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An exceptionally large, hermatypic colony of Porites sp. has been identified and measured at Ta’u, American Samoa. This coral was measured in November 2019 as part of an effort to catalogue all large (≥ 2 m diameter) Porites colonies around Ta’u. Colonies exceeding 10 m in diameter were recorded on three different sides of the island with seasonally different wave exposures. The largest colony measured 8 m tall, 69 m in circumference and had a diameter of 22.4 m. To date, this is the biggest colony recorded in American Samoa, and one of the largest documented worldwide. It is currently unknown why such large corals exist around this particular island. Possible explanations include mild wave or atmospheric climates and minimal anthropogenic impacts. Physiologically, these colonies may be resistant and/or resilient to disturbances. Large, intact corals can help build past (century-scale) climatic profiles, and better understand coral persistence, particularly as coral communities worldwide are declining at rapid rates.

High densities of two corallivorous gastropods, Drupella cornus and D. rugosa, may delay the recovery of coral reefs impacted by mass bleaching events by aggregating on the remaining corals. Following severe bleaching in April/May 2016 that resulted in the loss of up to 80% of the living coral cover from reefs in South Male, Maldives, aggregations of up to 250 Drupella per coral were recorded on surviving colonies. The distribution of snails was not random; larger aggregations were seen on reefs with fewer remaining live corals and also on the largest corals. Branching, digitate and tabular corals, especially species of Acropora and Pocillopora, sustained the highest mortality from the bleaching. Remaining colonies of these taxa exhibited the highest occurrence of snails and the most extensive snail predation, although less-preferred taxa such as Montipora, Porites, Astreopora, Cyphastrea and Pachyseris were also targeted. Drupella also concentrated on broken Acropora branches and overturned colonies; on some reefs, these were the only surviving acroporids, and many of them did not bleach. Continued predation pressure from Drupella may eliminate formerly dominant corals, including genets that are resistant to higher sea water temperatures.

Culcita spp. are facultative corallivores that can have a selective effect on coral composition due to their feeding preference for Acropora spp. and Pocillopora spp. Although Culcita are normally rare (