(Press-News.org) Contact information: Mario Aguilera
scrippsnews@ucsd.edu
858-534-3624
University of California - San Diego
Rising ocean acidification leads to anxiety in fish
Study shows acidity levels projected by the end of the century results in behavioral changes that could impact feeding, fisheries
A new research study combining marine physiology, neuroscience, pharmacology, and behavioral psychology has revealed a surprising outcome from increases of carbon dioxide uptake in the oceans: anxious fish.
A growing base of scientific evidence has shown that the absorption of human-produced carbon dioxide into the world's oceans is causing surface waters to decline in pH, causing a rise in acidity. This ocean acidification is known to disrupt the growth of shells and skeletons of certain marine animals but other consequences such as behavioral impacts have been largely unknown.
In a study published in the journal Proceedings of the Royal Society B (Biological Sciences), scientists at Scripps Institution of Oceanography at UC San Diego and MacEwan University in Edmonton, Canada, have shown for the first time that rising acidity levels increase anxiety in juvenile rockfish, an important commercial species in California. Using a camera-based tracking software system, the researchers compared a control group of rockfish kept in normal seawater to another group in waters with elevated acidity levels matching those projected for the end of the century. They measured each group's preference to swim in light or dark areas of a testing tank, which is a known test for anxiety in fish. The researchers found out that normal juvenile rockfish continuously moved between the light and dark areas of the tank. However, experiments have shown that fish administered with an anxiety-inducing drug (anxiogenic) prefer the darker area and seldom venture into the light. Hence, dark-preference is indicative of increased anxiety in juvenile rockfish.
Next, the researchers found that rockfish exposed to acidified ocean conditions for one week also preferred the dark area of the tank, indicating they were significantly more anxious than their normal seawater counterparts. Rockfish exposed to acidified ocean conditions remained anxious even one week after being placed in seawater with normal carbon dioxide levels. Only after the twelfth day in normal seawater did the anxious fish behave like the control group and resumed normal behavior.
The researchers say the anxiety is traced to the fish's sensory systems, and specifically "GABAA" (neural gamma-aminobutyric acid type A) receptors, which are also involved in human anxiety levels. Exposure to acidified water leads to changes in the concentrations of ions in the blood (especially chloride and bicarbonate), which reverses the flux of ions through the GABAA receptors. The end result is a change in neuronal activity that is reflected in the altered behavioral responses described in this study.
"These results are novel and thought-provoking," said Martín Tresguerres, a Scripps marine biologist and study coauthor, "because they reveal a potential negative effect of ocean acidification on fish behavior that can possibly affect normal population dynamics and maybe even affect fisheries."
Tresguerres says anxious behavior is a concern for juvenile rockfish because they live in highly dynamic environments such as kelp forests and drifting kelp paddies that offer variable lighting and shading conditions.
"If the behavior that we observed in the lab applies to the wild during ocean acidification conditions, it could mean that juvenile rockfish may spend more time in the shaded areas instead of exploring around," said Tresguerres. "This would have negative implications due to reduced time foraging for food, or alterations in dispersal behavior, among others."
Alteration of GABAA receptor function in fish exposed to ocean acidification was originally described by Phil Munday (James Cook University, Australia), Göran Nilsson (University of Oslo) and collaborators, who found that ocean acidification impaired olfaction in tropical clown fish. The study by Hamilton, Holcombe, and Tresguerres adds anxiety behavior to the list of biological functions that are susceptible to future ocean acidification, and it is the first to describe effects of ocean acidification on the physiology and behavior of Californian fish.
"Behavioral neuroscience in fish is a relatively unexplored field, but we do know that fish are capable of many complicated cognitive tasks of learning and memory. Increased anxiety in rockfish could have a detrimental impact on many aspects of their daily functioning," said Trevor James Hamilton, a neurobiologist at MacEwan University and coauthor of the study.
Tresguerres noted that laboratory tests cannot fully model the steady progression of acidity levels that will be seen in the wild over years and decades. "Nonetheless, our results suggest that ocean acidification may affect an important aspect of fish behavior."
###
In addition to Tresguerres and Hamilton, Adam Holcombe of MacEwan University coauthored the study.
The National Science Foundation, UC San Diego Academic Senate, Scripps Institution of Oceanography, The Alfred P. Sloan Foundation, MacEwan Research Office, Arts and Science, and Student Enrichment Fund supported the research.
Rising ocean acidification leads to anxiety in fish
Study shows acidity levels projected by the end of the century results in behavioral changes that could impact feeding, fisheries
2013-12-05
ELSE PRESS RELEASES FROM THIS DATE:
Study identifies protein that helps developing germ cells wipe genes clean of past imprints
2013-12-05
Study identifies protein that helps developing germ cells wipe genes clean of past imprints
Tet1 helps erase epigenetic imprints from genome ahead of egg and sperm development; Tet1 flaws may play a role in some birth defects
BOSTON, December ...
Fledgling supernova remnant reveals neutron star's secrets
2013-12-05
Fledgling supernova remnant reveals neutron star's secrets
MADISON – With the help of NASA's Chandra X-ray Observatory and the Australia Telescope Compact Array, an international team of astronomers has identified the glowing wreck of a star that ...
Supernova blast provides clues to age of binary star system
2013-12-05
Supernova blast provides clues to age of binary star system
Data from NASA's Chandra X-ray Observatory has revealed faint remnants of a supernova explosion and helped researchers determine Circinus X-1 -- an X-ray binary -- is the youngest of this class of astronomical ...
Estrogen: Not just produced by the ovaries
2013-12-05
Estrogen: Not just produced by the ovaries
MADISON – A University of Wisconsin-Madison research team reports today that the brain can produce and release estrogen — a discovery that may lead to a better understanding of hormonal changes observed from before ...
NASA sees rainfall quickly fade in dying Depression 33W
2013-12-05
NASA sees rainfall quickly fade in dying Depression 33W
NASA's TRMM satellite noticed that rainfall became scarce in the Northwestern Pacific Ocean's thirty-third tropical depression in its second day of life. Tropical Depression 33W or TD 33W had weakened and ...
Active component of grape seed extract effective against cancer cells
2013-12-05
Active component of grape seed extract effective against cancer cells
A University of Colorado Cancer Center study published online ahead of print in the journal Nutrition and Cancer describes the laboratory synthesis of the most active component of grape seed extract, ...
Social stigmas against breast-feeding may contribute to African-American college students' hesitation
2013-12-05
Social stigmas against breast-feeding may contribute to African-American college students' hesitation
COLUMBIA, Mo. – African-American mothers breast-feed their children at lower rates than Caucasian, Latina and Asian mothers. This difference often has been ...
New observations from NASA's Van Allen Probes offer solution to radiation belts mystery
2013-12-05
New observations from NASA's Van Allen Probes offer solution to radiation belts mystery
In 1958, scientists discovered two gigantic belts of radiation around Earth that have provided tantalizing mysteries to researchers ever since. One unsolved ...
Glimpsing the infrastructure of a gamma-ray burst jet
2013-12-05
Glimpsing the infrastructure of a gamma-ray burst jet
A new study using observations from a novel instrument provides the best look to date at magnetic fields at the heart of gamma-ray bursts, the most energetic explosions in the universe. An international ...
University of Tennessee study finds crocodiles are cleverer than previously thought
2013-12-05
University of Tennessee study finds crocodiles are cleverer than previously thought
Turns out the crocodile can be a shrewd hunter himself; A University of Tennessee, Knoxville, researcher has found that some crocodiles use lures to hunt their prey
Turns ...
LAST 30 PRESS RELEASES:
New strategies to enhance chiral optical signals unveiled
Cambridge research uncovers powerful virtual reality treatment for speech anxiety
2025 Gut Microbiota for Health World Summit to spotlight groundbreaking research
International survey finds that support for climate interventions is tied to being hopeful and worried about climate change
Cambridge scientist launches free VR platform that eliminates the fear of public speaking
Open-Source AI matches top proprietary model in solving tough medical cases
Good fences make good neighbors (with carnivores)
NRG Oncology trial supports radiotherapy alone following radical hysterectomy should remain the standard of care for early-stage, intermediate-risk cervical cancer
Introducing our new cohort of AGA Future Leaders
Sharks are dying at alarming rates, mostly due to fishing. Retention bans may help
Engineering excellence: Engineers with ONR ties elected to renowned scientific academy
New CRISPR-based diagnostic test detects pathogens in blood without amplification
Immunotherapy may boost KRAS-targeted therapy in pancreatic cancer
Growing solar: Optimizing agrivoltaic systems for crops and clean energy
Scientists discover how to reactivate cancer’s molecular “kill switch”
YouTube influencers: gaming’s best friend or worst enemy?
uOttawa scientists use light to unlock secret of atoms
NJIT mathematician to help map Earth's last frontier with Navy grant
NASA atmospheric wave-studying mission releases data from first 3,000 orbits
‘Microlightning’ in water droplets may have sparked life on Earth
Smoke from wildland-urban interface fires more deadly than remote wildfires
What’s your body really worth? New AI model reveals your true biological age from 5 drops of blood
Protein accidentally lassos itself, helping explain unusual refolding behavior
With bird flu in raw milk, many in U.S. still do not know risks of consuming it
University of Minnesota research team awarded $3.8 million grant to develop cell therapy to combat Alzheimer’s disease
UConn uncovers new clue on what is leading to neurodegenerative diseases like Alzheimer’s and ALS
Resuscitation in out-of-hospital cardiac arrest – it’s how quickly it is done, rather than who does it
A closer look at biomolecular ‘silly putty’
Oxytocin system of breastfeeding affected in mothers with postnatal depression
Liquid metal-enabled synergetic cooling and charging: a leap forward for electric vehicles
[Press-News.org] Rising ocean acidification leads to anxiety in fishStudy shows acidity levels projected by the end of the century results in behavioral changes that could impact feeding, fisheries