Modelling the response of phytoplankton to mesoscale and submesoscale processes at the Sub-Antarctic Front

Authors

Zoë E. Waring, University of Plymouth

Document Type

Biological and Marine Sciences Article

Abstract

This study extends a basic NPZ (Nutrient, Phytoplankton, Zooplankton) model to investigate the impact of turbulence on phytoplankton growth. Despite recent studies suggesting that submesoscale dynamics are crucial for the transfer of energy and nutrients across eddies, there are relatively few in situ studies and none, before now, at the Sub-Antarctic Front (SAF) to the East of Drake Passage. This study draws on data collected at the SAF and predictions made by the model to give an insight into the processes governing phytoplankton growth across a cold core mesoscale eddy. Conductivity, temperature, nutrient and chlorophyll-a (chl-a) measurements were used to assess physical and biological differences across the eddy. These were then compared to predictions made by the model to assess the response of phytoplankton to the dynamical conditions across the eddy. It was found that the turbulent conditions at the eddy boundary are likely to support a phytoplankton bloom, subsequently triggering an increase in zooplankton. Increased zooplankton levels cause an increase in grazing which is likely to enforce top down control, reducing phytoplankton numbers. The processes controlling growth within the eddy are not so well defined, however it is thought that phytoplankton growth is sustained, although growth in situ may have been limited by a micronutrient such as iron that was not included in the model. A lack of iron was also thought to be the cause of low levels of chl-a outside of the eddy as no other limiting factors were identified in measured or modelled data.

Publication Date

2016-12-01

Publication Title

The Plymouth Student Scientist

Volume

9

Issue

2

First Page

49

Last Page

67

ISSN

1754-2383

Deposit Date

May 2019

Embargo Period

2024-07-03

URI

http://hdl.handle.net/10026.1/14128

Creative Commons License

This work is licensed under a Creative Commons Attribution 4.0 International License.

Recommended Citation

Waring, Zoë E. (2016) "Modelling the response of phytoplankton to mesoscale and submesoscale processes at the Sub-Antarctic Front," The Plymouth Student Scientist: Vol. 9: Iss. 2, Article 3.
Available at: https://pearl.plymouth.ac.uk/tpss/vol9/iss2/3