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Full-Text Articles in Life Sciences

Assessment Of Salmon Habitat On The Feather River, Nathan Sweem Aug 2014

Assessment Of Salmon Habitat On The Feather River, Nathan Sweem

STAR (STEM Teacher and Researcher) Presentations

Human activity in central valley streams has had a significantly negative impact on salmon habitat (Williams 2006). The presence of dams impedes sediment transport which is critical to salmon spawning (Williams 2006; Kondolf 1997). As part of an effort to enhance salmon spawning, the California Department of Water Resources added 7000 ft3 of gravel to Cottonwood Hatchery, Upper Auditorium, and Auditorium riffles on the Lower Feather River below the Thermalito Dam Complex in July of 2014. Stream conditions at Cottonwood Hatchery riffle were assessed by conducting analysis of sediment grain size, water depth and velocity, gravel permeability, and dissolved ...


Effects Of Pristane On Growth Of Pink Salmon (Oncorhynchus Gorbuscha), Brielle D. Kemis, Bonita Nelson Aug 2012

Effects Of Pristane On Growth Of Pink Salmon (Oncorhynchus Gorbuscha), Brielle D. Kemis, Bonita Nelson

STAR (STEM Teacher and Researcher) Presentations

Pristane is a naturally occurring hydrocarbon that is generated by copepods in marine ecosystems. Organisms that eat copepods do not readily metabolize pristane, which causes it to accumulate throughout the marine food web. Understanding how pristane affects marine fish is essential because pristane is often used as a bioindicator in lab studies and may be influencing results in those studies. Also, this hydrocarbon may significantly reduce growth of marine fish in the wild. A previous study indicated that pristane is an appetite suppressant and growth retardant in fish. However, the study implemented a feeding regime with unnaturally high levels of ...


Interspecies Comparison Of Αii-Spectrin Abundance Between Chinook Salmon And Steelhead, Brielle D. Kemis, Ann L. Miracle, Katie A. Wagner, Christa M. Woodley Aug 2011

Interspecies Comparison Of Αii-Spectrin Abundance Between Chinook Salmon And Steelhead, Brielle D. Kemis, Ann L. Miracle, Katie A. Wagner, Christa M. Woodley

STAR (STEM Teacher and Researcher) Presentations

Salmonids, such as Chinook salmon (Oncorhynchus tshawytscha) and steelhead (O. mykiss), are a staple economic, recreational, tribal, and environmental resource, yet many populations are unsustainable. This study was part of a broad scale effort to monitor the impact of downstream migration obstacles on juvenile salmonid health and survival, which is an essential step towards increasing Smolt-to-Adult Return ratios (SARs). The objective of this study was to determine if juvenile Chinook salmon and steelhead exhibit differing quantities of alphaII-Spectrin Breakdown Products (SBDPs) over two consecutive spring migration periods, indicative of neurogenesis rate and/or biological response to head injury. AlphaII-Spectrin is ...


Environmental Rearing Conditions Produce Forebrain Differences In Wild Chinook Salmon Oncorhynchus Tshawytscha, R. L. Kihslinger, Sean C. Lema, G. A. Nevitt Oct 2006

Environmental Rearing Conditions Produce Forebrain Differences In Wild Chinook Salmon Oncorhynchus Tshawytscha, R. L. Kihslinger, Sean C. Lema, G. A. Nevitt

Biological Sciences

Recent studies suggest that hatchery-reared fish can have smaller brain-to-body size ratios than wild fish. It is unclear, however, whether these differences are due to artificial selection or instead reflect differences in rearing environment during development. Here we explore how rearing conditions influence the development of two forebrain structures, the olfactory bulb and the telencephalon, in juvenile Chinook salmon (Oncorhynchus tshawytscha) spawned from wild-caught adults. First, we compared the sizes of the olfactory bulb and telencephalon between salmon reared in a wild stream vs. a conventional hatchery. We next compared the sizes of forebrain structures between fish reared in an ...


Evidence That Thyroid Hormone Induces Olfactory Cellular Proliferation In Salmon During A Sensitive Period For Imprinting, Sean C. Lema, Gabrielle A. Nevitt Oct 2004

Evidence That Thyroid Hormone Induces Olfactory Cellular Proliferation In Salmon During A Sensitive Period For Imprinting, Sean C. Lema, Gabrielle A. Nevitt

Biological Sciences

Salmon have long been known to imprint and home to natal stream odors, yet the mechanisms driving olfactory imprinting remain obscure. The timing of imprinting is associated with elevations in plasma thyroid hormone levels, with possible effects on growth and proliferation of the peripheral olfactory system. Here, we begin to test this idea by determining whether experimentally elevated plasma levels of 3,5,3′-triiodothyronine (T3) influence cell proliferation as detected by the 5-bromo-2′-deoxyuridine (BrdU) cell birth-dating technique in the olfactory epithelium of juvenile coho salmon (Oncorhynchus kisutch). We also explore how natural fluctuations in thyroxine (T4 ...


Phenotype Management: A New Approach To Habitat Restoration, Jason V. Watters, Sean C. Lema, Gabrielle A. Nevitt Aug 2003

Phenotype Management: A New Approach To Habitat Restoration, Jason V. Watters, Sean C. Lema, Gabrielle A. Nevitt

Biological Sciences

The goal of habitat restoration is to provide environmental conditions that promote the maintenance and growth of target populations. But rarely is it considered how the allocation of resources influences the diversity of phenotypes in these populations. Here we present a framework for considering how habitat restoration can shape the development and expression of phenotypes. We call this approach phenotype management as it entails restoring the resources in a habitat to manage phenotypic diversity. Phenotype management is achieved by manipulating the spatial and temporal distribution of resources to alter the degree of competition among individuals. Differences in competition, in turn ...


Re-Evaluating Nadph-Diaphorase Histochemistry As An Indicator Of Nitric Oxide Synthase: An Examination Of The Olfactory System Of Coho Salmon (Oncorhynchus Kisutch), Sean C. Lema, Gabrielle A. Nevitt Nov 2001

Re-Evaluating Nadph-Diaphorase Histochemistry As An Indicator Of Nitric Oxide Synthase: An Examination Of The Olfactory System Of Coho Salmon (Oncorhynchus Kisutch), Sean C. Lema, Gabrielle A. Nevitt

Biological Sciences

The NADPH-diaphorase (NADPH-d) histochemical technique is commonly used to localize the nitric oxide (NO)-producing enzyme NO synthase (NOS) in neural tissues. In the olfactory tissues of vertebrates, however, NADPH-d staining can be present without the detection of NOS by other methods. We used pharmacological controls to determine whether NADPH-d staining was indicative of NOS in olfactory tissues from coho salmon (Oncorhynchus kisutch). We also compared NADPH-d staining with immunoreactivity to NOS. NADPH-d staining localized to the olfactory epithelium and to the glomerular layer of the olfactory bulb. Two NOS inhibitors, L-N-nitroarginine and L-N-methyl-L-arginine, failed to ...