Prof Stephen Hawkins1,2,3,4,5, Dr Janette Allen3, Dr Stephen Wilkinson3, Dr Nicola Fielding3, Mr Wahaj Brown-Kahn1, Ms Anastasia Forbes1, Dr Nova Mieszkowska3,5, Dr Katrin Bohn4,6, Dr Louise Firth1,5
1University Of Plymouth, Plymouth, UK, 2University of Manchester, , UK, 3University of Liverpool, Liverpool, UK, 4University of Southampton, Southampton, UK, 5Marine Biological Association of UK, Plymouth, UK, 6Natural England, Nottingham, UK
Enclosed 18th, 19th and early 20th century dock-basins in macro-tidal estuaries and canalised rivers became increasingly redundant from the 1960s onwards, with bigger ships and containerisation. This led to former port-complexes becoming the focus for ambitious urban-renewal schemes in cities such as Bristol, Liverpool, London and Manchester in the 1980s. High quality water was crucial to their appeal and success. Studies stretching back to 1980 in Sandon Dock and the South Docks Liverpool, showed how both bottom-up manipulation by mixing and top-down control by biofiltration from naturally-settling mussels (Mytilus edulis) improved water quality. Mussels enhanced biodiversity as ecosystem engineers. Early succession from 1988 to 1996 is described. The volume of the Albert Dock was calculated to pass through a mussel every 2-3 days. Episodic anoxic events ceased occurring. Follow up studies in 2012 and 2022 demonstrated the long-term stability of these novel ecosystems (“cubist lagoonoids”). This was despite some minor changes in the salinity regime. Concerns that colonisation by starfish (Asterias), with occasional individuals present from the early 1990s onwards, might lead to decline in mussels and hence biofiltration did not materialise. In addition to mussels there is now a diverse filter-feeding assemblage of sponges, tunicates, bryozoans, barnacles and amphipods mostly growing on and amongst the mussel-matrix. Algae extended deeper in the clearer water. The ecosystem services provided by mussels and other filter-feeders in improving water quality have enhanced the amenity value of the waterside location, facilitating a cultural quarter and major tourist attraction, plus residential use of refurbished warehouses.
Biography:
Steve Hawkins started work on the ecology and restoration of disused dock basins of North-west England from Manchester University in 1980 (as there were no nearby rocky shores) and subsequently at Liverpool University as an excuse to have a dodgy night out and escape the Isle of Man. Louise Firth encouraged re-surveying the docks in 2012 to assess the resilience of these novel ecosystems. Lock-down meant dry Masters projects prompting data archaeology from unpublished PhD theses and surveys in 2012. Normal service resumed in 2022 with a partial re-survey by a Masters student supervised by Nova Mieszkowska and Steve.
