Modelling the fate and cycling of organic pollutants in the ocean
Fig. 1. Cartoon presenting important processes connected to the fate and transport of highly water-soluble and highly POC-attached persistent organic pollutants in the oceanic environment simulated by the FANTOM model. Uptake and transport through the food web is not included.
Persistent organic pollutants (POPs) are highly toxic chemicals used in agriculture and industry, and released during combustion processes. They enter the ocean through the sea-surface and in river input from surrounding industrial and agricultural countries.
POPs undergo a series of processes in the ocean. POPs partition according to their hydrophobicity/lipophilicity - they either dissolve in water or sorb to organic matter, depending on their properties.
Hydrophobic POPs sorb to organic matter and work their way up the food chain – they bioaccumulate and biomagnify – and are thus a threat to species at the top of the food chain, fish and mammals, and human beings (consumers).
We are modelling exchange processes of these POPs as they move up the food chain.
Fig.2 Time series of total mass of γ-HCH in water (a), and sediment (b), and PCB 153 in water (c), and sediment (d), for the three 10-year periods 2006–2015, 2046–2055 and 2090–2099. February and August (F and A) and the year number (1–10) are shown on the x axis.
We are also interested in modelling the effects of climate change on POP in the ocean.
Fig. 2 shows time series of POP concentrations in water and sediment for three 10 year slices in the 21st century and examples of effects of climate change on these.
Panel 2 shows that total mass of g-HCH in sediment is increasing in the future relative to the present.
Panel 4 shows the total mass of PCB 153 in sediment decreases faster in future years relative to the present as a result of increasing number and intensity of storms.
We are always looking for good numerate students to work on these challenging and interesting projects.
Please do contact Kieran O’Driscoll if you are interested.