zaterdag 29 december 2012

2012-12-29 09:27 hbos going deep again



Weather : Clouded / S wind 6 bft / Rain 0 mm / 1007.2 hpa
Divers : Kacper ,Axel,
Goal : Look around , measure visibility.
Max depth : 19.8 mtr
Duration : 65 minutes
Air temp : 11.0 celsius
Water temp : 6,6 celsius minimum
Fish: > 3 eal, 2 catfish, 3 Perch, 1 Zander all in the deep.
Baseline visibility: 6 mtr depth -> 9 meters.
Secchi visibility: 6 meter depth -> 12 mtr
Plants: Elodea (waterpest) is diminishing at the entry point. though a young plant is growing being Potamogeton Crispus. At 20 mtr depth loose bushes of Elodea can be found which have bigger leafs than the ones at about 2-3 mtr depth.
Remarks > 10 divers. We were heading for the yellow buoy. We have passed 2 ridges. We took a right turn and the bottom slopes nicely. There is a huge clay boulder. Then we turned east again and found the air hoses which supply the northwest pontoon. They are curled up and attached to the anchor of the yellow buoy. A steel line guides to the pontoon. At 9 mtr depth on our measurement pile a beautiful sponge grows. Also patches of darkgreen algea on the pile. Temperature is now stable. 

zaterdag 22 december 2012

2012-12-21 15:09 hbos Top layer sediment ..WOW!!


Weather : rainy / S wind 4 bft / Rain 1.1 mm / 1001.7 hpa
Divers : Ted,Gery,Remko,Martien,Axel,
Goal : get sediment specimen at 20 mtr and specimen from pile at 6 mtr depth
Max depth : 20.0 mtr
Duration : 69 minutes
Air temp : 7.0 celsius
Water temp : 5,2 celsius minimum
Fish: > 1 eal, 1 catfish
Remarks: > 5 divers. Taking specimens is fun especially when you want to know what you will find under de microscope..  Result is astonashing.. See movie I made from under de microscope. 
The variety of cells and organisms is infinite.

Look at videowall on righthand side of the blogsite






maandag 17 december 2012

2012-12-15 16:14 hbos CLEANUP DIVE!!

Weather : CloudedSSW wind 4 bft / Rain 1.1 mm / 995.1 hpa
Divers : John,Ted,Gery,Remko,Mark,Marco,Maurits,Ferry,Iva,Jack,Rick,Robin,Axel,
Goal : Cleaning up plastic / tin cans / lost fishinglines and weights
Max depth : 14.9 mtrs
Duration : 67 minutes
Air temp : 8.0 celsius
Water temp : 5,2 celsius minimum
Fish: > 2 eals, 
Remarks: There is enough waste to organise such a cleanup dive so we rounded up a team of 14 divers. We split them up in groups and divided them in sectors so we would cover as much terrain as possible.


Team ZEEP had provided potatonets to collect the waste in. The saturday before they had set up an cleanupdive 50 divers strong for the Vinkeveense plassen. This lake is way bigger than Hbos. Anyway when the teams set off my buddy and I had set the goal to collect fishing lines from the NW pontoon. 
 The enthousiasm was great when we piled up the catch.  After having a nice cup of coffee and some cookies we dumped the waste in the container and headed home. Anyway there's more to cleanup so every dive we do we take some waste along with us. With that we make a good step in keeping this lake special.

2012-12-15 14:31 hbos Placing SETL plate H106

Weather : CloudedSSW wind 4 bft / Rain 1.1 mm / 995.1 hpa
Divers : John, Axel
Goal : Placing new SETL plate and moving.
Max depth : 19.7 mtrs
Duration : 31 minutes
Air temp : 8.0 celsius
Water temp : 5,2 celsius minimum
Fish: > 1 very small Perch, 
Visibility : 7,5 meters at 3 meter depth 
               7,5 meter at 6 meter depth
Secchi viz: 10 meter at 3 meter depth

Remarks: Moving SETL plate H136 to new location and placing a new plate H106 on new location.
Below is photo of H106. I've had permission from Vork & Mes to use a new location.
For visibility we started using Secchi equivelant of 10 cm diam instead of the standard 20 cm disc in addition to Baseline for scientific reason


vrijdag 14 december 2012

2012-12-13 New baseline meter / Catfish


Weather : Clear / SE wind 2 bft / Rain 0.0 mm / 1008.7 hpa
Divers : Remko,Iva, Axel
Goal : Visibility go-see into the deep
Max depth : 19.7 mtrs
Duration : 67 minutes
Air temp : -1.0 celsius
Water temp : 5,6 celsius minimum
Fish: > 2 eals, > 5 Perch, > 5 Ruffe and some redbellshrimp free swimming, 1 catfish
Visibility : 8,0 meters at 3 meter depth 
               8,0 meter at 6 meter depth

Remarks: 3 divers in water. No thermocline nice and clear water
New baselinemeter is made of trespa where the white top layer has been milled away until the black baselayer becomes visible. Special thanks to Patrick.


donderdag 6 december 2012

2012-12-06 20:10 Sediment measuring

Weather : Clear / S wind 5 bft / Rain 0.0 mm / 1009.1 hpa
Divers : John,Kacper, Axel
Goal : Visibility, Random Sediment measuring / SETL check
Max depth : 14.9 mtrs
Duration : 50 minutes
Air temp : 2.0 celsius
Water temp : 7,2 celsius minimum
Fish: > 2 eals, > 5 Perch, > 5 Ruffe and some redbelly shrimp free swimming
Visibility : 7,5 meters at 3 meter depth 
               7,5 meter at 6 meter depth

Remarks: 3 divers in water. No significant thermocline. From 0-15 mtr. 
Today it is JOhn's 500th dive. First we do a check on where we are going to hang our 5 SETL plates. We have official authorisation of the Restaurant.  So they are aware of what is going to hang there. One tiny Perch sat on the SETL plate H135. Both Plates are clean but the stones and laundryline has grown some organisms on it.
Then we lowered down to do viz measurements. At the bottom at about 13 mtr we did a sediment thickness measurement. Next to the pile it was 50 cm until we hit hard bottom. A few meters south from the pile the stick hit some more dense layers, but came to about 110 cm depth. We just took random measurements to get an idea. At some point event at 7 mter depth there was a sediment layer of 100 cm! Byu the looks of it the more you come to the shore the more dense it becomes. At the reel we have 80 cm
The concrete mixer is gone by the way. I guess it hase been replaced to another location.

It was a very interesting dive with suprisingly much fish.  

zondag 18 november 2012

2012-11-18 08:32 Catfish and mini mud geisser

Weather : Overcast / NW wind 3 bft / Rain 0.0 mm / 1014.9 hpa
Divers : Remko, Stans, Axel
Goal : Visibility, Catfish
Max depth : 20.0 mtrs
Duration : 64 minutes
Air temp : 6.0 celsius
Water temp : 9,6 celsius minimum
Fish: > 5-10 eals resting at bottom. 1 catfish, some shrimp at depth
Visibility : 6,5 meters at 3 meter depth 
               7 meter at 6 meter depth and approx 3 mtr at 19 mtr depth.

Remarks: > 10 divers in water. No thermocline. From 0-20 mtr. 
After about 27 minutes we finally found what we came to see. First I found a piece of eal of about 3-4 cm thick. I know that Catfish also eat eal, but I never expected the Catfish to actually bite off chunks. 
Within a radius of about 3 meters I spotted the tail and when I approached it, it turned around and swam underneath me. We followed it for about 40 seconds and left it alone again when it turned around.
When it swam clouds of mud washed off it's skin so by the looks of it it too embedds itself in the bottom sediment.
Futher at 15 meter depth there were more clouds of dust. We came across a tiny sediment geisser from the bottom. My guess an eal embedded itself in the sediment, but I'm not sure.

Photo and video footage of the catfish and sediment geisser can be seen on this page where you can see two movies.

Please treat this beautifull Catfish with respect !!!


 

woensdag 14 november 2012

2012-11-13 19:46 Going deep!


Weather : Overcast / S wind 3 bft / Rain 0. mm / 1028.4 hpa
Divers : Remko, Kacper, Axel
Goal : Search Catfish
Max depth : 20.1 mtrs
Duration : 55 minutes
Air temp : 9.0 celsius
Water temp : 10,4 celsius minimum
Fish: > 5 big perch at about 13-15 mtr depth. 5-10 eals resting at bottom. > 10 Ruffe big and small. Loads of free swimming and hunting shrimp.
Visibility : 7 meters at 3 meter depth and approx 2 mtr at 19 mtr depth
Remarks: 3 divers in water. We went via the NW pontoon searching depth and stayed about 10 min at 19 meters. from about 17 mtr depth and down there is some airborn sediment but is coagulating into mucous like threads. I've seen that before.
No significant thermocline. From 0-9 mtr 11,2 celsius and 9-20 mtr depth 10,8 celsius.

zondag 11 november 2012

2012-11-11 09:52 The great visibility test


Weather : Clouds with sunshine / SW wind 4 bft / Rain 0. mm / 1011.6 hpa
Divers : Remko, John, Stans, Thijs, Jurre, Koos, Jan, Kacper, Axel
Goal : The Great visibility check
Max depth : 13.4 mtrs
Duration : 63 minutes
Air temp : 11.2 celsius
Water temp : 10,8 celsius minimum
Fish: > only a few young perch between the reedside
Visibility : 7 meters at 3 meter depth 
Remarks: > 15 divers in water.
Today I had asked 7 divers to do a visibility check using the same spool and visibility plate.On this plate you can see both Baseline and Secchi (two white squares) as shown in picture below.
I've used black and white insulation tape because it isn't glossy as laminated ones.
Every diver had to measure 3 times doing:
1-> Baseline meter two outer lines disappear and middle one still visible using lamp (Prescribed method)
2-> Baseline meter three lines disappear using lamp (Alternative method)
3-> Secchi 2 white blocks disappear wihtout using lamp

Of the 7 people the results were pretty constant. I also had asked them to determine which distance was the most realistic in their view.
In general 
1-> at 6,5 -7 meters the divers were still visible (This was considered the most realistic value)
2-> at 8-9 meters the divers began to fade and were not that recognizable anymore
3 -> at 10-11 only the white cylinders were seen but divers were not visible anymore.
On the righthand side you can see the measurements of each diver with the average values.
The lamps did have any effect with the sun shining, although it might give that little extra when it is clouded.

I've done quite a few tests, but never with a group of people this large. I will rest my case and never use anything else again :). I've also corrected the results in my logs.
It is unanimous... Baseline meter gives the best results!




vrijdag 9 november 2012

2012-11-08 19:34 Big shrimp / Temp drops rapidly.

Weather : overcast / W wind 3 bft / Rain 0. mm / 1016.3 hpa
Divers : Remko, John, Axel
Goal : Check SETL plates. Viz check
Max depth : 12.9 mtrs
Duration : 55 minutes
Air temp : 10.4 celsius
Water temp : 11,2 celsius minimum
Fish: > 1 juvenile Zander at about 12 mtrs. 1 young pike (30-40 cm) Furthermore we've seen Perch and Ruffes. just one big 3 cm long blue shrimp called Atheaphyra desmarestii. I've never seen this one here before though.
Plants : Elodea still stable from 1-5 mtr depth. 
Visibility :  7 mtr at 3 meter depth 
8 mtr at 6 meter depth. Remarks: 3 divers, No thermocline. Milky like water. 
SETL H135 (white tiewrap) : stable. algea threads gone.
SETL H136 (black tiewrap) : Totally clean. 




dinsdag 30 oktober 2012

2012-10-28 09:53 hbos Many divers in water

Weather : overcast/ SSW wind 3 bft / Rain 0.1 mm / 1014.2 hpa
Divers : Mark, Kacper, John, Marcel, Axel
Goal : Video documentation of bottom structure
Max depth : 15.3 mtrs
Duration : 70 minutes
Air temp : 5.7 celsius
Water temp : 13,6 celsius minimum
Fish: > 5 eal embedded in bottom at about 12-14 mtr depth. 1 Zander at about 13 mtrs. Furthermore I've seen no Perch and no Ruffes
Plants : Elodea still stable
Visibility : 7 mtr at 7 meter depth at reel.
Remarks: > 30 divers, No thermocline. We went in the water before the many divers took to the water and we measured visibility. After the many divers submerged. the visibility dropped rapidly. Therefore we canceled the videomaking and just went diving.
There was already much sediment afloat up to a depth of 13 meters. So apparently many divers during the past week have caused this while the wind and natural circulation takes care of the rest.
But that is offcouse logical if the have the choice to dive in Toolenburgplas with a visibility of about 2-3 meters of Hbos with 9-10 mtrs visibility... choice is made very easy.

dinsdag 23 oktober 2012

2012-10-23 20:04 hbos mist is sinking deeper

Weather : overcast/ E wind 2 bft / Rain 0.0 mm / 1023.7 hpa
Divers : Mark, Axel
Goal : Check depth of mistlayer and visibility measurement
Max depth : 18.1 mtrs
Duration : 59 minutes
Air temp : 13.0 celsius
Water temp : 14,0 celsius minimum
Fish: > 3 eals, few perch, and resting Ruffe.
Plants : Elodea is the dominant species but leaves are already getting brownish
Visibility : 10 mtr at 7 meter depth using black/white Secchi shone at with lamp.
Remarks: 2 divers, No thermocline. Very clear water and mist layer is now lowered from 16 to 17 meter depth. Temperature varies from 14.0 to 14,6 so no TC. 
Beautiful clay reefs. Spotted an followed anchor from the NW pontoon and went under the pontoon. The concrete blocks hang at about 12 meters only about 2 meters from the bottom. Lots of old entangled fishinglines on which Christatella Mucedo (mosdiertes) grow at around 9 meters depth. I guess a few caught fish swam over here to deliberately entangle fish lines or people have been fishing from the pontoon. Distance pontoon and shore is about 100 meters. 
The black/white Secchi is the standard for me. Gives perfect and same readings during day with ambient light and in nighttime with a 2200 lumen dive lamp shone from a distance.
In this case 10 meters.

zondag 21 oktober 2012

2012-10-21 10:16 hbos 180 minute dive. airpumps stopped

Weather : overcast/ NE wind 4 bft / Rain 0.0 mm / 1017.0 hpa
Divers : Remko, Iva, Vincent, Thijs, Jan, Axel
Goal : Check SETL plates, visibility and get an overall impression
Max depth : 7.9 mtrs
Duration : 180 minutes
Air temp : 11.0 celsius
Water temp : 14,0 celsius minimum
Fish: > 5 Pike, 2 eals, schools with young perch, 2 eals, 6 jellyfish at about 5-7 meters depth on north and south part of the narrowest part of the lake.
Plants : Elodea is the dominant species, 1 bush of some waterplant.
Visibility : 9,0 mtr at 3 and 10 mtr at 6 meter depth using Sechhi.
Baseline meter gave 6,5 meters where the divers could clearly be seen.
Remarks: > 10 divers, No thermocline. Very clear water. 

SETL H135 (white tiewrap) : stable. Only algea grows on side and on top of the plate.
SETL H136 (black tiewrap) : Totally clean probably due to diver bubbles.
In SW corner the visibility was reduced probably due to NE wind. Only the NE side has more fish.
passed 3 fishing lines with 1 dead herring as bate.  The lake is getting clearer now that the airpumps have stopped.


zaterdag 13 oktober 2012

2012-10-11 20:04 hbos eals and Carp. Last watersamples

Weather : lightclouds / OSO wind 3 bft / Rain 0.1 mm / 1009.2 hpa
Divers : Remko,Ben, Axel
Goal : Check SETL plates, watersamples , visibility, in search of Thermocline
Max depth : 18,4 mtrs
Duration : 87 minutes
Air temp : 9,5 celsius
Water temp : 15,6 celsius minimum
Fish: > 3 young Pike, 4 eal, school with common roach about 10 cm feeding on the explosion of shrimp. 1 Carp, 1 giant copepod.
Plants : Elodea is growing upto 7 meters with white roots. Very few algea dots only on north side
Visibility : 5,0 mtr at 5,5 and 6 meter depth.  (baseline meter because of bad light conditions)Remarks: 3 divers, No thermocline. a little milky. Down to 18 meters the temperature is constant. Mist layer starting at 17 meters.

CO2 is still pretty high and PH is fairly low probably due to much rainfall lately.
SETL H135: Few dots of brown coloured growth is starting. Few threads of tube algea attached to it
SETL H136: Just a brownish glow at the outer corners of the plate few threads of tubealgea landed on it and a few waterfleas have gathered underneath it.

woensdag 3 oktober 2012

2012-10-02 19:55 hbos SETL H135 growth after 5 days!!

Weather : sheep clouds / SSW wind 4 bft / Rain 0.05 mm / 1011.9 hpa
Divers : John, Thijs, Axel
Goal : Check SETL plates, watersamples , visibility
Max depth : 10,4 mtrs
Duration : 54 minutes
Air temp : 12.7 celsius
Water temp : 16.8 celsius minimum
Fish: > 1 young Pike, 1 eal, > 5 bigger perch active, larger snails, active shrimp in and near clayblocks.
Plants : Green algea diminishing. rest of plants is stable. Elodea not growing deeper than 7-8 meter. Pile at 3 meter suddenly showing more tube algea.
Visibility : 5,5 mtr at 3 and 6 meter depth.  (baseline meter because of bad light conditions.
Remarks: 3 divers, No thermocline.many free floating algea.

SETL H135: Few dots of brown coloured growth is starting. Few threads of tube algea landed on it
SETL H136: Just a brownish glow at the outer corners of the plate few threads of tubealgea landed on it.
 

zaterdag 29 september 2012

2012-09-27 20:37 hbos SETL project started

Weather : Light clouds / SW wind 3 bft / Rain 0.9 mm / 1005 hpa
Divers : John, Kacper, Thijs, Axel
Goal : Placing SETL plates
Max depth : 16.1 mtrs
Duration : 68 minutes
Air temp : 12.2 celsius
Water temp : 17.2 celsius minimum
Fish: > 2 Pikes, 1 common bream, ruffe and perch resting on bottom or hanging next to the piles of the paviljoen. Hunting shrimp with their bums op and spread antenni.
Plants : Green algea diminishing. rest of plants is stable. Elodea not growing deeper than 7-8 meter.
Visibility : Estimated 8,0 mtr
Remarks: >5 divers, Thermocline and mist are gone upto 16 mtr under SW ponton. Tarpaulin is completely overgrown by zebramussels again and is surrounded by Elodea. Same situation as december when I first photographed it. SETL plate number H135 and H136 placed.

Project SETL has been enabled by a new collaboration with Duik Team Haarlemmermeer (DTH). They already have a SETL station since 2008 for Toolenburgplas. Interresting is to know what organisms will settle on these plates. Every 3 months these plates are renewed and organisms which have settled on these plates will be analysed. Normally these plates should have been placed on sept 15th, but this is a trial run. On dec 15th one plate will be picked up and the other will hang there permanently. On stichting Anemoon you can find out more about the SETL project. Special thanks to DTH. 
 

zondag 23 september 2012

2012-09-23 11:34 hbos 12 jellyfish / head to head with pike

Weather : Cloudy / E wind 3 bft / Rain 0.00 mm / 1009 hpa
Divers : Remko, Guus, Axel
Goal : watersamples / visibility
Max depth : 14.6 mtrs
Duration : 84 minutes
Air temp : 11.5 celsius
Water temp : 18.0 celsius minimum
Fish: > 1 school of young perch and individials. 12 Freshwater Jellyfish in several sizes. 1 Eal, 1 very curious Pike
Plants : Green algea diminishing. rest of plants is stable.
Visibility : 8,0 mtr at 6 mtr depth, 8,0 mtr at 3 mtr depth
Remarks: At 14,5 mtr the dense milk layer was gone. Probably is now deeper. An incredible count of 12 Craspedacusta Sowerbii which were very active at this time of day. We spotted 4 near entry point at 4 meter depth with bottom at 9-10 mtr or so. Near Paviljoen I spotted 7 and 1 at 13-14 meter depth away from Paviljoen. The sponges are growing very hard on the pile near the measurepoint. You can see young zebramussels everywhere. Then there's mr Pike. It swam towards me and offcourse the battery of my camera was dead. It looked me straight into my eyes. I backed up a bit and he followed me. When I changed course going backward...it followed me. It's eyes rolled forward as much as it could and tried to get me in focus. When I swam backwards it kept a distance of 1 meter. I could clearly see it's toolbox with these tiny teeth. This went on for about 4 minutes. Then I turned my side towards it and immediately it changed course and swam away very gently. Regardless the fact a Pike is smaller than a human it still deserves great respect. It's head is impressive, but infact it's entire body is one large muscle. Fact was I had picked up a tin can from the bottom and folded it on my lamp. I completely held te lamp away from the Pike, but it just might triggered it to take a closer look.  A dive I will never forget and I surely want to get to know more about a pike's body language.

donderdag 20 september 2012

2012-09-19 20:20 hbos

Weather : Cloudy / W wind 3 bft / Rain 0.00 mm / 1018.6 hpa
Divers : Mark, Axel
Goal :Look around
Max depth : 14.7 mtrs
Duration : 48 minutes
Air temp :  10.0 celsius
Water temp : 19.2 celsius minimum
Fish: > young perch and Ruffe resting at bottom.
Plants : Green algea dots south at Paviljoen have some new green patches. Potamogeton is sometime completely wrapped in green algea.
Visibility : 5,0 mtr at 6 mtr depth, 5,0 mtr at 3 mtr depth
Remarks:  At 14,5 mtr there is still a dense layer of mist. Spotted a swimming Dikerogammarus Villosus (killer shrimp) which is a threat to the environment. I killed it probably in vane, but anyway.
Also found 1 Corbicula fluminea (Asian clam) overgrown by zebramussels. The surface water temperature will now go down rapidly. So now it is interesting to see what happens to the temperatures in the watercolumn at different depths. Very little plankton in the water column. Swimming Mosquito like larvea at 3 mtr depth just above algea growth. baby shrimp swimming around and adults more active but only near ands in crevasses and minicaves.

2012-09-16 09:57 hbos Jellyfish again!

Weather : Cloudy / SSW wind 3 bft / Rain 0.00 mm / 1012.2 hpa
Divers : John, Thijs, Kacper, Jelle, Axel
Goal : Water samples / Visibility
Max depth : 14.5 mtrs
Duration : 56 minutes
Air temp :  17.9 celsius
Water temp : 19.3 celsius minimum
Fish: > 1 jellyfish, Carps , 1 fat eal at 14 mtr, > 20 young perch scattered
Plants : Green algea dots near entry point diminishing a bit, while at other locations it is stable, Potamogeton and Elodea get uncovered again.
Visibility : 5,5 mtr at 6 mtr depth, 5,5 mtr at 3 mtr depth
Remarks:  At 14,5 mtr there is a dense layare of mist without being a thermocline. We saw the actual anchor of the anchorline. No shrimp. Spotted 1 living Paintersmussel (Unio pictorum) at 12 mtr depth. Normally you will find only empty shells. This is truly an indiginous species and filter water better than zebra mussels.

zondag 9 september 2012

2012-09-09 10:22 hbos Jellyfish and rising CO2 at 6 mtr depth!

Weather : Sunny / S wind 3 bft / Rain <0.00 mm / 1011.2 hpa
Divers : John, Thijs, Kacper, Axel
Goal : Water samples / Visibility / Check deep pontoon.
Max depth : 17.8 mtrs
Duration : 86 minutes
Air temp :  26 celsius
Water temp : 13.6 celsius minimum
Fish: > 2 eal, scattered young Perch, not in schools anymore, 1 Jelly fish see movie (Craspedacusta Sowerbii at 10 mtr depth), Copepods!
Plants :Big dots of algea up to 4 mtr, one Chara plant (kranswier) , but I have to find out what it is exactly
Visibility : 7,5 mtr at 6 mtr depth, 7 mtr at 3 mtr depth
Remarks: > 10 divers. Copepods active even at 14 mtr up to 7 mtrs. At 17,8 my divelamp seemed to have switched off, but it was the extremely poor visibility under the Thermocline at 15 mtrs. Temp dropped from 21 - 14 degrees. At measurepoint young mussels attached to the rope at 6 mtr depth, where as at 3 mtr ..nothing. So at 6 mtr the conditions are presumably better. Christatella Mucedo (mosdiertjes) at southside of Paviljoen growing on the green algea dots.but also in the shade just under de Paviljoen on a concrete overgrown beam. Even young mussels grow on pondweed at about 6 mtr depth. Discovered a new plant at 3 mtr at entry/exit point being Zannichellia palustris.. plant was also recorded in 2006 according to official reports.
First eal rested at 13 mtr depth. Noticed a track of a bigger crab at 12 mtr... looked like wolhandkrab. At surface and only at Northside some very small dots of bluealgea like (do not know if it is the real thing) Same as last year. It was stable.
 

zaterdag 8 september 2012

2012-09-06 19:57 Toolenburgplas Many fish!!

Weather : Light clouds / W wind 2 bft / Rain <0.00 mm / 1026.8 hpa
Divers : Remko, Thijs, Kacper, Axel
Goal : n search of the Catfish!!
Max depth : 8.6 mtrs
Duration : 100 minutes
Air temp :  14.9 celsius
Water temp : 19.2 celsius minimum
Fish: >100 Perch big and small, Shrimps are extremely active swimming. many copepods, >10 European Chub (Kopvoorn), >10 Common Roach (blankvoorn), > 5 young pike (approx 20-30 cm), 1 very big pike,  > 50 Young Ruffe

Plants :Hardly any green algea, Chara Globularis (Kranswier), Potamogeton growing over 2 mtr high.
Visibility : approx 4-5 mtr 
Remarks: > 4 divers. Water is full of life as opposed to Haarlemmermeerse bos (hbos) . Copepods are almost gone in hbos. Young fish counts in hbos are already decreasing (less zooplankton) while in Toolenburg there is an abundance. I only saw one dot of green algea while in hbos it is still growing. Average temperature is also about 2 degrees celsius lower than hbos.

woensdag 5 september 2012

2012-09-04 20:16 hbos SW ponton

Weather : Light clouds / W wind 2 bft / Rain <0.00 mm / 1022.6 hpa
Divers : Remko, Ted, Axel,
Goal : Look at airstation ponton SW corner
Max depth : 16.2 mtrs
Duration : 74 minutes
Air temp :  17.8 celsius
Water temp : 19.2 celsius minimum
Fish: > Young Perch and Ruffe resting on bottom. Shrimps are extremely active swimming with the bums up. I saw swimming mosquito larvea at 6 meters, Some mini copepods but not as abundant as I had expected. A layer of sediment already settled on most waterplants.
Plants : Elodea (waterpest) stable, wire algea not growing below 4 mtr. Potamogeton are covered in algea dots
Visibility : approx 3 mtr at 3 mtr
Remarks: > 10 divers in a club hence the extreme amount of airborne sediment. We went for the SW ponton to check it's state. The airhose had broken of so the air bubbled directly from the hose. Airnozzel itself is hanging around 8-9 meters. There is a sharp thermocline at 15,2 mtrs under the ponton goning from  20.8 celsius to 19.2 celsius. Max depth there was 16.2 so in fact only 1 meter layer. At way back going SW and going north west we had very bad visibility from previous divers. Frogkick would make a large difference. Any way we did not see the sweetwater jellyfish.

maandag 3 september 2012

2012-09-02 10:31 hbos

Weather : Clouded / SW wind 3 bft / Rain <0.05 mm / 1024.1 hpa
Divers : Joris, Ted, Gery, Axel,
Goal : Watersamples, Visibility
Max depth : 15.5 mtrs
Duration : 102 minutes
Air temp :  16.2 celsius
Water temp : 20.8 celsius minimum
Fish: > Young Perch in smaller schools, 2 older Perch, 1 eal at 14,0 mtr, 1 zander (widened gillplate), Sweetwater jelly fish was spotted earleier at 15 mtr. No waterfleas at this time of day.
Plants : Elodea (waterpest) stable, wire algea not growing below 4 mtr. Potamogeton are covered in algea dots
Visibility : 5 mtr at 6mtr depth, 5 mtr at 3 mtr depth
Remarks: > 4 divers.Visibility is better but then the temperature has decreased a little too by 1 celsius. Anyway the visibility has not increased during closing of the divesite during Mysteryland. Eventhough there was a mist at 15 mtr we felt no thermocline. There were also 7 lines perfectly parallel to eachother. Did not seem to be fishing lines since it was twisted wireline material. We wel check tuesday to see if they are still there. significantly less abundant counts of young perch on the southwest side as opposed to the rich fishcounts (young perch and ruffe on the east side near the beaches. Interresting dive since we probably dove under the pontoon. This one makes way more noise then the other two pontons. This one is closer to the compressor.

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.