First-Summer Survival and Growth of Juvenile Atlantic Salmon in Headwater Streams: Implications for Restoring Connectivity at Road Culverts
The Machias River, located in downeast Maine, harbors one of the few remaining wild populations of Atlantic salmon Salmon salar in the U.S. and provides a model system for investigating the productive capacity of headwater streams currently inaccessible to wild salmon because of impassable culverts....
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ftmaineuniv:oai:digitalcommons.library.umaine.edu:etd-2878 2023-06-11T04:10:15+02:00 First-Summer Survival and Growth of Juvenile Atlantic Salmon in Headwater Streams: Implications for Restoring Connectivity at Road Culverts Ashe, Wesley Craig 2012-12-01T08:00:00Z application/pdf https://digitalcommons.library.umaine.edu/etd/1849 https://digitalcommons.library.umaine.edu/context/etd/article/2878/viewcontent/AsheWC2012.pdf unknown DigitalCommons@UMaine https://digitalcommons.library.umaine.edu/etd/1849 https://digitalcommons.library.umaine.edu/context/etd/article/2878/viewcontent/AsheWC2012.pdf Electronic Theses and Dissertations Atlantic salmon Fish migration Headwater streams Fish habitat improvement Animal Sciences Aquaculture and Fisheries Ecology and Evolutionary Biology Terrestrial and Aquatic Ecology text 2012 ftmaineuniv 2023-05-04T18:01:45Z The Machias River, located in downeast Maine, harbors one of the few remaining wild populations of Atlantic salmon Salmon salar in the U.S. and provides a model system for investigating the productive capacity of headwater streams currently inaccessible to wild salmon because of impassable culverts. Historically, headwater streams provided high-quality nursery habitat to juvenile salmon as they encompass > 70% of the total stream area in a watershed, and have more favorable and consistent temperature regimes, more available food, and fewer predators than larger rivers. In spring 2010 and 2011, we stocked salmon fry in twenty study reaches and quantified survival and growth across multiple environmental gradients. Fry migration was quantified at representative sites with directional traps, where movement was invariably in a downstream direction, negligible in distance, away from suboptimal habitat, and predominantly within days of stocking. Despite near drought conditions in 2010, late summer electrofishing resulted in fry abundance, apparent survival, growth, biomass, density, and PBI (potential biomass index) estimates that were comparable to 2011 values. Due to the low water event in 2010, the physical habitat variables prevailed, as warmer early season water temperatures, greater water depths, more abundant large wood, reduced detritus substrate, faster late season velocity, and larger drainage areas contributed most to fry metrics. In 2011, a more benign environment persisted, and biotic habitat variables were also important, as brook trout Salvelinus fontinalis, early season abundance and mass of drifting invertebrates, and late season drifting Diptera, Ephemeroptera, Plecopetera, Trichoptera (EPT), and terrestrial inputs contributed most to fry metrics. Our results indicate that headwater streams, although variable in their productive capacity, are essential rearing habitat for juvenile Atlantic salmon. We suggest that based on a select suite of habitat variables, problematic culverts can be targeted ... Text Atlantic salmon The University of Maine: DigitalCommons@UMaine |
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Open Polar |
collection |
The University of Maine: DigitalCommons@UMaine |
op_collection_id |
ftmaineuniv |
language |
unknown |
topic |
Atlantic salmon Fish migration Headwater streams Fish habitat improvement Animal Sciences Aquaculture and Fisheries Ecology and Evolutionary Biology Terrestrial and Aquatic Ecology |
spellingShingle |
Atlantic salmon Fish migration Headwater streams Fish habitat improvement Animal Sciences Aquaculture and Fisheries Ecology and Evolutionary Biology Terrestrial and Aquatic Ecology Ashe, Wesley Craig First-Summer Survival and Growth of Juvenile Atlantic Salmon in Headwater Streams: Implications for Restoring Connectivity at Road Culverts |
topic_facet |
Atlantic salmon Fish migration Headwater streams Fish habitat improvement Animal Sciences Aquaculture and Fisheries Ecology and Evolutionary Biology Terrestrial and Aquatic Ecology |
description |
The Machias River, located in downeast Maine, harbors one of the few remaining wild populations of Atlantic salmon Salmon salar in the U.S. and provides a model system for investigating the productive capacity of headwater streams currently inaccessible to wild salmon because of impassable culverts. Historically, headwater streams provided high-quality nursery habitat to juvenile salmon as they encompass > 70% of the total stream area in a watershed, and have more favorable and consistent temperature regimes, more available food, and fewer predators than larger rivers. In spring 2010 and 2011, we stocked salmon fry in twenty study reaches and quantified survival and growth across multiple environmental gradients. Fry migration was quantified at representative sites with directional traps, where movement was invariably in a downstream direction, negligible in distance, away from suboptimal habitat, and predominantly within days of stocking. Despite near drought conditions in 2010, late summer electrofishing resulted in fry abundance, apparent survival, growth, biomass, density, and PBI (potential biomass index) estimates that were comparable to 2011 values. Due to the low water event in 2010, the physical habitat variables prevailed, as warmer early season water temperatures, greater water depths, more abundant large wood, reduced detritus substrate, faster late season velocity, and larger drainage areas contributed most to fry metrics. In 2011, a more benign environment persisted, and biotic habitat variables were also important, as brook trout Salvelinus fontinalis, early season abundance and mass of drifting invertebrates, and late season drifting Diptera, Ephemeroptera, Plecopetera, Trichoptera (EPT), and terrestrial inputs contributed most to fry metrics. Our results indicate that headwater streams, although variable in their productive capacity, are essential rearing habitat for juvenile Atlantic salmon. We suggest that based on a select suite of habitat variables, problematic culverts can be targeted ... |
format |
Text |
author |
Ashe, Wesley Craig |
author_facet |
Ashe, Wesley Craig |
author_sort |
Ashe, Wesley Craig |
title |
First-Summer Survival and Growth of Juvenile Atlantic Salmon in Headwater Streams: Implications for Restoring Connectivity at Road Culverts |
title_short |
First-Summer Survival and Growth of Juvenile Atlantic Salmon in Headwater Streams: Implications for Restoring Connectivity at Road Culverts |
title_full |
First-Summer Survival and Growth of Juvenile Atlantic Salmon in Headwater Streams: Implications for Restoring Connectivity at Road Culverts |
title_fullStr |
First-Summer Survival and Growth of Juvenile Atlantic Salmon in Headwater Streams: Implications for Restoring Connectivity at Road Culverts |
title_full_unstemmed |
First-Summer Survival and Growth of Juvenile Atlantic Salmon in Headwater Streams: Implications for Restoring Connectivity at Road Culverts |
title_sort |
first-summer survival and growth of juvenile atlantic salmon in headwater streams: implications for restoring connectivity at road culverts |
publisher |
DigitalCommons@UMaine |
publishDate |
2012 |
url |
https://digitalcommons.library.umaine.edu/etd/1849 https://digitalcommons.library.umaine.edu/context/etd/article/2878/viewcontent/AsheWC2012.pdf |
genre |
Atlantic salmon |
genre_facet |
Atlantic salmon |
op_source |
Electronic Theses and Dissertations |
op_relation |
https://digitalcommons.library.umaine.edu/etd/1849 https://digitalcommons.library.umaine.edu/context/etd/article/2878/viewcontent/AsheWC2012.pdf |
_version_ |
1768384551875248128 |