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.
A sudden drop in outdoor temperature increases the risk of respiratory infections
11.01.2017 | University of Gothenburg
Urbanization to convert 300,000 km2 of prime croplands
27.12.2016 | Mercator Research Institute on Global Commons and Climate Change (MCC) gGmbH
Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.
While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...
Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales
Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...
Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.
As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...
At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).
Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...
Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.
The cells of the mouth, nose and intestinal mucosa produce large quantities of a chemical called sialic acid. Many bacteria possess a special transport system...
10.01.2017 | Event News
09.01.2017 | Event News
05.01.2017 | Event News
17.01.2017 | Earth Sciences
17.01.2017 | Materials Sciences
17.01.2017 | Architecture and Construction