Species-Specific Response of Corals to Imbalanced Ratios of Inorganic Nutrients.

Dissolved inorganic phosphorus (DIP) is a limiting nutrient in the physiology of scleractinian corals. Anthropogenic addition of dissolved inorganic nitrogen (DIN) to coastal reefs increases the seawater DIN:DIP ratio and further increases P limitation, which is detrimental to coral health. The effects of imbalanced DIN:DIP ratios on coral physiology require further investigation in coral species other than the most studied branching corals.

High pCO promotes coral primary production.

While research on ocean acidification (OA) impacts on coral reefs has focused on calcification, relatively little is known about effects on coral photosynthesis and respiration, despite these being among the most plastic metabolic processes corals may use to acclimatize to adverse conditions. Here, we present data collected between 2016 and 2018 at three natural CO seeps in Papua New Guinea where we measured the metabolic flexibility (i.e.

Suitability of the shallow water hydrothermal system at Ambitle Island (Papua New Guinea) to study the effect of high pCO on coral reefs.

Volcanic CO seeps were successfully used to predict coral reef response to ocean acidification, although toxic elements, often characteristic of hydrothermal vents were rarely reported. We measured the physicochemical conditions, seawater carbonate chemistry and trace elements in Tutum Bay, Papua New Guinea. There, intense emission of hydrothermal fluids and CO expose the coral reef to a seawater pH between 7.

Evidence for mitigation of coral bleaching by manganese.

Unprecedented mass coral bleaching events due to global warming and overall seawater pollution have been observed worldwide over the last decades. Although metals are often considered as toxic substances for corals, some are essential at nanomolar concentrations for physiological processes such as photosynthesis and antioxidant defenses. This study was designed to elucidate, the individual and combined effects of nanomolar seawater enrichment in manganese (Mn) and iron (Fe), on the main physiological traits of Stylophora pistillata, maintained under normal growth and thermal stress conditions.

Enhancement of coral calcification via the interplay of nickel and urease.

Corals are the main reef builders through the formation of calcium carbonate skeletons. In recent decades, coral calcification has however been impacted by many global (climate change) and local stressors (such as destructive fishing practices and changes in water quality). In this particular context, it is crucial to identify and characterize the various factors that promote coral calcification.

Nickel and ocean warming affect scleractinian coral growth.

The sensitivity of corals and their Symbiodinium to warming has been extensively documented; however very few studies considered that anthropogenic inputs such as metal pollution have already an impact on many fringing reefs. Thus, today, nickel releases are common in coastal ecosystems. In this study, two major reef-building species Acropora muricata and Pocillopora damicornis were exposed in situ to ambient and moderate nickel concentrations on a short-term period (1h) using benthic chamber experiments.

Responses of two scleractinian corals to cobalt pollution and ocean acidification.

The effects of ocean acidification alone or in combination with warming on coral metabolism have been extensively investigated, whereas none of these studies consider that most coral reefs near shore are already impacted by other natural anthropogenic inputs such as metal pollution. It is likely that projected ocean acidification levels will aggravate coral reef health. We first investigated how ocean acidification interacts with one near shore locally abundant metal on the physiology of two major reef-building corals: Stylophora pistillata and Acropora muricata.