New research out of KFUPM is showing that temperatures in the Arabian Gulf are rising higher, at faster rates, and for longer stretches than the fragile marine life inhabiting its lagoons are capable of surviving.

“Summer temperatures are now exceeding the upper thermal limits of the creatures’ survivability thresholds,” said Professor Michael Kaminski, lead researcher from the College of Petroleum Engineering and Geoscience. “They can thrive in the winter, but summer temperatures will kill them.”

These findings were published in August 2024 in the journal Palaeogeography, Palaeoclimatology, Paleoecology in an article titled, “Survival of biocalcifying shallow-marine benthic organisms in the coastal areas of the Arabian Gulf under conditions of global warming: Is there a limit to their resistance?”

Small creatures ranging from microscopic to snails the size of a child’s fingernail become trapped in beachside lagoons along the Arabian Gulf of Saudi Arabia when a combination of high tide and strong winds blow sea water up past the normal high tide lines. Once the tide and winds subside, the animals remain in standing seawater that heats up as the sun beats down. When the ground and/or water temperature rises above 48 Celsius, the sea snails die.

Now, this has always happened to the sea creatures living the Arabian Gulf, says Prof. Kaminski. What’s different today, he said, is that the rate of daily high temperature is increasing in frequency, the daily temperatures are getting hotter, and the season of hot days is stretching farther into the fall than previous years.

“Is it becoming too warm for them? Yes,” he said, adding, “Is their growing season too short? We don’t know.”

The sea snails being studied range from Mud Creeper, Horn Shells, Olive Shells, Cone Shells, and Ark Shells to name a few.

To establish at what temperature the mollusks will die, Sinatrya Diko Prayudi, one of six researchers on the study, took the snails to the lab and put them under a series of heat stress tests. A snail’s natural defense mechanism when trapped in high heat is to enter a heat coma. Once the temperature drops, they return to normal. However, it was found in the lab setting that once the heat exceeds 47 Celsius, the snails do not come out of the heat coma, and they die.

The mud creepers, for example, are known in the Gulf Region to be somewhat more tolerant of heat than other parts in the world. Most marine animals will tolerate up to 46 Celsius, said Prof. Kaminski, but our snails can tolerate a little higher, at 47 Celsius.

But once the heat exceeds their limit, the snails die. And in the lagoons of Saudi Arabia’s Eastern Province, in some places the ground temperatures are heating up to more than 60 Celsius, and the season of heat is lasting longer each summer, stretching into mid-to-late October.

The survival of these small, fragile mollusks matters in terms of food security, explained Prof. Kaminski.

“These creatures are considered a key species because they form the base of the food chain from which other animals depend on,” he said. “With Climate Change being a factor, we have to ask what effect will that have on the food chain.”

“Climate Change models have already predicted there will be the presence of a summer kill zone for these intertidal organisms,” said Kaminski. “These models suggested that by 2050, portions of the Arabian Gulf may become too hot to support animal life.

“At our studied localities on the western coast of the Arabian Gulf, these predictions have already become a fact.”

Data collection by Prof. Kaminski and his colleagues continues in the lagoons of Half Moon Bay along the western shores of the Arabian Gulf so that humanity can understand what it means that these small marine animals are experiencing a mass extinction event.

“We need to understand the resilience of these marine animals because birds and other animals depend on them,” said Prof. Kaminski.