-fold increase in plasma lactate concentrations. These physiological changes were significant compared with resting control fish and usually returned to resting levels by 1-4 h after fatigue. Our estimates of U crit for Pacific lampreys are the first quantitative measures of their swimming performance and suggest that these fish may have difficulty negotiating fishways at dams on the Columbia River, which can have water velocities approaching 2 m/s. Our physiological results indicate that tagged and untagged Pacific lampreys show similar metabolic dysfunction after exhaustive exercise but recover quickly from a single exposure to such a stressor.

Transactions of The American Fisheries Society, 2005