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Fish Health

USGS investigates pathogen discovery, causes, and drivers; researches disease ecology and immunology; and develops advanced tools for surveillance, risk assessment, and control of diseases that impact aquatic organism health to support the management, conservation, and restoration of aquatic species.

Filter Total Items: 43

Fish Health

Fish are an important component of marine ecosystems, but relatively little is known of their health, in part because sick and dying fish are difficult to detect.
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Fish Health

Fish are an important component of marine ecosystems, but relatively little is known of their health, in part because sick and dying fish are difficult to detect.
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Water Temperature in Rivers and Streams

Increases in summer stream temperature as a result of human impacts and climate change may exceed the thermal tolerances of aquatic biota that are adapted to colder environments and climates. The combined effects of humans and climate change are of global concern across the range of coldwater aquatic organisms.
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Water Temperature in Rivers and Streams

Increases in summer stream temperature as a result of human impacts and climate change may exceed the thermal tolerances of aquatic biota that are adapted to colder environments and climates. The combined effects of humans and climate change are of global concern across the range of coldwater aquatic organisms.
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A Website Tool for Predicting Triploidy in Larval Fish Spawns

Differentiating diploids from triploids at the earliest life stage possible allows for a more efficient use of resources including production time and rearing space. Thus, a reliable flow cytometric (FCM) method has been developed to discriminate triploids from diploids at the larval stage. In order to help simplify the process of differentiating triploids from diploids, we propose a simple...
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A Website Tool for Predicting Triploidy in Larval Fish Spawns

Differentiating diploids from triploids at the earliest life stage possible allows for a more efficient use of resources including production time and rearing space. Thus, a reliable flow cytometric (FCM) method has been developed to discriminate triploids from diploids at the larval stage. In order to help simplify the process of differentiating triploids from diploids, we propose a simple...
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Distribution and Controls Over Habitat and Food Web Structures and Processes in Great Lakes Estuaries

Rivermouth ecosystems, or freshwater estuaries, are the focus of human and wildlife interactions with the Great Lakes. They are highly valued as the region’s urban, industrial, shipping and recreational centers; and home to recreational harbors, wildlife viewing and production, beaches and urban riverfronts. Rivermouths are also both the mixing zones where nutrients from upstream watersheds are...
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Distribution and Controls Over Habitat and Food Web Structures and Processes in Great Lakes Estuaries

Rivermouth ecosystems, or freshwater estuaries, are the focus of human and wildlife interactions with the Great Lakes. They are highly valued as the region’s urban, industrial, shipping and recreational centers; and home to recreational harbors, wildlife viewing and production, beaches and urban riverfronts. Rivermouths are also both the mixing zones where nutrients from upstream watersheds are...
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Rainbow Trout Abundance and Movement in the Colorado River in Grand Canyon

Just below Glen Canyon Dam on the Colorado River is a very popular Blue Ribbon trout fishery known for its rainbow trout. However, approximately 78 miles downstream, near were the Little Colorado River flows into the Colorado River, is a population of endangered humpback chub. The introduced rainbow trout can negatively affect native humpback chub by competing with them for food (immature black...
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Rainbow Trout Abundance and Movement in the Colorado River in Grand Canyon

Just below Glen Canyon Dam on the Colorado River is a very popular Blue Ribbon trout fishery known for its rainbow trout. However, approximately 78 miles downstream, near were the Little Colorado River flows into the Colorado River, is a population of endangered humpback chub. The introduced rainbow trout can negatively affect native humpback chub by competing with them for food (immature black...
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Determination of the Acute Toxicity of Model-based Candidate Chemical Toxicants to Native and Nonnative Fish Species in Static Exposures

Invasive fishes are of considerable concern to aquatic resource managers. For example, the common carp (Cyprinus carpio), originally brought over from Eurasia sometime in the 1800s are now ubiquitous in U.S. waters. Although they have been around for over 100 years and have become part of U.S. culture, they are still highly detrimental to aquatic ecosystems and a method to eradicate and control of...
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Determination of the Acute Toxicity of Model-based Candidate Chemical Toxicants to Native and Nonnative Fish Species in Static Exposures

Invasive fishes are of considerable concern to aquatic resource managers. For example, the common carp (Cyprinus carpio), originally brought over from Eurasia sometime in the 1800s are now ubiquitous in U.S. waters. Although they have been around for over 100 years and have become part of U.S. culture, they are still highly detrimental to aquatic ecosystems and a method to eradicate and control of...
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Uncovering the Base of the Food Web: Primary Production Dynamics in the Colorado River

Algae, phytoplankton, and rooted macrophytes represent the base of many aquatic food webs and are known as primary producers. Through photosynthesis, these organisms convert sunlight energy into chemical energy (i.e., carbon) that in turn fuels the growth of animals such as macroinvertebrates and fish. This project uses high frequency measurements of dissolved oxygen, which is a by-product of...
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Uncovering the Base of the Food Web: Primary Production Dynamics in the Colorado River

Algae, phytoplankton, and rooted macrophytes represent the base of many aquatic food webs and are known as primary producers. Through photosynthesis, these organisms convert sunlight energy into chemical energy (i.e., carbon) that in turn fuels the growth of animals such as macroinvertebrates and fish. This project uses high frequency measurements of dissolved oxygen, which is a by-product of...
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Effects of Water Clarity on Survival of Endangered Humpback Chub

Introduced rainbow trout and brown trout are considered a threat to the endangered humpback chub in the Colorado River in Grand Canyon. These introduced species eat native fish, but impacts are difficult to assess because predation vulnerability depends on the physical conditions under which predation takes place. We studied how predation vulnerability of juvenile humpback chub changes in response...
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Effects of Water Clarity on Survival of Endangered Humpback Chub

Introduced rainbow trout and brown trout are considered a threat to the endangered humpback chub in the Colorado River in Grand Canyon. These introduced species eat native fish, but impacts are difficult to assess because predation vulnerability depends on the physical conditions under which predation takes place. We studied how predation vulnerability of juvenile humpback chub changes in response...
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Gulf Sturgeon Ecological Investigations

The Gulf sturgeon, Acipenser oxyrinchus desotoi, has been listed as Threatened since 1991. Beginning in 1986, USGS has been investigating sturgeon population abundance and ecology throughout its range, but mostly in the Suwannee River.
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Gulf Sturgeon Ecological Investigations

The Gulf sturgeon, Acipenser oxyrinchus desotoi, has been listed as Threatened since 1991. Beginning in 1986, USGS has been investigating sturgeon population abundance and ecology throughout its range, but mostly in the Suwannee River.
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Preserving Gulf Sturgeon—A Fish Tale of Gargantuan Proportions

It's hard to imagine a better job than doing fieldwork with the USGS Coastal Ecology crew as they work to keep tabs on the Gulf sturgeon population.
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Preserving Gulf Sturgeon—A Fish Tale of Gargantuan Proportions

It's hard to imagine a better job than doing fieldwork with the USGS Coastal Ecology crew as they work to keep tabs on the Gulf sturgeon population.
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Paddlefish Tracking Map - Visualizing U.S. Fish and Wildlife Service Tower and Boat Observational Data

Partnering with the Caddo Lake Institute, the USGS WARC Advanced Applications Team developed a web-based mapping application that visualizes the paddlefish tracking observations being collected by FWS.
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Paddlefish Tracking Map - Visualizing U.S. Fish and Wildlife Service Tower and Boat Observational Data

Partnering with the Caddo Lake Institute, the USGS WARC Advanced Applications Team developed a web-based mapping application that visualizes the paddlefish tracking observations being collected by FWS.
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Impacts of Sea Level Rise & Ecosystem Restoration on Wildlife

The interior marshes of the Ten Thousand Islands National Wildlife Refuge (TTINWR) are currently negatively impacted by sea level rise through saltwater intrusion from the south which furthers mangrove encroachment into the freshwater marsh.
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Impacts of Sea Level Rise & Ecosystem Restoration on Wildlife

The interior marshes of the Ten Thousand Islands National Wildlife Refuge (TTINWR) are currently negatively impacted by sea level rise through saltwater intrusion from the south which furthers mangrove encroachment into the freshwater marsh.
Learn More