Kelp forests are often called the rainforest of the sea. They support wide varieties of marine life. Sea otters are both a sentinal and a keystone species for the health of kelp forests. Without sea otters, there is a shift in the ecosystem that can severly damage the kelp forests.
Primary Production Sources and Bottom-up Limitations in Nearshore Ecosystems Active
By Alaska Science Center
April 19, 2018
Kelp forests are among the world’s most productive habitats, but recent evidence suggests that production is highly variable.
Return to Ecosystems >> Fish and Aquatic Ecology
Our ability to forecast the fate of ecosystems and species hinges on an understanding of how biological systems respond to their environment. In this project, natural indicators of diet (stable isotopes) and production (otolith growth increment width) in two common fishes were used to investigate energy pathways and biophysical relationships in nearshore kelp forests spanning two large marine ecosystems with contrasting oceanography, the upwelling system of the California Current and the downwelling system of the Alaska Coastal Current. This study is an integral component of the USGS Pacific Nearshore Project and the data and results from this project are being used to understand differences in nearshore production from California to Alaska and the resulting population trajectories of sea otters, a keystone predator in kelp forest ecosystems and an important subsistence resource in Alaska.
Sources/Usage: Public Domain. View Media Details
Sources/Usage: Public Domain. View Media Details
Below are other science projects associated with this project.
Fish and Aquatic Ecology
Fish and aquatic habitats in Alaska support important commercial, sport, and subsistence fisheries and provide forage fish that support wildlife populations. The USGS Alaska Science Center conducts interdisciplinary research to inform local, state, federal, and international policy makers regarding conservation of fish, aquatic species, and their habitats. We work collaboratively with hydrologists...
Assessing heat stress in migrating Yukon River Chinook Salmon
We will examine evidence of heat stress in Yukon River Chinook salmon ( Oncorhynchus tshawytscha ) using heat shock proteins and gene expression.
Condition of Forage Fish in Prince William Sound During the Marine Heatwave
Changes in the body condition of a key forage fish species, Pacific sand lance ( Ammodytes personatus ), are examined to understand how energy transfer to predators may have been disrupted during the recent marine heatwave in the North Pacific (late 2013 to mid 2016).
Arctic Lake Food Webs
From 2011 to 2013 we investigated freshwater food webs of Arctic Coastal Plain lakes in Alaska to improve our understanding how Arctic freshwater food webs may respond to landscape change the warmer, drier future.
Ecosystem Shifts in Arctic Seas
In addition to the direct effects of sea ice loss on walrus ( Odobenus rosmarus divergens ) and polar bears ( Ursus maritimus ) that use ice as a platform, the decline of Arctic sea ice is predicted to promote a fundamental ecosystem shift from benthic animals that forage on the sea floor to pelagic animals that forage near the sea surface.
Lake Trout Biochronologies as Long-term Climate and Productivity Indicators in Alaska Lake Ecosystems
High latitude ecosystems are among the most vulnerable to long-term climate change, yet continuous, multidecadal indicators by which to gauge effects on biology are scarce, especially in freshwater environments.
Hydro-Ecology of Arctic Thawing (HEAT): Ecology
Permafrost thaw is leading to a myriad of changes in physical and chemical conditions throughout the Arctic.
Effect of Elodea spp. on Fish Performance Mediated Through Food Web Interactions
The potential for invasive species introductions in Arctic and Subarctic ecosystems is growing as climate change manifests and human activity increases in high latitudes.
Sockeye Salmon Migrating at the Northern Edge of Their Distribution
The physiological challenge for anadromous fish to migrate upriver to spawn and complete their life cycle is influenced by river temperature.
Nearshore Fish Surveys in the Beaufort Sea
Nearshore systems provide habitat to a unique community of marine and diadromous (lives in both fresh and saltwater) fish and support high fish abundance.
Below are multimedia items associated with this project.
Kelp Forest
Kelp forests are often called the rainforest of the sea. They support wide varieties of marine life. Sea otters are both a sentinal and a keystone species for the health of kelp forests. Without sea otters, there is a shift in the ecosystem that can severly damage the kelp forests.
Kelp Greenling Among Seafloor Cover of Mixed Composition
Digital still photograph offshore of Half Moon Bay, California, showing a kelp greenling, encrusting sponges, red algae, cup coral, in mixed gravel, cobbles, and rugose rock outcrop with scattered shells at a depth of 9 meters.
Digital still photograph offshore of Half Moon Bay, California, showing a kelp greenling, encrusting sponges, red algae, cup coral, in mixed gravel, cobbles, and rugose rock outcrop with scattered shells at a depth of 9 meters.
- Overview
Kelp forests are among the world’s most productive habitats, but recent evidence suggests that production is highly variable.
Return to Ecosystems >> Fish and Aquatic Ecology
Our ability to forecast the fate of ecosystems and species hinges on an understanding of how biological systems respond to their environment. In this project, natural indicators of diet (stable isotopes) and production (otolith growth increment width) in two common fishes were used to investigate energy pathways and biophysical relationships in nearshore kelp forests spanning two large marine ecosystems with contrasting oceanography, the upwelling system of the California Current and the downwelling system of the Alaska Coastal Current. This study is an integral component of the USGS Pacific Nearshore Project and the data and results from this project are being used to understand differences in nearshore production from California to Alaska and the resulting population trajectories of sea otters, a keystone predator in kelp forest ecosystems and an important subsistence resource in Alaska.
Sources/Usage: Public Domain. View Media DetailsMap of black rockfish (left) and kelp greenling (right) sampling locations in the northeast Pacific Ocean with pie charts representing the relative carbon contributions from kelp (brown) and phytoplankton (green) primary producers estimated using carbon (δ13C) and nitrogen (δ15N) stable isotope values of muscle tissue. Black rockfish feed pelagically in the nearshore water column and kelp greenling feed benthically in nearshore waters. Mixing models were used to estimate carbon contributions based on site-specific phytoplankton and kelp and trophic discrimination factors (mean ± SD) of 1.0 ± 1.0‰ for δ13C per trophic level. Image credits: kelp and phytoplankton Jane Thomas and Tracey Saxby, IAN Image Library (http://ian.umces.edu/imagelibrary) and fish pictures, Washington Department of Fish and Wildlife. From publication: https://doi.org/10.1016/j.ecss.2016.08.039(Credit: Vanessa von Biela, USGS. Public domain.)
Sources/Usage: Public Domain. View Media DetailsHans Bruning (left; first mate on the Snow Goose) and Tim Tinker (right) watch as USGS biologist Vanessa von Biela dissects kelp greenling (Hexagrammos decagrammus) for their otoliths—earbones whose growth rings can reveal a fish's age and indicate how fast the fish grew in certain years. Picture taken on board the M/V Snow Goose in southeast Alaska.(Public domain.) - Science
Below are other science projects associated with this project.
Fish and Aquatic Ecology
Fish and aquatic habitats in Alaska support important commercial, sport, and subsistence fisheries and provide forage fish that support wildlife populations. The USGS Alaska Science Center conducts interdisciplinary research to inform local, state, federal, and international policy makers regarding conservation of fish, aquatic species, and their habitats. We work collaboratively with hydrologists...Assessing heat stress in migrating Yukon River Chinook Salmon
We will examine evidence of heat stress in Yukon River Chinook salmon ( Oncorhynchus tshawytscha ) using heat shock proteins and gene expression.Condition of Forage Fish in Prince William Sound During the Marine Heatwave
Changes in the body condition of a key forage fish species, Pacific sand lance ( Ammodytes personatus ), are examined to understand how energy transfer to predators may have been disrupted during the recent marine heatwave in the North Pacific (late 2013 to mid 2016).Arctic Lake Food Webs
From 2011 to 2013 we investigated freshwater food webs of Arctic Coastal Plain lakes in Alaska to improve our understanding how Arctic freshwater food webs may respond to landscape change the warmer, drier future.Ecosystem Shifts in Arctic Seas
In addition to the direct effects of sea ice loss on walrus ( Odobenus rosmarus divergens ) and polar bears ( Ursus maritimus ) that use ice as a platform, the decline of Arctic sea ice is predicted to promote a fundamental ecosystem shift from benthic animals that forage on the sea floor to pelagic animals that forage near the sea surface.Lake Trout Biochronologies as Long-term Climate and Productivity Indicators in Alaska Lake Ecosystems
High latitude ecosystems are among the most vulnerable to long-term climate change, yet continuous, multidecadal indicators by which to gauge effects on biology are scarce, especially in freshwater environments.Hydro-Ecology of Arctic Thawing (HEAT): Ecology
Permafrost thaw is leading to a myriad of changes in physical and chemical conditions throughout the Arctic.Effect of Elodea spp. on Fish Performance Mediated Through Food Web Interactions
The potential for invasive species introductions in Arctic and Subarctic ecosystems is growing as climate change manifests and human activity increases in high latitudes.Sockeye Salmon Migrating at the Northern Edge of Their Distribution
The physiological challenge for anadromous fish to migrate upriver to spawn and complete their life cycle is influenced by river temperature.Nearshore Fish Surveys in the Beaufort Sea
Nearshore systems provide habitat to a unique community of marine and diadromous (lives in both fresh and saltwater) fish and support high fish abundance. - Multimedia
Below are multimedia items associated with this project.
Kelp ForestKelp forests are often called the rainforest of the sea. They support wide varieties of marine life. Sea otters are both a sentinal and a keystone species for the health of kelp forests. Without sea otters, there is a shift in the ecosystem that can severly damage the kelp forests.
Kelp forests are often called the rainforest of the sea. They support wide varieties of marine life. Sea otters are both a sentinal and a keystone species for the health of kelp forests. Without sea otters, there is a shift in the ecosystem that can severly damage the kelp forests.
Kelp Greenling Among Seafloor Cover of Mixed CompositionDigital still photograph offshore of Half Moon Bay, California, showing a kelp greenling, encrusting sponges, red algae, cup coral, in mixed gravel, cobbles, and rugose rock outcrop with scattered shells at a depth of 9 meters.
Digital still photograph offshore of Half Moon Bay, California, showing a kelp greenling, encrusting sponges, red algae, cup coral, in mixed gravel, cobbles, and rugose rock outcrop with scattered shells at a depth of 9 meters.
- Publications