WCO Benthic survey

The PML benthic survey is an ongoing ecological time-series. The time-series aims to capture the natural temporal and spatial variability of the marine biological ecosystems encompassed by the Plymouth Sound and contiguous coastal waters. Initiated in 2008 and currently supported by the NERC CLASS programme, the survey is aggregated with the Western Channel Observatory due to the uniqueness and comprehensiveness of the datasets collected. Unique to the UK, the multidisciplinary nature of the benthic survey has created a highly valuable resource for ecosystem management.

L4 is an exposed site with a depth of approximately 50 m, with sediments ranging from mud to sand. The benthic survey monthly sampling further augments an already exhaustive sampling regime to allow the critical inclusion of the biological components to Bayesian environmental models (e.g. ERSEM). Biological community structure is studied and analysed in parallel to a range of environmental and sediment parameters such as sheer stress, granulometry, redox, CHN, productivity and steroid analysis providing a wholistic ecosystem approach. Reproductive stages of selected macrofauna species have been determined through histology in addition to processes in the marine nitrogen cycle. Since 2009 bimonthly estimates of anammox and denitrification rates have been monitored, as have nutrient fluxes between the sediment and the water column. Other parameters incorporated into the survey include nitrous oxide and methane (greenhouse gases), bioturbation and bioirrigation. Further enriching the comprehensiveness of the long-term time-series the benthic survey continues to develop into the future bringing together aspects of the UN sustainability goals including carbon sequestration involving innovative blue carbon mitigation modelling techniques, cutting edge molecular eDNA methodologies and AI learning using new smart-sound technologies which all aim towards supporting policy development.