Checklist of marine algae and seagrasses from the ponds of the Pelican Cays, Belize

• Published in: Atoll research bulletin Vol. 474; pp. 151 - 206
• Main Authors: Littler, Diane S., Littler, Mark M., Brooks, Barrett L.
• Format: Journal Article
• Language: English
• Published: 2000
• Subjects: Caulerpa nummularia; Gracilaria; Marine; ASW, Belize, Pelican Cays
• ISSN: 0077-5630
• DOI: 10.5479/si.00775630.474.151

One hundred and fifty two species of marine macrophytes (148 algae and 4 vascular plants) were recorded from ponds (embayments, bays, coves, and lagoons) within the Pelican Cays, a recently recognized atoll-like system of the Rhomboid Cays in the Central Province of the Belize Barrier Reef. Of the algae, 64 were Rhodophyta, 59 Chlorophyta, 16 Phaeophyta, and 9 Cyanophyta; 4 Magnoliophyta also were present. This unusually high marine plant biodiversity (for such a small geographic area) can be traced to the unique commingling of four major biomes-mangrove, coral, seagrass, and algal-under stable oligotrophic conditions (as indicated, for example, by the area's consistently "gin-clear" waters). The cays also have three distinct habitat types: hanging roots, peat banks, and pond floors. The pond floors (bases) contain abundant psammophytic seagrasses and Chlorophyta (rhizophytes), anchored on the shallow horizontal margins. The suspended mangrove roots support combinations of delicate plant and animal taxa not found on the embedded roots, peat banks, or pond bases. The adjacent peat banks support more herbivore-resistant (calcified, tough, and chemically defended) taxa, indicative of a relatively grazer-accessible habitat. Between-pond floristic differences appear to be minor, but populational abundances vary greatly, probably because of the circulation and size of the ponds. One algal species, the giant-cell Caulerpa nummalaria, has not been found elsewhere in the Western Atlantic. Commercially valuable red algal agar-producers (Gracilaria, Hydropuntia) and carigeenan-producers (Meristiella) abound near the openings to several of the ponds. An unusual number of macroalgal species have attained record large sizes in these ponds. We fully documented all taxa to provide an initial checklist, with collection data for the major ponds of the Pelican Cays, as well as overall ranges for the Caribbean and adjacent seas.