FAU Institutional Repository
Total Page:16
File Type:pdf, Size:1020Kb
FAU Institutional Repository http://purl.fcla.edu/fau/fauir This paper was submitted by the faculty of FAU’s Harbor Branch Oceanographic Institute. Notice: ©1997 The Biological Society of Washington http://www.brynmawr.edu/biology/BSW/. This manuscript is an author version with the final publication available and may be cited as: Littler, D. S., & Littler, M. M. (1997). An illustrated marine flora of the Pelican Cays, Belize. Bulletin of the Biological Society of Washington, 9, 1‐149. BULLETIN OF THE BIOLOGICAL SOCIETY OF WASHINGTON 9:1-149. 1997 1 An illustrated marine flora of the Pelican Cays, Belize Diane S. Littler and Mark M. Littler (DSL, MML) Department of Botany, National Museum of Natural History, Smithsonian Institution, Washington, D.C. 20560, U.S.A. (DSL)Division of Marine Science, Harbor Branch Oceanographic Institution, 5600 U.S. 1 North, Fort Pierce, Florida 34946, U.S.A. ABS7RA CT.-The Pelican Cays, Belize, Central America, represent a benign and biologically diverse environment dominated by sessile photosynthetic and filter-feeding populations. Most are delicate and particularly susceptible to physical damage and eutrophication. Pelican Cays has a rich marine flora, totaling 190 taxa, with 86 Rhodophyta (red algae), 23 Phaeophyta (brown algae), 72 Chlorophyta (green algae), 5 Cyanophyta (blue-green algae) and 4 Magnolio phyta (flowering plants). Each species description includes the author citation, original refer ence, basionym and synonyms when appropriate. The detailed descriptions are accompanied by line drawings of anatomical and morphological features to aid in identification. Distribu tions are listed for the Caribbean Basin, along with the habitat where each taxon is typically found, and 73 new seaweed records are added for Belize. The cause of the exceptionally high biodiversity in such a small area is the unusual convergence of complex mangrove, coral, sea grass and algal biomes under stable oligotrophic conditions. Nearly one-fourth of the macro phyte flora are rare or uncommon species. The long-lived coarse, leathery and calcareous form groups dominate with 67% of the taxa, indicative of constant, low-nutrient conditions. Few of the ephemeral filamentous and sheet-like green algae that predominate under elevated nutrient regimes are present. The preponderance of long-lived red algal taxa (86 of 190 total macrophyte taxa) is a further indication of a relatively pristine environment. Botanical survey and inven tory information on the spectacular Pelican Cays ecosystem is provided in the hope of contrib uting toward a timely conservation plan and responsible management of the resource. The atoll-like Pelican Cays, located in the In comparison, the treatment "Marine Plants Central Province of the Belize Barrier Reef of the Caribbean and Adjacent Seas" (Littler (Maps 1-3), comprise a pristine, low-energy, et al. 1989) contained only 209 taxa obtained mangrove-island ecosystem dominated by over an 8-year period. In the past, we have sessile photosynthetic and filter-feeding popu recorded rich floras of important undocu lations. Most are morphologically delicate mented macrophytes in Belizean mangrove and vulnerable to damage from boat wakes, systems such as Twin Cays (Littler et al. 1985) physical disturbance and sedimentation, as and Tobacco Range (Littler et al. 1995). well as natural (Lapointe et al. 1993) and an However, the Pelican Cays' macrophytic di thropogenic (Littler et al. 1993) eutrophica versity far exceeds that of Twin Cays and To tion. The predominant algal form groups bacco Range combined. The cause of this (67% of taxa are coarsely-branched thick unusually high marine plant biodiversity in leathery or calcareous forms) indicate con such a small geographic area is the unique stant, low-nutrient conditions with a paucity juxtaposition of mangrove, coral, seagrass and of the filamentous and sheet-like green algal algal biomes under stable oligotrophic condi forms that characterize nearby eutrophic tions (e.g., indicated by consistently "gin mangrove cays (e.g., Man-of-War Cay, Chan clear" waters). The preponderance of long nel Cay, Douglas Cay). lived red algal taxa (86 out of 190 total macro The macrophyte biodiversity of the Peli phyte taxa) is a further indication of a rela can Cays area (190 taxa) is greater than any tively benign, pristine environment (Littler et comparable system studied in the Caribbean. al. 1987). 2 BULLETIN OF THE BIOLOGICAL SOCIETY OF WASHINGTON 4 18m 01'~oO;N ::.<Q IJ c::p, .: '..' t' d' Columbus Reef 3m 1S066'N Tobacco R:a,nge.. '~.·00 14m f. .' . :~::· Man:u·.••... :.:' of Tobacco Reef .. War Cay ;~; Twin Cays ~. Blue Ground ~~:~.: Range' .. ;~; South WaterCay ~. '.~' Carrie BowCay }:< ':~': ..' Curlew Bank .; 18m ., , :) I: •. ~ .~ :"::!: o • 16"46'N ::: 5m'·.;"" .:~;~v ....... South Cut 22m Douglas CaY:'Il! -:;. PIe lean'Cay~/.·o.:.Q 1··: .::: .::'.:;. :': ':i "il\: : :.'. 18m -~: ..~.j~.~;.~~:{ .::.:> (J .;.y 16"3S'N - ..; o ! I II \- ..' 5km "" ... » I 86"1SW >'I88"06W Map 1. Location of the atoll-like Pelican Cays group on the Central Province of the Belize Barrier Reef, Central America. NUMBER 9 3 Our emphasis is primarily on the large Methods and Materials macrophytic forms that are not ubiquitously dispersed by birds, wind-aerosols and ships. Collections from the Pelican Cays' man We cover the three major phyla of marine grove prop roots, seagrass flats and shallow algae, Rhodophyta (red algae, 86 taxa), Phaeo ribbon reefs were made from February 1992 phyta (brown algae, 23 taxa) and Chlorophyta to May 1995 by hand while snorkeling. (green algae, 72 taxa). Also included are Cya SCUBA diving was employed to collect from nophyta (blue-green algae,S taxa), which rep the deeper slopes of seagrass beds and ribbon resent an important macrophytic component reefs. During February 1993, we began re in some habitats, and the flowering plant phy cording observations of populations and is lum Magnoliophyta (seagrasses, 4 taxa), even land systems in the Pelican Cays Group using though generally omitted from algal floras names of locations from charts and some of and texts. The seagrasses playa major role in our own site designations (Maps 2, 3). Our the ecology and population dynamics of Peli research team has now made multiple sea can Cays' ecosystems and, therefore, must be sonal marine plant collections at 43 different incorporated in any comprehensive treat sites from the 11 major islands of the Pelican ment. Cays. Manatee Cay was collected at 11 sites, Bird Cays at 6 sites, Fisherman's Cay at 5 sites The algal biodiversity of the unique Peli and the remaining cays at 3 sites each. A co can Cays is documented as a first step toward ordinated transect method was used among establishing a baseline of systematic informa the three divers to facilitate complete system tion essential to further research and of use to atic and habitat coverage. Specimens for managers of this remarkable resource. The pressing were combined in large mesh bags, approach used is an illustrated flora, whereby while separate plants were placed in individual each taxon is given a general morphological plastic bags at the time of collection, later description followed by a more technical ana transferred to polycarbonate scintillation vi tomical treatment, and a plate of one to five als, fixed in 5% Formalin and finally pre diagnostic habit and anatomical line drawings. served in 70% ethyl alcohol. This resulted in The product is a fully illustrated floristic 150 identified bulk collections for pressing treatment that can also serve as a field guide to and 300 separate identified collections pre the marine plant life of the Pelican Cays. served in individual labeled vials. In the labo ACKNOWLEDGMENT.5.-Special thanks for ratory, portions of each species' collection support and funding go to Harbor Branch were retained in vials with liquid preservative, Oceanographic Institution (HBOI Contribu while the remainder of thalli and bulk materi tion No. 1189) and the Smithsonian Marine als :rere dried and pressed as herbarium Station at Link Port, Florida (SMSLP Contri specimens bution No. 429). Both organizations were Dried herbarium collections, wet preserved extremely helpful during all aspects of this materials and, when at the Carrie Bow Cay work. Additional funding was provided by (CBC) field station, living specimens were NSF Grant DEB-9400534 and the Caribbean examined macroscopically and microscopi Coral Reef Ecosystem Program of the Na cally, after portions were prepared on glass tional Museum of Natural History (CCRE slides for anatomical study. Thallus sections Contribution No. 523). We gratefully ac were made by hand (in the field) or by freez knowledge Barrett L. Brooks for his continu ing microtome, stained with 1% aniline blue ing support and assistance throughout all of and mounted using a 20% glucose syrup (Karo our field and laboratory efforts and Michael J. Syrup, Corn Products, Inc.) solution in dis Wynne and Richard B. Searles for their thor tilled water containing a trace of phenol. All ough reviews and excellent suggestions, which anatomical illustrations were drawn with a improved the manuscript considerably. camera lucida on a Zeiss Universal Micro David B. Lellinger's excellent review, helpful scope to assure accuracy; internal meas suggestions and editorial assistance made the urements were made with a calibrated ocular final publication possible. micrometer. The specimens generated by this 4 BULLETIN OF THE BIOLOGICAL