Environmental controls on foraging and growth of juvenile salmonids in a Southeast Alaska watershed
Thesis (M.S.) University of Alaska Fairbanks, 2023 Small coastal drainages in southeast Alaska (SEAK) support an exceptionally vast and productive region of anadromous fish habitat. However, streamflow patterns within this region are changing. It is expected that hydrologic inputs to streamflow will...
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ftunivalaska:oai:scholarworks.alaska.edu:11122/14631 2023-11-05T03:44:31+01:00 Environmental controls on foraging and growth of juvenile salmonids in a Southeast Alaska watershed Fitzgerald, Kevin A. Falke, Jeffrey Bellmore, Ryan Fellman, Jason Westley, Peter 2023-08 http://hdl.handle.net/11122/14631 en_US eng http://hdl.handle.net/11122/14631 Department of Fisheries Coho salmon Southeast Alaska Pink salmon Spawning Master of Science in Fisheries Thesis ms 2023 ftunivalaska 2023-10-12T18:03:18Z Thesis (M.S.) University of Alaska Fairbanks, 2023 Small coastal drainages in southeast Alaska (SEAK) support an exceptionally vast and productive region of anadromous fish habitat. However, streamflow patterns within this region are changing. It is expected that hydrologic inputs to streamflow will shift toward increased rain-water contribution, and that extreme high and low water events will become more frequent. Such changes will likely alter the foraging and growth environment of juvenile salmonids throughout this landscape, yet implications of hydrologic change to juvenile salmonid rearing habitats are poorly understood. Moreover, basic questions regarding streamflow impacts on fish foraging and the relative importance of marine-derived resources (MDR) from spawning to juvenile salmonid growth remain unanswered. In this thesis, I explore how environmental conditions within a small coastal watershed of SEAK influence the foraging and growth patterns of two anadromous juvenile salmonid species. In Chapter 1, I examine how streamflow impacts consumption rates and MDR utilization by juvenile Coho Salmon (Oncorhynchus kisutch) and Dolly Varden (Salvelinus malma), and show that early-season streamflow patterns significantly affect fish foraging, where low flows specifically constrain consumption rates and reduce fish growth. These constraints may have particularly negative impacts on fish growth in years of persistent low water conditions, as they could inhibit later-season access to MDR via gape-limitation. In Chapter 2, I build upon findings of MDR contributions to Coho Salmon growth by showing that Pink Salmon (Oncorhynchus gorbuscha) spawning patterns may confer disparate growth conditions between years. Together, results of these chapters provide mechanistic insights into environmental controls of fish foraging and growth in SEAK watersheds. Moreover, they improve understandings of implications of hydrologic change for anadromous salmonid rearing habitats in SEAK, and addresses flow-foraging knowledge gaps ... Thesis Oncorhynchus gorbuscha Pink salmon Alaska University of Alaska: ScholarWorks@UA |
institution |
Open Polar |
collection |
University of Alaska: ScholarWorks@UA |
op_collection_id |
ftunivalaska |
language |
English |
topic |
Coho salmon Southeast Alaska Pink salmon Spawning Master of Science in Fisheries |
spellingShingle |
Coho salmon Southeast Alaska Pink salmon Spawning Master of Science in Fisheries Fitzgerald, Kevin A. Environmental controls on foraging and growth of juvenile salmonids in a Southeast Alaska watershed |
topic_facet |
Coho salmon Southeast Alaska Pink salmon Spawning Master of Science in Fisheries |
description |
Thesis (M.S.) University of Alaska Fairbanks, 2023 Small coastal drainages in southeast Alaska (SEAK) support an exceptionally vast and productive region of anadromous fish habitat. However, streamflow patterns within this region are changing. It is expected that hydrologic inputs to streamflow will shift toward increased rain-water contribution, and that extreme high and low water events will become more frequent. Such changes will likely alter the foraging and growth environment of juvenile salmonids throughout this landscape, yet implications of hydrologic change to juvenile salmonid rearing habitats are poorly understood. Moreover, basic questions regarding streamflow impacts on fish foraging and the relative importance of marine-derived resources (MDR) from spawning to juvenile salmonid growth remain unanswered. In this thesis, I explore how environmental conditions within a small coastal watershed of SEAK influence the foraging and growth patterns of two anadromous juvenile salmonid species. In Chapter 1, I examine how streamflow impacts consumption rates and MDR utilization by juvenile Coho Salmon (Oncorhynchus kisutch) and Dolly Varden (Salvelinus malma), and show that early-season streamflow patterns significantly affect fish foraging, where low flows specifically constrain consumption rates and reduce fish growth. These constraints may have particularly negative impacts on fish growth in years of persistent low water conditions, as they could inhibit later-season access to MDR via gape-limitation. In Chapter 2, I build upon findings of MDR contributions to Coho Salmon growth by showing that Pink Salmon (Oncorhynchus gorbuscha) spawning patterns may confer disparate growth conditions between years. Together, results of these chapters provide mechanistic insights into environmental controls of fish foraging and growth in SEAK watersheds. Moreover, they improve understandings of implications of hydrologic change for anadromous salmonid rearing habitats in SEAK, and addresses flow-foraging knowledge gaps ... |
author2 |
Falke, Jeffrey Bellmore, Ryan Fellman, Jason Westley, Peter |
format |
Thesis |
author |
Fitzgerald, Kevin A. |
author_facet |
Fitzgerald, Kevin A. |
author_sort |
Fitzgerald, Kevin A. |
title |
Environmental controls on foraging and growth of juvenile salmonids in a Southeast Alaska watershed |
title_short |
Environmental controls on foraging and growth of juvenile salmonids in a Southeast Alaska watershed |
title_full |
Environmental controls on foraging and growth of juvenile salmonids in a Southeast Alaska watershed |
title_fullStr |
Environmental controls on foraging and growth of juvenile salmonids in a Southeast Alaska watershed |
title_full_unstemmed |
Environmental controls on foraging and growth of juvenile salmonids in a Southeast Alaska watershed |
title_sort |
environmental controls on foraging and growth of juvenile salmonids in a southeast alaska watershed |
publishDate |
2023 |
url |
http://hdl.handle.net/11122/14631 |
genre |
Oncorhynchus gorbuscha Pink salmon Alaska |
genre_facet |
Oncorhynchus gorbuscha Pink salmon Alaska |
op_relation |
http://hdl.handle.net/11122/14631 Department of Fisheries |
_version_ |
1781704550246252544 |