Low-level nutrient enrichment during thermal stress delays bleaching and ameliorates calcification in three Hawaiian reef coral species [PeerJ]

Terrestrial-based nutrient pollution has emerged as one of the most detrimental factors to coral health in many reef habitats. Recent studies have shown that excessive dissolved inorganic nutrients can reduce coral thermal tolerance thresholds and even exacerbate bleaching during thermal stress, yet the effects of minor nutrient enrichment under heat stress have not been extensively studied. In this study, Lobactis scutaria, Montipora capitata, and Pocillopora acuta colonies under heated conditions (~30.5 °C) were exposed to low and balanced nitrogen and phosphorous concentrations over a 31-day heating period. Coral colonies were collected from Kāne‘ohe Bay, O‘ahu, which has a unique history of nutrient pollution, and held in mesocosms that allowed for environmental manipulation yet are also influenced by local field conditions. Principal findings included delays in the bleaching of nutrient-enriched heated colonies as compared to heated-only colonies, in addition to relatively greater calcification rates and lower proportions of early-stage paling. Species-specific outcomes were prevalent, with L. scutaria demonstrating no difference in calcification with enrichment under heat stress. By the end of the heating stage, however, many heated colonies were at least partially impacted by bleaching or mortality. Despite this, our findings suggest that low levels of balanced nutrient enrichment may serve as a mitigative force during thermal events. Further field-based studies will be required to assess these results in different reef habitats.

Coral Calcification and Ocean Acidification

Announcement, SOEST

PDF) Moderate chlorophyll-a environments reduce coral bleaching

Ocean warming and acidification uncouple calcification from

PDF) Growth and survival among Hawaiian corals outplanted from

Low-level nutrient enrichment during thermal stress delays

Low-level nutrient enrichment during thermal stress delays

PDF) The Effects of Temperature, Light, and Feeding on the

The coral conservation crisis: interacting local and global

Physiological acclimatization in Hawaiian corals following a 22

PDF) Coral taxonomy and local stressors drive bleaching prevalence

Evidence for mitigation of coral bleaching by manganese

PDF) Moderate chlorophyll-a environments reduce coral bleaching