Archive for July, 2010

AONB landscape records

The AONB is gradually accumulating a series of photographic records from important GIS-referenced sites around the South Hams.   The background to their project is described if you click here – The Bigger Picture – project overview.

The most recent photograph taken from Folly Hill Farm is shown below.

Duke’s Mill Creek (aka Weredown Marsh) plant survey

The results of a general survey, conducted in 2009, of plant life in Duke’s Mill Creek (aka Weredown Marsh) are  now available for inspection on the ECOLOGY page of this website, courtesy of the landowner. 

Following an enthusiastic uprooting of Himalayan Balsam on Sunday 18th July, 2010, by ACA volunteers there will be a few less of these invasive aliens appearing next year, we hope.  Interestingly,  the annual plant is not mentioned   in the survey; possibly it was the wrong season of the year.

SOUTH EFFORD MARSH – THE ENVIRONMENT AGENCY’S PROPOSAL

Following an EA community ‘consultation’ event on 7th July 2010, the Aune Conservation Association’s (ACA) management committee has considered the issues and has unanimously agreed the following statement of its opposition, on environmental grounds, to the proposal to create a salt marsh at South Efford. 

In the current economic climate, there is a separate but parallel argument against the proposal based on the spurious expenditure of scarce financial resources.

 

Background information:

  • The EA hopes to expose South Efford marsh to frequent tidal flooding as part of a national salt marsh habitat creation programme. 
  • The entire area of South Efford marsh would be flooded with salt water by a process of ‘regulated tidal exchange’. 
  • The sole objective is to meet a UK Biodiversity Action Plan (UKBAP) salt marsh creation target by March 2011.
  • The source of the £200,000 (approximately) project funds is DEFRA’s flood risk prevention and so-called ‘managed realignment’ policy which addresses the perceived effects of climate change on sea levels.

 

South Efford Marsh (by John Peters)

 

The environmental issues:

  1. The project is an experiment with unexplored environmental consequences.   Not only is the successful creation of a viable salt marsh in doubt, based upon similar experiments elsewhere in the UK,  but the effects of flooding this site on the integrity of neighbouring properties, on the river’s hydrology and geomorphology, and on navigation by river craft are unknown. 
  2. However, it can be stated with absolute certainty that the effects on the freshwater ecology of the existing floodplain and grazing marsh* would be devastating. 
  3. There are no funds or resources available to maintain the salt marsh, its borders or the sophisticated tidal exchange mechanism in the medium- or long-term.
  4. The ecology of the existing grazing marsh at South Efford was last surveyed in 1992.  The results are listed in the Devon Biodiversity Records Centre and reveal the existence of at least two nationally scarce plant species – the Balm-leaved Figwort and the Elongated Sedge (see ‘Wildlife sites & species’, ECOLOGY page).  However, because the site is not listed under the  EU Habitats Directive (which aims to protect the wild plants, animals and habitats that make up our diverse natural environment), there is no obligation for the EA to survey the site and identify the flora and fauna that would be destroyed; an unscientific approach.   An environmental impact assessment would be required by the EA if any other party were to propose such a dramatic change in the use of the land.  As it is,  the EA can grant itself consent to proceed.
  5. There is no intention by the  EA to manage the new salt marsh themselves – they would need to recruit management ‘partners’ (none is known at present), presumably, with the necessary resources.
  6. There is no intention by the EA to create anything other than salt marsh;  the EA will sell the land, otherwise.
  7. The EA has shown a lukewarm response to suggestions for  improving public access to any new salt marsh for the education and/or recreation of the community.
  8. Salt marsh already exists in several other places in the Avon estuary.  The quality of some of this marsh is deteriorating due to nutrient enrichment of the water, erosion and trampling (Atkins survey of 2005 for AONB; see the ECOLOGY page of this website ).  Arguably, the EA’s funds would be better spent on improving the existing salt marsh in other areas of the estuary.  However, the current EA strategy is dictated by the source of the funding.

* Coastal and floodplain grazing marsh is a priority habitat in the UK Biodiversity Action Plan (UKBAP), meaning that not only should existing habitat of this type be maintained but there are regional targets for the creation of new grazing marsh.   The Devon BAP states that the county has a critically small amount of grazing marsh and, at South Efford, the salt marsh creation objective is in direct conflict with a Biodiversity South West BAP target to increase regional floodplain and grazing marsh. NB The EA is a partner in Biodiversity South West!    Somewhat perversely, the Devon Coastal and Floodplain Grazing Marsh project in the South Hams is funded by the Environment Agency, with the aim of promoting increased awareness and environmentally sympathetic management of this priority habitat!  It seems that taxpayers’ funds are being used for directly conflicting purposes within the same organisation.    

In the UKBAP, the term Grazing Marsh is used  to describe seasonally waterlogged grassland (and associated ditches) which is grazed by stock and forms part of a wetland system, including wet grassland and floodplain meadows, agriculturally improved or unimproved in nature.   Commonly, this land has been ‘reclaimed’ from the sea, by enclosing inter-tidal areas behind a sea wall, which were then drained using a network of ditches.  The ditches are especially rich in plants and invertebrates.  Sluices control the water levels in the ditches which act as ‘wet fences’ – giving these areas a characteristically wide and open appearance with few fences or hedges. 

The UKBAP states that Grazing Marshes are particularly important for the number of breeding waders such as snipe Gallinago gallinago, lapwing Vanellus vanellus and curlew Numenius arquata they support. Internationally important populations of wintering wildfowl also occur including Bewick swans Cygnus bewickii and whooper swans Cygnus cygnus.

 

DWARF SPIKE RUSH – THE SEARCH CONTINUES!

Sadly, the Dwarf Spike Rush (Eleocharis parvula) remained an unseen rarity as it  eluded our efforts to find it on our expedition into the mud at Aveton Gifford on 1st July, mostly due on this occasion to a higher tide than expected (the plant only grows below Mean High Water).    

It is several years since the plant was last seen at this site, the only one in Devon from which it has been recorded.      A dense blanket of  an, as yet, unidentifed seaweed was covering much of the exposed mud and did not help our search.  Might this thick blanket have overwhelmed the Spike Rush?  Might this extremely rare plant - in UK terms – have died out?  Could this covering of weed be due to higher levels of nutrients in the water than previously?