sea grass bed in South and what were the pressures on the seagrass - PowerPoint PPT Presentation

How the Zostera noltii sea grass bed in South and what were the pressures on the seagrass habitat during Dublin Bay changed this period? over the summer of 2019

• Carbon sequestration • 35 times quicker than rainforest • Sediment trapping • Prevents erosion • Nursery ground for other species Why is it • Shrimps, small fish important? • Food for Brent Geese • Nutritious, protein rich • Water quality indicator in the Water Framework Directive • Indicative of water quality

Brent Feeding on the seagrass Geese

• First official record: 1954 • In 1983 approx. 1.4 ha Zostera noltii • In 1993 approx. 1.75 ha starting 10-20 m seagrass on from the seawall protecting houses • In July 2019 approx. 1.8 ha starting 5 m Merrion from the seawall • One of only two locations in the Dublin area strand

Heat Blackened brittle blades in the seagrass bed stress

Unhealthy seagrass Healthy seagrass envrionment environment

Green opportunistic seaweed • Grows in long strands attached to a razorfish shell or a cockle • The loose end of the strand floats freely in the high tide • Unattached seaweed and other loose debris get attached to the strand • When the strand gets too heavy it breaks free and floats off with the tide • When the tide recedes again the seaweed mould descends on the sediment • Anaerobic conditions occur

Anaerobic sediment

Direct Disturbance People & Dogs Vehicles Litter

Sewage overflow Sanitary litter Can cause nutrient enrichment

Theme 1: Strengthen the knowledge base of decision- makers for the conservation and management of biodiversity, and protect species and habitats of conservation value within Dublin City

Act ctio ion 2: Continue to map the distribution, and assess the abundance and conservation status Recommendations: - Yearly survey of the Zostera noltii bed - Intertidal mudflat temperature measurement during heatwaves and development of anaerobic mud, and fate of mud snails ( Hydrobia spp. ) - Sediment samples taken for analysis - Measurement of nutrient levels in the freshwater stream - Monitoring of the growth of Salicornia europaea and the formation of a new lagoon

Actio ion 3: Develop site-specific best management guidelines for legally protected species within Dublin City, and communicate with landowners and users Recommendations: - Design and put up new signage in locations closer to the seagrass bed - involve the Sandymount and Merrion Residents association and local residents, as they are very knowledgeable and interested in protecting the Zostera noltii bed.

Thank you ! Rita Hagan rhagan100@gmail.com 087-7512955