Zoom into a coral reef and discover photosynthetic algae inside the coral’s cells.
Reef-building corals rely on these symbionts for their survival.
Monday, May 25, 2015
Sunday, May 24, 2015
Saturday, May 23, 2015
El Niño explained
What is El Nino and what does it mean?
In this animated video, we explain what El Nino is and how it affects weather around the world.
From MetOffice
El Niño and La Niña are terms which describe the biggest fluctuation in the Earth's climate system and can have consequences across the globe.
The fluctuation sees changes in the sea-surface temperature of the tropical Pacific Ocean which occur every few years.
What causes El Niño?
These events are due to strong and extensive interactions between the ocean and atmosphere.
They are associated with widespread changes in the climate system that last several months, and can lead to significant human impacts affecting things such as infrastructure, agriculture, health and energy sectors.
The name 'El Niño' nowadays is widely used to describe the warming of sea surface temperature that occurs every few years, typically concentrated in the central-east equatorial Pacific.
'La Niña' is the term adopted for the opposite side of the fluctuation, which sees episodes of cooler-than-normal sea surface temperature in the equatorial Pacific.
These episodes alternate in an irregular inter-annual cycle called the El Niño Southern Oscillation (ENSO).
Southern Oscillation is the term for atmospheric pressure changes between the east and west tropical Pacific that accompany both El Niño and La Niña episodes in the ocean.
ENSO is the dominant feature of climate variability on inter-annual timescales.
Our research helped show that El Niño and La Niña cycle has impacts all over the world.
For example, El Niño years are one factor that can increase the risk of colder winters in the UK.
We now better understand these impacts and reproduce many of them in our climate models.
Friday, May 22, 2015
Ocean's hidden world of plankton revealed in 'enormous database'
The Tara, a 36-meter schooner, traveled over 180,000 miles collecting biological samples.
©bepoles/Tara Expéditions
From BBC by Rebecca Morelle
The hidden world of the ocean's tiniest organisms has been revealed in a series of papers published in the journal Science.
An international team has been studying samples of plankton collected during a three-year global expedition.
Planktonic organisms such as these single-celled creatures are found throughout the oceans
They have so far found 35,000 species of bacteria, 5,000 new viruses and 150,000 single-celled plants and creatures.
They believe that the majority of these are new to science.
Dr Chris Bowler, from the National Centre for Scientific Research (CNRS), in Paris, told BBC News: "We have the most complete description yet of planktonic organisms to date: what's there in terms of viruses, bacteria and protozoa - we finally have a catalogue of what is present globally."
This tiny crustacean was found in a sample taken in the South Pacific
Planktonic organisms are minute, but together they make up 90% of the mass of all of the marine life in the oceans.
They include viruses, bacteria, single-celled plants and creatures (protozoa).
They form the very base of the food chain, and produce - through photosynthesis - half of the oxygen we breathe.
However, until now, little has been known about this unseen ocean ecosystem.
The Tara expedition, primarily funded by the French fashion designer Agnes B, set out to change that.
Many of the organisms are new to science
An international team of scientists took part in expeditions onboard the Tara schooner between 2009 and 2013.
It sailed 30,000km across the world's oceans, with researchers collecting 35,000 samples, taking them from the very top layers of the ocean down to 1,000m below the waves.
The project has cost about 10m euros.
It sailed 30,000km across the world's oceans, with researchers collecting 35,000 samples, taking them from the very top layers of the ocean down to 1,000m below the waves.
The project has cost about 10m euros.
So far the team has analysed 579 of the 35,000 samples that were collected
New viruses
So far the scientists have analysed 579 of the 35,000 samples collected, presenting the results in five scientific papers.
Dr Bowler said the research was transforming our understanding of these ocean communities.
"For the viruses, we describe about 5,000 virus communities - only 39 of these were previously known.
"And for protists - unicellular organisms - we estimate something like 150,000 different taxa.
"There are about 11,000 formally described species of plankton - we have evidence for at least 10 times more than that."
The analysis has revealed that many of the organisms are sensitive to temperature
The researchers also looked at how the different organisms interacted
Of the 35,000 microbes found, most had been seen before, however a genetic analysis of them revealed many new genes.
"We have 40 million genes - about 80% of which are new to science," explained Dr Bower.
The researchers also analysed how plankton communities are organised.
"We have thrown all of these together to see who interacts with whom," said Dr Bower.
"We now have a big dataset where we can ask: 'who do you always find with someone else?' or 'who do you never find with someone else'.
"This helps us to describe symbiosis and interactions that go beyond grazing and predator-prey relationships."
"We have 40 million genes - about 80% of which are new to science," explained Dr Bower.
The researchers also analysed how plankton communities are organised.
"We have thrown all of these together to see who interacts with whom," said Dr Bower.
"We now have a big dataset where we can ask: 'who do you always find with someone else?' or 'who do you never find with someone else'.
"This helps us to describe symbiosis and interactions that go beyond grazing and predator-prey relationships."
Planktonic organisms such as these tiny jellyfish and fish are found throughout the oceans
'Enormous' database
The researchers have found that many of the organisms, particularly the bacteria, are sensitive to temperature.
Dr Bowler said: "It is temperature that determines what sort of communities of organisms we find.
The researchers have found that many of the organisms, particularly the bacteria, are sensitive to temperature.
Dr Bowler said: "It is temperature that determines what sort of communities of organisms we find.
If we look at our data and we see what organisms are there, we can predict with 97% probability the temperature of the water they are living in.
"These organisms are most sensitive to temperature, more than anything else, and with changing temperatures as a result of climate change we are likely to see changes in this community."
The researchers say that this scientific analysis is just the beginning.
They are making their findings freely available to the scientific community to gain a better understanding of this vital but unseen underwater world.
Dr Bowler continued: "The amount of data we have released is already enormous; it is one of the largest databases of DNA available to the scientific community. But we've analysed perhaps 2% of the samples we have collected throughout the world - so there is a huge amount of work to do in the future to understand even more about the functioning of these marine ecosystems and the importance of that for the wellbeing of the planet.
"So it's really just the beginning of the study."
"These organisms are most sensitive to temperature, more than anything else, and with changing temperatures as a result of climate change we are likely to see changes in this community."
The researchers say that this scientific analysis is just the beginning.
They are making their findings freely available to the scientific community to gain a better understanding of this vital but unseen underwater world.
Dr Bowler continued: "The amount of data we have released is already enormous; it is one of the largest databases of DNA available to the scientific community. But we've analysed perhaps 2% of the samples we have collected throughout the world - so there is a huge amount of work to do in the future to understand even more about the functioning of these marine ecosystems and the importance of that for the wellbeing of the planet.
"So it's really just the beginning of the study."
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