Use this URL to cite or link to this record in EThOS:
Title: Dissolved organic nitrogen dynamics and influence on phytoplankton
Author: Moschonas, Grigorios
ISNI:       0000 0004 5918 0405
Awarding Body: University of Aberdeen in association with University of the Highlands and Islands
Current Institution: University of Aberdeen
Date of Award: 2015
Availability of Full Text:
Access from EThOS:
Full text unavailable from EThOS. Please try the link below.
Access from Institution:
A balanced nitrogen (N) cycle is paramount for the ecology and biogeochemistry of planet Earth. Human activities are now causing an imbalance in the N cycle, with several negative effects on the marine environment. However, our knowledge of the marine N cycle remains incomplete, especially with regards to the role of dissolved organic N (DON). Therefore, there is need to study the role of DON more extensively to aid in restoring balance to Earth's ecosystems and biogeochemical cycles. This project investigated DON dynamics and influence on phytoplankton in coastal and shelf seas (CSS) to the west of Britain where DON was understudied. First, selected methods for the measurement of N uptake rates, urea and dissolved free amino acid (DFAA) concentrations were reviewed and tested. Then, they were used to study the spatial and temporal DON dynamics in the shelf region to the west of Britain (Irish Sea and adjacent shelf), the in-situ seasonal DON dynamics and N uptake in relation to phytoplankton community composition and abundance in Loch Creran, and the influence of DON on the phytoplankton community composition and abundance in controlled nutrient uptake kinetics and growth experiments and ecosystem modelling. The main findings were: DON was important in the N dynamics of the Irish Sea and adjacent shelf waters; DON was correlated with changes in phytoplankton community composition in Loch Creran; its seasonal cycle suggested its importance as an N source for the development of the spring bloom; these ideas were further supported by controlled laboratory experiments and ecosystem modelling.
Supervisor: Not available Sponsor: Scottish Association for Marine Science
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available
Keywords: Phytoplankton ; Nitrogen cycle