Description
Coastal systems lie at the interface between the land and sea and are generally the most easily accessed and utilised marine environments for a range of industrial and recreational purposes. This is exemplified in many estuarine systems, which often are bordered by areas of urbanisation for historic or contemporary reasons due to the access they provide to adjacent marine systems and inland areas of habitation, industry, and/or agriculture. Estuaries also play an important ecological role as habitats for migratory birds and fishes, adding to the perceived intrinsic and recreational value of the system. However, an extensive (and growing) array of anthropogenic pressures have the potential to manifest deleteriously (Gunderson et al., 2016), perhaps most insidiously through the interactions of stressors which are present at levels considered individually safe, or at least sublethal. At the base of many estuarine food webs are the microphytobenthos (MPB), an autotrophic assemblage which include diatoms and cyanobacteria which can form visible biofilms in depositional intertidal sediments. The MPB are not only important primary producers, but also play a key role in ecosystem engineering through the reduced erosion of sediments by the exudation of EPS (extracellular polymeric substances) (Chen et al., 2017). However, we have only a limited understanding of how these assemblages respond to stressor exposure, particularly multiple stressor exposure. We conducted a series of experiments using a tidal mesocosm system to assess the response of MPB to glyphosate exposure, a common industrial and commercial herbicide, as well as to nanoparticles of TiO2, which are found in an extensive range of products. Both chemicals can be detected in watercourses and are known to chemically interact (Ilina et al., 2017), and therefore serve as a case study for interactions which may manifest at a biological level. Experiments were then conducted in the field at the Eden Estuary (Fife), to investigate the extent to which laboratory findings can be extrapolated to the real environment, as it was expected that the scale and features of a natural system would buffer to some extent against negative impacts which arise in a more confined microenvironment. Findings indicate a clearly negative impact of the herbicide on MPB biomass, but a negative impact of TiO2 only at intermediate levels of the herbicide, hinting at an interaction effect.| Period | 5 Oct 2021 |
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| Event title | MASTS ASM 2021: Working to Reverse the Tide on Climate and Global Change |
| Event type | Conference |