The coral reef off Israel’s southern coast has seen a worrying rise in water temperature and a 50 percent drop in sea urchin, which play a key role in its ecosystem, a government report finds

Zafrir Rinat Aug 3, 2022

The coral reef in Eilat, in 2018.
The coral reef in Eilat, in 2018.Credit: Prof. Maoz Fine/Bar Ilan University

The coral reef off Eilat’s shore is struggling to recover from a storm that damaged it more than two years ago, a report issued by the Environmental Protection Ministry on Wednesday said.

The study found a worrying rise in water temperatures and a sharp drop in the population of sea urchins that play a critical role in its ecology.

An unusually powerful storm struck the area in March 2020 that destroyed some of the coral and buried many in sand and carried human debris into it. The storm caused the loss of between 6 percent and 22 percent of the reef’s coral cover. Today, according to the study, the reef has not only not recovered, but has seen a further drop of 5 percent in its coral cover.

Another alarming trend is the continued increase in deep-water temperatures, which had been detected in earlier surveys. Surface temperatures have been on the rise since 1988 at an average rate of half a degree every decade. As a result surface temperatures in the waters near Eilat are now 2.5 times the global average, according to estimates by a team of United Nations scientists to study climate change (Intergovernmental Panel on Climate Change).

A view of Eilat after the storm, in 2020.
A view of Eilat after the storm, in 2020.Credit: Mori Chen

The report, which was prepared by the Interuniversity Institute for Marine Sciences in Eilat, was presented by Dr. Yonathan Shaked and Prof. Amatzia Genin to the executive committee of the monitoring program funded by the Environment Ministry.

The Eilat reef is considered unique because of the ability it has developed to withstand rising water temperatures. But, too sharp an increase may damage its coral. At one of the measuring stations, the highest temperatures since scientists began recording them in 2004 were documented in the past year.

The report also found that the Gulf of Eilat’s biological diversity was also damaged. That was expressed mainly in a 50 percent decline in the number of sea urchins, compared with 2019 and in a relative order of magnitude to their number at the beginning of the monitoring activity. Sea urchins, who sustained losses during the storm two years ago, play a critical role in protecting the reef from the algae that compete with the corals for colonization sites.

The monitoring program also follows developments with seaweed that lives in the northern Gulf of Eilat and adjacent to the most southern beach in Israel, near the border with Egypt. Seaweed helps sustain the rich population of aquatic life. But in the last two years, there has been no sign of seaweed on the southern beach to a depth of tens of meters, which is likely to have an impact on the ability of other life in the area.

Nevertheless, some of the measurements taken in connection with the reef show signs of stability. The report found that a wide range of coral species hadn’t undergone significant change and in coral reserves, a large number of new corals have formed.

The coral reef in Eilat, in 2021.
The coral reef in Eilat, in 2021.Credit: Dror Zurel

“The survey findings show that despite the fact that the Red Sea is a large body of water shared by many countries, the main impact on the system in Israel’s marine areas originates in Israel,” said Prof. Noga Kronfeld-Schor, the Environment Ministry’s chief scientist and chairman of the monitoring program’s executive committee.

“In addition to that, the report also showed the changes the maritime system is undergoing due to the climate crisis. This is a sensitive and important system, for which we must do as much as we can to prevent further damage to it,” she said.

In addition, the ministry is concerned that development of a seaside promenade planned by the Eilat municipality will cause further damage to the reef. Environmental Protection Minister Tamar Zandberg agreed this week with the city to form a joint committee to study the impact of the project on the shoreline and the reef.

A ministry report released last September found that the reef was contending with worsening environmental pressures, some of them connected with climate change, including rising sea temperatures; an increase in concentration of harmful materials; growing amounts of refuse on the seabed; and changing water chemistry, as well as the specific impact of the 2020 storm.