BEIRUT — Galvanized by human carbon pollution, Lebanon’s waters have been slowly but steadily heating up in recent years, threatening to wreak havoc on both the environment and society in the already embattled country, scientists told L’Orient Today.
As scientists measure higher global ocean temperatures this month, Lebanon’s fishermen witness increased numbers of invasive species that could harm the marine ecosystem.
Lebanon’s average sea surface temperature has consistently risen since scientists first began recording it monthly in 1999, oceanographer and researcher Abed El Rahman Hassoun told L’Orient Today.
Dubbed the “lung of the earth,” oceans and seas absorb the heat caused by greenhouse gasses, including carbon dioxide, released into the atmosphere mainly by human industrial activities like the burning of fossil fuels for electricity, heat and transportation.
Rising sea temperatures “will affect the concentration of oxygen [in the sea], and, in turn, the nutrients available for marine ecosystems and marine resources,” Hassoun indicated.
“We are already hearing many complaints from local fishermen that, for example, a species of fish or shrimp is now disappearing from the Lebanese waters, and that they are seeing more and more invasive species coming from the Red Sea,” the scientist added.
Invasion of alien marine species
Due to rising temperatures, the climate of the Eastern Mediterranean is starting to mimic that of the Red Sea, and is progressively being established as a suitable environment by a number of non-native species, Hassoun explained.
These invasive marine species that have entered the Levantine basin, ravaging the marine ecosystem, include “the lionfish and puffer fish, as well as small organisms like phytoplankton that might be toxic and that might generate harmful algal blooms,” he added.
Fisherman Marwan Issa, the head of the Fishermen Coop in Amchit, told L’Orient Today that he has been noticing an uptick in the population of lionfish and pufferfish, two ferocious predators, neither of which is naturally found in the Mediterranean Sea.
Since they have no natural predators in the Mediterranean Sea, these invasive species could significantly decimate the populations of the Mediterranean's native fish, which fishermen rely on commercially.
“They are consuming all baby fish, especially the pufferfish, which we have been noticing in huge quantities,” Issa said. “No matter how many we haul out [of the sea], the quantity never exceeds two or three percent of its current population in our waters.”
Issa also decried the fact that these invasive species tend to tear their fishnets and ruin other fishing equipment that have experienced severe price hikes in recent years due to Lebanon’s nearly four-year economic crisis.
Miled Fakhry, the director of Lebanon’s National Center for Marine Sciences, says that “the rising sea temperatures [in Lebanon] are creating a more favorable environment for the blooming of alien species of jellyfish,” among other non-native marine species.
Last July, swarms of non-native venomous jellyfish arriving from the Indian Ocean and the Red Sea through the Suez Canal, invaded Lebanon’s Mediterranean Sea in the north.
Some fishermen described the jellyfish numbers as “unprecedented,” but, according to Fakhry, the jellyfish numbers that invade Lebanon’s waters annually in the summer are subject to change as it depends on how the jellyfish pulse along the sea currents.
Fakhry also warned that rising sea temperatures will lead to the extinction of some marine organisms, destroy marine habitats and create a “disequilibrium” in the marine environment.
Meager funding for marine research
Fakhry echoed Hassoun’s account, saying that Lebanon has recorded a trend in rising sea temperature since 1999, but that the data is imperfect.
He said the data has yet to be published in scientific journals and Lebanon doesn’t have “continuous data” about its sea temperature due to research centers’ poor equipment. The National Center for Marine Sciences takes the temperature every month one time and tries to make a trend out of it over the years, he added.
The National Council for Scientific Research, which incorporates several research centers including the National Center for Marine Sciences, is a public institution that depends on dwindling and unreliable governmental funding, Fakhry previously told L’Orient Today.
Global record sea-surface heat sparks fears
In Lebanon, the data of the National Center of Marine Sciences has not yet shown “anomalies” when it comes to the year-to-year average sea surface temperature in April.
This unfortunately is not the case for the world’s oceans.
In early April, the average surface temperature of the oceans, excluding polar waters, reached 21.1 degrees Celsius, beating the annual record of 21 degrees Celsius set in March 2016, according to data from the United States NOAA observatory that goes back to 1982.
Although sea temperatures began to drop at the end of the month worldwide, they have remained above seasonal records for the past six weeks. Fears that the warming El Nino weather phenomenon could load even more heat into the climate system have started to rise.
"During El Nino years, the deep ocean releases heat to the surface and warms the atmosphere," said Sallee, a UN climate researcher.
When you take into account the background rise in sea surface temperatures, "2023 doesn't look too out of place relative to other El Nino years," climate scientist David Ho, a professor at the University of Hawaii at Manoa, said on Twitter.
But scientists have cautioned that the real concern is the temperature rise over decades and beyond.
"It's the long-term sea surface temperature trend that should alarm us," he added.
The most immediate consequence of the surge in ocean temperatures is more marine heatwaves, which Ho said "act like underwater fires" with the potential to irreversibly degrade thousands of square kilometers of underwater forest, for example of kelp or corals.
Scientists expect that excess heat stored in the world's waters will eventually return to the Earth system and contribute to more global warming.