New Millennium Divers Parker and Martin M. were able to take an early out from work on this Wednesday afternoon and assess the Patton Beach station. Conditions were superb, flat water, minimal boat activity, sunny and in the mid 70's. Previous weather patterns have been calm.
The animal life was scarce with the exception of crayfish feeding on recently discarded fish carcasses from the local sport fishing operations at the nearby marina. The presence of Diaptomus and Mysis Shrimp were non existant - a stark contrast from our January 1, 2014 dive. The lake was very calm and clear.
Project Baseline Statistics
Depth: 35' per benchmark gauge - 30' and 32' per digital gauges on divers
Visibility: 50-60 feet on the near side of 50
Temperature: 50F on all gauges
New Millennium Divers Todd K and Martin M took advantage of a cold and snowy day (that was not forecast) to enjoy a Project Baseline: Tahoe dive to the Sand Harbor station. It was a great dive out to the outer wall structure and ran 70 minutes at a max depth of 101 feet with an average depth of 49 feet but the most significant visual of this day was the water level never before seen by either divers in over 30 years of diving Lake Tahoe. Please watch this 24 second video, it tells the entire story...
The level of Tahoe is now below its natural rim and to put some perspective to this image, in 31 months, July 2011 to February 2014 the lake has dropped some 5 feet as calculated from the data gathered by the Project Baseline conservation initiative presently underway in Tahoe. In July, 2011 our Project Baseline depth benchmark read 25/26 feet and on Sunday February 2, 2014 it read 20 feet. In a lake with 191 square miles of surface area this 5 foot drop equates to approximately 200 billion gallons of water!
The divers did not observe any Diaptomus (zooplankton) or Mysis Shrimp on this dive. Unlike the New Years day dive at the Patton Beach station where they were quite populace.
Project Baseline Statistics
Depth: 20' per benchmark gauge/17' per digital gauge (FFW)
Visibility: 40-50 feet approaching 50'
Temperature: 44f per benchmark gauge/44f per digital gauge
Photo: Taken 5 October 2013 ( Just to the left of the depth benchmark )
On January 1, 2014, New Millennium divers, Michael S. and Martin M. planned a dive to see how the recent massive high pressure sitting over Northern Nevada since December 3rd, would affect Tahoe's visibility and water conditions. Also knowing that the Limnologists from Wright State University in Ohio are still needing rock/algae samples from 20, 25 & 30 meters, NMDE felt that a solid mission could be formed and executed.
Arriving at the lake, the water was mirror flat. There was no wind, blue skies and upon arrival the air temperature was 24f at waters edge. A perfect day. Upon departure at noon, the conditions were the same and the temperature was 48f. The high for the day was 51f. Incredible for January 1st!
There were two objectives for this dive. First to evaluate the conditions at the Project Baseline station and second to retrieve rock/algae samples from 20, 25, & 30 meters. A secondary objective was to make sure the line to the FISH was still intact after its reestablishment during a previous dive.
The plan was to enter water, doubles and scooter, head to the line leading to the "FISH", evaluate the station then take a 150degree bearing and scooter out to 90 feet - US divers are not very good with the metric system...90 feet is close enough to 30 meters, right? Once at depth, rock samples would be collected then a bearing change to 240 degrees for 2 minutes and then another bearing change to 330 degree back toward the beach collecting rock samples along the way at 75 feet and 60 feet.
Entry was at 9:50am and exit was 11:20am with a total runtime of 71 minutes at a maximum depth of 96 feet (average depth was 54 feet). Scooter speed at approximately 125feet/min.
Upon entry and descent the line was completely intact all the way to the PBTahoe station located at the FISH. Descent was at 5 feet and it took 12 minutes to scooter to the FISH. Evaluations were made and recorded in the wetnotes. The "high pressure" system seems to have no benefit upon the visibility as we could see 30 feet and make out the 40 foot marker but could not see clearly the "4". This is consistent with the past 2 dives.
Continuing it took another 15 minutes to reach the planned depth of 90 feet. The biggest realization was the thickness and volume of Mysis Shrimp at 45 feet on the way out. From the beach to 45 feet they were not being looked for, however it was obviously recognized that as the depth increased, there was still a high concentration of Mysis Shrimp but diminishing all the way to 90 feet. As a result, the divers turned their evaluation to the water column to determine the concentration of Diaptomus (Zooplankton) which was also incredibly high. Higher than remembered for this time of year. A heightened awareness began and it was again observed that from depth back to 45 feet the concentrations of Mysis Shrimp increased and then decreased as the divers continued shallower. At about 15 feet, the Mysis Shrimp were very scarce as well as the Diaptomus. At 45 feet the bottom was completely covered. It was an unreal site and extremely difficult to photograph - Mike tried. Diagram of Lake Tahoe animal species. With the exception of crayfish, no other animal species were seen.
Here is a 44 second video clip of the Patton Beach, Project Baseline Tahoe, station. This will provide a very clear understanding of how the scientifically consistent baseline data is obtained for each site:
PBTahoe Stats:
Depth: 34 feet (30ffw per a digital gauge)
Temp: 50f (46f per a digital gauge)
Visibility: 20-30 feet
Photo: (A standard photo was not taken due to the last dive being so recent, 15 November, 2013.)
