(Press-News.org) New research has found as climate change causes the world's oceans to warm, baby sharks are born smaller, exhausted, undernourished and into environments that are already difficult for them to survive in.
Lead author of the study Carolyn Wheeler is a PhD candidate at the ARC Centre of Excellence for Coral Reef Studies at James Cook University (Coral CoE at JCU) and the University of Massachusetts. She examined the effects of increased temperatures on the growth, development and physiological performance of epaulette sharks--an egg-laying species found only on the Great Barrier Reef. She and her team studied the sharks as embryos and as hatchlings.
"We tested shark embryos in waters up to 31°C," Ms Wheeler said.
"The hotter the conditions, the faster everything happened, which could be a problem for the sharks. The embryos grew faster and used their yolk sac quicker, which is their only source of food as they develop in the egg case. This led to them hatching earlier than usual."
This meant hatchlings were not only smaller, they needed to feed almost straight away--while lacking significant energy.
Co-author Associate Professor Jodie Rummer, also from Coral CoE at JCU, says the waters of the Great Barrier Reef will likely experience summer averages close to or even in excess of 31°C by the end of the century.
Since sharks don't care for their eggs after they are laid, a shark egg must be able to survive unprotected for up to four months. Dr Rummer flags rising ocean temperatures as a major concern for the future of all sharks--both egg-laying and live-bearing species.
"The epaulette shark is known for its resilience to change, even to ocean acidification," Dr Rummer said. "So, if this species can't cope with warming waters then how will other, less tolerant species fare?" she said.
Sharks and the class of animals they belong to, which includes rays and skates, are slow growing. They also don't reproduce that often compared to other fishes. The populations of these creatures are already threatened across the globe.
The study suggests the sharks of the future will be born--or hatch, in this case--not only at a disadvantage but into environments that are already at the warmest they can tolerate.
"The study presents a worrying future given that sharks are already threatened," Ms Wheeler said.
"Sharks are important predators that keep ocean ecosystems healthy. Without predators, whole ecosystems can collapse, which is why we need to keep studying and protecting these creatures."
"Our future ecosystems depend us taking urgent action to limit climate change," Dr Rummer said.
INFORMATION:
The research was a collaborative effort between the Anderson Cabot Center for Ocean Life and the husbandry staff at the New England Aquarium in Boston. The New England Aquarium has a successful breeding program for epaulette sharks.
PAPER
Wheeler C, Rummer J, Bailey B, Lockwood J, Vance S, Mandelman J. (2020). 'Future thermal regimes for epaulette sharks (Hemiscyllium ocellatum): growth and metabolic performance cease to be optimal'. Scientific Reports, 10: 79953. DOI: 10.1038/s41598-020-79953-0
CONTACTS
Carolyn Wheeler
E: carolyn.wheeler@my.jcu.edu.au
A/Prof Jodie Rummer
P: +61 (0)439 166 171
E: jodie.rummer@jcu.edu.au
FOR FURTHER INFORMATION
Melissa Lyne / Coral CoE
P: +61 (0)415 514 328
E: melissa.lyne@jcu.edu.au
COLUMBUS, Ohio - An unfortunate truth about the use of mechanical ventilation to save the lives of patients in respiratory distress is that the pressure used to inflate the lungs is likely to cause further lung damage.
In a new study, scientists identified a molecule that is produced by immune cells during mechanical ventilation to try to decrease inflammation, but isn't able to completely prevent ventilator-induced injury to the lungs.
The team is working on exploiting that natural process in pursuit of a therapy that could lower the chances for lung damage in patients on ventilators. Delivering high levels of the helpful molecule with a nanoparticle was effective ...
Abu Dhabi, United Arab Emirates, January 12, 2020: New research from NYU Abu Dhabi's Laboratory of Neural Systems and Behavior for the first time used an animal model to demonstrate how abnormal sleep architecture can be a predictor of stress vulnerability. These important findings have the potential to inform the development of sleep tests that can help identify who may be susceptible -- or resilient -- to future stress.
In the study, Abnormal Sleep Signals Vulnerability to Chronic Social Defeat Stress, which appears in the journal Frontiers in Neuroscience, NYUAD Assistant Professor of Biology Dipesh Chaudhury and Research Associate Basma Radwan describe their development of a mouse ...
ORLANDO, Fla. -- A new national survey by the Orlando Health Heart & Vascular Institute finds many Americans would delay doctor's appointments and even emergency care when COVID-19 rates are high. The survey found 67 percent of Americans are more concerned about going to medical appointments when COVID-19 rates are high in their area and nearly three in five (57 percent) are hesitant to go to the hospital even for an emergency.
In a time when every trip out of the house and every person we come in contact with poses a threat of contracting COVID-19, ...
WASHINGTON - Computer-based artificial intelligence can function more like human intelligence when programmed to use a much faster technique for learning new objects, say two neuroscientists who designed such a model that was designed to mirror human visual learning.
In the journal Frontiers in Computational Neuroscience, Maximilian Riesenhuber, PhD, professor of neuroscience, at Georgetown University Medical Center, and Joshua Rule, PhD, a postdoctoral scholar at UC Berkeley, explain how the new approach vastly improves the ability of AI software to quickly learn new visual ...
The Korea Institute of Science and Technology (KIST) has announced that the research team led by Dr. Kim Kyoung-Whan at the Center for Spintronics has proposed a new principle about spin memory devices, which are next-generation memory devices. This breakthrough presents new applicability that is different from the existing paradigm.
Conventional memory devices are classified into volatile memories, such as RAM, that can read and write data quickly, and non-volatile memories, such as hard-disk, on which data are maintained even when the power is off. In recent years, related academic and industrial fields have been combining their advantages to accelerate the development of next-generation memory that is fast and capable of maintaining data even when the power is off.
A spin memory ...
The leaf vasculature of plants plays a key role in transporting solutes from where they are made - for example from the plant cells driving photosynthesis - to where they are stored or used. Sugars and amino acids are transported from the leaves to the roots and the seeds via the conductive pathways of the phloem.
Phloem is the part of the tissue in vascular plants that comprises the sieve elements - where actual translocation takes place - and the companion cells as well as the phloem parenchyma cells. The leaf veins consist of at least seven distinct cell types, with specific roles in transport, metabolism and signalling.
Little is known about ...
A team of HIV researchers, cellular biologists, and biophysicists who banded together to support COVID-19 science determined the atomic structure of a coronavirus protein thought to help the pathogen evade and dampen response from human immune cells. The structural map - which is now published in the journal PNAS, but has been open-access for the scientific community since August - has laid the groundwork for new antiviral treatments tailored specifically to SARS-CoV-2, and enabled further investigations into how the newly emerged virus ravages the human body.
"Using X-ray crystallography, we built an ...
A new study published in the American Journal of Preventive Medicine found a 25% increase in food insufficiency during the COVID-19 pandemic. Food insufficiency, the most extreme form of food insecurity, occurs when families do not have enough food to eat. Among the nationally representative sample of 63,674 adults in the US, Black and Latino Americans had over twice the risk of food insufficiency compared to White Americans.
"People of color are disproportionately affected by both food insufficiency and COVID-19," said Jason Nagata, MD, MSc, assistant professor of pediatrics at the University of California, San Francisco and lead author on the study. "Many of these individuals have experienced job loss and higher rates of poverty during the ...
During April 2020, while the UK was in full lockdown, there was a drop of more than a third in the number of people seeking help for mental illness or self-harm according to research involving 14 million people registered at general practices across the four nations of the UK which was published today in The Lancet Public Health*.
The research, 'Effects of the COVID-19 pandemic on primary care-recorded mental illness and self-harm episodes in the UK: a population-based cohort study', was conducted by the National Institute for Health Research Greater Manchester Patient Safety Translational Research Centre (NIHR GM PSTRC). The Centre is a partnership between The University of Manchester and Salford Royal NHS Foundation ...
In a surprising discovery, Princeton physicists have observed an unexpected quantum behavior in an insulator made from a material called tungsten ditelluride. This phenomenon, known as quantum oscillation, is typically observed in metals rather than insulators, and its discovery offers new insights into our understanding of the quantum world. The findings also hint at the existence of an entirely new type of quantum particle.
The discovery challenges a long-held distinction between metals and insulators, because in the established quantum theory of materials, insulators were not thought to be able to ...
