Polycyclic aromatic hydrocarbons alter the structure of oceanic and oligotrophic microbial food webs

Cerezo, Maria Isabel; Agusti, Susana

Polycyclic aromatic hydrocarbons alter the structure of oceanic and oligotrophic microbial food webs

Type

Article

Authors

Cerezo, Maria Isabel
Agusti, Susana

KAUST Department

Biological and Environmental Sciences and Engineering (BESE) Division
Marine Science Program
Red Sea Research Center (RSRC)

Online Publication Date

2015-11-06

Print Publication Date

2015-12

Date

2015-11-06

Abstract

One way organic pollutants reach remote oceanic regions is by atmospheric transport. During the Malaspina-2010 expedition, across the Atlantic, Indian, and Pacific Oceans, we analyzed the polycyclic aromatic hydrocarbon (PAH) effects on oceanic microbial food webs. We performed perturbation experiments adding PAHs to classic dilution experiments. The phytoplankton growth rates were reduced by more than 5 times, being Prochlorococcus spp. the most affected. 62% of the experiments showed a reduction in the grazing rates due to the presence of PAHs. For the remaining experiments, grazing usually increased likely due to cascading effects. We identified changes in the slope of the relation between the growth rate and the dilution fraction induced by the pollutants, moving from no grazing to V-shape, or to negative slope, indicative of grazing increase by cascade effects and alterations of the grazers' activity structure. Our perturbation experiments indicate that PAHs could influence the structure oceanic food-webs structure.

Citation

Cerezo MI, Agusti S (2015) Polycyclic aromatic hydrocarbons alter the structure of oceanic and oligotrophic microbial food webs. Marine Pollution Bulletin 101: 726–735. Available: http://dx.doi.org/10.1016/j.marpolbul.2015.10.004.

Acknowledgements

Ministerio de Economía y Competitividad[CTM2012-32603]
Ministerio de Ciencia e Innovación[CSD2008-00077]