(Press-News.org) CAMBRIDGE, MD (May 11, 2015)--A recent study of harmful algal blooms in the Chesapeake Bay and its tributaries by the University of Maryland Center for Environmental Science show a marked increase in these ecosystem-disrupting events in the past 20 years that are being fed by excess nitrogen runoff from the watershed. While algal blooms have long been of concern, this study is the first to document their increased frequency in the Bay and is a warning that more work is needed to reduce nutrient pollution entering the Bay's waters.
The Chesapeake Bay and its tributaries have long been suffering from harmful algae blooms caused by excess nutrients running off of the land, due largely to a continually growing population in the Baltimore-Washington corridor and the development of animal and plant agriculture in its watershed. The harmful algae blooms addressed in this paper are happening in addition to the usual spring and summer temperature-dependent blooms that result in dead zones in the Bay.
"The increasing frequency and intensity of these harmful algae blooms will impact our ability to achieve the ultimate goal of restoring a healthy ecosystem in the Bay and put a premium on effective methods to reduce nutrient pollution," said Don Boesch, President of the University of Maryland Center for Environmental Science. "This study points to the need for continued efforts to reduce the amount of nitrogen running off the land and into the Chesapeake Bay and its tributaries."
The Chesapeake Bay is not the only place facing such problems. Similar events are happening off the coast of China and in many parts of Europe. "We're seeing this all over the world. More blooms, more often, lasting longer. In many places these trends are consistent with increased nitrogen loads," said study author Pat Glibert, professor at the University of Maryland Center for Environmental Science's Horn Point Laboratory.
The study focused on three of the most common microscopic algae in the Chesapeake Bay that can produce toxic or nuisance conditions when they become very abundant. These are commonly known as harmful algal blooms, or HABs. Two are caused by dinoflagellate species, Prorocentrum minimum and Kalrodinium veneficum, and the third by cyanobacteria, sometimes called blue-green algae.
The study examined water quality data collected by the Maryland Department of Natural Resources from 1991 through 2008. During this period, the average number of Prorocentrum miminum bloom events observed per year doubled. The blooms were more likely in May and resulted in the reddish waters most commonly known as 'mahogany tide.' Such blooms are of increasing global concern and can severely reduce the amount of oxygen available to living things, kill fish and alter food webs.
The annual occurrences of Kalrodinium veneficum blooms have increased significantly from fewer than five events per year to more than 30 in the five-year time period from 2003 to 2008. These blooms, also found worldwide, are more likely in the summer, produce a toxin that has been implicated in fish-kill events in the Chesapeake Bay, as well as associated with failure of oyster spawning and development.
The frequency of blooms of cyanobacteria in the tidal waters of the Chesapeake estuary has increased from about 13 per year in the 1990s to 23 in the 2000s. Cyanobacteria are the major causes of HABs in freshwater environments, a rapidly expanding global problem that threatens human and ecosystem health. It was cyanobacteria blooms in Lake Erie that last year required shutting down the water supply in Toledo, Ohio.
This study aids in the broader understanding of the complex mechanisms that influence harmful algal bloom progression in bodies of water rich in organic nutrients such as phosphorus and nitrogen, and points to the direct need to reduce nutrient pollution in the face of both urban and agricultural development.
"There is a relationship with nutrients--as we change the nitrogen to phosphorus ratio we tend to create opportunities for these species to bloom," said Glibert. "We need to pay more attention to reducing nitrogen. We've made some progress but still have efforts to go."
"Temporal and spatial changes in Chesapeake Bay water quality and relationships to Prorocentrum minimum, Karlodinium veneficum, and CyanoHAB events, 1991-2008" was published in the journal Harmful Algae by Patricia Gilbert of the University of Maryland Center for Environmental Science, Ji Li of the University of Maryland, Department of Environmental Science and Technology, and Youghui Gao of the University of Delaware. Drs. Li and Gao conducted this research with Professor Glibert when they were graduate students at the UMCES Horn Point Laboratory.
INFORMATION:
UNIVERSITY OF MARYLAND CENTER FOR ENVIRONMENTAL SCIENCE
The University of Maryland Center for Environmental Science unleashes the power of science to transform the way society understands and manages the environment. By conducting cutting-edge research into today's most pressing environmental problems and training the next generation of environmental scientists, we are developing new ideas to help guide our state, nation, and world toward a more sustainable future. From the mountains to the sea, our five research centers include the Appalachian Laboratory in Frostburg, the Chesapeake Biological Laboratory in Solomons, the Horn Point Laboratory in Cambridge, the Institute of Marine and Environmental Technology in Baltimore, and the Maryland Sea Grant College in College Park. http://www.umces.edu
University of Melbourne animal welfare researcher Dr Jean-Loup Rault says the prospect of robopets and virtual pets is not as far-fetched as we may think.
His paper in the latest edition of Frontiers in Veterinary Science argues pets will soon become a luxury in an overpopulated world and the future may lie in chips and circuits that mimic the real thing.
"It might sound surreal for us to have robotic or virtual pets, but it could be totally normal for the next generation," Dr Rault said.
"It's not a question of centuries from now. If 10 billion human beings live ...
ATLANTA--Confirming what many parents already know, researchers at Georgia State University and the University of Washington have discovered that toddlers, especially those with siblings, understand how the sounds they make affect people around them.
The findings are published in the Journal of Cognition and Development.
There has been limited research on what children understand about what others hear, with previous studies focusing only on whether a sound could be heard. This study takes a new approach to learning what children understand about sound by introducing ...
ANN ARBOR--Climate helps drive the erosion process that exposes economically valuable copper deposits and shapes the pattern of their global distribution, according to a new study from researchers at the University of Idaho and the University of Michigan.
Nearly three-quarters of the world's copper production comes from large deposits that form about 2 kilometers (1.2 miles) beneath the Earth's surface, known as porphyry copper deposits. Over the course of millions to tens of millions of years, they are exposed by erosion and can then be mined.
Brian Yanites of the ...
In a sobering finding for global health authorities and governments around the world, a group of leading epidemiologists say two in three deaths globally -- or 40 million people -- go unreported. And one in three births -- another 40 million people -- go unregistered.
University of Melbourne Laureate Professor Alan Lopez, one of The Lancet series lead authors, has been leading a global campaign to improve how countries capture civil registration and vital statistics (CRVS). The four-paper Lancet series promote the case to change CRVS systems to collect more reliable ...
A new study links a father's age at birth to the risk that his child will develop blood and immune system cancers as an adult, particularly for only children. The study, which appears in the American Journal of Epidemiology, found no association between having an older mother and these cancers.
The proportion of parents who delay having children until age 35 or older continues to increase, but the long-term health consequences for these children are still emerging. Studies suggest higher risk of several conditions including several childhood and adult-onset cancers in ...
DURHAM, N.H. -- The underlying physical process that creates striking "breaking wave" cloud patterns in our atmosphere also frequently opens the gates to high-energy solar wind plasma that perturbs Earth's magnetic field, or magnetosphere, which protects us from cosmic radiation. The discovery was made by two University of New Hampshire space physicists, who published their findings in the online journal Nature Communications Monday, May 11, 2015.
The phenomenon involves ultra low-frequency Kelvin-Helmholtz waves, which are ubiquitous throughout the universe and create ...
The soft signs of compulsive gambling -- high energy levels, unreasonable expectations, extreme competitiveness, distorted optimism and above-average IQs -- are often the very traits that characterize competing athletes. However, precious little research is available on the prevalence of gambling among athletes and the relevant warning signs.
A new Tel Aviv University study published in The American Journal of Addictions indicates that high-schoolers involved in competitive sports are at an elevated risk of gambling. According to the research, led by Dr. Belle Gavriel-Fried ...
Whether it's being outbid at the last second in an online auction or missing the winning lottery number by one digit, we often come so close to something we can "almost taste it" only to lose out in the end. These "near wins" may actually boost our motivation to achieve other wins, leading us to pursue totally unrelated rewards, according to new research in Psychological Science, a journal of the Association for Psychological Science.
"Our research suggests that at least in some cases, losing has positive power. While we often think of motivation as being targeted to ...
Irvine, Calif., May 11, 2015 - Driving down a dimly lit road at midnight can tax even those with 20/20 vision, but according to a recent UC Irvine study, the brain processes the experience no differently than if it were noon. The same study also reveals how quickly the brain adapts to vision loss, contradicting earlier research and opening the door to novel treatments.
The findings, which appear in the April 21 edition of Proceedings of the National Academy of Sciences, are significant for those who have suffered retinal damage or disease, said cognitive scientist Alyssa ...
The increase in atmospheric CO2 concentration has allowed trees across Europe to use their available water resources more efficiently, new research has shown.
Over the course of the 20th century, the so-called water use efficiency has risen nearly 20% from the increase in atmospheric CO2 concentrations.
These results, produced by an international research team, including experts from the University of Exeter, are reported in leading scientific journal Nature Climate Change.
Trees take up carbon dioxide from the air through tiny pores on their leaves called stomata and ...
