A new publication from researchers at the University of Southampton and the National Oceanography Centre, Southampton highlights the importance of nutrients for coral reef survival.
Despite the comparably small footprint they take on the ocean floor, tropical coral reefs are home to a substantial part of all marine life forms. Coral reefs also provide numerous benefits for human populations, providing food for millions and protecting coastal areas from erosion. Moreover, they are a treasure chest of potential pharmaceuticals and coral reef tourism provides recreation and income for many.
Unfortunately, coral reefs are declining at an alarming rate. To promote management activities that can help coral reef survival, an international group of world renowned scientists have summarised the present knowledge about the challenges that coral reefs are facing now and in the future in a special issue of the journal Current Opinion in Environmental Sustainability.
The contribution of scientists from the University of Southampton to this special issue, which highlights the crucial role of nutrients for the functioning of coral reefs, can be freely downloaded from;
The University of Southampton researchers who are based at the Coral Reef Laboratory in the National Oceanography Centre, Southampton, explain that “too many” nutrients can be as bad for corals as “not enough”.
Professor Jörg Wiedenmann, Professor of Biological Oceanography at the University of Southampton and Head of the Coral Reef Laboratory, says: “The nutrient biology of coral reefs is immensely complex. It is important to distinguish between the different direct and indirect effects that a disturbance of the natural nutrient environment can have on a coral reef ecosystem.”
Since corals live in a symbiotic relationship with microscopically small plant cells, they require certain amounts of nutrients as “fertiliser”. In fact, the experimental addition of nutrients can promote coral growth. “One should not conclude from such findings, however, that nutrient enrichment is beneficial for coral reefs – usually the opposite is true,” explains Dr Cecilia D’Angelo, Senior Research Fellow in the Coral Reef Laboratory and co-author on the article.
Professor Wiedenmann, whose research on coral reef nutrient biology is supported by one of the prestigious Starting Grants from the European Research Commission, adds: “Too many nutrients harm corals in many different ways, easily outweighing the positive effects that they can undoubtedly have for the coral–alga association. Paradoxically, the initial addition of nutrients to the water column might result in nutrient starvation of the corals at a later stage. In this publication, we conceptualise the important role that the competition for nutrients by phytoplankton, the free-living relatives of the corals’ symbiotic algae, may have in this context.”
“Nutrient pollution will continue to increase in many coral reefs. Therefore, an important prerequisite to develop efficient management strategies is a profound understanding of the different mechanisms by which corals suffer from nutrient stress.”
Temperature, not snowfall, has been driving the fluctuating size of Peru’s Quelccaya Ice Cap, whose dramatic shrinkage in recent decades has made it a symbol for global climate change, a Dartmouth-led study shows.
The findings support many scientists’ suspicions that tropical glaciers are rapidly shrinking because of a warming climate, and will help scientists to better understand the natural variability of past and modern climate and to refine models that predict tropical glaciers’ response to future climate change.
The study appears in the journal Geology.
Dartmouth glacial geomorphologist Meredith Kelly and her lab team used field mapping combined with the beryllium-10 surface exposure dating method and ice cores obtained by Ohio State University paleoclimatologist Lonnie Thompson to examine how the Quelccaya Ice Cap has expanded and retreated over the past millennium. It is the first time that a record of past glacial extents has been compared directly with an annually dated ice core record from the same ice mass.
During the last millennium, a significant cooling event known as the Little Ice Age occurred, but scientists don’t know what caused the cooling or its geographic extent. The Dartmouth-led team determined beryllium-10 ages of moraines – or glacier sediments — that mark the past positions of Qori Kalis, an outlet glacier that has been monitored by Thompson since he first visited Quelccaya in the early 1960s. The Quelccaya Ice Cap, the largest ice mass in the tropics, sits 18,000 feet above sea level in the Peruvian Andes.
The results show that Qori Kalis advanced to its late Holocene maximum position prior to 520 years ago and subsequently retreated with only minor re-advances since that time. The comparison of the moraine record with the ice core record suggests that temperature was the driving force of glacial expansion and retreat, says Justin Stroup, lead author and a PhD candidate in Dartmouth’s Department of Earth Sciences.
“This is an important result since there has been debate about the causes of recent tropical glacial recession – for example, whether it is due to temperature, precipitation, humidity, solar irradiance or other factors,” says Kelly, a co-author of the study. “This result agrees with Professor Thompson’s earlier suggestions that these tropical glaciers are shrinking very rapidly today because of a warming climate.”
Furthermore, the ebbs and flows of other glaciers in tropical South America are similar to the Qori Kalis extents, indicating a regionally consistent pattern of past climate conditions. On a global scale, the results suggest that glaciers were larger than present and depositing moraines in both northern and southern hemispheres at about the same time, indicating that the climate mechanisms which caused the late Holocene cooling likely influenced a globally synchronous pattern of cooling.
Study investigates extraordinary trout with tolerance to heavily polluted water
New research from the University of Exeter and King’s College London has shown how a population of brown trout can survive in the contaminated waters of the River Hayle in Cornwall where metal concentrations are so high they would be lethal to fish from unpolluted sites. The team believe this is due to changes in the expression of their genes. The research was funded by NERC and the Salmon and Trout Association.
The researchers compared the trout living in the River Hayle with a population living in a relatively clean site in the River Teign. The results showed that the accumulation of metals in the kidney and liver – where metals are stored and detoxified – were 19 and 34 times higher in the Hayle trout, respectively. In the gill, concentrations averaging 63 times higher were present in the Hayle fish, but there were no differences in metal content in the gut. This accumulation of metals in the Hayle fish highlights their extraordinary tolerance of the extreme metal concentrations in their environment.
In order to investigate how the Hayle brown trout are able to tolerate such high levels of metal exposure, and also look for potential signs of toxicity, advanced high throughput sequencing was conducted at the Exeter Sequencing Facility to sequence the genes and then measure changes in their expression between the two river sites. The gene encoding a protein, metallothionein, responsible for binding, storing and detoxifying a number of metals, was found to be highly expressed in the River Hayle trout, indicating its importance in their ability to tolerate metals in their environment. Evidence of the presence of other metal-binding and transporting proteins, particularly those responsible for handling iron, was also found.
Usually metals cause toxicity in fish by causing oxidative damage and disrupting the balance of ions in the body. The team found evidence that to counter this toxicity, Hayle fish showed changes in genes responsible for maintaining the balance of these ions in the body and a modest increase in anti-oxidants.
This work was led by T. Uren Webster, Dr R. van Aerle and Dr E Santos from the University of Exeter and Dr N Bury from King’s College London, and has been published in the journal Environmental Science & Technology.
Tamsyn Uren Webster said: “The work demonstrates that this population of brown trout has developed strategies for dealing with the metal pollution in the water and accumulation in their tissues avoiding the lethal damage that such concentrations of metals would normally cause.”
A detailed understanding of how the Hayle trout population has developed this tolerance could have potential implications for re-stocking rivers and increasing food security in polluted regions of the world.
Dr Eduarda Santos said: “The story of the brown trout in the river Hayle is a fascinating one, demonstrating its resilience and its ability to defeat the odds and tolerate the challenges imposed upon them as a result of human activities. Many aspects of this story remain untold: we do not know how or when this tolerance has arisen, and, most importantly, we do not know what the future holds for them if they are challenged with further stressors in their environment. But we know that such populations need careful management; if the Hayle brown trout, with their unique physiology, were to be lost, it is possible that this river may never be home to brown trout again. Therefore, understanding the relationship of fish with their environment is a crucial requirement to effectively manage and protect our aquatic ecosystems.”
Dr Nic Bury said: “Cornwall has a rich history of mining activity. Despite the cessation of the majority of this activity in the 19th and 20th centuries a number of rivers and estuaries, still possess elevated metals. Brown trout are extremely sensitive to metals when tested in the laboratory. However, biology is remarkable and adaptable, and it is astonishing that trout are able to survive and flourish in the river Hayle. It may be that this population is unique and an important component of the genetic diversity of brown trout.”
View the paper online: http://pubs.acs.org/doi/abs/10.1021/es401380p
About the University of Exeter
The Sunday Times University of the Year 2012-13, the University of Exeter is a Russell Group university and in the top one percent of institutions globally. It combines world-class research with very high levels of student satisfaction. Exeter has over 18,000 students and is ranked 7th in The Sunday Times University Guide, 10th in The Complete University Guide, 10th in the UK in The Times Good University Guide 2012 and 12th in the Guardian University Guide 2014. In the 2008 Research Assessment Exercise (RAE) 90% of the University’s research was rated as being at internationally recognised levels and 16 of its 31 subjects are ranked in the top 10, with 27 subjects ranked in the top 20. The University has invested strategically to deliver more than £350 million worth of new facilities across its campuses in the last few years; including landmark new student services centres – the Forum in Exeter and The Exchange on the Penryn Campus in Cornwall, together with world-class new facilities for Biosciences, the Business School and the Environment and Sustainability Institute. There are plans for another £330 million of investment between now and 2016.http://www.exeter.ac.uk
The humble bumblebee is a happy helpful garden critter, but because of many different issues is disappearing far too quickly. Something needs to be done about it, and now is the time to start. Bumblebees are endearing and familiar insects. Their animated behaviour and deep buzz as they fly from flower to flower makes them a delight to watch.
Sadly though, our bumblebees have been declining because of changes in agricultural practises that have largely removed flowers from the landscape, leaving the bumblebees with little to feed upon. Most UK species have declined greatly in recent years, and two have become extinct in the UK since 1940.
Even worse, bee killing pesticides and chemicals are still being used in the UK. Friday 15 March, 2013 was a terrible day for bees as the EU failed to ban three neonicotinoid pesticides. Decision-makers failed to recognise the weight of evidence against bee-damaging, neonicotinoid pesticides.
However the process doesn’t end here and the European Commission may still be able to enforce a ban.
Visit http://www.soilassociation.org/supportus/keepbritainbuzzing to register for your own free seeds to start your bee friendly garden.
Click this link to visit the RHS pages to understand which plants can make a bee friendly garden – http://www.rhs.org.uk/Gardening/Sustainable-gardening/Plants-for-pollinators
To get involved join http://bumblebeeconservation.org/
To educate your little hatchlings visit Wikipedia http://en.wikipedia.org/wiki/Bumblebee
NASA’s Operation IceBridge scientists have begun another season of research activity over Arctic ice sheets and sea ice with the first of a series of science flights from Greenland.
A specially equipped P-3B research aircraft from NASA’s Wallops Flight Facility in Wallops Island, Va., is operating out of airfields in Thule and Kangerlussuaq, Greenland, and Fairbanks, Alaska. The flights will carry out survey flights over land and sea ice in and around Greenland and the Arctic Ocean through early May.
NASA began the Operation IceBridge airborne campaign in 2009 as a way to continue the record of polar ice measurements made by NASA’s Ice, Cloud and Land Elevation Satellite’s (ICESat) after the satellite stopped gathering data. By flying campaigns in the Arctic and Antarctic each year, IceBridge is maintaining a continuous record of change until the launch of ICESat-2 in 2016.
This year’s IceBridge campaign will continue closely monitoring Arctic sea ice and key areas of the Greenland ice sheet, while expanding coverage in Antarctica.
“Our long term plan, beginning with the Arctic 2013 campaign, is to scale back the land ice portion of the campaign while maintaining the same coverage of sea ice as in previous campaigns,” said Michael Studinger, IceBridge project scientist at NASA’s Goddard Space Flight Center in Greenbelt, Md.
Dramatic changes to Arctic sea ice, such as the record-breaking minimum levels reached in 2012, and the potential societal effects of ice loss in the region are driving the demand for sea ice measurements. The mission will survey areas of Arctic sea ice near Greenland with flights out of the U.S. airbase in Thule. IceBridge also will carry out a series of flights from Fairbanks to measure ice in the Beaufort and Chukchi seas north of Alaska. Researchers will gather critical data during their flights between Greenland and Alaska.
In addition to sea ice, IceBridge will survey the Greenland Ice Sheet in the interior of the country and in rapidly changing areas along the coast, such as the Jakobshavn Glacier.
“We’re starting to see how the whole ice sheet is changing,” Studinger said. “Thinning at the margins is now propagating to the interior.”
IceBridge scientists will collaborate with other groups doing research in the region, such as the U.S. Army Corps of Engineers Cold Regions Engineering Laboratory in Hanover, N.H., and the Naval Research Laboratory (NRL) in Washington. The laboratories are working together to collect snow depth measurements on Elson Lagoon near Barrow, Alaska, to help NRL evaluate a snow radar they are using.
Joining the IceBridge team are three teachers who will spend time working with the researchers to learn about polar science. High school science teachers from Libertyville, Illinois; Aalborg, Denmark; and Sisimiut, Greenland, will spend time aboard the P-3B during IceBridge survey flights.
IceBridge is providing these teachers with a research experience they can use to better teach science and inspire their students to study scientific fields. The teachers’ involvement is the result of a partnership with the U.S. State Department, the governments of Denmark and Greenland, and the National Science Foundation-funded Polar Teachers and Researchers Exploring and Collaborating program.
For more about Operation IceBridge and to follow this year’s campaign, visit: http://www.nasa.gov/icebridge
For more about PolarTREC and the IceBridge teacher research experience, visit: http://go.nasa.gov/13cycwM
The Amazon rainforest and the word “deforestation” have gone hand in hand for many years. But today, I want you to substitute that word with “improvement” – because things are getting better.
The destruction of the rainforest is now at its lowest rate since monitoring regimes began in Brazil 24 years ago.
Although 4,600 square kilometres of forest were still lost between July 2011 and July 2012, this was a 27% reduction on the previous 12 months. In the Mato Grosso region the reduction was 31% and in Para it was 44%.
As deforestation releases large quantities of CO2, Brazil has been one of the largest greenhouse gas emitters in the world. Any reduction to this is very encouraging news and shows just how much is possible when stringent environmental policy is enforced.
The Brazilian government hopes to reduce deforestation to 3,925 square kilometres by 2020; this is now looking achievable.
Things can only get better.
For more information see here: http://www.treehugger.com/natural-sciences/amazon-deforestation-rate-lowest-record.html