The discovery of a rare habitat and vulnerable species in Poole Harbour
Authors: Bone, J., Rubuffo, J., Hughes, J. and Herbert, R.
Start date: 25 April 2017
Coastal lagoons are priority habitats in the UK and are listed under Annex 1 of the EC Habitats Directive owing to their scarcity. They are highly productive ecosystems and provide a range of ecosystem services and support other coastal ecosystems such as seagrass beds and salt marshes, and are therefore valuable sources of natural capital. However, lagoons are particularly vulnerable to anthropogenic disturbance which can be exacerbated by climate change pressures. A Student Environment Research Team (SERT) conducted a survey to assess species diversity and abundance, sediment type, and verify the inflow of seawater at a lake on Brownsea Island in Poole Harbour, UK. Core samples were taken for lab analysis, sweep netting was used to assess in situ fauna in the water column and salinity and temperature readings were taken. The starlet anemone Nematostella vectensis, IUCN Red Listed as Vulnerable, was positively identified in situ, a species endemic to coastal lagoons and saltmarshes. Salinity readings and visual verification of a seawater inflow via a channel confirmed the formation of a new lagoonal inlet at Brownsea Island. The discovery of a rare habitat and vulnerable species could enhance the case for extending the MPA boundary to include the new lagoon. A larger lagoon exists <1km east of the new lagoon and is used by some of the >20,000 waterfowl that visit Poole Harbour, yet is under threat from sea level rise. An additional lagoon habitat could ameliorate the effects of climate change induced habitat loss and loss of ecosystem services.