Details of Award
NERC Reference : NE/V009877/1
Assessing the bioavailability of iron in southeast Pacific seawater to phytoplankton using iron uptake rates
Grant Award
- Principal Investigator:
- Dr A Milne, University of Plymouth, Sch of Geog Earth & Environ Sciences
- Grant held at:
- University of Plymouth, Sch of Geog Earth & Environ Sciences
- Science Area:
- None
- Overall Classification:
- Unknown
- ENRIs:
- None
- Science Topics:
- Biogeochemical Cycles
- Microbial communities
- Primary production
- Ecosystem Scale Processes
- Nutrient limitation
- Biogeochemical cycles
- Environmental Microbiology
- Microbial communities
- Nutrient cycling
- Microalgae
- Microbiology
- Abstract:
- NERC: Isobel Turnbull: NE/S007334/1 Tiny single-celled plants, called phytoplankton, need nutrients such as carbon to live and grow in the surface waters of the ocean. Carbon dioxide in the atmosphere naturally dissolves into the surface ocean, providing phytoplankton with a source of carbon which can be used and turned into organic matter; a process known as photosynthesis which helps to regulate global climate. In addition to carbon, phytoplankton also require other essential nutrients to grow and one critical nutrient is iron. Unfortunately, iron does not dissolve well in seawater, and therefore the dissolved concentrations are generally found at low levels throughout the oceans. In certain oceanic regions, the levels of dissolved iron drop so low that they can limit phytoplankton growth, one such region is the Southern Ocean. Fortunately, seawater contains a wide variety of dissolved organic compounds, ones that we are familiar with such as carbohydrates and amino acids, as well as ones that we know little about. These lesser known organic compounds (known as ligands) bond to iron and help keep it dissolved. These ligands significantly impact the amount of iron that can be acquired by phytoplankton, making it more 'bioavailable'. Hence, both iron availability and the presence of these ligands can affect phytoplankton growth/photosynthesis and therefore have an impact on our climate. However, a lack of understanding of what makes up the ligand pool in natural seawater makes it difficult to determine the bioavailability of iron. One way to assess this, is to inject natural seawater with radioactive iron which will attach itself to the various ligands present; a process known as radiolabelling. The amount of actual iron that is bioavailable can then be assessed through the rate of radiolabelled-iron uptake by natural phytoplankton cultures that have been added to the seawater mix. This project aims to do this with seawater taken on an expedition to the southeast Pacific sector of the Southern Ocean. Iron uptake rates will be obtained for seawater collected from three different stations and three different depths, and provide a proxy for how 'bioavailable' the iron in the study region is. This information can then be used in climate models, enabling us to better understand the impact of iron availability in this region on carbon uptake by phytoplankton and predict how future changes to the ocean state may impact the carbon cycle.
- NERC Reference:
- NE/V009877/1
- Grant Stage:
- Completed
- Scheme:
- NC&C NR1
- Grant Status:
- Closed
- Programme:
- Globalink Placement
This grant award has a total value of £8,778
FDAB - Financial Details (Award breakdown by headings)
| Exception - Other Costs |
|---|
| £8,778 |
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