Field biology of Halimeda tuna (Bryopsidales, Chlorophyta) across a depth gradient: comparative growth, survivorship, recruitment, and reproduction

    Authors

    P. S. Vroom; C. M. Smith; J. A. Coyer; L. J. Walters; C. L. Hunter; K. S. Beach;J. E. Smith

    Comments

    Authors: contact us about adding a copy of your work at STARS@ucf.edu

    Abbreviated Journal Title

    Hydrobiologia

    Keywords

    Halimeda tuna; coral reef; alizarin; Florida Keys; Ericthonius; brasiliensis; Dictyota; GREEN-ALGA-HALIMEDA; GREAT-BARRIER-REEF; SAN-SALVADOR ISLAND; CORAL-REEFS; FLORIDA-KEYS; SPECIES COMPOSITION; UNCHARTED SEAMOUNT; WATER; CALCIFICATION; CAULERPALES; Marine & Freshwater Biology

    Abstract

    Growth, survivorship, recruitment, and reproduction of Halimeda tuna, a dominant green alga in many reef systems of the Florida Keys, were monitored at a shallow back reef ( 4 - 7m) and deep reef slope ( 15 - 22 m) on Conch Reef. Despite lower light intensities and similar grazing pressures, amphipod infestations, and epiphyte loads at both sites, the deeper site exhibited significantly higher growth rates in summer months over a 4-year period than found for the shallow population, possibly because of higher nutrient levels at depth and photoinhibition of shallow plants. Sexual reproductive events occurred simultaneously across the entire reef, with up to 5% of the population at both sites developing gametangia. New upright axes formed from zygotes, asexual fragmentation, or vegetative runners. Plants appear to have persistent basal stumps that survive harsh environmental conditions, even if upright, photosynthetic axes are removed. Sexual reproduction and 'smothering' by epiphyte overgrowth are hypothesized to be two causes of death for individuals.

    Journal Title

    Hydrobiologia

    Volume

    501

    Issue/Number

    1-3

    Publication Date

    1-1-2003

    Document Type

    Article

    Language

    English

    First Page

    149

    Last Page

    166

    WOS Identifier

    WOS:000186041800016

    ISSN

    0018-8158

    Share

    COinS