Roger L. Kaesler

Fourier Analysis of the Ostracode Margin

Abstract: Fourier analysis can be used as an objectivedescriptor of the ostracode margin. Results of the three examples suggest that the method explained may give information of interest to systematist. Use of Fourier analysis issuggested both for research on specimens and for study of illustrations from the literature.

Magnesium in Calcite of Marine Ostracoda

Results of 255 microprobe analyses of Holocene marine Ostracoda show that, for the 21 specimens analyzed, the greatest variation in mole percent MgCO 3 occurs within calcite of individual carapaces rather than between carapaces collected from warm and cold water. Within a single genus, however, differences between specimens from different environments may reflect differences in water temperature.

Cluster Analysis of Data from Limnological Surveys of the Upper Potomac River

In a study of data from limnological surveys of a portion of the upper Potomac River, cluster analysis and correlation coefficients have shown that redundancy exists in the data. Aquatic insects and, to a lesser extent, diatoms have distributions that most nearly represent the total biota. It is suggested that the study of these two groups and the exclusion of other algae, protozoans, other invertebrates and fish would significantly reduce the cost of such surveys without appreciably affecting the information they provide. INTRODUCTION Limnological surveys of the kind reported by Patrick, Cairns and Roback (1967) of the Savannah River between South Carolina and Georgia have typically involved study by a team of specialists of almost the entire biota, including diatoms and other algae, protozoans, aquatic insects, other invertebrates and fish, from several stations for each of several years. Such surveys are usually used to monitor a source of potential pollution, such as thermal pollution from the outfall of a power station. Because the results of limnological surveys may be used as evidence in the courts, it is imperative that standard methods be used both for the surveys themselves and for their interpretation (Patrick, 1949). Nevertheless, it is clear that a great deal of redundancy may be introduced by the study of the entire biota, so that the cost of limnological surveys could be reduced if only those groups of organisms were selected for study that have distributions that are highly correlated with other major groups. The purpose of this research was to investigate the hypothesis that data from limnological surveys typically include a great deal of redundancy. In this paper we show that this isi true, we present the results of Q-mode cluster analysis using several groups of organisms, and we indicate which groups of organisms are likely to best summarize the distribution of the total biota. We have selected for study data from limnological surveys of the upper Potomac River directed by Dr. Ruth Patrick. Cairns, Kaesler and several co-authors have studied distribution of the several groups of organisms and have described in detail the sampling procedures and methods of analysis used (Cairns and Kaesler, 1969; Roback, Cairns and Kaesler, 1969; Cairns, Kaesler and Patrick, 1970; Cairns and Kaesler, 1971; and Kaesler, Cairns and Bates,, 1971). Data from the surveys are on file as follows: protozoans, National Auxiliary Publications Service No. 00362 and No. 89021; insects, 1National Auxiliary Publications Service, 22 West 34th Street, New York, N.Y. 10001, U.S.A. Microfiche copies

Cluster analysis of potomac river survey stations based on protozoan presence-absence data

1.00 per set; 8 x 11 inch photo copies

Use of Indices of Diversity and Hierarchical Diversity in Stream Surveys

3.00 per set.

Role of Electrofishing in Assessing Environmental Quality of the Wabash River

Four high-water and six low-water limnological surveys of a portion of the Potomac River were made from 1956 to 1965; samples were collected at three stations on each survey to determine the effects of operation of the PEPCO Dickerson Power Station on the aquatic biota. Cluster analyses were made of various combinations of Jaccard coefficients relating 46 aggregations of 647 protozoan species.Similarities of aggregations of species within a survey were nearly always greater than similarities among aggregations from different surveys, indicating linear or along-stream environmental influences. Within-survey similarities for the early and late surveys were usually higher than similarities within middle-year surveys, a possible indication of environmental change at all stations, including the control, and subsequent biotic readjustment. Clustering of the 1956 aggregations, taken under high-water conditions before plant operations began, with aggregations from other surveys for any one station indicate that 1956 may have been different from other survey years. One explanation is that increased urbanization upstream from the power station after 1956 caused some environmental change. No changes in aquatic biota could be attributed to thermal pollution as a direct result of operation of the electric power generating station.

The depth distribution of recent marine Ostracoda from the southern Strait of Magellan

Brillouins equation (H) for species diversity is preferred to other measures from information theory because it is not biased and does not require unrealistic assumptions about the populations being sampled. Diversities of small replicated samples give a better indication of environmental differences between stations than single large samples. Species diversity may be partitioned hierarchically either according to the categories of the taxonomic hierarchy or any other hierarchy. Taxonomic hierarchical diversity reveals components of diversity at each taxonomic level. For several examples, generic diversity revealed nearly as much about community structure as species diversity, suggesting that discriminating higher taxa rather than identifying species can be often used in aquatic ecology, with savings of time and money. Hierarchial diversities of classifications based on functional morphology and trophic group analysis appear to be promising for applied work and worthy of further investigation.

CHANGES IN PERMIAN MARINE OSTRACODE FAUNAS DURING REGRESSION, FLORENA SHALE, NORTHEASTERN KANSAS

The fish community of the middle Wabash River has been studied since 1973 from the standpoint of its capacity for measuring the biological impact of various kinds of point influences, such as thermal, municipal, and industrial effluents. Of particular interest has been the potential value of various community parameters as indicators of environmental quality, since individual species populations tend to vary markedly from year to year. The primary sampling method consisted of repeated direct-current electrofishing through a series of 0.5-km-long zones located strategically throughout 274 km (170 miles) of river, divided into twelve reaches. The use of cluster analysis and community indexes, including a composite index, has been of value in isolating problem areas prior to the development of lethal environmental conditions and in gaging the degree of environmental benefit resulting from improved waste treatment.

Redundancy in data from stream surveys

From 16 sediment samples collected from the Chilean part of the Strait of Magellan, 2338 Ostracoda were recovered. These represent 61 species belonging to 45 genera and 16 families. Previous work in the Tierra del Fuego Province has shown the faunas to be highly endemic, resulting from the relative isolation of the region and its particular climatic and oceanographical characteristics. The fauna of the Strait of Magellan is similar to those previously described with one notable exception: the occurrence of deep-water, psychrospheric species at shallow depths. Species of Bradleya, Agrenocythere, Poseidonamicus, Bythoceratina, and Legitimocythere, usually recorded from bathyal to abyssal depths of more than 1000 m, were found together in the same samples with a typical, shelf fauna. Such unusual depth distribution of psychrospheric species may have resulted from the extremely cold temperature and low salinity of the water in the southern Strait of Magellan, coupled with the upwelling of cold, deep water masses.

Cluster analysis of occurrence and distribution of insect species in a portion of the Potomac River

The Florena Shale (Permian, Wolfcampian) of the Midcontinent of North America was deposited in a restricted marine basin. Shifting environments due to marine regression caused a gradual change in the ostracode fauna. Cluster analysis and ordination by nonmetric multidi- mensional scaling of data on ostracode relative abundances revealed three ostracode assemblages, each characteristic of a different environment. The Cryptobairdia seminalis assemblage from the lowest Florena Shale is characteristic of deeper water, offshore, marine environments with only minor influx of terrigenous mud. The Amphissites centronotus assemblage found above the C. seminalis assemblage occupied a similar environment, but with greater influx of terrigenous mud and intervals of increased turbidity. The Knightina texana assemblage occurs stratigraphically highest and probably represents a quiet-water, very shallow, nearshore, marine environment. Al- though protected from strong wave and current activity, the water mass was occasionally turbid. Species diversity of ostracodes is high both at the base of the Florena Shale, which was deposited in the most offshore position, and again at the top of the lower part of the Florena Shale, which was deposited nearer to the shore. In contrast to diversities of assemblages of ostracodes from similar environments in other stratigraphic units, the K. texana assemblage has an anomalously high diversity. This is due in part to time averaging of adjacent ostracode assemblages and a strong taphonomic overprint.