Coral reefs in the Gulf of Eilat are robust, despite rising temperatures in the Red Sea, an annual government report published Tuesday said, while warning that massive coastal development projects currently at the planning stage must be closely monitored to ensure they don’t add further pressure.
The report, issued by the Environmental Protection Ministry and covering 2018, said the reefs’ condition remain stable. Average coral density was marginally lower than that recorded in 2016 and 2017, but significantly higher than during the early years of monitoring, which began in 2004, indicating the fluctuations are natural.
The diversity of the coral is changing only slightly from year to year. Since 2004, there has been a gradual increase in the percentage of medium and large coral colonies, indicating improved coral survival over time.
The report, based on ministry-funded research by the Inter-University Institute for Marine Sciences in Eilat, confirmed other recent studies about the state of the Eilat ecosystem, at a time when tropical reefs around the world are collapsing due to pollution, warming seas and increased acidity.
According to the United Nations, ocean acidity — caused by the absorption of increased carbon dioxide that results from human activity — has risen by 30 percent since the beginning of the Industrial Revolution. This is 100 times faster than any change in acidity experienced by marine organisms for at least the last 20 million years. Business-as-usual scenarios for carbon dioxide emissions could make the ocean up to 150% more acidic by 2100, the UN has warned.
The annual report of the Israel National Monitoring Program at the Gulf of Eilat, authored by Dr. Yonathan Shaked, director of the program, and the program’s scientific director Prof. Amatzia Genin, warned that increased acidity in the Red Sea in the future is likely to damage corals whose skeletons are made of calcium carbonate. It is these corals that help build the reefs.
The Red Sea is heating up slowly but steadily, with an average sea surface temperature rise of around 1.8% over the past 30 years, according to the report,
The research also found that a decade after the banning of “cages” for fish farming, which caused substantial damage to corals, parasites linked to the cages are still being found in wild fish.
Concerns over nearby projects
The research team’s brief for 2018 expanded to gather data that will be needed for the planning of large projects. These include a pipeline to carry Red Sea water to the rapidly declining Dead Sea and a massive aquaculture industrial park in Eilat being advanced by the Agriculture Ministry. Regarding the latter, the report said all efforts must be made to ensure that water from the park does not flow into the sea.
Urban development poses a key challenge for marine ecosystems. Sewage, water infused with fertilizers, rain that runs off into the sea carrying pollutants with it, and fish farms are just some of the sources that, if they reach the sea, can increase the nutrient content and cause rapid growth of algae, which can take space and light from young corals, inhibiting the growth of reefs.
In order to protect the balance, the report said fishing for algae-eating fish should be prohibited in the northern part of the Gulf of Eilat and enforcement is needed to uphold a ban on harming sea urchins along the entire Eilat coast, and especially near the reefs. Urchins are the most important invertebrate grazers and consumers of algae in coral colonies.
The report urged the creation of a marine nature reserve off of Eilat’s northern coast to protect carpets of sea grass that stabilize the sandy sea bottom, protecting it from the effects of storms, and provide food, habitat, and nursery areas for many vertebrate and invertebrate species. Sea grass cover appears to be unstable over the years, the report said, but it is still early to diagnose why.
The reefs of the Gulf of Eilat are becoming one of the last few refuges for corals in the world. Scientists hypothesize that they originated in the Indian Ocean, where temperatures were and still are much higher than those in the Red Sea, moving north over thousands of years to colonize the latter after the last ice age ended, while retaining their ability to withstand warmer seas.