Updated for 2004   Graphs only.

             The following has been updated to include in the charts and graphs the data for 2001. Only the charts have been updated to 2004 except for the Calanoids, they've been graphed but looking at how the three months data fits I don't think the graphs add any clarity so I've decided not to do them for the the Cyclopoids and Nauplii.
 
 

                                                       MONTHLY AVERAGES FOR COPEPODS

                      At times I think it is totally ludicrous to think the samples taken have any significance at all. I am taking a paltry bucket of water from the Lake and expecting a little 12.5 liter bit of water to represent what is occurring in the Lake's 100 billion liter biologic community. The only reason I can even have the temerity to suggest such a thing is that all the other researcher have done the same. Granted they may have taken a couple hundred more liters in their samples, but this is the merest pittance in difference when compare with the volume of water flowing through the Lake. Besides where my samples lack individual size the gathering of samples has been continually carried on longer than any sampling I know of  in the Lake. So while I don't hold the following numbers in high esteem I assign even less worth to most studies done in the past which may have only covered one year or had only 20 or 30 samples per year.

So let us crunch some numbers. Remember I'm an amateur, with but a touch of knowledge of biology and even less knowledge of statistics. The numbers generated below were taken from 12.5 liters samples. The samples were taken twice a week since 1992 (though I have not been religious about getting the samples, there are a few weeks were only one sample was taken and other weeks over the years when no sample was taken at all). When I first started this project I felt compelled to attempt to get samples year round under any conditions, this became a mission from God. After a couple of years of pounding through the ice to get to the water I gave up on taking winter samples so the continuous range of samples really extends only from April to December.

Addressing the question of methodology; I've had to make up my own method of counting the creatures. First I walk out on the stone jetties at the Veterans Memorial Park, tie a rope to a plastic bucket that I've put a rock in, toss it out and let it sink. Twelve point five liters of water from the buckets is filter through two coffee filters until about 50 to 100 ml. are left. This water is than pour into a small dish at about 10 to 20 ml. at a time and the animals counted using a dissecting microscope. I only count animals greater than. 05 mm. In case anyone is wondering why 12.5 liters is the amount of water used in the sample let me explain. I was going to use ten liters as the sample size so I figured I would measure out ten liters using two liter Pepsi bottles, trouble is a two liter bottle holds more than two liters when filled to the top, they hold about .5 liters more. I didn't realize this for several years into the study when I measured the water again using a measuring cup marked in liters. Rather than changing the sample size I just continued to take 12.5-liter samples.

 

                                                                                      CALANOID COPEPODS

                                                                   Monthly Averages for Calanoid Copepods

The following data is based on 12.5-liter samples taken twice a week. All the samples were taken in the morning from the same location.

 

 

Average of the Calanoids Apr. thru Dec.   1994    1995    1996   1997    1998   1999   2000      2001

                                                                            31.3     20.9    23.04   25.3   15.34  10.29    17        10.5
 
 

*Except for the extraordinary number of animals found on one sampling date the number of calanoid copepods would have shown a marked decline in 1997. That date was June 15. The sample had the extraordinary number of 880 calanoids in the 12.5 liter sample. The total number of calanoids found for the entire year in about 50 samples minus the June 15 date was 1130, thus the one sample had more animals than all the samples for the entire year. I have belabored the point of the non randomness of the zooplankton in the 1996 report and so will not cover that ground again. What I want to point out here is that if the June 15 sample is dropped from the reporting than the copepods had a steep drop in their numbers in 1997 and the average for the month of June would be 52 per sample rather than 144 per sample. The average for the year would drop from 25.3 per sample to 11.4 per sample. Whether this dropping of the sample from the total counts is valid I leave up to the reader but if the June 15 sample is ignored than the calanoids have had a major decline in 1997.

             There is also a statistical anomaly in the December 2000 sample of 12/10. This sample had 99 calanoids in it which skewed upward the whole average greatly. Below are the numbers for the whole month. A note about the few December samples taken: this has been the first year for quite a while that the near shore area of the Lake has frozen over this early, which is why so few sample were taken.

12/3     13.00
12/6     20.00
12/10   99.00
12/13    7.00

        Not only were the Calanoids found in high numbers but so were (to a lesser but significant extent) the Cyclopoids, as will be seen below. Again, oh what to do with these anomalies?

                                                                      CALANOID COPEPODS 1993 TO 1998

                                                                     CYCLOPOID COPEPODS

The table does not include the cyclopoid T. Mexicanus pranis. This small copepod was found very sporadically in the samples until this year. Though when it was found it could be found in large numbers.

 

          Average for the years    1994    1995    1996    1997    1998    1999     2000         2001

Apr. to Dec.                           18.3      34.2    24.5    10.3     12.8     29.7        13.6          62.2

There were a total of  29 plankton water samples taken in 2004. The samples were taken between April 2 and
July 12. There were  in April  8 samples taken
                                   May   8 "                  "         The July samples present a problem in that the three samples
                                   June   9 "                  "          taken at the beginning of the month had a high animal count
                                   July    4 "                  "          which if averaged in to what would normally occur in July as
                                                                              the number of animals tapered off would give a much lower
                                                                              average number of animals.
 Below is just the current data for more details on the methods and meanings of the numbers here listed see the links below.
 

*The average for July, 1999 is skewed by one sampling date (July 14) with a total of 638 cyclopoids in the sample. Eliminating the one sample from the average for the month gives a new monthly average of 23.7.A further note on this sample. After taking the plankton sample from off the jetty I went out in a boat about a 1/2 mile from shore to get the benthic sample in about 15 feet of water. The number of cyclopoids in that 5-liter sample was 184. Multiplying this by 2.5 to make it equal the plankton sample gives a total of 460. Meaning this massing of cyclopoids in the area probably covered a large area. The cyclopoids totals taken from each sample for the month of July were:

July 5           45

               8           21

               11           1

               14       638

               21         60

              28            8

              Avg     111.4

               The December of 2000 samples, as mention above,  had a day of aberration in the samples. Below are all the samples for the month.

12/3       6.00
12/6     15.00
12/10   32.00
12/13     6.00

      Below is a graph of the cyclopoids found in the 12.5 liter samples again in for the months of May and June from 1993 to 2000.

        Granted there is one heck of spike in the June of 1995 average, still I don't think the cyclopoids numbers changed enough to say that their numbers have decreased in the samples to any significant extant (this is where it would be useful to know how to compute the margin of error in the data).

 
 

                                                                   COPEPOD  NAUPLII

No attempt was made to distinguish between cyclopoid and calanoid copepods. I'm not sure if I could have told the difference between the two even it the attempt had been made.

NAUPLII

 
 Yearly average    1994     1995    1996    1997    1998    1999       2000           2001

from Apr to Dec.  39.26    53.17   41.21   25.03   16.26   13.23      16.77           7.9

      The graph below of the Nauplii is different from those above in that I have included the month of April to the months of May and June. The reason is that the Nauplii begin their population increase a month earlier than the adults (which only makes sense). It would appear that the number of nauplii found in the samples has gone down from their high numbers in 1996 and before.

 

                                                                                      SUMMARY

        Six or seven years seems hardly sufficient to say there has been any change in the long term number of copepods found in the Lake.. And having taken only somewhere between 500 and a 1000 samples seem paltry when one considers the sample size compared to the size of the Lake, but its all I've got to work with. What makes arriving at any kind of meaningful statement about changes in the number of copepods foolhardy in my case is that I have no idea how these animals actually disperse themselves in the water. I think I can safely say that there is not always a random distribution of the animals, and not knowing how often the animals swarm it becomes impossible to determine the value or meaning of the samples taken.