The Abu Dhabi Blue Carbon Demonstration Project

Carbon Values of Blue Carbon Ecosystems

Calculating carbon values Replicate plots along transects were assessed for plant cover and sampled for above-ground biomass and soil carbon stocks (total, organic and inorganic) to depths up to 3 metres depending on the substrate. At intertidal sites, additional data were collected to inform a mechanistic understanding of carbon cycling including water table depth, pore-water chemistry, root zone redox potential, and soil respiration. High resolution location and elevation data were collected via Kinematic GPS and a mobile base station. In the laboratory, above and below- ground carbon stocks were calculated through allometric equations. Carbon and nitrogen analyses were performed by an elemental analyzer. Sampling and analysis followed scientifically recognized standards and procedures adapted to the Emirate’s environmental context. Resulting carbon values Across the range of ecosystems studied, algal mats showed the highest combined above and below ground carbon stocks per hectare. Overall Blue Carbon stocks are estimated to be highest in seagrass, due to the large extent of the ecosystem.

Coastal sabkha, which is considered an associated ecosystem, holds significant amounts of carbon, highlighting the importance of well-informed planning of sabkha conversion. Average total carbon stock in planted mangroves of different ages (79,92 tonnes/ha) was lower than that of natural mangroves (109,79 tonnes/ha). See figure 7 for details. Overall, Blue Carbon ecosystems in Abu Dhabi are calculated to store over an estimated 41 million tonnes of carbon dioxide equivalent (CO 2 equivalent) within the soil and biomass, more than the Emirate’s annual emissions from the oil and gas (26,4 million tonnes) or water and electricity (30,9 million tonnes) sectors 1 .

1 Statistical Yearbook of Abu Dhabi 2013

Figure 6 Carbon stock sampling locations

Coastal Sabkha Seagrass Mangrove Saltmarsh Algal mat

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