Repository logo
 

Seasonal trophic niche dynamics of mottled sculpin and juvenile brown trout in a regulated Rocky Mountain river

dc.contributor.authorPlatis, Nitsa, author
dc.contributor.authorKanno, Yoichiro, advisor
dc.contributor.authorJohnson, Brett, advisor
dc.contributor.authorKampf, Stephanie, committee member
dc.date.accessioned2024-01-01T11:24:19Z
dc.date.available2024-01-01T11:24:19Z
dc.date.issued2023
dc.description.abstractIn temperate ecosystems, resource availability fluctuates seasonally due to changes in environmental conditions and productivity throughout the year. Intra- and inter-specific trophic niche overlap under resource limitation is a measure of competitive interactions and influences species coexistence and community dynamics, but patterns of this overlap are highly variable among regions and communities. In this study, we analyzed stomach content samples and stable isotope signatures to evaluate seasonal trophic niche dynamics of mottled sculpin Cottus bairdii (80-130 mm total length) and juvenile brown trout Salmo trutta (80-200 mm) in the Blue River, Colorado, USA, where aquatic production varies seasonally and has been reduced due to upstream dams. Prey biomass (i.e., benthic macroinvertebrates) peaked in spring and declined through summer and autumn. Stomach content and stable isotope analysis results revealed diet composition of mottled sculpin and brown trout shifted seasonally in response to changes in resource availability. In autumn, both species exhibited the highest frequency of empty stomachs and expanded population trophic niches due to increased inter-individual diet variation despite decreased individual trophic niche breadth. Interspecific trophic niche overlap was relatively high across all seasons, but the lowest degree of overlap occurred in autumn of both years. Isotopic analysis revealed similar trends of wider isotopic niches and reduced overlap in autumn compared to spring. Taken together, our data indicate that seasonal variation impacts individual and population-level trophic niche dynamics, as well as interspecific niche overlap between mottled sculpin and juvenile brown trout. These two species occur sympatrically in many coldwater streams throughout North America, and our findings indicate trophic segregation under resource limitation may serve as a mechanism that facilitates their coexistence.
dc.format.mediumborn digital
dc.format.mediummasters theses
dc.identifierPlatis_colostate_0053N_18133.pdf
dc.identifier.urihttps://hdl.handle.net/10217/237372
dc.languageEnglish
dc.language.isoeng
dc.publisherColorado State University. Libraries
dc.relation.ispartof2020-
dc.rightsCopyright and other restrictions may apply. User is responsible for compliance with all applicable laws. For information about copyright law, please see https://libguides.colostate.edu/copyright.
dc.subjectstream fish
dc.subjectaquatic ecology
dc.subjecttrophic niche
dc.titleSeasonal trophic niche dynamics of mottled sculpin and juvenile brown trout in a regulated Rocky Mountain river
dc.typeText
dcterms.rights.dplaThis Item is protected by copyright and/or related rights (https://rightsstatements.org/vocab/InC/1.0/). You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s).
thesis.degree.disciplineFish, Wildlife, and Conservation Biology
thesis.degree.grantorColorado State University
thesis.degree.levelMasters
thesis.degree.nameMaster of Science (M.S.)

Files

Original bundle
Now showing 1 - 1 of 1
Loading...
Thumbnail Image
Name:
Platis_colostate_0053N_18133.pdf
Size:
1.33 MB
Format:
Adobe Portable Document Format