donderdag 26 juli 2012

2012-07-25 20:15 hbos Dense milky layer up to 7-8 mtr

Weather : Clear / N wind 2 bft / Rain  0.0 mm / 1016 hpa
Divers : Ted, Axel
Goal : Visibility, Watersample, check TC
Max depth : 16.7 mtrs 
Duration : 72 minutes
Air temp :  27.7 celsius
Water temp : 17.2 celsius minimum
Fish: > young fish (perch) more scattered also at 14 mtr depth- no waterfleas nore copepods (eenoogskreeftjes)
2 Eal, > 20 Ruffe, 1 Zander at 14 mtr. And as far as I can see quite a lot of Melt (Esmerus Eperlanus) (Spiering)
Plants : Pondweed (ELodea) Gutweed still in same state being shrunk in small quantities
Potamogeton species still there.
Visibility  : 2 mtr at 3 mtr depth, 2.5 mtr at 6 mtr depth
Yellow viz: 2 mtr at 3 mtr depth, 2,5 mtr at 6 mtr depth
Remarks: The milky white layer more like a dense mist and light scatters. You cannot even see 100% sharp anymore. Layer is from 7-8 mtr depth upto the surface. Underneath that layer the temperature graph on my computer shows a sawtooth model. Going up and down 0,7 celcius. You can actually see the dustlayers in the water.
At 14-15 mtrs another layer and at 16 mtr the temp drops from 18.3 to 17.2. Not a major difference though.
This time we experimented visibility with a Secchidisk like plate with yellow/black and with white/black squares. No difference between white and yellow. This time Baseline viz with lightsource and yellow viz without lightsource gave same readings. 
In nighttime you often see small elongated fish desperately trying to escape from your lightbeam. Occaisionally they swim right into the lightbeam hitting your lamp. It guess it is a Melt (Spiering).


woensdag 18 juli 2012

2012_07_17 20:15 hbos Loads of fish! NO3 level rising

Weather : Cloudy /  WSW wind 3 bft / Rain  0.4 mm / 1019 hpa
Divers : Remko, Kacper, .Mark, Ted, Axel
Goal : Visibility, Watersample, Drills
Max depth : 14.8 mtrs 
Duration : 111 minutes
Air temp :  17.7 celsius
Water temp : 18.8 celsius minimum
Fish: > schools young Perch under Paviljoen - babyshrimp almost gone, waterfleas gone.
4 Pike, 2 Eal, > 100 Young Ruffe even at 6 mtr depth on bottom, Mini snails are still abundant at the bottom at 2-7
Plants : Pondweed (ELodea) is now really starting to grow larger at 19 celsius. Gutweed almost gone.
Wirealgea is gone.From 5 mtr depth and up large Potamogeton species > 1 mtr
Visibility  : 5 mtr at 3 mtr depth, 5.5 mtr at 6 mtr depth
Yellow viz: 5.5 at 3 mtr , 6,0 at 6 mtr depth.
Remarks : > 5 divers. After rainfall more milky. At 14,5 mtr depth a dense milky layer at Paviljoen.
On piles new individual mussels white coloured are starting to grow.
Test with visibility using a weak lightstick. Gave same result as yellow plate.

vrijdag 13 juli 2012

2012-07-12 20:04 hbos Gutweed diminishing at 19 celsius

Weather : Cloudy /  WSW wind 3 bft / Rain  32.3 mm / 1011.4 hpa
Divers : Remko, Kacper, Axel
Goal : Visibility, Watersamples
Max depth : 14.3 mtrs 
Duration : 95 minutes
Air temp :  14.0 celsius
Water temp : 19.2 celsius minimum
Fish: > 100 young Perch now in actively (fast) swimming schools - clouds of babyshrimp, waterfleas seen in large quantities in Northside at 5 mtr, but much less  at 7-8 mtr depth. 1 Zander, 5 Pike, 2 Eal, > 20 Young Ruffe, american crayfish with one pincher (Orconectus limosus). mini snails are abundant at the bottom at 2-7 mtr which ni retrospect is the case for many weeks actually
Plants : Pondweed (ELodea) is now really starting to grow larger at 19 celsius. Gutweed is diminishing rapidly.
Wirealgea is almost gone.
Visibility  : 5 mtr at 3 mtr depth, 5 mtr at 6 mtr depth
Yellow viz: 6.5 at 3 mtr , 6 at 6 mtr depth.
Remarks : > 5 divers. A concretemixer had been placed next to Reel. It is unknown who placed it. At 7 mtr 120 degrees crossover. Spotted the boat again at 13.7 mtrs and large remnants of the bridge. Schools of youg perch are now racing around and Pike's are present lurking on these schools at about 5 mtrs near the bottom. You can clearly see more activity at these temperatures of 19-20 celsius. 
Water is still somewhat milky.


donderdag 5 juli 2012

2012-07-03 20:30 hbos Algea starting to influence visibility

Weather : Cloudy / S wind 2 bft / Rain  0.3 mm / 1016.3 hpa
Divers : Patrick,Ted,Kacper, Axel
Goal : Visibility, Watersamples and skills
Max depth : 10.9 mtrs 
Duration : 67 minutes
Air temp :  18.9 celsius
Water temp : 18.4 celsius minimum
Fish: > 10 perch - smallerlouds of shrimp, less waterfleas.
Plants : not taken any notice
Visibility  : 3.5 mtr at 3 mtr depth, 4 mtr at 6 mtr depth
Yellow viz: same
Remarks : > 5 divers. Water is getting milky green. It looks as if algea growth is starting.
The CO2 is slightly increasing at 6 mtr depth according to sample results