Projects per year
Abstract
Nitrogen (N) is often the key nutrient limiting primary production in coastal waters. Quantifying sources and sinks of N is therefore critical to understanding the factors that underpin the productivity of coastal ecosystems. Constraining nitrogen inputs can be difficult for some terms such as N fixation and marine exchange as a consequence of uncertainties associated with scaling and stochasticity. To help overcome these issues, we undertook a N budget incorporating an isotope and mass balance to constrain N sources in a large oligotrophic coastal embayment (Western Port, Australia). The total N input to Western Port was calculated to be 1400 Mg N year-1, which is remarkably consistent with previous estimates of sedimentation rates within the system. Catchment inputs, N fixation, marine sources and atmospheric deposition comprised 44, 28, 28 and 13% of N inputs respectively. Retention of marine-derived N equated to 3 and 10% of total N and NOx flushed through the system from the marine end-member. The relatively high contribution of N fixation compared with previous studies was most likely to be due to the high proportion of nutrient-limited intertidal sediments where N is mediated by seagrasses and sediment cyanobacteria.
Original language | English |
---|---|
Pages (from-to) | 701-709 |
Number of pages | 9 |
Journal | Marine and Freshwater Research |
Volume | 73 |
Issue number | 5 |
DOIs | |
Publication status | Published - May 2022 |
Keywords
- N
- denitrification
- isotope
- nitrogen
- nitrogen budget
- nitrogen fixation
- seagrass
- tidal flat
Projects
- 1 Finished
-
The recovery of seagrass beds: The role of catchments and options for management responses
Cook, P., Beardall, J., Cartwright, I., Keough, M. J., Mac Nally, R., Ross, D., Santos, I., Cinque, K., Coleman, R., Howe, S. & Lee, R.
Australian Research Council (ARC), Melbourne Water Corporation (trading as Melbourne Water) (Victoria), Environment Protection Authority (trading as EPA Victoria) , Parks Victoria, Southern Cross University, University of Melbourne, University of Tasmania
2/06/14 → 31/12/17
Project: Research