Crossness site manager Karen Sutton reports on events, wildlife, upcoming site maintenance activity and impending disruption to the Thames path arising from Environment Agency works.
Events:
Crossness hosted the ‘BEXLEY GREEN DRINKS’ on 11th Sept, which is the social and networking event for local wildlife, conservation and sustainability people in the Borough, and a migrant bird walk on the 19th. Reports on these have appeared in previous ‘Bexley Wildlife’ posts.
Wildlife:
Ancient Greenfinch:
Our volunteer, Roger, a licenced bird ringer, received notification from the BTO that a Greenfinch ringed at Crossness on 30th October 2005 as a first year male was found dead (killed by a cat) in Thelwall, Warrington on 27th August 2019. Duration: 5049 days, Distance: 278 km. A 14 year old Greenfinch – quite a record!
Aquatic invertebrate surveys:
We commissioned some aquatic invertebrate surveys (primarily for beetles) back in Autumn 2016 and Spring 2017 across the nature reserve and the southern marsh (12 sampling stations on each site), which revealed some rather interesting invertebrates, of which a good number are considered nationally scarce. When we experienced a pollution incident from the adjacent sewage treatment works in winter 2017, we decided that it would be a good idea to repeat those surveys to give us a clearer idea of the impacts, so we repeated the surveys in Autumn 2018 and Spring 2019.
Although there was the expected and marked differences at individual sampling stations, overall the repeat surveys produced an aquatic species list of high quality, with the species index score showing a slight improvement! So the good news is that there was a remarkable similarity between the two surveys, and that the entomologists think that the pollution incident has had minimal long-term effects – phew!
The full report is provided as a pdf (at the foot of this post) for those of you that might be interested in the detail. The report concludes that the aquatic habitats at Crossness remain largely in good health and that the areas most affected by the pollution incident are recovering well.
Work coming up:
There’s a lot of work coming up on site over the next few weeks and months. Work that you will see going on, includes:
* The installation of a small boardwalk to get visitors over the flooded section of path on Crossness Southern Marsh (the location in which there are currently stepping stones) – next couple of weeks
* Painting/treating the exterior of the bird hide – next couple of weeks/months, depending on weather conditions
* Cut and removal of vegetation on the nature reserve and southern marsh paddocks, involving large agricultural machinery – next couple of weeks
Other work coming up, but not yet timed-in, includes:
* Replacement of the mini-beast area fencing; digging out of Phragmites/Typha on the Education Pond
* Installation of an access structure to the wader scrape island
* Surfacing of the circular path in the Protected Area South
* Resurfacing of Footpath 2 that runs alongside Great Breach Dyke West (between the Protected Area and the southern area kissing gate)
* Ditch dredging on Crossness Southern Marsh
In addition to our work, there’s a large Environment Agency project coming up. I have mentioned this before, but the plans are now longer and more detailed. It involves the refurbishment of the Great Breach Pumping Station and significant work to the outfall. The schedule currently shows work taking place between December 2019 and April 2020. For at least some of that time, there will be path closures in place. Our section of the Thames Path will be closed, and unfortunately, the diversion is long, involving a 57 minute long walk. My understanding is that the ‘Urgent Works’ is the part of the programme that will most affect visitors. This will involve closure of the Thames Path, but also tankering away of the removed silt via our main access path and the Norman Road gates.
The EA has said that it hopes to close the footpath between the east of Riverside Resource Recovery Ltd. and a point immediately to the west of Crossness Sewage treatment plant, with a diversion route signposted. Prior to the closure, it will put up notices along the path to make people aware of the closure when it comes into effect …. However, the footpath will most likely be open at weekends and outside of working hours and the nature reserve will be accessible to members of the public along the access track from Norman Road during weekdays when works are ongoing.
Karen Sutton, Crossness Nature Reserve Manager
karen.sutton@thameswater.co.uk
Crossness Nature Reserve, Crossness Sewage Treatment Works, Bazalgette Way (formerly Belvedere Road), Abbey Wood, London SE2 9A
What was the pollution incident at Crossness?