Some of Bill’s notes

Pond 3 with a secchi disk of 18” had phytoplankton of 83,183/ml. Detritus densities of sizes 0.1-1um were 931,300/ml, and 1-5+um were 347,500/ml. Detritus is almost always much more abundant (at least 10-100 times) in surface waters than the phytoplankton. The detrital component of the food web has proven to be very important in the aquatic ecosystems. Lots of zooplankton food available in pond 3.

I think the brown hue in this pond is due mainly to the Dinobryon (Chrysophyta) and the Euglenophytes such as Euglena, Phacus, Trachelomonas, Strombomonas. Pond 3 is rich in species of Euglenophyta. I have read that Euglenophyta as a group typically prefer waters rich in dissolved organics (DOC); maybe from leaves? Dinobryon is known to be phagotrophic (phagotrophy) and ingests bacteria and tiny detritus in addition to being photosynthetic.

Phytoplankton was diverse in this pond with lots of species. Most abundant specie in Pond 3 was a colonial green algae Coelastrum sphaericum (see Pd3Ful2). It exists as groups of 4-32 cells in arrangements of triangle or square depending on number of cells. Small unidentifiable Picoplankton and microflagellates were second and third most abundant taxa. Scenedesmus a green algae was 4th most abundant.

Pond 2 with a secchi disk of 30” had phytoplankton of 22,894/ml. Detritus densities of sizes 0.1-1um were 597,700/ml, and 1-5+um were 180,700/ml. Detritus is almost always much more abundant (at least 10-100 times).

Dominant species were Picoplankton 7200/ml, and Merismopedia tenuissima 4800/ml, and Microflagellates unidentified 3,800/ml. Many analysts do not count picoplankton because it is too small to see at 400X magnifications, which is a 400X count method often used by many labs, including universities. Thus many phytoplankton studies neglect the picoplankton component of the plankton community. Marine picoplankton has been studied the most, although freshwater picoplankton has been studied quite a bit, including by myself (“Picoplankton Counts Greatly Alter Phytoplankton Quantitative Analyses Results”. 1998. E.W.Wilde & W.R.Cody, J.Freshwater Ecology 13;(1) 79-85). Look at the picture on the right side edge and 3rd picture down. This colony has lots of small cells. When this colony breaks apart all those tiny cells become part of the picoplankton. Picoplankton is all single photosynthetic cells that have sizes of 2-3um dia and less, usually down to around 1um. I only count those that are 2-3 um dia.

Pond 2 had the lowest species diversity of 16 taxa in a standard count. All the species encountered were many of the same species that were also present in Ponds 3 and 1.

I made a special burnt mount preparation to look at some diatoms of Pond 2. Most of the diatoms were rare, in the sample. I thought you would like to see pictures of some of them. Attachment EW diatomsP2 . One of the pictures in this plate is not a diatom. It belongs to a genus of scaled Chrysophyte called Mallamonas (probably M. tonsurata).
Two interesting species of diatoms occurred in the Ponds as common or rare taxa. One was a centric diatom that I do not see very often – Aulacoseira tenera (1056/ml) Ponds 1 & 2. The other was a needle shaped diatom with a swollen middle - Fragilaria longifusiformis (upper left picture of EW Pd2 PL1 and EW DiatomsP2). It occurred in all three ponds but was most abundant in Pond 3 (6000/ml) . F. longifusiformis is a new name for this species. It was transferred from Synedra planktonica to the new name in 2006. Last time that I saw it was in some South Carolina samples. A. tenera and F. longifusiformis most generally occur in lower alkalinity waters.
Two other interesting species in Pond 2 two were Anabaena sp1 (1420 cell equivalents/ml) and Anabaena sp2 (182 cell equivalents/ml). I could not positively determine a specie name for either of the Anabaena. Some Anabaena are morphologically variable species and positive identification can at times be difficult. Both Anabaena were also in Pond 1 as rare taxa.

Pond 1 with a secchi disk of 24” had phytoplankton of 124,320/ml. Detritus densities in this pond were the highest of all three ponds: sizes 0.1-1um were 3,197,000/ml, and 1-5+um were 973,000/ml. Detritus is almost always much more abundant (at least 5-50 times). Notice in the back ground of picture EW Pd1 GroupA there is a lot of what looks like dirt or dust. The magnification for this picture is 400X and estimate the detritus at 1000X. It does not have any bilateral or radial symmetry, not round nor having any special symmetry. This is the detritus that I describe or make note of in the samples. The smallest particles of 0.1-1 um you don’t see at 400X.
This is from Wetzel 2001, Limnology Lake & River Ecosystems: Detritus is technically called particulate organic matter (POM). Many organisms ingest variable amounts of particulate detritus (dead organic matter) which I have noted, normally dominates the plankton. Studies indicate that up to 99% of the organic matter fluxes within aquatic ecosystems are detrital-based, however the predation based paradigms continue to prevail as the primary constructs of ecosystem operations, whereas in reality they are the minority. Essentially, all inland water ecosystems are microbially based heterotrophic ecosystems in which heterotrophic utilization of organic matter within lakes and streams exceeds - usually greatly exceeds - autochthonous autotrophic production . Wetzel says, Detrital DOC and POC have long been known to exceed by many times the amount of organic carbon present as living material in the form of bacteria, plankton, flora, and fauna. ). As you can see my estimates of the living particulate organic carbon (POC) i.e.phytoplankton comprise a small part of the potential total POC.
Dominant species in Pond 1 were Aphanocapsa small colony at 36,000/ml, Chroococcus microscopicus at 19,200/ml, and Picoplankton at 17,520/ml. In this pond Aphanocapsa and Chroococcus exist as small colonies of very small cells about 1 um dia. In picture EW Pd1 GroupA at the bottom center there what I call an Aphaocapsa colony. There is another group of this type of cells to the left on the right side of that narrow finger-like thing (Eunotia bilunaris) coming up from the bottom. When these colonies break up the cells become part of the Picoplankton. When they decay into smaller particles or become manure, they become a portion of the dead detrital organic matter, – detritus.
In the counts, Pond 1 had the most number of species 35, Pond 2 had 16 species and Pond 3 had 26 species. Higher species diversity is a good feature.