Thousands of small fish carcasses have washed up lifeless on the shores of Kuwait, Oman, Saudi Arabia and other Gulf States since early May. This phenomenon has spawned a plethora of crazy conspiracy theories that have gained traction on social media, including one that Iran is trying to poison its neighbours.
In Kuwait, more than 60 tonnes of dead fish have been cleaned up since the beginning of the month.
Kuwaiti authorities made vain attempts to reassure the population. The Minister of Communication, Mohammad al-Abdallah, said on May 1, 2017 that no toxic substances were discovered during tests carried out on the the dead fish.
However, few people seemed to be reassured by these declarations. Fishermen and consumers alike panicked. In a video posted on May 5, 2017, a desperate fisherman accuses “mafias” of wanting to destroy the fishing industry. Whilst on camera, he also seizes the opportunity to invite viewers to contact him if they want to buy some of the fish he has in a plastic basin at his feet.
Another video, also posted on May 5, shows how deserted the fish market in Kuwait City is, even during what is normally the market’s busiest time of day.
Huge numbers of dead fish have also been washing up on the beaches of Saudi Arabia and Oman. As political and religious tensions between the Sunni Gulf States and their Shiite neighbour, Iran, tend to run high, social media was soon swamped with conspiracy theories blaming Iran for the mysterious fish deaths.
If the man who filmed this video (below) is to be believed, all these dead fish washed up on a beach in the Ahsa region in Saudi Arabia perished because the Iranians dumped chemical waste in the sea.
To find out more about what could be causing the deaths of these fish, the FRANCE 24 Observers team contacted Aws Alghunaim, a researcher at the Kuwait Institute for Scientific Research. He explained that this was the result of a natural phenomenon that scientists call a "red tide".
"Red tides happen all over the world"
Red tides are caused by the presence of algal blooms called phytoplanktons. When there is an unusually high concentration of these algal blooms, they give the sea a reddish colour, hence the name. Sometimes, the water takes on a brownish or yellowish tinge.
Red tides occur when this algal bloom accumulates rapidly, which often happens when there is an overabundance of nutrients. The algae feeds off nutrients brought from the earth to coastal waters.
When wastewater is dumped into the sea, it leads to an excess of nutrients in the seawater, which, in turn, causes excessive growth of algal blooms.
Phytoplanktons have an incredibly short lifespan: they only live for a few days. When they die, they sink towards the bottom of the ocean, where they are quickly eaten by bacteria. To do this, the bacteria consume huge amounts of oxygen from the water. The lack of oxygen in the water causes the death of entire schools of fish.
“Lots of sun and a calm sea create conditions perfect for algae to bloom”
However, an overabundance of nutrients in the water isn’t the only cause of red tides. This phenomenon only occurs when several different factors come together. Lots of sun and a calm sea create conditions perfect for algae to bloom, which is the kind of weather we've been having since late April. Usually, red tides only tend to happen in July or August.
Some phytoplanktons also contain substances that are toxic for fish. However, in this case, we didn’t find any trace of toxic substances in the samples that we analysed in our labs. However, we did discover that certain phytoplanktons contain small spikes that inflicted fatal injuries on the gills of some of the fish.
I laugh when I watch the videos that have been circulating online that broadcast conspiracy theories that Iran is responsible for the deaths of these fish because it dumped nuclear and other forms of toxic waste into the sea. Scientists are very familiar with red tides. They occur all over the world, from Australia to the Gulf of Mexico.
This has been happening in Kuwait, Oman and Saudi Arabia since the 1990s. But scientists still struggle to determine exactly what role human activity and pollution play in this phenomenon.