Apparent recruitment failure for the vast majority of coral species at Eilat, Red Sea

Abstract

The status of coral reefs is often portrayed by parameters (e.g., coverage, bleaching, diseases, nutrients and rugosity) assigned to adult populations. Yet, coral recruitment is essential for sustaining coral populations, especially in the aftermath of major disturbances. Studying earliest coral recruitment at species level can reveal declines in the recovery potential and resilience of coral populations and communities, even if adult abundance and coral cover is sustained. Rates of coral recruitment were quantified once a month for 4 yrs from tiles and stones (Eilat, Red Sea), revealing a dramatic discrepancy in coral species recruited (n = 15) compared to adult-species currently on site (n = 55), with 1–2 dominant species accounting for ≥ 80% of recruits. The low rates and limited diversity of settling corals recorded in this study appear unlikely to sustain contemporary coral assemblages, so unless there are marked changes in the settlement dynamics, we would expect to see inevitable declines in the abundance and diversity of reef corals at these locations.