A centuries-old manmade reef in the Caribbean does not substitute natural reefs in terms of species assemblages and interspecific competition

• Published in: Marine pollution bulletin Vol. 169; p. 112576
• Main Authors: Hill, Claudia E.L., Lymperaki, Myrsini M., Hoeksema, Bert W.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.08.2021; Elsevier BV
• Subjects: 18th century; Algae; Artificial reef; Artificial reefs; Colonization; Community composition; Competitors; Composition; Coral reefs; Corals; Crustose coralline algae; Human-made structures; Millepora spp; Palythoa caribaeorum; Species; Species composition; Species richness; Substrates; Turf; Turf algae; Caribbean area; Millepora spp; Turf algae; Artificial reef; Crustose coralline algae; Palythoa caribaeorum; 18th century
• ISSN: 0025-326X; 1879-3363
• DOI: 10.1016/j.marpolbul.2021.112576

With increasing maritime activities in the proximity of coral reefs, a growing number of manmade structures are becoming available for coral colonisation. Yet, little is known about the sessile community composition of such artificial reefs in comparison with that of natural coral reefs. Here, we compared the diversity of corals and their competitors for substrate space between a centuries-old manmade structure and the nearest natural reef at St. Eustatius, eastern Caribbean. The artificial reef had a significantly lower species richness and fewer competitive interactions than the natural reef. The artificial reef was dominated by a cover of crustose coralline algae and zoantharians, instead of turf algae and fire corals on the natural reef. Significant differences in species composition were also found between exposed and sheltered sites on both reefs. Our study indicates that even a centuries-old manmade reef cannot serve as a surrogate for natural reefs. [Display omitted] •Age is a key determinant of community composition on manmade reefs.•Crustose coralline algae and zoantharians (Palythoa caribaeorum) dominate the shallow, artificial reef.•Turf algae and fire corals (Millepora spp.) dominate the adjacent natural reef.•The artificial reef hosts a diverse community of its own with fewer species interactions.•The artificial reef does not serve as a surrogate for the natural reef.