The Eden Estuary Salt Marshes

The Eden Estuary salt marshes act as a blue carbon store, nature reserve and flood defence for surrounding land. Out of Scotland’s 249 salt marshes, the Eden estuary is the 22nd largest surficial organic carbon store.1 However the Eden salt marshes are currently being damaged from the effects of erosion. Anthropogenic activity such as the construction of hard engineering techniques has eroded some of the upper salt marsh.2 In addition, climate change and sea-level rise are reducing the abundance of healthy salt marsh area. It is predicted that by the 22nd century , the Eden estuary will lose 56% of its salt marsh area due to sea-level rise.3 Salt marsh degradation triggers the release of stored blue carbon into Earth’s atmosphere. Moreover, the loss of this vegetated area puts the land behind at risk of flooding and erosion, this includes the St Andrews Links golf courses. It is therefore crucial that the Eden estuary salt marshes are protected to prevent the loss of stored blue carbon, biodiversity and valuable land assets

The Green Shores team transplant various native grasses into the barren areas of salt marsh with the aim of enhancing sedimentation and the binding of sediment. As a volunteer at the Green Shores Project, I work with Helena Simmons (Outreach Officer), in a polytunnel next to the salt marsh, preparing transplants.

Saltmarsh Grass (Puccinellia maritima) from the Tay, Dornoch Firth and the Eden are propagated to produce numerous transplants.  Below are images of propagated Saltmarsh Grass in the Green Shores polytunnel:

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Additionally, Sea Club Rush (Bolboschoenus maritimus) is also propagated for transplanting. The strength of the plants roots allows it to thrive in the harsh environment of a salt marsh.

Sea Club Rush being propagated in the Green Shores polytunnel

Transplants are prepared a year in advance. To enhance plant growth, newly propagated plants are given fresh water and grown in a warmer environment. Thereafter, the transplants must experience a gradual adjustment to salt marsh environments before being transplanted in the salt marsh to prevent shock. Before propagated plants are ready to be transplanted, they undergo salt water and cold temperature treatments outside the polytunnel.

The work carried out by the Green Shores Project is being continuously monitored. Sediment cores from the restored salt marsh are analysed for organic carbon content in the University’s Geography and Geoscience labs. To learn more about the Green Shores Project or to get involved volunteering click here.

References

  1. Austin, W., Smeaton, C., Riegel, S., Ruranska, P. and Miller, L. (2021). Blue carbon stock in Scottish saltmarsh soils Scottish Marine and Freshwater Science Vol 12 No 13. [online] doi:https://doi.org/10.7489/12372-1. 
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  2. Maynard, C., McManus, J., Crawford, R.M.M. and Paterson, D. (2011). A comparison of short-term sediment deposition between natural and transplanted saltmarsh after saltmarsh restoration in the Eden Estuary (Scotland). Plant Ecology & Diversity, 4(1), pp.103–113. doi:https://doi.org/10.1080/17550874.2011.560198.
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  3. Austin, W., Smeaton, C. and Houston, A. (2022). Scottish saltmarsh, sea-level rise and the potential for managed realignment to deliver blue carbon gains. [online] doi:https://doi.rg/10.7488/era/2370
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Shoreline flooding and erosion prevention methods: Cost-Benefit Analysis

Author: Ariana Ressallat White