Ecology and Systematics of Foraminifera in Two Thalassia Habitats, Jamaica, West Indies MARTIN A. BUZAS, ROBERTA K. SMITH, and KENNETH A. BEEM SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY • NUMBER 31 SERIES PUBLICATIONS OF THE SMITHSONIAN INSTITUTION Emphasis upon publication as a means of "diffusing knowledge" was expressed by the first Secretary of the Smithsonian. In his formal plan for the Institution, Joseph Henry outlined a program that included the following statement: "It is proposed to publish a series of reports, giving an account of the new discoveries in science, and of the changes made from year to year in all branches of knowledge." This theme of basic research has been adhered to through the years by thousands of titles issued in series publications under the Smithsonian imprint, commencing with Smithsonian Contributions to Knowledge in 1848 and continuing with the following active series: Smithsonian Contributions to Anthropology Smithsonian Contributions to Astrophysics Smithsonian Contributions to Botany Smithsonian Contributions to the Earth Sciences Smithsonian Contributions to the Marine Sciences Smithsonian Contributions to Paleobiology Smithsonian Contributions to Zoology Smithsonian Studies in Air and Space Smithsonian Studies in History and Technology In these series, the Institution publishes small papers and full-scale monographs that report the research and collections of its various museums and bureaux or of professional colleagues in the world cf science and scholarship. The publications are distributed by mailing lists to libraries, universities, and similar institutions throughout the world. Papers or monographs submitted for series publication are received by the Smithsonian Institution Press, subject to its own review for format and style, only through departments of the various Smithsonian museums or bureaux, where the manuscripts are given substantive review. Press requirements for manuscript and art preparation are outlined on the inside back cover. S. Dillon Ripley Secretary Smithsonian Institution SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY • NUMBER 31 Ecology and Systematics of Foraminifera in Two Thalassia Habitats, Jamaica, West Indies Martin A. Buzas, Roberta K. Smith, and Kenneth A. Beem SMITHSONIAN INSTITUTION PRESS City of Washington 1977 ABSTRACT Buzas, Martin A., Roberta K. Smith, and Kenneth A. Beem. Ecology and Systematics of Foraminifera in Two Thalassia Habitats, Jamaica, West Indies. Smithsonian Contributions to Paleobiology, number 31, 139 pages, 38 figures, 8 plates, 34 tables, 1977.—Homogeneous Thalassia beds in back-reef flat (less than 1 m) and Discovery Bay (about 3 m) were sampled for 12 successive months in Jamaica, West Indies. Living foraminifera were enumerated in each of four monthly replicates consisting of 20 ml of sediment. At the sampling times, water temperature, sediment temperature, salinity, oxygen saturation, water pH, sedi­ ment pH, sediment median, sediment sorting, turbidity, particulate organic carbon, Thalassia weight, and weight percent silt plus clay were measured. In all, 18,644 individuals belonging to 143 species were picked, sorted, and identified. The back-reef flat habitat contained 7,745 individuals belonging to 115 species, while the Discovery Bay contained 10,899 individuals belonging to 117 species. Fisher's log-series fits the distribution of species abundances at both habitats well. The number of species, information function, and equitability are usually greater at Discovery Bay for individual 20 ml samples. A general linear model consisting of parameters for station differences, overall periodicity, interaction of station differences and overall periodicity, and environ­ mental variables was constructed. The densities of the 19 most abundant species were statistically analyzed individually (univariate) and simultaneously (multi­ variate). Univariate analyses indicate six species have significant station differences (95% level) and seven exhibit periodicity. The environmental variables are not significant for any of the species. Multivariate analyses indicate a significant difference between stations and an overall periodicity. As in the univariate analyses, environmental variables are not significant. The results suggest that in tropical habitats changes in species densities are regulated biotically. The new species Ammonia jacksoni, Elphidium norvangi, Fissurina goreaui, Discorbinella minuta, Glabratella altispira, and G. compressa are described. Taxonomic remarks are presented for most of the species. OFFICIAL PUBLICATION DATE is handstamped in a limited number of initial copies and is recorded in the Institution's annual report, Smithsonian Year. SERIES COVER DESIGN: The trilobite Phacops rana Green. Library of Congress Cataloging in Publication Data Menon, A. G. H. Ecology and systematics of foraminifera in two Thalassia habitats, Jamaica, West Indies. (Smithsonian contributions to paleobiology ; no. 31) Bibliography: p. 1. Foraminifera—Jamaica. 2. Protozoa—Classification. 3. Protozoa—Ecology. 4. Protozoa Ja­ maica. 5. Thalassia. I. Smith, Roberta K., 1931—joint author. II. Beem, Kenneth A., joint author. III. Title. IV. Series: Smithsonian Institution. Smithsonian contributions to paleo­ biology ; no. 31. QE701.S56 no. 31 [QL368.F6] 560'.8s [593'.12'097292] 76-608169 Contents Page Introduction ... 1 Location, Field, and Laboratory Methods . 1 Environmental Variables . .... 3 Univariate Analyses 8 Statistical Model ... 8 Sample Size . ... 12 Statistical Analyses of Species 12 Summary of Species Analyses 37 Statistical Analyses of Genera . 41 Multivariate Analyses . 43 Relative Abundance ... 46 Species Proportions 46 Distribution of Species Abundance 50 Species Diversity 51 Discussion .... 56 Systematic Catalog 61 Appendix: Number of Individuals Observed in 20 ml Replicate Samples 110 Literature Cited 118 Plates 123 in Ecology and Systematics of Foraminifera in Two Thalassia Habitats, Jamaica, West Indies Martin A. Buzas, Roberta K. Smith, and Kenneth A. Beem Introduction Specimens deposited in the National Museum of Natural History, Smithsonian Institution, are listed Most ecological studies of foraminifera try to under the acronym "USNM" (for the collection relate patterns of distribution and abundance to numbers of the old United States National environmental variables. The results of such studies Museum). show that foraminifera can be used to identify ACKNOWLEDGMENTS.—We thank M. Abrams, T. particular environments with relative ease. Relating Chin, G. Heim, L. Keller, C. McCloy, J. Sanner, patterns to environmental variables has proved K. Smith, L. Thompson, and B. Williams for help much more difficult. While such studies number in in the laboratory. The foraminiferal samples were the hundreds, only a handful exist where the re­ collected by J. B. C. Jackson, who also measured searcher has sampled the same area quantitatively the environmental variables in the field. Dante over the period of a year or two. Moreover, none Piacesi greatly helped to facilitate the computer of these are in a tropical environment. analyses of the data. The foraminifera were drawn The present study examines two habitats within by Lawrence Isham. Finally, we thank J. B. C. homogeneous beds of Thalassia in Jamaica, West Jackson and M. Silver for their helpful reviews Indies. One habitat is a back-reef flat barely under of the manuscript. This research was supported in water at low tide. The other is at a depth of about part by the Smithsonian Research Foundation. 3 m in the serene waters of Discovery Bay. Environ­ mental variability is, as one would expect, greater at the former so the habitats provide a contrast along Location, Field, and Laboratory Methods a stress gradient. Measurement of species densities and environmental variables were made monthly Pear Tree Bottom (station 1) is located between over the period of a year with replication to permit Discovery Bay and Runaway Bay on the north extensive statistical analyses. coast of Jamaica, West Indies (Figure 1). About 80 m from shore a boulder crest is usually exposed Martin A. Buzas, Department of Paleobiology, Smithsonian at all tides. Shoreward lies a back-reef flat built Institution, Washington, D. C. 20560. Roberta K. Smith, Earth up by accumulation of calcareous sediments and Sciences, University of California at Santa Cruz, Santa Cruz, stabilized by Thalassia and Diplanthera. Station 1 California 95060. Kenneth A. Beem, Department of Physics and Geoscience, Montgomery College, Rockville, Maryland is located about 20 m from mean-high water on the 20850. back-reef flat within a homogeneous patch of SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY 77° 24' iflV IJ CARIBBEAN SEA SCALE 0 1 2 KILOMETERS DISCOVERY BAY PEAR TREE BOTTOM RIVER JAMAICA 77° 24' 77 21' FICURE 1.—Location of sampling areas. Thalassia. During high tides the reef flat has an and measured the environmental variables. A brief open circulation with the sea, while at low tides outline is presented here. Four replicate foraminif- the reef flat is isolated and has a water depth of eral samples were taken each month by inserting about 10-15 cm, and a weak counterclockwise core liners (internal diameter 2.54 cm) into current. randomly chosen cells. In all, 96 such samples were Discovery Bay (station 3) is roughly circular, obtained over 12 successive months. Buffered for­ measuring about 1 km in the east-west direction and malin was added in the field, and upon returning 1.5 km north-south (Figure 1). A fringing reef to the laboratory