Climate Change

In the study, researchers reviewed some of the ground­breaking and recent coral-bleaching discoveries from an ecological, molecular and physiological viewpoint.

Seagrasses need nutrients to thrive, particularly nitrogen (N). Up to now, it has been assumed that the nitrogen is taken up by the seagrasses through leaves and roots from the surrounding seawater and sediment.

However, in many of the regions where seagrasses are most abundant, there is little nitrogen to be found. Furthermore, while nitrogen is abundant in the sea in its elemental form (N₂), seagrasses cannot use it in this form. 

Due to climate change, the average temperature in the Mediterranean Sea rises by one degree every thirty years, and this rate has been increasing. Because of this, the marine creatures there have been shifting their habitats to the deeper, cooler depths of the ocean.

Researchers reached this conclusion after reviewing research involving the depth distribution of 236 marine species like fish, crustaceans and mollusks collected in previous bottom-trawl surveys.

Corals are able to respond to changes in their environment through acclimation (the physiological process of becoming accustomed to a new condition) and adaptation and researchers believe natural populations may already be adapting to increasing sea surface temperatures.

Ocean warming is causing declines of coral reefs globally, raising critical questions about the potential for corals to adapt. In the central equatorial Pacific, reefs persisting through recurrent El Niño heatwaves hold further important clues; We have previously reported on Red Sea coral resilience to climate change.

On 20 February 2016, tropical cyclone Winston struck Fiji. It was described as the most destructive cyclone ever to strike in the Pacific. With winds of up to 280km/h, the coral reefs in the Namena Marine Reserve and Vatu-i-Ra Conservation Park off Fiji were completely destroyed.

To understand how cyclones affect coral reefs and how fast the reefs recover, the team at Wildlife Conservation Society (WCS) Fiji conducted three surveys at different times—one month after, six months after and in December 2020 (more than four years after the cyclone).

Researchers at Michigan State University and the University of Hawaii at Manoa have been uncovering clues as to why some corals bleach while others are resistant, information that could help reefs better weather warming waters in the future.

The team analysed the biochemistry of corals using mass spectrometers to understand what set resistant corals apart from susceptible ones. The scientists found that two different communities of algae lived within the corals. Inside the algae cells were compounds known as lipids.

Researchers conclude the northward range shift demonstrates water temperatures within their preferred temperature range of juvenile white sharks are becoming harder to find.

The animals have historically remained in warmer waters in the southern California Current; Between 1982 and 2013, the northernmost edge of the juveniles' range was located near Santa Barbara (34° N).