The two Frog Pond (Pond #9) samples are both “surface tows”, with FROG 1 from the shore and FROG2 from the central part of the pond. Both FROG samples are dominated by a large filter feeding cladoceran, Diaphanosoma brachyurum Lieven and a selective feeding copepodid, both herbivores. FROG2 sample contained Scapholeberis kingi Sars, a small cladoceran filter feeder and nauplii, also a small filter feeder. All these taxa represent a propensity toward feeding on small phytoplankton, as represented by the majority of phytoplankton identified. The D. brachyurum can also select larger and more motile phytoplankton (as the smaller Rhodomonas and the Chromonas sps. identified). The copepodid, an intermediate stage between nauplii and adult calanoid or cyclopoid copepoda, have the ability to individually select and manipulate food and as more active swimmers are adapted to exploiting the niche held by those areas of higher phytoplankton concentrations and largest of the species (the larger Rhodomonas sp. andSynedra sp.).
The BEAR samples (BEARI and BEAR2) are shown to be >80% similar, even though BEAR1 is a surface tow, and BEAR2 is a bottom tow. The most unique difference in zooplankton between them is the presence of the fairy and seed shrimp, identified from BEARI, the surface tow. Both of the shrimp species typically swim upside-down and filter feed just below the surface. The seed shrimp will also feed on the periphyton of submerged aquatic macrophytes.
There are three pond comparisons, based on the zooplankton identified, in which there was no similarity. All three comparisons involved BEAR2 sample. The first, is between BEAR2, a bottom sample, with FROG1, a surface sample. Suggesting a strong difference between zooplankton assemblages throughout the water column, even in depths as shallow as 1.5-2 meters. This was further suggested by pond sample WH13, in which the fairy shrimp was again identified, an indication that WH13 is also a surface sample. Pond sample WH11A was the third comparison with no similarity and again, with BEAR2. Indicating that WH11A was either a surface tow or a similar, but more shallow pond.
There was a large diversity in the zooplankton identified, however little seasonal variability was shown. Thirteen taxa were present in less than five samples and of the remaining five taxa, three were present throughout the sampling period. Only the cladocerans, S. kingi and Daphnia catawba exhibited possible change. S. kingi was present in July and August but not the September sample. D. catawba was not identified in July but was in the August and September samples.
This short study, even with a scarce number of samples, does suggest possible trends within the water column and seasonally, over time. Greater sampling within several ponds over time would be more helpful and highly suggested.
4.3 Flora Discussion
Twenty-nine taxa of vascular plants were identified during the floristic survey of the White Horse Ponds conducted on August 21, 1993. This survey effort was sufficient to generally characterize the flora of the ponds and their immediate vicinity. It is likely, however, that the vascular flora of this region is considerably more diverse than these survey results indicate. Additional surveys in July, September, and, even, October would be useful in fully assessing the diversity of vascular plants of the White Horse Bluffs.
***previous*** — ***next***
