vrijdag 31 augustus 2012

2012-08-28 hbos papa's Beachhouse Jellyfish!!!!

Weather : light clouds / S wind 2 bft / Rain 0.00 mm / 1017.2 hpa
Divers : John, Ted, Iva, Axel,
Goal : Reconaissance dive to SE ponton
Max depth : 14.1 mtrs
Duration : 79 minutes
Air temp :  14.6 celsius
Water temp : 21.2 celsius minimum
Fish: > loads of young Perch and Ruffe at about 6 mtr, Middle aged Perch, 1 eal at 12,5 mtr, few young zanders, Spined loach, Sweetwater jelly fish, Copepods (roeipootkreeftjes), Smelt,
Plants : Elodea (waterpest) abundant. wire algea not growing below 4 mtr. One Water Mil-foil plant (Aarvederkruid) at 3 mtr. Potamogeton
Visibility : no readings
Yellow viz: no readings
Remarks: > 7 divers. Visit to the pontoon again to see if there's any current underneath it.  Near ponton we found larger Copepods. The airnozzle of the ponton was very spectacular to see and we filmed this. See video wall!
There was almost no noise from the bubbles. Iva spotted a jellyfish and the actually feed on copepods.
From the ponton we went towards the east again on 10-12 mtrs. We were not able to do a viz reading, because of the darkness. Near the nozzle only one little Perch hung out between the bubbles to catch small prey. Millions of Hydra's and mussels grow on the nozzleplate. 
The pontons are in a bad state will probably shutdown permanently because the toxic blue algea doesn't manifest itself anymore. Also the pontoons cost about Euro 15000,- per season (from april till october).
Pumps which have a total capacity of 375 m3 air /hour need maintenance and electrical power to run.
the pontoons will remain on site in 2013 in the event blue algea starts to grow again. 

donderdag 23 augustus 2012

2012-08-23 19:48 Papa's beachhouse

Weather : light clouds / W wind 3 bft / Rain 0.00 mm / 1014.0 hpa
Divers : Remko, Thijs, Iva, Axel,
Goal : Reconaissance dive to SE ponton
Max depth : 15.8 mtrs
Duration : 62 minutes
Air temp :  17.5 celsius
Water temp : 18.8 celsius minimum
Fish: > loads of young perch and Ruffe, 1 eal in the carwreck, 1 Zander, few young zanders.
Plants : Elodea abundant. wire algea only growing in areas where people do not swim
Visibility : no readings
Yellow viz: no readings
Remarks: > 5 divers. Thermocline at 15 mtr dropping from 22.0 to 18.8 celsius. not spectacular but you could feel it. Below thermocline zero visibility. 1 big zander at about 10 mtr overtook us .
 

dinsdag 21 augustus 2012

2012-08-21 20:11 Papa's Beachhouse

Weather : Sunny / WSW wind 2 bft / Rain 0.1 mm / 1016.7 hpa
Divers : Erna,Axel
Goal : look around NE side
Max depth : 10.7 mtrs
Duration : 60 minutes
Air temp : 22.0 celsius
Water temp : 22.0 celsius minimum
Fish: > young perch, young Ruffe,  1 cranky pike, 1 spined Loach (kleine modderkruiper)
Plants :Elodea very abundant up to 60-80 cms,Wirealgea in huge plucks of algea are mainly at the spots where the sun shines the longest and up to a depth of 4 meters where temp is just over 22 celsius!!!,
Visibility : from 0-3 mtrs depth less, but improves below
Remarks: > 5 divers. Beautiful clay ridges at 6 mtrs loads of fish a

2012-08-19 10:46 Papas BeachHouse NO3/CO2 rising!!

Weather : Sunny / SSW wind 2 bft / Rain  0.00 mm / 1014.7 hpa
Divers : Ted, Kacper, Thijs, Axel,
Goal : Reconaissance dive doing whole lap from Papa's Beach House, Watersamples,
Max depth : 10.7 mtrs
Duration : 153 minutes
Air temp :  24.9 celsius
Water temp : 21.6 celsius minimum
Fish: > 1000 young perch, 8 eal, 6 Carp, 1 pike
Plants :Varying. Elodea in the shady areas, Potamogeton species not as abundant anymore. Wirealgea starts growing again.  Huge plucks of algea are mainly at the spots where the sun shines the longest and up to a depth of 4 meters where temp is just over 22 celsius!!!, 
At NE corner in the beachzone young Cristatella Mucedo (mosdier) colonies are spotted in large quantities.
Visibility  : 6 mtr at 3 mtr depth, 7 mtr at 6 mtr depth  (Sun is shining very bright)
Yellow viz: 6 mtr at 3 mtr depth, 7 mtr at 6 mtr depth  (Sun is shining very bright)
Remarks:  > 10 divers. Going clockwisestaying mainly at average depth of 6 mtr. Visibility thoughout varies enormously. At  southeast small beach more and taller Elodea (Waterpest) than at the South (big) beach. Regardless of the many swimmers, visibility is oke along the beach. Narrow area is the steepest going almost vertical at some point at the south. I thought I saw another boatlike shape, but it was a clay plate after rubbing the mussels off.In the shade areas the visibility is better than in the sunny areas. 
Rise in nitrate and carbondioxide levels are significant!!! see watersample table at righthand side!!

donderdag 16 augustus 2012

2012-08-14 20:12 Papa's Beach House

Weather : Clouded / E wind 2 bft / Rain  < 0.05 mm / 1013.0 hpa
Divers : Ted, Kacper, Axel
Goal : Reconaissance dive doing half a lap from Papa's Beach House
Max depth : 16.6 mtrs
Duration : 83 minutes
Air temp :  20.8 celsius
Water temp : 16.8 celsius minimum
Fish: > young perch 3 eal, 1 Zander, 3 pike, > 10 Ruffe
Plants :This side mainly has Elodea and hardly any Potamogeton species. 
Visibility  : not registered
Yellow viz: not registered
Remarks:  7 divers. Going clockwise via the south east beach to the narrowest part and crossover going East to the other side via the bottom. At 16 meters the water is colder than the westside at 16 meters.
There is even a patch of fungi growing on the bottom in small grey/white pointy dots. Under 6 meters the visibility is rather well and has the same characteristics as the West side. There is one active ponton near the southeast beach which seem to have no negative affect on the viz. We passed it at about 7-8 meters where is was pretty clear. At bottom about 13 mtr one Zander. When we reached the eastside there were again great looking blocks of clay and the airtube which have many (useless) tie-raps on them. One fishline and near the end we saw a tree log standing upright at about 7-9 mtr depth. More light coloured soft clay blocks which eroded into layers. 
Great dive. View short video to see how we lapped the eastern part.

2012-08-09 20:28 hbos GOPro and Secchi test

Weather : Clouded / NE wind 2 bft / Rain  0.00 mm / 1026.3 hpa
Divers : Joris, Axel
Goal : Visibility
Max depth : 14.2 mtrs
Duration : 96 minutes
Air temp :  16.3 celsius
Water temp : 18.8 celsius minimum
Fish: > young perch, 1 dark striped pike.
Plants :Elodea is growing. Potamogeton seems to diminish
Visibility  : 3,5 mtr at 3 mtr depth
Yellow viz: 3,5 mtr at 3 mtr depth
Remarks:  > 5 divers. No mucous like threads anymore as dive before.
Little Perch approx 5 cm are abundant and are swimming in schools. 
Next to Paviljoen there is a clear stretch where as a little further from the Paviljoen visibility gets less.
It is now becoming obvious that the mussels are doing a great job filtering the water. In a layer of about 50 cm above a musselrich patch the water is more clear than other areas where mussels are less abundant lets say over a sandy bottom. We took a tour prom the Paviljoen going right at 13 mtrs. There are beautiful blocks to be seen there. When you get near the active ponton the visibility gets worse when you go deeper than 15 mtrs. 
We made a video of this dive inclusing a visibility reading. Take a look at the video box at this site

zondag 12 augustus 2012

Contact with Community council and Rijnland


I have had contact with Rijnland.net to introduce Project Baseline and to see if our findings can be used or if we can we provide specific information about the lake they might need. Their reaction was positive and they will look into the offer. Rijnland operates and manages the airpumps. Also the community council was positive and gave me usefull information about the lake's history and other organisations who are in in the contact with the council about the lakes. It is just a matter of time to see if one or more collaborations between organisations and Project Baseline are possible.
History of Haarlemmermeersebos is updated.

dinsdag 7 augustus 2012

2012-08-07 14:38 hbos Algeabloom starting?

Weather : Clouds / W wind 3 bft / Rain  ?.? mm / 1018.0 hpa
Divers : Erna, Axel
Goal : Visibility, Watersamples.
Max depth : 9.7 mtrs
Duration : 56 minutes
Air temp :  17.0 celsius
Water temp : 20.8 celsius minimum
Fish: > young fish (perch and next to Paviljoen at 4,5 mtr young Ruffe, 1 eal, 1 Carp, 1 dark striped pike.
Plants : It looks as if Potamogetons are less abundant near entry, but Elodea (Waterpest) is growing. The sediment colours the Elodea in a light brownish green. As you go deeper the Elodea is dark and fresh green
Visibility  : 3,5 mtr at 3 mtr depth, 4 mtr at 6 mtr depth
Yellow viz: 3,5 mtr at 3 mtr depth, 3,5  mtr at 6 mtr depth
Remarks:  2 divers. The top layer of the water seems to become greenish of colour and starts to thicken. Little mucouslike threads are sinking. 
Little Perch approx 5 cm are abundant and are swimming in schools. 
A school of young Ruffe are in en very clear patch next to the Paviljoen at 4-5 mtr depth. A dark striped pike was probably hunting the young Ruffe as we blew it's cover. 
We cleaned up a plastic bag filled with rubble and removed various cans and plastic waste.
It strikes me how fast (large) Mussels are settling on plastic and tin cans.
There is probably a need for more hard substrate for the mussels to grow on in a depthrange from 2-6 mtrs.
I'm thinking about placing plates at various depths and see how fast mussels settle on it.
These mussels filter the water.

donderdag 2 augustus 2012

2012-07-31 20:19 hbos

Weather : Overcast / S wind 3 bft / Rain  6.0 mm / 1016.3 hpa
Divers : Kacper, Axel
Goal : Visibility, Watersamples /Drills
Max depth : 11.7 mtrs
Duration : 54 minutes
Air temp :  15.3 celsius
Water temp : 19.2 celsius minimum
Fish: > young fish (perch )
Plants :No significant change
Visibility  : 3,0 mtr at 3 mtr depth, 4 mtr at 6 mtr depth
Yellow viz: 2,5 mtr at 3 mtr depth, 2,0  mtr at 6 mtr depth
Remarks:  > 5 divers still milky till about 7,5 mtr depth
Focus was on drills.