Fouling reefal communities on artificial reefs: Does age matter?

Abstract

Man-made submerged structures, including shipwrecks, offering substrata for fouling organisms and fish, have been classified secondarily as artificial reefs (ARs). The current approach in AR design is that of low-profile structures placed on the seabed and attempting to mimic natural reef (NR) communities with the aim of mitigating degraded marine ecosystems. To examine the validity of this concept, a long-term comparison of the developing AR fouling communities to those of nearby NRs is required. A survey of the fouling reefal organisms was conducted on seven shipwrecks (Red Sea, Egypt), comprising three young (ca 20 years old) and four old (>100 years old) unplanned ARs, in comparison to nearby NR communities. The hypothesis tested was that the age of the ARs shapes the structure of their fouling coral communities. The results demonstrated distinct differences between ARs and NRs and between young and old ARs. While the species composition on ARs may resemble that of NRs after approximately 20 years, obtaining a similar extent of coral cover may require a full century. Moreover, differences in structural features between ARs and NRs may lead to differences in species composition that persist even after 100 years.

Macrobenthic colonization on the derelict Fisheries Vessel Khronometer, Cristo Rey Submarine Park, Argentina

“…These hard bottoms present a horizontal orientation at similar depths; thus, it is not surprising that community structures on artificial and natural hard substrates with similar structural features will become almost indistinguishable (Perkol‐Finkel et al, ). Perkol‐Frinkel et al ( found that, in tropical waters, the species composition found on shipwrecks are similar to that on natural reefs after approximately 20 years. However, in temperate seas these similarities between natural and artificial substrates can be evidenced very quickly, at ~5 years.…”

Recruitment of benthic invertebrates in high Arctic fjords: Relation to temperature, depth, and season

“…The first colonists on isolated hard substrata (at temperate latitudes) are typically fast‐growing poor competitors, such as acorn barnacles and spirorbid polychaetes (Dean and Hurd ; Chalmer ). Later in succession, slow‐growing superior competitors dominate (Perkol‐Finkel et al ; Edwards and Stachowicz ). We hypothesize that the recruits to our experimental substrata will be primarily fast‐growing, poor competitors.…”

Wrecks on the Bottom: Useful, Ecological Sentinels?

“…Studying wrecks in the North Sea, Australia and Red Sea, Guerin (2009), Walker et al (2007 and Perkol-Finkel et al (2005, 2006 also agreed that the geometrical complexity of wreck structures plays a key role in determining species colonization. On muddy bottoms of the Ligurian Sea, vertical surfaces of studied shipwrecks were dominated by Ostrea edulis and Corynactis viridis.…”