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 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.