[upstarts1979]

3 pics of the salt spring.
All around the Flashes is dry, but immediately around the spring it is extremely soft deep mud.
Once again the overnight rain never materialised, it is going to take many days of continuous rain to even wet the 2nd Flash.

Dave did you get the samples? If not I have put them in the lock up on top of the food barrel lid?

[Phil Andrews]

Originally Posted by Woodchat

Spent an hour or so at the flashes this evening. Looks like the recent rain has had no effect at all on the water levels.

A Juv/1W Mediterranean Gull dropped in to the roost at ~7:30 pm - John Ridley spotted it first. The two Black-tailed Godwits fed on the first flash and a juv Common Tern came in just as it was getting dark. As we left, a Peregrine was dive-bombing a Buzzard near the transmitters.

John - the new first flash island looks very promising.

Below is a poor record shot of the Med - the light was fading fast.

Mike - does this look like the same Med that you had on Thursday?

[discors]

Both previous Sabines and Wilsons have been in September with Laughing Gull and a good spread of Sandwich Terns and even a Great Skua. Ever the optimist.
Interesting photo's of the saline spring. Is that the bobble of a Blues supporter hat sinking in the mud at the end of the footsteps going one way. A fitting end to an upstart?

[upstarts1979]

Originally Posted by discors

Both previous Sabines and Wilsons have been in September with Laughing Gull and a good spread of Sandwich Terns and even a Great Skua. Ever the optimist.
Interesting photo's of the saline spring. Is that the bobble of a Blues supporter hat sinking in the mud at the end of the footsteps going one way. A fitting end to an upstart?

No I think it is the stuff we give the Villa (sh**)SOTV

we'll be back

[Woodchat]

Originally Posted by upstarts1979

3 pics of the salt spring.
All around the Flashes is dry, but immediately around the spring it is extremely soft deep mud.
Once again the overnight rain never materialised, it is going to take many days of continuous rain to even wet the 2nd Flash.

Dave did you get the samples? If not I have put them in the lock up on top of the food barrel lid?

Yes cheers John, I got the samples and have measured the salinity levels:

The 'salt' spring contains 9,200 milligrams per litre total dissolved solids (TDS, i.e. salts). This is surprisingly dilute.

The salinity of the first flash is currently 26,300 milligrams per litre TDS. Not surprisingly (considering the low water levels) this is the highest salt concentration I've ever recorded for the first flash (about 75% as salty as seawater).

BTW John I have sent you a reply to your text - if you haven't received any of the 3 texts I've sent you today, I think there is something wrong with your network. Thanks again for the samples, mate.

[Phil Andrews]

Originally Posted by upstarts1979

Re shoveler In normal years September through to mid October they feed mostly on the Flashes in the evenings (2nd Flash), after the first cold spells the invertebrates decline. This coincides with the shoveler moving to the Moors, where they form into tight pirouetting flocks stirring up their food. Last year the Moors flock never formed, this we attributed to the daily incursion from the stockman into Amy's marsh. I think this year numbers will be well down as the Moors cannot provide enough food at this time.
I will go through my note books and check out the early years. I know in the 90's we boasted 1% of the national winter population, which was classed as ' of National importance'.

Just to excite Oriole Boy (he told me to just cant wait to see another bar chart on this thread) I attach the average half-monthly peak counts over the period 1998 (when this type of data was first logged) until 2010.

Shoveler has a distribution quite unlike any other species - number rise rapidly in early autumn to peak in late October before falling away in mid winter, only to gently rise again in late winter / early spring.

[Woodchat]

Originally Posted by upton-till-i-die

Just to excite Oriole Boy (he told me to just cant wait to see another bar chart on this thread) I attach the average half-monthly peak counts over the period 1998 (when this type of data was first logged) until 2010.

Shoveler has a distribution quite unlike any other species - number rise rapidly in early autumn to peak in late October before falling away in mid winter, only to gently rise again in late winter / early spring.

Interesting, Phil. I would've thought bimodal distributions like this would be fairly normal for species that are basically winter visitors but have peaks during passage-migration periods. I would be interested to see comparative graphs for Teal and Snipe. Cheers.

[Phil Andrews]

Originally Posted by Woodchat

Interesting, Phil. I would've thought bimodal distributions like this would be fairly normal for species that are basically winter visitors but have peaks during passage-migration periods. I would be interested to see comparative graphs for Teal and Snipe. Cheers.

Attached is the average half-monthly peak counts for Teal (also covering 1998 to 2010). Following the same autumn increase as other ducks, for some reason Teal has a secondary spike at the end of the year (supported by data from several years - not just one rogue count) before numbers tail off again. Whilst there is a slight increase on passage in early Spring this is far more pronounced with Shoveler.

[Phil Andrews]

Similar exercise undertaken for Snipe (again 1998-2010). Numbers build up much slower in the autumn compared to the duck species. Whilst the overall pattern of a dip in December followed by a rise in late winter mirrors the duck species, unlike them the peak for Snipe in the late winter / early spring is higher than that of the autumn movement.

[Phil Andrews]

Originally Posted by upton-till-i-die

Good passage of seabirds up the Severn today as far as Lydney / Slimbridge at least (Gannet, Fulmar, Sab's Gull, Manx Shear, Arctic Skua etc); there may be a goody - and I don't mean Mr Oddie - waiting to be found by someone tomorrow.

So far today a Sab's has been found at Belvide and a Manxie at Draycote; surely there must be a pelagic species lurking somewhere in Worcestershire?

[Woodchat]

Originally Posted by upton-till-i-die

Similar exercise undertaken for Snipe (again 1998-2010). Numbers build up much slower in the autumn compared to the duck species. Whilst the overall pattern of a dip in December followed by a rise in late winter mirrors the duck species, unlike them the peak for Snipe in the late winter / early spring is higher than that of the autumn movement.

Cheers Phil,

Snipe and shoveller seem to follow a fairly similar pattern with obvious peaks in autumn and spring. Perhaps these two species are more susceptible (cf. Teal) to mid-winter freeze-ups, forcing them to move out and seek milder climes. During snow-cover last year, I noticed how the Teal would often resort to feeing in the hen brook.

[beyonder]

Originally Posted by Woodchat

Yes cheers John, I got the samples and have measured the salinity levels:

The 'salt' spring contains 9,200 milligrams per litre total dissolved solids (TDS, i.e. salts). This is surprisingly dilute...

Could that suggest this is just low lying. It seemed so to me. The whole area was very boggy and the mud much deeper than the rest of the flash (my excessive bmi had me struggling way before John ). Does that suggest the "silt" settles there?

If this isn't a "spring" Where is the salt coming from? John showed me the effect of the salt on the vegetation in that area.

[upstarts1979]

Originally Posted by beyonder

Could that suggest this is just low lying. It seemed so to me. The whole area was very boggy and the mud much deeper than the rest of the flash (my excessive bmi had me struggling way before John ). Does that suggest the "silt" settles there?

If this isn't a "spring" Where is the salt coming from? John showed me the effect of the salt on the vegetation in that area.

Paul as I approached the 'spring' the area got progressively wetter and muddier, which would suggest that the water is quite close to the surface in that area. The wet patch might be a 'blow hole' similar to a volcano only water comes out who knows.

conversely and a bit controversial, after looking at the photos I wonder if it could be a 'sump hole' whereby all the water actually drains out through it at low water, would this explain the low salinity (just a thought) I think you might be right Paul, . Perhaps when the water table increases salt water might percolate to the surface, as in the volcano analogy.

[beyonder]

Originally Posted by upstarts1979

...conversely and a bit controversial, after looking at the photos I wonder if it could be a 'sump hole' whereby all the water actually drains out through it at low water, would this explain the low salinity (just a thought) I think you might be right Paul, . Perhaps when the water table increases salt water might percolate to the surface, as in the volcano analogy.

(I should preface all my comments with "I'm no expert".) ...but you could be right. According to my wellie-gauge there was a greater depth of black silt top layer here than where we'd been digging the channel.

The low salinity is a puzzle.

Does that area get used less by the birds? I had the impression that might be the case, hence the interest.

[Woodchat]

Originally Posted by beyonder

Could that suggest this is just low lying. It seemed so to me. The whole area was very boggy and the mud much deeper than the rest of the flash (my excessive bmi had me struggling way before John ). Does that suggest the "silt" settles there?

If this isn't a "spring" Where is the salt coming from? John showed me the effect of the salt on the vegetation in that area.

This could still be the primary source of the salt since, during the winter, 9000 mg/l is still higher concentration (hypertonic) relative to the mean bulk winter concentration of the second flash (about 7000 mg/l). This concentration-gradient in winter could lead to steady ingress of salt via diffusion (or effusion) into the bulk of the water-body. Evaporation then concentrates the salt in the second flash greatly during the spring / summer and the source becomes hypotonic (lower concentration) relative to the bulk. In this situation there would otherwise be a tendency for the dissolved salt to diffuse the other way but it appears that the interface may be so small that this may not occur to any significant degree (although hypotonic solution could and probably does flow from the source into the bulk, diluting it - depending on the hydrostatic pressure of the source). In effect, the source probably acts as a "one-way-valve" which allows slow ingress of salt into the flashes system but no real mechanism for it to flow backwards (to where it came from). The only known mechanism for salts to leave the flashes system is via the hen brook and I have also been monitoring this by measuring the salinity of the brook above and below the outflow-sluice. At the moment the 'loss' of salts into the brook is negligible as the flash water-levels are very low and the flow through the sluice is virtually non-existent. However, it becomes significant during high water / flooding events. I'll attach a graph later...

There are obviously still a lot of unknowns but I hope to understand it more in due course.

A graph indicating the salinity of the hen brook above and below the outflow sluice is attached. During last autumn / winter, the downstream salinity was generally higher than upstream (of the sluice). This indicates the flow of saline waters from the flashes into the hen brook during this period. There is a notable 'spike' in the downstream concentration in late August/September last year when rains caused a 'flushing' of salt-water from the flashes into the brook via the outflow. As water-levels subsided and the flow from the first flash into the brook reduced (during spring / summer 2011) the salt levels above and below the outflow sluice converge - indicating that virtually no salts are being leached out of the flashes in this period.

[beyonder]

Originally Posted by Woodchat

This could still be the primary source of the salt...

Thanks for the explanation. In short - it may be counter-intuitive from a layman's point of view but scientifically perfectly possible. Which is the point of all your good work of course.

[upstarts1979]

Originally Posted by Woodchat

This could still be the primary source of the salt since, during the winter, 9000 mg/l is still higher concentration (hypertonic) relative to the mean bulk winter concentration of the second flash (about 7000 mg/l). This concentration-gradient in winter could lead to steady ingress of salt via diffusion (or effusion) into the bulk of the water-body. Evaporation then concentrates the salt in the second flash greatly during the spring / summer and the source becomes hypotonic (lower concentration) relative to the bulk. In this situation there would otherwise be a tendency for the dissolved salt to diffuse the other way but it appears that the interface may be so small that this may not occur to any significant degree (although hypotonic solution could and probably does flow from the source into the bulk, diluting it - depending on the hydrostatic pressure of the source). In effect, the source probably acts as a "one-way-valve" which allows slow ingress of salt into the flashes system but no real mechanism for it to flow backwards (to where it came from). The only known mechanism for salts to leave the flashes system is via the hen brook and I have also been monitoring this by measuring the salinity of the brook above and below the outflow-sluice. At the moment the 'loss' of salts into the brook is negligible as the flash water-levels are very low and the flow through the sluice is virtually non-existent. However, it becomes significant during high water / flooding events. I'll attach a graph later...

There are obviously still a lot of unknowns but I hope to understand it more in due course.

The next time I put salt on my chips I will think about this
Nice one Dave, I am sure the trust would agree with your hypothesis, NOT.
Basically they wouldn't have a clue

[UW82]

Today's highlights:

MOORS:
Med Gull (1w)-----------Common Tern
Hobby-------------------Green Sand (2)
Common Sand----------Lapwing (c60)
Herring Gull (3)---------L B B Gull (13)
Pochard (3)-------------Shoveler (4)
BH Gull (c300)----------Barnacle Goose
Sand Martin (c20)------House Martin (c30)

NORTH MOORS:
No indication of Cettis Warbler-------Water Rail
Reed Warbler

FLASHES:
Green Sand (4)------------Peregrine
Kingfisher------------------Teal (13)
BH Gull (c90)--------------Whitethroat reported.


Des.

HEN POOL:
Reed Warbler

[rollingthunder]

Indeed, Salt is Droitwichs' 'raison d'etre' - So important that the Romans called the place 'Salinae'. UW. with its' unique range of both freshwater and saline habitats would'nt exist without the flooded workings below and the upwelling of brine. The Romans built mosiac 'salt-ways' radiating out from Droitwich to take the stuff far and wide. The deposits were so rich that 2 1/2 pounds per gallon of water could be extracted, that is ten times that of sea water and only matched by the Red Sea! The re-opened canal was one of the reasons for construction (i shall be there next year) - The second syllable 'wich' is often associated with brine production, a good example being the towns of Cheshire, Northwich etc. When i was a little boy i remember my Gran buying blocks of salt from the salt-seller off of his horse and cart and this had come up 'the salt road' from Droitwich - the main road that passes by UW - i hope all the Avocets are reading this!

Attached is a sculpture dedicated to the Salt workers in Droitwich, all the birders should pay their respects.............

Laurie

[rollingthunder]

How times change - just found this photo, check out the 'scopes and 'bins especially the 'Pirates of the Carribean' Brass monster in the foreground!

What was the year and what was the bird?

I think only John would remember those halcyon days............

Laurie

[timmyjones]

Originally Posted by rollingthunder

How times change - just found this photo, check out the 'scopes and 'bins especially the 'Pirates of the Carribean' Brass monster in the foreground!

What was the year and what was the bird?

I think only John would remember those halcyon days............

Laurie

Already seen this photo so I won't give it away, but a fair few years before I was born. Although the scope I use now was made about 5 years before this photo was taken!!!

[upstarts1979]

Originally Posted by rollingthunder

How times change - just found this photo, check out the 'scopes and 'bins especially the 'Pirates of the Carribean' Brass monster in the foreground!

What was the year and what was the bird?

I think only John would remember those halcyon days............

Laurie

I remember it well Laurie, Falmouth beach for the UK's first Forsters Tern. A similar photo also appeared in the Sun newspaper, I was in that one with fellow upstarts. Dave Farrow(upstart) on floor in check jacket, later that day we went to see Stiff Little Fingers in Falmouth

John

[UW82]

Originally Posted by rollingthunder

How times change - just found this photo, check out the 'scopes and 'bins especially the 'Pirates of the Carribean' Brass monster in the foreground!

What was the year and what was the bird?

I think only John would remember those halcyon days............

Laurie

I think the twitch was the UK first Forster's Tern c1980.

Des.

[CaveLight]

Originally Posted by upstarts1979

I remember it well Laurie, Falmouth beach for the UK's first Forsters Tern. A similar photo also appeared in the Sun newspaper, I was in that one with fellow upstarts. Dave Farrow(upstart) on floor in check jacket, later that day we went to see Stiff Little Fingers in Falmouth

John

And Stiff Little Fingers wrote a song about that scope "Suspect Device".

[upstarts1979]

Originally Posted by CaveLight

And Stiff Little Fingers wrote a song about that scope "Suspect Device".

good call Dave
John