Posts Tagged ‘water quality’

SPRING NOTES

SPRING NOTES – AUNE CONSERVATION ASSOCIATION

Life in the Devon Avon continues much as normal although recreational activity in the estuary has been severely curtailed during ‘Lockdown’.   Unfortunately, our social gathering in the form of the Tidal Road clean-up planned for the end of April was another casualty of the coronavirus pandemic and advice on social distancing, etc.  Our Spring AGM will probably suffer the same fate.

 

As for normality, this is the time of year when as salmon begin to mature, they adapt for life in salt water in an intermediary stage known as smolts.  This process marks the beginning of their first migration from their home river to the ocean.   Anadromous fish, like salmon, that move from fresh to salt water and back again over the course of their lives, must be able to change their physiology – the way their bodies work.  In a process called smoltification, salmon adapt to the changes salt water causes to their bodies.  In fresh water, the salmon’s body is saltier than the water in which it swims. To work properly, the body needs salt so it tries to keep the salt in.  Some escapes, but the salmon gets enough from the food it eats to make up for the loss.  In the ocean, the water is saltier than the salmon’s body needs to be, so it must try to keep the salt out and the water in.  When salmon swim in the ocean, the salt water draws water out of the fish’s cells.  Salmon adapt by drinking seawater to replace the water their cells lose.  They excrete the excess salt through their gills and urine. As the smolts prepare for ocean life, their appearance also changes, from the dark colours of the fry to the silvery colour of adult salmon. This helps them hide in the light conditions of the surface waters of the open ocean, where there is no dark shade from overhanging trees.  While approximately 30 fry from a redd of 2000 to 2500 eggs grow into smolts, less than four survive to become adults.

 

We are now approximately midway through the smolt migration season, locally, but a big problem in the Devon Avon (Aune) is the potential shortage of water to enable these migrations to occur.  The Aune is a spate river meaning that it is rain-fed, short and fast flowing so the run-off time is quicker; water levels rise and fall relatively quickly, especially upstream.  The water level recorded at the gauging station near Didworthy usually ranges between 0-1.40m; early on 3rd May it was 0.37m.  In contrast, downstream at Loddiswell (usual range from 0.25m -1.80m); the level was 0.26m and falling.  The Avon dam exacerbates the problem of seasonal water shortages although, as part of the original agreement when the dam was built in the 1950s, an ecological ‘bank’ or ‘freshet’ of water should be released in times of drought.    Some years ago, we managed to negotiate with the Environment Agency (EA) and Southwest Water (SWW) to make sure these water releases actually happened – for the first time since the dam was built.   Unfortunately, owing to retirements and headcount reductions in both organisations, the agreement details seemed to become ‘forgotten’ despite my best attempts to familiarise replacement staff with the arrangements.  Happily, following yet more staff reassignments and the appointment of a new, better informed, EA fisheries officer to cover our region, I have just been notified that  because April was a very dry month – although it is raining as I write – the overspill from the dam has been very small of late.    Therefore, a ‘freshet’ of water will be arranged with SWW.  Hopefully, more smolts will make their way to the sea as a result and will eventually come back to our river as adult fish.

 

Stuart Watts – May 2020

A report from the Avon Estuary Forum of 3rd March 2020

The Avon Estuary Forum (AEF) is a biannual meeting of all those agencies and individuals with a relevant interest although discussions often include upstream matters that might affect the estuary.   The Forum is usually held in Thurlestone Parish Hall and anybody is welcome to attend.   If you’d like to be added to the mailing lists for alerts, please contact nigel.mortimer@southdevonaonb.org.uk.

 

The meeting on 3rd March was my second as Chairman and I have decided to provide occasional reports  to widen the information base beyond the distribution of the formal notes that are provided prior to our next meeting (on 13th October in this case).

 

Ryan Hooper (Estate Manager & Bantham Harbourmaster) announced that the Bantham Estate would continue the operation of the Avon Patrol in 2020, financed as previously by South Hams DC and the Bantham Estate, with voluntary contributions from the Aune Conservation Association (ACA), the Avon Valley Ski Club (AVSC) and the Duchy of Cornwall.   Last summer, the revamped patrol made a valuable contribution to the safety and security of many estuary users.

 

There was further discussion, without resolution, about possible improvements to the Bantham/Bigbury ferry operation and how these might tie in with changes to the England Coast Path proposals from Natural England, to the advantage of walkers and regional tourism.  Funding is one unsettled issue.

 

Public participation in several consultations was invited.  The first involves the South Devon Catchment Partnership and ‘Challenges and Choices’ (see – http://south-devon.org/challenges-and-choices/).  That consultation explains why water is such a vital resource, describes the challenges that threaten the water environment, explores how we can work together to manage our waters, looks at who should pay for the actions needed and, importantly, invites input on all these issues.  In that context, there was considerable discussion about river water quality and how standards can be maintained in the face of severe Environment Agency staff cuts. The second consultation, open until 6th April, (see – https://consult.defra.gov.uk/mmo/draft-south-west-inshore-and-offshore-marine-plans/) is about marine planning in the SW, including the Avon Estuary (now designated as a Marine Conservation Zone).  We also heard about proposed new ‘bag limits’ that might be imposed by the Inshore Fisheries & Conservation Authority (IFCA) on the hand collection of foreshore species such as bait worms, scallops, cockles, mussels and limpets but the deadline for that consultation has now passed!

 

As a direct outcome of the meeting, I have contacted Devon & Severn IFCA about local reports of diseased crabs and lobsters by AVSC members.    It seems likely, from a brief Internet search and the description provided at our meeting, that these crustaceans might be the victims of ‘black spot’ disease – a bacterial infection (see picture obtained from the internet) .

Have any other ‘potters’ seen evidence of this disease locally?   Please let us know.

 

The Outdoor Swimming Association has told me that there will be a new event this year – the Bantham ‘Boomerang’ on Friday 3rd July, whereby swimmers will enter the water at Bantham beach at around 1630 and swim upstream with the tide.  All swimmers will turn with the tide at 18.00 (wherever they may be!) and return to Bantham – the last swimmers are expected to be out of the water by 20.00.  The Bantham ‘Swoosh’ will take place on Saturday 4th July, with swimmers entering the water at Aveton Gifford from 06.00 and exiting at Bantham by 09.15.  Please beware of swimmers and let’s hope nobody will get a dose of ‘black spot’!

REPORT ON AVON ESTUARY FORUM

At last evening’s Avon Estuary Forum (AEF) there was a detailed discussion about the state of the Avon Estuary Patrol.   Here is my view of the situation.
Historically, this service has operated on a rather haphazard and informal basis depending upon the Patrol Officer’s availability and the apparent need during busy periods.  This year, the patrol was operated, as previously, by Marsh Dawes – the Bantham Harbourmaster – for the months of July, August and September following the outcry that erupted when SHDC had proposed to disband the service earlier in the year.   However, for the first time,  the ACA and others received an incident report for each of the three operational months and it is obvious that there is a strong requirement both for an advisory  service to deter speeding and other potentially dangerous activities, and – importantly –  to act as a deterrent against widespread abuse of the waterway and its bye-laws if it were to be left unpatrolled.
The fate of the patrol in 2019 is currently uncertain.  However, because of the outcry that arose about abandonment this year, the new Salcombe Harbourmaster is taking a much more active interest in the Avon than previously and he and other stakeholders – including the ACA – will be involved in the discussion about the patrol’s future before a final decision is made by SHDC.   At the AEF last evening, there was general agreement that because of the increased recreational use of the estuary, there is a greater need than ever for a patrol – which should be available on a more extensive and routine basis than previously: the operation should respond to the changing need.
Obviously, such increased patrol activity would carry increased costs and these will form an important part of the debate about the future operation and its funding.  One of the future scenarios may be that current contributors (ACA, Avon Valley Ski Club, Duchy of Cornwall, Bantham Estate) will be asked to pay more to keep the patrol running, a second scenario is that the donor base might be widened (possibly to include parish councils or river users, as two examples); a third is that the Patrol Officer role might be incorporated with other roles around the estuary to create a full-time position – possibly as part of the Bantham Estate.
An extraordinary AEF will be held in February to debate and review progress on the matter.
Other matters raised at the meeting included:-
1) Environment Agency – it is the intention to invite stakeholders to suggest where and when more comprehensive water sampling could be carried out in the estuary.  The background to this was not explained but the ACA would be enthusiastic supporters!
2) IFCA (Inshore Fisheries and Conservation Authority) –  the public is encouraged to report any unmarked (therefore unlicensed) lobster/ crab pots or suspected illegal fishing (01803 856648 or, out of hours,  07740175479).
3) RYA (Royal Yachting Association) – the public is encouraged to report any poorly marked fishing gear via the website.

AVON ESTUARY WATER QUALITY

Click on the following link for an updated message about the estuary’s water quality, biosecurity, etc.

Water quality – November 2018e

Avon runs low

The Environment Agency has two gauging stations for monitoring water levels on the Avon, at Didworthy and Loddiswell.  Data from both indicate a severe reduction in water flow during the current very dry spell of weather, especially in the lower reaches.

On Saturday 21st July, the depth at Didworthy was 0.35m (normal range = 0- 1.4m) and at Loddiswell was 0.19m (normal range = 0.25-1.8m).