Scientists at the Scripps Oceanography Institution and UC San Diego technicians used new software to identify the spectacular growth following a bleaching incident on the reefs enveloping the remote Palmyra Atoll of the tropical Pacific. Their research was published in Coral Reefs on April 5th, 2019.
In 2015, Palmyra experienced its warmest water in recorded history, prompting a widespread bleaching event that affected more than 90% of the island’s corals. Researchers discovered that most corals recuperated, with less than 10 percent dying, notwithstanding pervasive bleaching.
The findings are based on detailed reef tracking and provide accurate observations as to how corals evolve. The experts examined a data set gathered over eight years with thousands of photos of the very same coral region. These images have been put together using software used to create 3D photo ecosystems, like the virtual coral depiction. This technology was developed by the 100 Island Challenge, a cooperative group of marine ecologists in order to observe reefs around the world.
The researchers coupled this imaging technology with VisCore, a new custom visualization drm that enables users to re-examine the thousands of photographs comprising the virtual reef. The project was facilitated by trying to bring together Scripps researchers and UC San Diego’s Jacobs School of Engineering with a sense of commitment to the venture, said Falko Kuester, UC San Diego’s professor of computing and structural engineering.
The researchers were able to monitor the recovery of corals closely together with documenting the bleaching. Searching the reef’s photomosaics following the initial bleaching event, Fox and team recorded growth in an essential species of reef-building, crustose coralline algae. This alga helps strengthen coral and encourages juvenile reef settlement. Researchers found that in places where reef died and was covered with reef – smothering cyanobacteria, the algae was replaced by the pink crustose coralline. This happens because of the larger ecosystem’s health, as Palmyra has vigorous herbivorous marine life that can regulate the growth of harmful cyanobacteria.
Monitoring such recuperation mechanisms in particular coral colonies provides researchers with a better understanding of how individual corals deal with ecological pressures in the oncoming era of climate change. Typically, with transect sampling, alterations in reefs were measured with divers recording their observations across the reef. Coral scientists can look at demographic indications in a vast area with the reef mosaics and VisCore’s pinpoint accuracy. The colony-specific data gives more accuracy and displays both regional and national patterns, like mapping the population growth in a specific country.
“Using a combination of novel technology and more traditional approaches, our team showed that the reefs of Palmyra did not suffer the same fate as many other reefs during the recent global bleaching event,” said Jen Smith, a Scripps scientist and co-founder of the 100 Island Challenge.
This study was funded from 2009 – 2018 by large donations to the Smith and Sandin laboratories from the Scripps Family Foundation, the Bohn Family, the Wilson family, Marcia Grand and many other donors.