Toggle Main Menu Toggle Search

Open Access padlockePrints

Large-scale associations between macroalgal cover and grazer biomass on mid-depth reefs in the Caribbean

Lookup NU author(s): Professor Nick Polunin

Downloads

Full text for this publication is not currently held within this repository. Alternative links are provided below where available.


Abstract

Since the 1970s, macroalgae have become considerably more abundant on many Caribbean reefs and overfishing of grazing fishes has been implicated as a contributory factor. We explored relationships between algal cover and grazers (biomass of herbivorous fishes and abundance of the sea-urchin Diadema antillarum) on mid-depth reefs (12-15 m) in 19 areas at seven locations in Jamaica, Barbados, Belize, Grand Cayman and Cuba, between April 1997 and April 1998. Diadema antillarum density was never > 0.01 m(-2), while herbivorous fish biomass (acanthurids and scarids greater than or equal to 12 cm total length) varied from 2-5 g m(-2) in Jamaica to 17.1 g m(-2) in Barbados. and was strongly correlated. negatively with macroalgal cover and positively with 'cropped' sub-stratum (sum of 'bare', turf and crustose-coralline substrata) cover. However. overfishing of herbivorous fishes alone cannot explain the widespread abundance of macroalgae. as even on lightly fished reefs, macroalgal cover was mostly > 20%. Herbivorous fish populations on those reefs were apparently only able to maintain approximately 40-60% of reef substratum in cropped states, but due to low space-occupation by coral and other invertebrates. 70-90% of substratum was available to algae. The abundance of macroalgae on lightly fished reefs may therefore be a symptom of low coral cover in combination with the continuing absence of Diadema antillarum.


Publication metadata

Author(s): Williams ID, Polunin NVC

Publication type: Article

Publication status: Published

Journal: Coral Reefs

Year: 2001

Volume: 19

Issue: 4

Pages: 358-366

ISSN (print): 0722-4028

ISSN (electronic): 1432-0975

Publisher: Springer


Actions

Find at Newcastle University icon    Link to this publication


Share