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Facilitating Access to Global Observing Systems Data and Information

GCOS Ocean Surface ECV
Phytoplankton

Definition: Phytoplankton (phyto = plant, planktos = to wander) are single celled plants which live in the surface waters of the oceans.  Most of them simply drift around the ocean in the surface currents but some can move a tiny bit on their own. They use sunlight, carbon dioxide (CO2) and water, in a process called photosynthesis, to produce organic compounds which they use for food and to make their cells.  One waste product is oxygen and this makes it possible for animals to live on earth.  Phytoplankton remove almost as much carbon dioxide from the air as land plants and, therefore, help regulate our climate. Phytoplankton also need nutrients to grow.  They need a wide variety of chemical elements but the two critical ones are nitrogen and phosphorous since they are needed in quite large amounts but are present in low concentrations in seawater.  Nitrogen and phosphorous are like the fertilisers we add to land plants and are used to make proteins, nucleic acids and other cell parts the phytoplankton need to survive and reproduce. Phytoplankton need nutrients in well defined ratios. For every 106 atoms of carbon they make into organic matter, they need 16 atoms of nitrogen and 1 atom of phosphorous. Most can't use atmospheric nitrogen gas (N2) directly but need chemically reactive forms of nitrogen such as nitrate (NO3-) or ammonium (NH4+).  There is always plenty of carbon dioxide so phytoplankton keep growing until they have used up all of the useable nitrogen or all of the phosphorous, which ever runs out first. In most of the ocean, nitrogen runs out first and growth is said to be nitrogen limited. The Eastern Mediterranean Sea is phosphorous limited, here growth stops when phytoplankton have used up all the phosphorous even though there is still nitrogen in the water. (from the Espere-ENC web site)

Introduction: Climate variability significantly impacts, and will continue to impact, plankton in the ocean, both the microflora (e.g., phytoplankton) and the microfauna (e.g., zooplankton), over both short (seasonal to interannual) and long-term (decadal) time scales. Changes in temperature, salinity, freshwater discharge and loadings of sediments and nutrients, acidification, light, wind forcing, and currents impact the abundance, distribution, phenology, diversity, and productivity of these organisms. They are at the basis of the marine food web and not fished by humans, therefore the impact of climate on plankton are significant and will have impacts on the rest of the marine ecosystem including on living marine resources used by humans. This has both ecological as well as socio-economic implications.  Sustained, coordinated efforts are necessary to assess and monitor these changes over time.
 
Contributing networks and satellite observations include continuous Plankton Recorder Tows, Ocean Colour Radiances observed by satellites, and OceanSITES reference moorings.

Monitoring of Marine Biodiversity and Habitat Properties
 
Marine habitats (e.g., coral reefs, mangroves, seagrass beds, intertidal zones, kelp forests, sea ice) are extremely sensitive to the impacts of climate variability and change.  In particular, climate-related changes in sea level, temperature, salinity, precipitation, freshwater inputs, light, ocean acidification, wind forcing, currents, and waves can all lead to significant habitat alterations and loss of biodiversity, with a related loss in ecosystem services, especially in combination with local anthropogenic disturbances and forcing (e.g., changes in land cover and land use, eutrophication, pollution). Coral reefs especially are at significant risk, facing more frequent and severe bleaching events and disease outbreaks associated with warmer oceans, as well as rising ocean acidification, sea level, and severe storm impacts.   
 
Contributing networks and satellite observations include:

  1.  The Global Coral Reef Monitoring Network (GCRMN).
  2.  The sea grass net global coastal monitoring network.
  3.  High spatial resolution optical satellite sensors (Landsat etc.) and
  4.  Low-resolution environmental satellite monitoring (SST etc.)

 
Issues and needs relative to observation of coral reef and other marine habitats include:

  1.  In situ networks do not provide adequate coverage or sampling relative to the required space and time scales.
  2.  Need to improve connections between global, regional and local observing and sampling efforts, and improve coordination and information flow amongst remote sensing, in situ monitoring and modelling efforts.
  3.  Need to develop and expand local research and monitoring capacity.
  4.  Ecological monitoring needs to be accompanied by socio-economic monitoring toward improved coordinated management efforts.
  5.  Improved data management and exchange mechanisms are needed, particularly across the land-sea interface.  
  6.  Develop capacity in remote sensing and in situ monitoring to respond rapidly to reporting of unusual or anomalous events on coral reefs.
  7.  Develop and sustain a high spatial and spectral resolution capacity to assess coral reef and other marine habitat changes, particularly hyperspectral satellite observations.

 
To address the issues raised above, it is proposed that PICO and OOPC work with nations, GRAs and existing observations networks (e.g., GCRMN) to establish a global network of long-term observation sites covering all major ocean habitats and encourage collocation of physical, biological and ecological measurements to enable clearer identification of climate changes at these sites (see also Actions C22, C23). 

(Source: WMO/IOC Implementation Plan for the Global Observing System for Climate in Support of the UNFCCC (2010 Update) GCOS-138/GOOS-184/GTOS-76/WMO-TD/No. 1523)

Additional Information:

References:

Data, Product, Metadata and Information Access

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Non-satellite or in situ Satellite