What extreme heat means for the Mediterranean Sea

Subject: Geography

Section: Places in news

What are the solutions to heat stress:

Weeks of scorching heat have tormented the Mediterranean.
Wildfires blazed across nine nations, spanning Algeria to Greece.
Beyond threatening land and ecosystems, these surging temperatures also imperil marine life. By July’s end, the sea surface shattered records at 28.7°C (83.66°F), exceeding 30°C in the east. With August’s heat looming, further escalation is likely.

Some facts about the Mediterranean Sea:

It is an intercontinental sea that is bordered by the continent of Europe in the north, by Asia in the east, and by Africa in the south.
In the west, the Mediterranean Sea is connected to the Atlantic Ocean via the narrow Strait of Gibraltar.
In the extreme northeast, it is connected to the Black Sea via the Dardanelles Strait, the Sea of Marmara, and the Bosporus Strait.
The Mediterranean Sea is also connected to the Red Sea via the Suez Canal in the southeast.
22 countries and one territory (Gibraltar – a British Overseas Territory) have coasts on the Mediterranean Sea.
The European Countries are Spain, France, Italy, Malta, Monaco, Slovenia, Croatia, Bosnia and Herzegovina, Montenegro, Albania, and Greece.
The West Asian (Middle Eastern) countries bordering the Mediterranean Sea are Turkey, Syria, Lebanon, Israel, the Palestine Gaza Strip and the divided island of Cyprus.
Five North African nations have coasts on the Mediterranean Sea: Morocco, Algeria, Tunisia, Libya and Egypt.
The Mediterranean Sea offers a staggering 46,000 km (28,600 mi) long coastline and includes 15 marginal seas, such as the Balearic Sea, the Adriatic Sea, the Levantine Sea and the Ionian Sea.

What is Marine Heat Waves:

A marine heatwave is defined as when seawater temperatures exceed a seasonally-varying threshold (usually the 90th percentile) for at least 5 consecutive days. Successive heatwaves with gaps of 2 days or less are considered part of the same event.
Due to increased greenhouse gas emissions, extended periods of extreme warming in seas and oceans have increased in frequency by 50% in the past 10 years and are becoming more severe.

What are the causes of Marine Heat Waves:

The main cause of marine heat waves is the increase in ocean temperature due to the absorption of greenhouse gasses from the atmosphere, which leads to global warming.
Natural climate variability can also contribute to marine heat waves, including changes in ocean currents, weather patterns, and atmospheric circulation.
El Niño-Southern Oscillation (ENSO) and the Indian Ocean Dipole (IOD) can contribute to the occurrence of marine heat waves.
The other common drivers of marine heatwaves include ocean currents which can build up areas of warm water and air-sea heat flux, or warming through the ocean surface from the atmosphere.
Winds can enhance or suppress the warming in a marine heatwave, and climate modes like El Niño can change the likelihood of events occurring in certain regions.

What species and ecosystems are worst hit by marine heat waves:

Rising water temperatures prove most detrimental to benthic species residing at the ocean, lake, or river bottoms. These organisms, such as corals, mussels, and seagrasses, are unable to migrate and are critical for ecosystem health.
Benthic creatures play roles in water filtration, food chains, and habitat provision. Notably, the Neptune grass is severely impacted, hindering its role as a carbon sink.

What is the Impacts of Marine Heatwaves:

Coral bleaching: Marine heatwaves can lead to coral bleaching, which is the loss of photosynthetic algae, called zooxanthellae, from the coral. This can ultimately lead to the death of coral.
Ocean acidification: Marine heatwaves can exacerbate ocean acidification, which is the increase in acidity of seawater due to the absorption of carbon dioxide from the atmosphere. This can have negative impacts on marine organisms that build shells or skeletons out of calcium carbonate, such as corals and some types of plankton.
Harmful algal blooms: Marine heatwaves can cause harmful algal blooms, which can produce toxins that are harmful to humans and marine life.
Ocean circulation: Marine heatwaves can also affect ocean circulation by altering the temperature and density of ocean water, which can have implications for ocean currents and the transport of nutrients and heat around the globe.
Marine biodiversity: Marine heatwaves can affect the composition and abundance of marine species, leading to changes in marine biodiversity.