CORVALLIS, Ore. – One of the largest and longest experiments ever done to test the impact of nutrient loading on coral reefs today confirmed what scientists have long suspected – that this type of pollution from sewage, agricultural practices or other sources can lead to coral disease and bleaching.
A three-year, controlled exposure of corals to elevated levels of nitrogen and phosphorus at a study site in the Florida Keys, done from 2009-12, showed that the prevalence of disease doubled and the amount of coral bleaching, an early sign of stress, more than tripled.
However, the study also found that once the injection of pollutants was stopped, the corals were able to recover in a surprisingly short time.
"We were shocked to see the rapid increase in disease and bleaching from a level of pollution that's fairly common in areas affected by sewage discharge, or fertilizers from agricultural or urban use," said Rebecca Vega-Thurber, an assistant professor in the College of Science at Oregon State University.
"But what was even more surprising is that corals were able to make a strong recovery within 10 months after the nutrient enrichment was stopped," Vega-Thurber said. "The problems disappeared. This provides real evidence that not only can nutrient overload cause coral problems, but programs to reduce or eliminate this pollution should help restore coral health. This is actually very good news."
The findings were published today in Global Change Biology, and offer a glimmer of hope for addressing at least some of the problems that have crippled coral reefs around the world. In the Caribbean Sea, more than 80 percent of the corals have disappeared in recent decades. These reefs, which host thousands of species of fish and other marine life, are a major component of biodiversity in the tropics. Read more
Scientists are worried the Great Barrier Reef is on the verge of being hit by the most damaging crown of thorns starfish outbreak on record.
Sections of the reef between Cooktown and Cairns are already in the grip of an outbreak, the fourth recorded since the 1960s.
"At the moment the crown of thorns are still ramping up in numbers," said Col McKenzie, who heads the Association of Marine Park Tourism Operators (AMPTO).
"I would expect it would be 12 months before we'll see a full-on outbreak off Cairns."
Scientists say the growing plague, which comprises at least a million starfish over hundreds of kilometres, is steadily moving south with the ocean current. Read more
Dr. Ir. J.M. de Goeij. University of Amsterdam (UvA). Institute for Biodiversity and Ecosystem Dynamics – Aquatic Ecology and Ecotoxicology (IBED-AEE)
Sponges retain the majority of energy and nutrients produced on coral reefs, dissolved organic matter (DOM), and transfer it to reef fauna as cellular debris through a rapid cell turnover. DOM transfer through th sponge loop approaches the gross primary production rates required for the entire coral reef ecosystem.
Surviving in a Marine Desert: The Sponge Loop Retains Resources Within Coral Reefs
“Ever since Darwin’s early descriptions of coral reefs, scientists have debated how one of the world’s most productive and diverse ecosystems can thrive in the marine equivalent of a desert. It is an enigma how the flux of dissolved organic matter (DOM), the largest resource produced on reefs, is transferred to higher trophic levels. Here we show that sponges make DOM available to fauna by rapidly expelling filter cells as detritus that is subsequently consumed by reef fauna. This “sponge loop” was confirmed in aquarium and in situ food web experiments, using 13C- and 15N-enriched DOM. The DOM-sponge-fauna pathway explains why biological hot spots such as coral reefs persist in oligotrophic seas—the reef’s paradox—and has implications for reef ecosystem functioning and conservation strategies.”
Check out also an English subtitled Dutch TV program Labyrint TV, where we explain the sponge loop:
Science Daily. Oct. 9, 2013 — The seesaw variability of global temperatures often engenders debate over how seriously we should take climate change. But within 35 years, even the lowest monthly dips in temperatures will be hotter than we've experienced in the past 150 years, according to a new and massive analysis of all climate models. The tropics will be the first to exceed the limits of historical extremes and experience an unabated heat wave that threatens biodiversity and heavily populated countries with the fewest resources to adapt.
Ecological and societal disruptions by modern climate change are critically determined by the time frame over which climates shift. Camilo Mora and colleagues in the College of Social Sciences' Department of Geography at the University of Hawaii, Manoa have developed one such time frame. The study, entitled "The projected timing of climate departure from recent variability," will be published in the October 10 issue of Nature and provides an index of the year when the mean climate of any given location on Earth will shift continuously outside the most extreme records experienced in the past 150 years.
The new index shows a surprising result. Areas in the tropics are projected to experience unprecedented climates first — within the next decade. Under a business-as-usual scenario, the index shows the average location on Earth will experience a radically different climate by 2047. Under an alternate scenario with greenhouse gas emissions stabilization, the global mean climate departure will be 2069. Read more
The mystery of how coral reefs thrive in "ocean deserts" has been solved, scientists say.
Reefs are among Earth's most vibrant ecosystems, yet they flourish in waters lacking nutrients – a phenomenon known as Darwin's Paradox.
A team found that sponges keep the reef alive – by recycling vast amounts of organic matter to feed snails, crabs and other creatures.
Writing in Science, they hope their findings will aid conservation.
Sponges recycle nearly ten times as much matter as bacteria, and produce as much nutrition as all the corals and algae in a reef combined, the scientists calculate.
They are the "unsung heroes" of the reef community, said lead author Jasper de Goeij, an aquatic ecologist at the University of Amsterdam.
"Up until now no-one has really paid sponges much attention. They look nice, but everybody was more interested in corals and fish," he told BBC News. Read more
"For each fish that survives, 90 are flushed down the toilet."
October 2013. Though Finding Nemo introduced millions of viewers to the beauty of saltwater fish, Nemo and most of his friends may literally end up down the drain.
The World Wide Fund for Nature (WWF-Philippines) estimates that as many as 98 out of 100 wild-caught saltwater fish die within one year.
80% or marine fish die before they are sold
Due to the volatility of current capture, transport and shipping practices, about 80% of all marine fish die even before they are sold. Even more shocking is the fact that as much as 90% of those that are sold die within the first year. Only the hardiest – clownfish, damselfish, wrasses, gobies and blennies – or those lucky enough to be bought by elite hobbyists, survive.
Trade in Living Jewels
There are three basic types of fish – saltwater fish from the sea, freshwater fish from rivers or lakes, and brackish water fish from zones where fresh and saltwater mix. Because of the volatile nature of rivers, most fresh and brackish water fish have learned to adapt to dramatic fluctuations in water quality. Read more
Climate changes have increased the occurrence of infectious diseases in some natural and agricultural systems, and developing predictive early-warning systems will be crucial to combat their spread. A review article in the Aug. 2 issue of Science presents the current state of the science and forecasting recommendations.
In gorgonian corals, also known as sea fans, warmer temperatures increase defenses, but also lead to faster replication for coral pathogens and changes in associated bacteria. The sea fan system has become a model system for Harvell’s work to link changes in coral immunity to climate events. Disease outbreaks have coincided with warmer sea temperatures in the Caribbean, and warming has led to the emergence of new pathogens that have greatly reduced coral populations and led to ecosystem-wide repercussions, according to the paper.
July 24, 2013
The following is part five in a series on the NSF-NIH Ecology and Evolution of Infectious Diseases (EEID) Program.
Like all of us, corals get sick. They respond to pathogens (disease-causing microbes) and recover or die. But unlike us, they can't call a doctor for treatment.
Instead, help has arrived in the form of scientists who study the causes of the corals' disease, and the immune factors that might be important in their response and resistance.
With support from the National Science Foundation (NSF), scientists Drew Harvell and Colleen Burge of Cornell University and their colleagues have developed a catalog of genes that, the researchers say, will allow us to better understand the immune systems of corals called sea fans.
The marine ecologists have trained their undersea eyes on a particular sea fan species, Gorgonia ventalina, or the purple sea fan, found in the western Atlantic Ocean and the Caribbean Sea. Read more
Article: National Science Foundation. http://www.nsf.gov
News Desk on July 20, 2013
Washington, July 20 (ANI): A team of international researchers have compiled the first ever global atlas cataloguing marine plankton ranging in size from bacteria to jellyfish, to identify where, when, and how much oceanic plankton can be found around the globe.
The atlas, known as the Marine Ecosystem Biomass Data (MAREDAT), is the first step towards a comprehensive inventory of the marine biota based on counts of individual cells or organisms.
It will help researchers better understand marine biodiversity for conservation and monitoring and is the result of collaborations between scientists at the Woods Hole Oceanographic Institution (WHOI), the University of East Anglia, ETH Zurich, University of Manchester, Universite d’Angers and CNRS, the US National Oceanic and Atmospheric Administration (NOAA), together with many other scientific institutions around the world. Read more
Once a lush and healthy estuary, the Indian River Lagoon is now an enigmatic death trap. Running along 40 percent of Florida’s Atlantic coast, the lagoon’s brackish waters harbor a mysterious killer that has claimed the lives of hundreds of manatees, pelicans, and dolphins.
Nobody knows why.
In April, NOAA declared the spate of manatee deaths an Unusual Mortality Event, a designation granted when marine mammal deaths or strandings are significantly higher than normal, demand immediate attention, and are the result of a common but unknown cause. Soon, the bottlenose dolphin die-off may be given the same designation.
“We have to hope we can find the answer, because until we do, we don’t know how we can help prevent it in the future,” said Jan Landsberg, a research scientist with the Florida Fish and Wildlife Conservation Commission.
Since last July, 51 dolphins, 111 manatees, and as many as 300 pelicans have perished in the lagoon. The deaths don’t follow an obvious pattern: Manatees are dying so quickly that some still have food in their mouths, while the dolphins and pelicans appear to be starving to death.