Rising carbon dioxide levels in the ocean have been shown to adversely affect shell-forming creatures and corals, and now a new study by researchers at Scripps Institution of Oceanography at UC San Diego has shown for the first time that CO2 can impact a fundamental bodily structure in fish.
A brief paper published in the June 26 issue of the journal Science describes experiments in which fish that were exposed to high levels of carbon dioxide experienced abnormally large growth in their otoliths, or ear bones. Otoliths serve a vital function in fish by helping them sense orientation and acceleration.
The researchers had hypothesized that otoliths in young white seabass growing in waters with elevated carbon dioxide would grow more slowly than a comparable group growing in seawater with normal CO2 levels. They were surprised to discover the reverse, finding “significantly larger” otoliths in fish developing in high-CO2 water.
The fish in high-CO2 water were not larger in overall size, only the otoliths grew demonstrably bigger.
“At this point one doesn’t know what the effects are in terms of anything damaging to the behavior or the survival of the fish with larger otoliths,” said David Checkley, a Scripps Oceanography professor and lead author of the new study. “The assumption is that anything that departs significantly from normality is an abnormality and abnormalities at least have the potential for having deleterious effects.”
With carbon dioxide levels rising due to human activities, particularly fossil fuel burning, resulting in both increased ocean CO2 and ocean acidification, the researchers intend to broaden their studies to examine specific areas, such as determining whether the otolith growth abnormality exists in fish other than white seabass; locating the physical mechanism that causes the enhanced otolith growth; and assessing whether the larger otoliths have a functional effect on the survival and the behavior of the fish.
“Number three is the big one,” said Checkley. “If fish can do just fine or better with larger otoliths then there’s no great concern. But fish have evolved to have their bodies the way they are. The assumption is that if you tweak them in a certain way it’s going to change the dynamics of how the otolith helps the fish stay upright, navigate and survive.”
In addition to serving in orientation and acceleration, otoliths help reveal physical characteristics of fish. Because otoliths grow in onion-like layers, scientists use otoliths to determine the age of fish, counting the increments similar to tree-ring dating.
Coauthors of the paper include Andrew Dickson, John Radich and Rebecca Asch of Scripps Oceanography; Motomitsu Takahashi of the Seikai National Fisheries Research Institute in Nagasaki, Japan; and Nadine Eisenkolb of the University of Southern California.
The research was supported by the Academic Senate of UC San Diego.
Scripps News: scrippsnews.ucsd.edu
Scripps Institution of Oceanography, at UC San Diego, is one of the oldest, largest and most important centers for global science research and education in the world. The National Research Council has ranked Scripps first in faculty quality among oceanography programs nationwide. Now in its second century of discovery, the scientific scope of the institution has grown to include biological, physical, chemical, geological, geophysical and atmospheric studies of the earth as a system. Hundreds of research programs covering a wide range of scientific areas are under way today in 65 countries. The institution has a staff of about 1,300, and annual expenditures of approximately $155 million from federal, state and private sources. Scripps operates one of the largest U.S. academic fleets with four oceanographic research ships and one research platform for worldwide exploration.
Smart Data Transformation – Surfing the Big Wave
02.12.2016 | Fraunhofer-Institut für Angewandte Informationstechnik FIT
Climate change could outpace EPA Lake Champlain protections
18.11.2016 | University of Vermont
In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.
Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...
Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.
The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
08.12.2016 | Physics and Astronomy
08.12.2016 | Health and Medicine
08.12.2016 | Life Sciences