Case Study: The Windward Islands, Caribbean Sea

The Windward Islands, Caribbean Sea © Dr Howard Dryden

The team discusses how changes in nature are interrelated with the manifestations of climate change and argue that tackling greenhouse gas emissions is not enough.

The environmental degradation we observed is not unique to the Caribbean. While we have observed similar destruction throughout most of the developing world, the same is true for many medium- to high-income countries, but they have perhaps been better at hiding or navigating regulation breaches and illegal discharges. For example, 400,000 incidents or 3 million hours of illegal raw sewage discharged into rivers and coastal waters were reported in England in 2021.

Background Observations:

1. Our observations were undertaken just as the Caribbean Windward islands were 'opening up' to tourism in early 2022. We noted that there was little or no wastewater treatment, that most of the beaches and coastal waters were polluted, and coral reefs were stunted, bleached, and suffering from being coated in human waste, plastics of all sizes, and toxic chemical discharges from holiday resorts and industry. Plastic is transporting and spreading human pathogens, including parasites like giardia and cryptosporidium, as well as marine pathogens such as Vibrio bacteria. These are killing the corals, sea urchins and fish. It was clear that there had been a mass extinction of sea urchins this year (2021) and without sea urchins, algae covers and suffocates the coral.

2. High concentrations of herbicides and pesticides are used in the Caribbean. Many farmers take a short-term view and continue to use glycol-phosphate. It is strongly believed that income loss would be substantial and food prices would be too high for the population. Simply put by one farmer, "The more I use, the more money I make". There is no secret that many food sources on land and in the sea are now toxic and the ketone case in Martinique is well documented.

3. Partially combusted carbon from the burning of fossil fuels by the shipping industry, coal and petrochemicals is contributing to increased particle counts. From samples collected as part of our Citizen Science Sampling Project across the Equatorial Atlantic Ocean, sample analysis showed that particulates were from 20 to 1000 particles above 20microns per litre of seawater. Why does this matter? Carbon particulates carry toxic chemicals, and given the density, these are likely to be the main component of food for coral, protists, and zooplankton.

   The shipping industry burns 300million tonnes of dirty heavy oil every year with 6% of it entering the world's oceans.

   • That is 18 million tonnes of sub-micron particles dumped in the oceans every year. We counted between 100 and 1000 particles (above 20um) in every litre of water crossing the Atlantic Ocean.

   • 13 other vessels, taking 2 samples daily, confirmed the result. Leading marine biology and oceanographic institutions suggested, in advance of our Equatorial Atlantic sampling, that there would be around 20 particles per litre.

   • It is known that these particles are toxic to plankton and can affect their ability to reproduce. It is therefore not surprising that their numbers are dwindling or that coral is diseased, bleaching and crumbling, leaving coastal communities with poorer tourism offerings, depleted fishing grounds and weakened coastal defences in the face of more frequent and violent storm events.

   • While warming temperatures may contribute to bleaching events, healthy coral reefs would normally survive and recover from coral bleaching, but not if they have been stressed by disease and pollution.
4. Pollution from the Congo, Gambia and Amazon from municipal waste, agricultural run-off and deforestation has caused an explosion in the growth of pelagic Sargassum seaweed. It is estimated that each year, 20 million tonnes of this weed are growing in the Atlantic Ocean - that's more weed than plastic by weight. The Sargassum is carried by ocean currents across the Atlantic and into the Caribbean. Away from coastal waters, Sargassum uses up nutrients that would otherwise have been used by marine plankton. The net result is that marine plant growth is reduced, meaning no zooplankton for fish or whales or any other marine life.

   Once the Sargassum has used up all the phosphate, it starts sucking arsenic and heavy metals out of the ocean surface water. The weed then washes up on beaches, coral reefs or mangroves. These environments support more than 25% of all marine life in the oceans. The Sargassum decomposes to release hydrogen sulphide which forms sulphuric acid. Under these conditions, the arsenic and metals are reduced and turn into a form that dissolves back into the water. The arsenic is, therefore, all dumped directly onto the coral, beaches, and mangroves where juvenile fish are trying to survive. This is why fish have nearly all disappeared from the Caribbean and another reason for almost total destruction of the coral reefs.

   The results from the GOES citizen science project confirmed a 90% reduction in primary productivity in the Equatorial Atlantic. We are now hopeful that academic institutes will recognise the significance of our findings and quickly mobilise to confirm our results. Effectively, the Atlantic Ocean is now pretty much dead.

5. We have all been told that climate change is caused by greenhouse gas and increasing temperatures. This is not entirely true. Climate change and winds are caused by energy transfer from the oceans to the atmosphere. The warmer the ocean temperature, the more evaporation and the higher the strength of the winds. However, evaporation can also be stopped or reduced by a thin film of natural oil floating on the surface released by marine plants. Omega 3 oil, for example, is only produced by marine plants. When marine plants are present their oils contribute to reducing extremes in weather.

   The plants also produce a chemical called DMS (dimethyl sulphide) which, along with the aerosols of marine plankton, are responsible for seeding most of our cloud formation and precipitation. So irrespective of climate change, if we destroy plankton the planet will become more humid, climate change will accelerate, wind velocities will be extreme and, with no clouds, it will also become arid. Water vapour and humidity are 50% of all our greenhouse gases. We will lose the 'good' phytoplankton plants like diatoms and carbonate-based coccolithophores. These plankton especially the carbonate-based plants will all be dead in around 25 years due to ocean acidification.

   The smell of the ocean comes from coccolithophores, and they are in the air we breathe, our water and our food, but if their numbers are depleted, they will most likely be replaced by toxic dinoflagellates. Already we are seeing hazardous algae blooms (HABs) around the world which are killing people living by the ocean. This is coupled with increased levels of ciguatera disease caused by dinoflagellate-contaminated fish. Health authorities are now recommending that any fish from tropical water over 3kg in size should not be consumed (it used to be 10 kg). If the process continues it will become impossible to live by the sea, travel on the ocean or eat any marine fish.

We have two choices. We can choose to wake up, understand and address the real issue, or choose the game-over button for humanity come 2050.

This article has been provided by the courtesy of Ocean Cruising Club.