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Geology topics

Christopher A. Myrick

Publications and source records attributed to Christopher A. Myrick.

4 recordsLinked to original sources
USGS2021

Retention of passive integrated transponder tags in a small-bodied catfish

Members of the freshwater catfishes (order Siluriformes) are capable of transintestinal expulsion of foreign bodies, including internally implanted tags, which can bias movement and survival estimates. We evaluated long-term (120-week) retention rates of passive integrated transponder (PIT) tags in a laboratory setting to assess potential tag loss in Stonecat Noturus flavus . The PIT tags were surgically implanted into the peritoneal cavity of fish (n = 157) ranging from 71 to 213 mm TL. We demonstrated that Stonecats can successfully be tagged with 12- and 23-mm PIT tags with low levels of mortality (5.0%) and tag loss (9.6%). Based on individual encounter histories and covariates, we further evaluated our data set in a multistate framework using program MARK. Based on our findings, tag age has a negative effect on tag loss; if Stonecats lose tags, it is relatively soon after tagging. Additionally, Stonecat TL has a negative effect on tag loss, with tag loss decreasing with increasing fish TL.

North American Journal of Fisheries Management↗
USGS2016

Are we preparing the next generation of fisheries professionals to succeed in their careers?: A survey of AFS members

Natural resource professionals have frequently criticized universities for poorly preparing graduates to succeed in their jobs. We surveyed members of the American Fisheries Society to determine which job skills and knowledge of academic topics employers, students, and university faculty members deemed most important to early-career success of fisheries professionals. Respondents also rated proficiency of recently hired, entry-level professionals (employers) on how well their programs prepared them for career success (students and faculty) in those same job skills and academic topics. Critical thinking and written and oral communication skills topped the list of important skills and academic topics. Employers perceived recent entry-level hires to be less well-prepared to succeed in their careers than either university faculty or students. Entry-level hires with post-graduate degrees rated higher in proficiency for highly important skills and knowledge than those with bachelor's degrees. We conclude that although universities have the primary responsibility for developing critical thinking and basic communication skills of students, employers have equal or greater responsibility for enhancing skills of employees in teamwork, field techniques, and communicating with stakeholders. The American Fisheries Society can significantly contribute to the preparation of young fisheries professionals by providing opportunities for continuing education and networking with peers at professional conferences.

Fisheries↗
USGS2011

The effects of myxobolus cerebralis on the physiological performance of whirling disease resistant and susceptible strains of rainbow trout

The development of rainbow trout Oncorhynchus mykiss strains that are resistant to whirling disease has shown promise as amanagement tool for populationsin areas where Myxobolus cerebralisis present. However, the physiological effects of the disease on characteristics necessary for fish survival in natural river conditions have not been tested in many of these strains. Five rainbow trout strains were evaluated for their swimming ability and growth characteristics in relation to M. cerebralis exposure: the resistant German rainbow trout (GR) strain (Hofer strain), the susceptible Colorado River rainbow trout (CRR) strain, and three intermediate (hybrid) strains (F1 = GR ?? CRR; F2 = F1 ?? F1; B2 = backcross of F1 ?? CRR). Three broad response patterns among strain and exposure were evident in our study. First, exposure metrics, growth performance, and swimming ability differed among strains. Second, exposure to the parasite did not necessarily produce differences in growth or swimming ability. Exposure to M. cerebralis did not affect batch weight for any strain, and critical swimming velocity did not differ between exposed and unexposed families. Third, although exposure did not necessarily affect growth or swimming ability, individuals that exhibited clinical deformities did show reduced growth and swimming performance; fish with clinical deformities were significantly smaller and had lower critical swimming velocities than exposed fish without clinical deformities. Research and management have focused on GR ?? CRR hybrid strains; however, given the performance of the GR strain in our study, it should not be discounted as a potential broodstock. Additional field trials comparing the GR and F1 strains should be conducted before wholesale adoption of the GR strain to reestablish rainbow trout populations in Colorado. ?? American Fisheries Society 2011.

Journal of Aquatic Animal Health↗