The distribution of Recent benthic Foraminifera across habitats of Bocas del Toro, Caribbean Panama

Abstract

We use distributions of Recent benthic foraminifera in Bocas del Toro, Caribbean Panama, to distinguish tropical habitats. Two hundred thirty-seven species occur in 37 samples from substrata of the inner continental shelf (3.7 m) to upper slope (240 m). Cluster analyses of the assemblages primarily differentiate open-ocean from partially restricted, shallow coastal waters, and secondarily differentiate six main habitats with characteristic taxa as follows: shallow lagoon (inner shelf, 10-18 m): Ammonia beccarii, Nonionella atlantica; deep lagoon (inner to shallow middle shelf, 23-35 m): Cancris sagra, Lagenammina atlantica, Reussella minuta; channel (inner to middle shelf, 21-70 m): Bigenerina irregularis, Epistominella vitrea, Hanzawaia concentrica, Reussella spinulosa, Textularia schencki; reef (inner to middle shelf, 6-82 m): Amphistegina gibbosa, Discorbis mira, Eponides antillarum, Hauerina fragilissima, Nodobaculariella casis, Planulina exorna, Pyrgo subspaerica, Quinqueloculina bicornis, Q. collumnosa, Q. lamarckiana, Q. tricarinata, Rotorbinella umbonata, Textularia conica; middle (39 m) to shallow outer (120 m) shelf (excluding middle shelf to upper slope sediments mixed by downshelf transport): Cibicides aff. C. floridanus, C. pachyderma, agglutinated Miliolidae; and deep outer shelf (168 m) to upper slope (235 m): Bolivina lowmani, Cassidulina norcrossi australis, Gyroidina regularis, G. turgida, Uvigerina laevis, U. peregrina. Grain-size analyses show little differentiation of these environments, other than coarse sands of the reef habitat. Distributions of most of the above taxa, except for the reef habitat species, are uncorrelated with grain size and thus are the most useful for paleoenvironmental studies, although the reef taxa should also be useful when comparing samples with similar grain sizes.