Tuesday, 22 April 2014

Ladybird ladybird whence forth comest thou

The Safari is fairly certain we've got the words to a popular nursery rhyme and/or a bit of Willie Waggledagger quite wrong there.
After a bit of overnight rain we were quite hopeful of something being about so off to Patch 2 we went. A quick scan saw us looking at an more or less empty sea. A couple of Sandwich Terns and a Grey Seal were out in the murky sea, rain was still in the air.
A further couple of scans found us a Guillemot and not a lot else.
The main event was happening literally right under our nose, there were hundreds of Ladybirds on the seawall right by us. Looking further along the wall we saw there were thousands of them! nothing for it but to nip back over the road and swap the scope for the camera!
Without our specs we could see there were smaller ones amongst the 7-Spot Ladybirds, no not baby ones! Inspection of the pics we took showed them to be 11-Spot Ladybirds only about 4-5mm long.
Showery rain persisted throughout the morning meaning the works garden wasn't overly dogged and there was a chance of a migrant being dropped - none did! However just before lunch DB came by with one of her dogs and told us there was Goldfinch over in the far corner where the nice publicly spirited person outs the food out, we didn't see it but it was the first of the year here and when we were leaving to go home we saw a Greenfinch (P2 #51).
In the office we've been running a sort of experiment about a) how acidic is cola and b) what would be the effects of ocean acidification on marine life...there are some scary stories that increasing CO2 in the oceans will raise the pH meaning the small calcium shelled sea creatures will fail to survive and bring the ocean ecosystem to crashing halt. Hopefully the phyto-plankton which gives us about half of our all important oxygen won't be immediately affect - would you rather suffocate or starve?
So here we go - a selection of shells and a crab carapace where collected at random off the beach washed and dried and then covered with cola three weeks ago.
They are clockwise from top left, Green Shore Crab (Chitin not calcium carbonate), Common Cockle (hard thick tough shell, Striped Venus (another toughish one), Thin Tellin (delicate), Banded Wedge Shell (thin and  delicate), Rayed Trough Shell (thicker but still more delicate then the top two).
The experiment had to end today cos when we got into the office this morning after the holiday there was a distinct wiff of something none too pleasant - turned out to be festering cola rather than festering shellfish.
So the results were on the left a two bits of limestone and a piece of quartz, the limestone bits were in a different tub but had been there for the same length of time. They now had a chalky film on the outside which wrote on the black card, the quartz appeared to be unaffected.
A brief discussion with BD suggested the chitin of the crab would be unaffected by the acid (coulda done with some litmus paper to check the actual pH) but it had gone soft and papery. Very little change to the two hard shells, the Common Cockle and the Striped Venus, not even discoloured. 
The three more delicate shells did have some changes. The Banded Wedge Shell disintegrated with light pressure from a pencil, the Thin Tellin withstood more pressure but the corner gave way. The Rayed Trough Shell was perhaps the most interesting the pointed end of the shell had gone but the rest wasn't overly affected a part from some discolouration. 
So what does all that show, well three weeks in a cola bath doesn't do some shells much good but doesn't seem to harm others...what that sort of pH would do to the living animal inside the shell is a different matter entirely.
For reasons of fairness we should repeat the procedure using one of the two propriety colas rather than a supermarket own brand.
What is certain is ocean acidification is going to become a serious problem that isn't going away for at least a couple of millennia - you have been warned!
Where to next? Patch 2 might throw up a few more year birds, a Whimbrel was seen by AB not long after we'd gone back inside.
In the meantime let us know who descended en masse in your outback.

1 comment:

cliff said...

The ladybird photos are awesome Dave. I witnessed that same thing once, also on the Prom, but before my wildlife photography days.

I've never seen/photographed an 11-spot Ladybird - I'm very envious!