Coral

Two divers at a reef
Co-authors Argel Horton and Laura Arton applying the chlorine paste to a coral. The bright white area shows where the treatment has already been applied.

Chlorine and Cocoa Butter: A Formula for Treating Diseased Corals?

Treatment options for coral reefs stricken with tissue loss diseases often involve antibiotic treatments that can have an adverse impact on the surrounding environment and can lead to increased antibiotic resistance. 

An international team of researchers have developed an alternative treatment in the form of a paste made from chlorine and cocoa butter. Their findings were recently published in the Frontiers in Marine Science journal. 

Aerial image of Scott Reef

Connectivity Enhances Coral Reef Resilience

Coral reefs are among the planet’s most vital ecosystems, yet they face increasing threats from climate change, including bleaching events and destructive storms. A new study by the Australian Institute of Marine Science (AIMS) sheds light on the crucial role of connectivity between coral communities in helping reefs recover and adapt to environmental challenges.

Release of egg/sperm bundles from the table coral Acropora hyacintus at Palau

Corals' Survival Hinges on Proximity to One Another

In a new study, researchers have discovered that corals need to be within a few metres apart to successfully reproduce. 

“In what came as a surprise, we saw that corals needed to be within 10 metres of one another, and preferably closer than that for fertilisation to take place,” Professor Peter Mumby, from The University of Queensland, said.

This proximity requirement is much closer than previously thought.

Pillar coral
Pillar coral (Photo: Commander William Harrigan, NOAA Corps, Florida Keys National Marine Sanctuary / Public Domain)

The State of Our Beloved Coral

The latest reports from organisations like the International Union for Conservation of Nature (IUCN) and UN Environment Programme report that about 50% of the world's coral reefs are considered damaged or at risk of collapse, with some estimates suggesting that we could lose up to 90% of coral reefs by 2050 if current trends continue. This is a staggering figure when considering the ecological and economic importance of coral reefs.

This monumental coral of the species Pavona clavus is estimated to be around 300 years old, providing a unique window into historical oceanic conditions.

World’s Largest Coral Colony Discovered in Solomon Islands

(Top photo by Manu San Félix, National Geographic Pristine Seas, via press release)

The monumental coral, of the species Pavona clavus, was discovered by researchers of the National Geographic Pristine Seas project during an expedition to the remote Three Sisters Islands in the southwestern Pacific Ocean. Initially mistaken for a shipwreck or large rock due to its size, the structure was confirmed to be a single coral colony, surpassing previous records for individual corals.

Can Heat-Tolerant Corals Save the World’s Reefs?

As global warming devastates coral reefs, a controversial proposal to replace native coral species with heat-resistant ones from other regions is stirring debate. 

New York University’s Michael Webster and the University of Washington’s Daniel Schindler argue that “ecological replacement” may be essential for preserving reef ecosystems.

While this approach raises concerns, its supporters believe it might be the only realistic solution as ocean temperatures continue to rise.

Hawaiian Triggerfish on Ningaloo Reef
Hawaiian Triggerfish on Ningaloo Reef

Coral Catastrophe on Ningaloo Reef

An ecological disaster

Furthermore, the abundance of healthy coral colonies experienced a sharp decline from 3,452 individuals in 2018 to just 153 in 2022. The abundance of coral genera also took a significant hit, falling by 84.61% from 26 genera in 2018 to just four in 2022. Dominant genera such as Acropora, Montipora and Echinopora were eradicated from the study sites.

Rice Corals (Montipora capitata), Kane'ohe Bay, O'ahu, Hawaii

Coral Resilience Under Climate Stress: Insights from Hawaiian Reefs

In 2015, amidst a marine heatwave, Barott’s team tagged numerous coral colonies, initiating a study on coral adaptability. Their focus: the rice coral (Montipora capitata) and finger coral (Porites compressa), two dominant species in the region. Over the years, multiple heatwaves provided a unique opportunity to observe coral responses, revealing both resilience and vulnerability.

Mariah Opalek, at the water tanks where the research was conducted.

Coral Growth Depends on Type of Symbiotic Algae They Associate With

Scientists discover a surprising tradeoff in coral growth linked to the symbiotic algae they host. The research sheds light on the delicate balance that corals strike in adapting to rising ocean temperatures.

Corals derive much of their energy from the algae living within their soft tissue, and it appears that some symbiotic algae species help corals withstand warmer water better than others.