Susan Koenig | Impact of bauxite mining on limestone ecosystems in Jamaica

The Taino didn’t need to read science to appreciate what they saw before their eyes. They saw the same features that were recorded by naturalists and others in the 1700s and 1800s – that in the interior of the island, with its “countless hills, valleys, and glades”, Jamaica supported “majestic woods, where trees attain their greatest sizes”.

Long before the chemistry of the soils was understood, even 19th-century geologists such as James Sawkins appreciated that forest trees “thrive to the greatest perfection” in the deep, enclosed depressions that formed in concert with their limestone hillsides. As in countless other tropical limestone regions, the majestic trees were cleared from the largest depressions, which were then used for agriculture because it is in these depressions that deep “red dirt” soils accumulate.

As 2022 progresses, we have seen the National Environment and Planning Agency (NEPA) issue environmental permits to Noranda Jamaica Bauxite Partners II (NJBP II) to mine for bauxite within Special Mining Lease (SML) 173, a lease that includes a part of Cockpit Country that even James Sawkins clearly recognised, but which our Government chose to exclude when designating the protected area. We also see other Special Exclusive Prospecting Licences (SEPLs) encroaching Cockpit Country on the south and west as well as blanketing central St Ann and St Elizabeth. These leases and licences once again raise questions regarding the importance not only of Cockpit Country, but of all areas where bauxitic soils remain unmined: What is already known about the ecological impacts of bauxite mining, what remains unknown, and should precaution prevail in the face of the predictable unknowns?

LEGACY OF ENVIRONMENTAL ABUSE

The removal of bauxitic soils has left a legacy of incalculable environmental abuse and degradation of the island’s ecological heritage. Incalculable because even regulators and industry proponents, such as the Jamaica Bauxite Institute (JBI), report major data gaps, meaning they do not know. During my research on the environmental impacts of bauxite mining, the Mines and Geology Division (MGD) in the Ministry of Transport and Mining (MTM) was unable to provide any maps or data files showing the locations of mined-out ore bodies. How can the public (or regulators) assess and monitor the full environmental costs of bauxite mining when we are unable to independently verify the locations of all mined-out ore bodies and haul roads that have irreversibly altered the landscape?

We know from early government reports and the JBI that from 1952 through 2021, at least 645 million metric tonnes (by dry-weight) of bauxitic soils has been extracted from Jamaica. This “dry” 645 million metric tonnes, however, means that approximately 729 million metric tonnes of “wet red dirt” has been mined out over a span of seven decades. This is because “dry-weight” means that the extracted soils were kiln-dried to retain only 13 per cent moisture. Whhen extracted, Jamaica’s bauxitic soils have a natural free-moisture content of 20-30 per cent. Drying reduces the weight of dirt to be shipped. Thus, bauxite mining removes water from the environment.

Looking further at those 729 million metric tonnes of “wet red dirt”, when saturated at 26 per cent free-moisture content, this means there is 539 million metric tonnes of solid material and 189 million metric tonnes of water. Since one tonne of water is equal to 1,000 litres of water, bauxite mining has eliminated the capacity for Jamaica to have stored in the soil 189,000,000,000 (that is 189 BILLION) litres at any moment in time. Imagine the length and width of Kingston Harbour, with water to a depth of four metres (~ 13 feet) being kept in reserve at all times for use by people, animals, and plants in periods of drought.

Simply put, bauxitic soils in Jamaica store water. We know from research in other tropical countries that forest trees extract water held in soils to depths of at least 11-18 metres. For farmers, this deeply stored water in the soils means that crops can survive and grow even when the rain doesn’t fall for weeks. In fact, this eliminates the need for artificial irrigation. When deep, moisture-holding bauxitic soils are mined out, not only do we lose that storage capacity but rain falling on the land will reach the underground limestone more rapidly. This creates the risk of more intense discharge rates at riverheads and/or temporary flooding in upland depressions.

In 1947, the framers of The Mining Act failed to appreciate the significant role of soil in the water cycle. They instead focused on the top 15 centimetres (six inches) of soil, where nutrient recycling occurs. But by the 1970s, companies such as Alcan learned from experimental research that unless the reclaimed lands were intended to be used for “growing grass in perpetuity”, successful production of other crops required at least 30 centimetres of soil (and with their caveat that fertiliser dressings also were required). In the case of corn, at least 60 centimetres was needed.

HEALTHY AND PRODUCTIVE ENVIRONMENT

But what if a landowner was growing fruit or timber trees and wanted that same capacity or opportunity after mining? What if a young member of the household or a next generation wanted to restore farmland to forest to offset CO2 greenhouse gas emissions and play a part in mitigating climate change? Or what if they simply wished to continue producing their current agriculture crops for the domestic and export markets to not be “potential impact receptors” of bauxite mining? This descriptor was used in an Environmental Impact Assessment (EIA), explaining what would happen to farmers in one area of SML-173 and to explain why this one area was “clawed-back” from NJBP II and added to the Cockpit Country Protected Area in order to protect rural livelihoods. This begs the question: Shouldn’t all current and future generations – not only Cockpit Country communities but also those in all food-producing regions of the island – be afforded this protection to have the same potential and opportunities to enjoy a healthy and productive environment?

Today, tropical karst experts understand that sustainable agriculture and forest stature is achieved because of deep, moisture-holding soils. So now we must ask ourselves how much bauxite must remain in the ground to produce what the Taino witnessed: the majestic woods where trees attain their greatest sizes in the interior of Xaymaca and where ecosystem services of wood and water flowed undamaged. With the current climate crisis and the many uncertainties of how rainfall patterns will be altered in Jamaica, attention to our water resources is now even more critical.

The RED DIRT study can be found here at https://www.jamentrust.org/.

- Susan Koenig holds a doctorate in Forestry and Environmental Studies from Yale University. She is a co-founding director and manager of Windsor Research Centre in Trelawny. Send feedback to jamaicaenvironmenttrust@gmail.com.