Fish
Ocean acidification can have a wide variety of indirect impacts on fish, including altering behavior, otolith (a fish’s ear bone) formation, and young fish’s growth. Scientists at NOAA’s Fisheries Science Centers and research labs are learning about ocean acidification impacts on fish like rockfish, scup, summer flounder, and walleye pollock that are harvested commercially and recreationally. The research examines biological responses across the life cycle of fish, from impacts at early life stages (eggs and larvae) to “transgenerational” effects – how the exposure of adults to ocean acidification conditions can influence the survival and growth of their offspring.
China Rockfish
China rockfish (Sebastes nebulosus), have a range extending from California to Alaska and support a popular commercial fishery. Scientists at the Northwest Fisheries Science Center examined how larval growth and survival change under ocean acidification conditions.
Scup
Scup (Stenotomus chrysops) is a commercially and recreationally harvested fish found in coastal waters from Cape Cod, Massachusetts to Cape Hatteras, North Carolina. Scientists at NOAA’s Northeast Fisheries Science Center conducted laboratory studies to determine the effects of ocean acidification conditions on scup growth and otolith (ear bone) development in their first year of life.
Walleye Pollock
Alaskan walleye pollock (Theragra chalcogramma) support one of the largest fisheries in the world. Walleye pollock is a groundfish in the cod family found in North Pacific temperate and subarctic waters. Researchers at the Alaska Fisheries Science Center Newport, Oregon studied how early life stages of walleye pollock respond to ocean acidification conditions. Their investigations of egg development, larval growth and survival, and behavioral patterns and condition of juveniles found that walleye pollock show resilience to ocean acidification conditions.
Cobia
Cobia (Rachycentron canadum) is a large, pelagic fish found in most tropical and warm temperate regions around the globe. It is a top predator in marine ecosystems, and the target of high-value recreational and commercial fisheries. Scientists from the University of Miami and NOAA’s Atlantic Oceanographic and Meteorological Laboratory found that exposing larval cobia to ocean acidification conditions increased the size and density of their otoliths (ear bones). They used models to demonstrate that these changes could increase the hearing range of the larvae, altering how they perceive sounds in the world around them.
Coho Salmon
Coho salmon (Oncorhynchus kisutch), one of the six species of anadromous Pacific salmon species, is ecologically, culturally, and economically important. It spawns in streams around the northern Pacific Rim from California to Japan. Young coho salmon migrate from these streams to the sea to grow to maturity, and journey back to their natal streams to spawn the next generation. Salmon use their sense of smell to find their way back from the ocean to the stream where they hatched. Young salmon must imprint on the smell of their natal stream and also use their sense of smell to avoid predators. Scientists at the Northwest Fisheries Science Center have found that ocean acidification conditions affect the ability of juvenile coho salmon to smell and respond to scents. Ongoing research is examining whether the sensory systems of two other salmon species – pink and Chinook salmon – are similarly affected. These projects inform the conservation and management of salmon along the West Coast and in Alaska.
Forage Fish
Forage fish are small-bodied fish that play an important role in the ecosystem, transferring energy from plankton to larger fish, including those harvested by people. Scientists at the Northeast Fisheries Science Center’s Sandy Hook laboratory studied how two important forage fish from inshore East Coast waters, the mummichog (Fundulus heteroclitus) and the Atlantic silverside (Menidia menidia), may respond to ocean acidification conditions. Their studies focus on how exposure of adults to ocean acidification conditions can influence the survival and growth of their offspring. Such “transgeneration” work is vital for understanding how ocean acidification may influence populations in nature.
Flounder
Summer flounder (Paralichthys dentatus) and winter flounder (Pseudopleuronectes americanus) are ecologically and economically important species in Northeast and mid-Atlantic marine and estuarine ecosystems. Scientists at NOAA’s Northeast Fisheries Science Center in Sandy Hook, New Jersey examined the effects of increased ocean acidification on the survival and development of early life stages (eggs and larvae) of both flounder species.
Pacific Cod
Pacific cod (Gadus macrocephalus) is an important groundfish in the North Pacific and Bering Sea food webs and supports one of the nation’s largest and most valuable finfish fisheries. Researchers at the Alaska Fisheries Science Center are using genetic approaches to study how ocean acidification may affect Pacific cod over multiple life-history stages and generations. These studies use gene sequencing techniques to identify changes in molecular, metabolic, and physiological pathways that occur when larvae are exposed to ocean acidification. By identifying these cellular pathways, scientists can learn how species may become tolerant to ocean chemistry changes. Understanding the potential adaptation of a commercially important species will inform fisheries managers about the species’ sensitivity to future ocean conditions.
Arctic Cod
Arctic cod (Boreogadus saida) is a critical link in Arctic marine food webs, providing food for fish, seals, and whales, and is a commercially important species for Arctic fisheries. Scientists at the Alaska Fisheries Science Center are examining how ocean acidification and co-stressors like elevated temperatures impact adult Arctic cod. Experiments testing the effects of ocean acidification on reproductive output, egg quality, and larval production provide important data for risk assessments by regional fisheries.
Northern Rock Sole
Northern rock sole (Lepidopsetta polyxystra) is a commercially harvested flatfish in the Bering Sea and Gulf of Alaska groundfish fisheries. Harvest increased in recent years in response to the strong market for their roe. Thus, understanding the biological sensitivity to ocean acidification in roe is important both for their early survival and growth and to support this market. Alaska Fisheries Science Center researchers at the Newport, Oregon laboratory found that northern rock sole larvae were more likely to die and were in poorer condition when exposed to high levels of ocean acidification.
Sablefish
Sablefish (Anoplopoma fimbria), also known as black cod, is a marine groundfish that supports one of the most valuable commercial fisheries along the U. S. West Coast. Juvenile sablefish use their sense of smell to find food, and any changes in their ability could have big consequences for their survival. Research at the Northwest Fisheries Science Center has shown that ocean acidification causes different responses in the sense of smell of sablefish compared to salmon. Ongoing experiments aim to figure out why the sablefish’s ability to smell may be more resilient to ocean acidification conditions than other species’ sensory systems.
