The Aquatic Ecology of Two Seasonal Marshes in Eastern South Dakota

Zooplankton, benthos, nekton, aufwuchs, and the physical-chemical limnology of two seasonal marshes in eastern South Dakota were monitored from April-June 1975. Bothwell and Lund Marshes contained water from 15 April-July 1975. The dominant i. ons, Ca ++, Mg+ +, and sulfate, made the water hardness non-carbonate. Floating vegetation, Lemna trisulca and Cladophora sp., became abundant in both marshes during the first week of June, and formed large thick mats by the end of June 1975. Daphnia pulex was the dominant zooplankter in Bothwell Marsh and made up 33% of the zooplankton density during the 1975 season. The population was triacmic, and ephippia formation for the populations of the next wet season occurred during mid-season (8 May-5 June). Diaptomus leptopus was the dominant zooplankter in Lund Marsh and made up 58% of the zooplankton density during the 1975 season. Only one cohort was produced, and egg production for the populations of the next wet season was highest about two weeks before the marsh dried. Daphnia pulex and D. leptopus may have competed for the same food resource, since an inverse species relationship occurred in both marshes. One species had high densities when the other had low densities. The mean seasonal benthic biomass (dry weight) was 100.04 kg/ha in Bothwell Marsh and 72.9 kg/ha in Lund Marsh. Chironomid larvae made up Over 90% of the invertebrate benthic standing crops in both marshes. Chironomus sp. larvae were the first to appear in early spring and had the highest standing crop before emergence in mid-season. Glyptotendipes sp. were collected as newly hatched larvae in mid-season and dominated the standing crop estimates in both marshes until the water disappeared. Standing crops of nekton and macroscopic aufwuchs in both marshes were dominated by axolotls of the tiger salamander. Ambystoma tigrinum. Axolotl densities made up only 1-3% of the nekton but their dry weights made up 36-70%. Axolotls were probably the main predators of invertebrates in the marshes. Gastropoda and Hirudinea were also abundant in both marshes. Most aquatic insects collected in the nekton and autwuchs were in the nympbal or larval stage. Body length and wing pad development of zygopteran and ephemeropteran nymphs were observed in preparation for adult emergence in mid- to late-June 1975. Macroscopic organisms in seasonal marshes may have originated from diapaused eggs and burrowing larvae which overwintered in the substrate; from immigrating adults which reproduced after ice melt ((A.tigrinum); and by being transported on migrating waterfowl (Hirudinea). Sufficient biomass of planktonic and macroscopic invertebrates could provide a fish forage base for rearing northern pike fry in seasonal marshes.

Name thesis:degree_name

Master of Science (MS)

Level thesis:degree_level

Thesis - Open Access

Discipline thesis:degree_discipline

Wildlife and Fisheries Science

Year

1976

Author dc:creator

• Donaldson, Walter K.

• Natural Resources and Conservation

Statement dc:rights

• <p>No Copyright - Non-Commercial Use Only<br /><a href="http://rightsstatements.org/vocab/InC-EDU/1.0/">http://rightsstatements.org/vocab/NoC-NC/1.0/</a></p>

Language dc:language

en

Repository record dc:identifier

https://openprairie.sdstate.edu/etd/41

OAI identifier oai:identifier

oai:openprairie.sdstate.edu:etd-1041