Podcast – Research into the affect of ocean acidification on pteropods, the canary of the ocean

Podcast with Dr Geraint Tarling, British Antarctic Survey

Scientists on the Road

One of our volunteers and helpers at the Winchester Science Festival was the journalist and press officer Maria Elena Ribezzo. Her role was double, a volunteer as well as a correspondent for Scientists on the Road.  Below Maria Elena’s thoughts of our day at Winchester.

By Maria Elena Ribezzo

From the 20th to the 22th of July, the beautiful medieval town of Winchester has hosted the annual Science Festival. The University of Southampton’s ‘Bringing Research to Life’ Roadshow was in the Discovery Centre with hands-on interactive science, showcasing different areas of research throughout the Festival.

DNA extraction, engineering design, Bio-energy generated from waste, new technologies. Topics covered were many: life sciences, neuro-psychology, maths and physics, sustainability, computing, space and engineering.

The Team - Marcello Passaro, Maria Elena Ribezzo, Victoire Rerolle, Abbie Chapman, Ed Waugh

Scientists on the road” were present with an experiment to explain to future scientists the Ocean Acidification and the impact of carbon dioxide absorbed by the ocean. 

Approximately one quarter  of carbon dioxide emitted by humans in the air is absorbed by the ocean. This alters the chemical composition of the sea: a more acidic water threatens the life conditions of organisms whose skeletons or cells are made of calcium carbonate, such as phytoplankton, snails, mussels or, more evident to the human eye, corals. In order to explain children how Ocean Acidification works, we used red cabbage juice, a safe acid/base indicator which reacts in a clear manner to the introduction of carbon dioxide by changing colour.

Abbie explains how the addition of CO2 makes water more acidic.

The young scientists, equipped with big protective goggles, gloves and lab coats, faced the terrible smell of cabbage juice and blew with a straw into test tubes, to see how CO2 emitted by their breath influenced the colour of the liquid. The carbon dioxide combines with the water in the cabbage juice to form carbonic acid, causing the pH of the solution to drop and the cabbage juice to turn pink. In order to accelerate the process, we also provided them with some dried ice. “Wow, it’s a cold volcano!” so  one young girl commented our experiment with wide amazed eyes .

The aim of the festival was to put in contact new generation with the world of science, to promote science education and science communication. At the end of the day, it took us just one young girl’s enthusiastic comment to understand  we had reached our goal. With that cold volcano in her hands, the 10-year old girl said to the parents: “I want to be a scientist!

 

 

Scientist on the Road Guest Scientist:  Ed Waugh  of National Oceanography Centre  gave a talk  at Winchester  Festival about “The exploration of the subglacial Lake Ellsworth in Antarctica.” 

 

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If you want to become a Scientist on the Road and participate in our events email Athena a.drakou@soton.ac.uk or contact us here

Variation allows phytoplankton to go global

Sea surface UKOA  Consortium participants, Jeremy Young (UCL) and Declan Schroeder (MBA) are between the authors of a research paper, which is published today in Nature.

Titled “Pan genome of the phytoplankton Emiliania drives its global distribution“, the paper compares the reference genome of one strain of Emiliana huxleyi to sequences from 13 other strains. The scientists found a pan genome composed of a set of core genes, along with genes that were unequally distributed between different strains. The findings indicate extensive genome variability and demonstrate that  E. huxleyi, which has long been considered a single species, harbours extensive genome variability reflected in different metabolic repertoires.

Figure: Emiliania huxleyi and its position in the eukaryotic tree of life. a, E. huxleyi has five well-characterized calcification morphotypes and an overcalcified state1. b, Cladogram showing the distinct branch occupied by the haptophyte lineage on the basis of RAxML analysis of concatenated, nuclear-encoded proteins after addition of homologues from CCMP1516 and a pico-prymnesiophyte-targeted metagenome8. Lineages with algal taxa are indicated (symbol). Filled circles represent nodes with ≥70% bootstrap support. The tree is rooted for display purposes only. Nature ISSN: 0028-0836 EISSN: 1476-4687

The findings also underpin  the capacity of E. huxleyi to thrive both in habitats ranging from the equator to the subarctic and to form large-scaleepisodic blooms under a wide variety of environmental conditions.

Betsy A. Read, et al “Pan genome of the phytoplankton Emiliania drives its global distribution” Nature doi:10.1038/nature12221

Press Release:

 Variation allows phytoplankton to go global

The reference genome of a marine phytoplankton called Emiliania huxleyi is reported this week in NatureE. huxleyi has a direct influence on the global carbon cycle, and the genomic plasticity of this species may provide insight into speciation and how organisms adapt to global climate change.

E. huxleyi can thrive in a range of dramatically different habitats, and have the capacity to form large-scale blooms from the equator to the subarctic. By comparing the reference genome of one strain of E. huxleyi to sequences from 13 other strains, Betsy Read and colleagues found a pan genome composed of a set of core genes, along with genes that were unequally distributed between different strains. The findings indicate extensive genome variability reflected in different metabolic repertoires, explaining in part how E. huxleyi has adapted to a wide variety of environments. E. huxleyi was thought to be a single species, but the high level of diversity uncovered in this study indicates a single strain is unlikely to be typical or representative of all strains.

Arctic photo in the final Ocean Exploration 2020 Photo Contest

Helen’s Smith Arctic photo made the final 5 of the Ocean Exploration 2020 Photo Contest category Scenic Seascapes. Congratulations Helen!

Arctic Reflection @Helen Smith, Southampton, Hampshire, UK

A stunningly blue and calm Arctic reflection of sea and sky divided by distant bright white ice and interrupted by ripples created by the ship. Taken June 15, 2012, on the RRS James Clark Ross in the Arctic sea ice between Svalbard and Greenland.

Source: Ocean Exploration 2020

Diatom and Coccolithophore SEM imaging by Helen Smith

Helen is a PhD student at the National Oceanography Centre studying phytoplankton community structure and carbon export.  She shares, for some time now, her ZEISS LEO 1450VP SEM imaging via Twitter; you can actually follow her work on Twitter with hashtag #PhytoplanktonID.

This is her Diatom and Coccolithophores SEM imaging Facebook Page, where you can have a look at some very beautiful images and share with the rest of the world your perfect ZEISS moments!

Diatom Asteromphalus hyalinus (false colour SEM) from 60oS Indian Ocean. Funding support from NERC, Defra and DECC to the pelagic consortium of the UK Ocean Acidification programme @Helen Smith

 

Coccoliths thrive despite ocean acidification

21 May 2013, by Harriet Jarlett – Planet Earth Online

Ocean acidification is damaging some marine species while others thrive, say scientists.

An international team studied the effect of ocean acidification on plankton in the North Sea over the past forty years, to see what impact future changes may have.

The study, published in PLoS One found that different species react in different ways to changes in their environment. As carbon dioxide emissions dissolve in seawater they lower the pH of the oceans making them more acidic and more corrosive to shells.

Limacina helicina. Credit: Planet Earth

Foraminifera and coccoliths, which are small shelled plankton and algae, appear to be surviving remarkably well in the more acidic conditions. But numbers of pteropods and bivalves – such as mussels, clams and oysters – are falling.

‘Ecologically, some species are soaring, whilst others are crashing out of the system,’ says Professor Jason Hall-Spencer, of Plymouth University, who co-authored the paper.

The scientists are unsure whether this drop in certain species is because of changing pH levels, or whether it is due to a combination of stress factors like warming, overfishing and eutrophication -which results from a build up of excess nutrients in water.

‘We found no statistical connection between the abundance of calcifying plankton and the changes in pH. If pH is affecting calcifying plankton in the area then its effect is being masked by other climatic effects. What we do know is that laboratory experiments have shown pH changes affect pteropods adversely,’ he says.

Scientists had previously thought the reason species react so differently to ocean acidification was due to variations in the mineral composition of the shells.

‘The aragonite skeleton of pteropods dissolves more easily in corrosive waters than the low-magnesium calcite that typifies many clams and other molluscs,’ explains Hall-Spencer. ‘But now we think that it’s not as simple as that. It depends partly on how stressed organisms are by other factors, such as lack of food. It also depends on their shape and their ability to protect their skeletons.’

It is possible that the rising levels of CO2 are boosting coccolith numbers by causing them to photosynthesise more and produce more energy.

The scientists used a database collected by the Sir Alaistair Hardy Foundation for Ocean Science, which has been continuously recording levels of plankton in the North Sea since 1931. But, despite being the best database available, it fails to monitor chemical changes, like acid levels, alongside ecological ones, like shifts in pteropod numbers.

Plankton sits at the bottom of the food chains, where it underpins all of our marine food sources. So if numbers drop significantly it could lead to food shortages, particularly in countries where people eat lots of seafood and fish.

Without improved monitoring , researchers say they will struggle to accurately test the consequences of ocean acidification.

‘CO2 is driving down the pH of water, but finding evidence for that and its ecological effects is proving tricky. Most work is done in the lab, so there’s not much good long term data on changes in the water,’ says Hall-Spencer.

Coccoliths appear to be able to cope with recent changes to their environment, the scientists don’t know how they will fare in the future.

‘We need an observing network to keep track of the effects of ocean acidification both chemically and biologically. Ecosystems are going to change, and if we want to protect fisheries, food sources and jobs we need to be forewarned,’ he concludes.

Read more: Beare D, McQuatters-Gollop A, van der Hammen T, Machiels M, Teoh SJ, et al. (2013) Long-Term Trends in Calcifying Plankton and pH in the North Sea. PLoS ONE 8(5): e61175. doi:10.1371/journal.pone.0061175

The UKOA Cruises’ Journals

Now you can read online all three scientific journals of the UKOA cruises in full, page by page, and it is exactly the same as the print edition.

First UKOA Cruise in the NW European Seas – June / July 2011

Read the blog here

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Second UKOA Cruise in the Arctic – June / July 2012

UKOA Arctic Cruise website

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Third UKOA Cruise in the Southern Seas January /February 2013

UKOA Antarctic Cruise website

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