Monitoring saltwater intrusion

Already creating havoc across the world, continuously rising sea levels owing to climate change are projected to expand coastal flooding over the next two decades, negatively affecting human and economic development. Despite this and other warnings emanating from recent data produced by the United Nations Development Programme in collaboration with Climate Impact Lab, there is no apparent shift in the trajectory of global human action that might allow this risk to abate or even slow.

While the data and its supporting report, published in November last year just ahead of the United Nations Climate Conference, concentrated on highly populated coastal cities and the likely devastation to homes and infrastructure, the effect on agricultural land should be of equal and perhaps even greater concern. In addition, the concomitant changes to ecosystems, which can sometimes be less immediately perceptible, but just as destructive, must also be seriously considered.

The intrusion of saltwater on agricultural land, owing not only to coastal flooding from rising sea levels, but from hurricanes which have shown an increase in number and violence, particularly in recent years, is a growing threat to global food security. This salinisation, which mostly occurs as a result of the impact of ocean activity, does not just affect the land, but rivers and other freshwater sources, changing their makeup over time and creating a domino effect of ecological problems.

This is not a predicament that has popped up suddenly, nor can a single coastal flood or hurricane have the long-reaching effects that are becoming increasingly evident. In fact, nature can and has been correcting saltwater intrusion on land. Rainfall washes it away or dilutes it enough so that it does not appear to be an issue. However, over time, and given the escalation in flooding and storms owing to global warming, there have been changes to soil health.

In the long term, this affects the soil’s permeability, causing loss of aeration and the ability of the soil to hold and filter nutrients. This manifests in gradually lower levels of productivity. More often than not, this does not rebound, leading to other complications including food insecurity; the proverbial catch-22.

All of this may seem to have nothing to do with the price of bread in Guyana, which will no doubt continue to preoccupy the average Joe and Jane on a daily basis, Monday’s trillion-dollar budget notwithstanding. That is far from correct.

Lest we forget, Guyana’s coast is some six feet (2 metres) below sea level at high tide. Highly fertile, the coastal plain is where much of the rice and cash crops the country currently produces are grown, along with sugar. Livestock farming is also heavily practised here.

Just last month, rice farmers in Mahaicony were bemoaning the intrusion of saltwater in the irrigation system that was threatening their crops. They told this newspaper that the issue had been ongoing since November. They had noted that this same problem had besieged them some years ago.

Usually, the farmers obtain the water to irrigate their rice fields from the Mahaicony River. However, they said, attempts to do this had introduced saltwater into the irrigation system, an indication that there was high salinity in the river. The farmers believed this was as a result of the prolonged dry season, which meant the water in the river was lower than usual. What was not clear was whether the salinity was merely owing to recent tidal action, or if it was an ongoing issue. The Ministry of Agriculture had moved to assist the farmers by providing fresh water for irrigation.

However, there was no indication as to whether the bigger picture was being addressed – salinity in the Mahaicony River, as well as its tributaries and other linked waterways. The point is that as a major resource in the area, the rivers are not just used by rice farmers. Undoubtedly they are also used by dairy and cash crop farmers as well as those with small holdings and perhaps even residents with

kitchen gardens. If, as it appears, there is not constant monitoring for salinity, who knows just how far the saltwater intrusion could have spread? Surely this is not an issue that farmers should have to inform the authorities about. Clearly it should be the other way around; and if we’re really serious about maintaining coastal agriculture, systems must be put in place that would address this quickly before crop loss occurs.

Furthermore, as mentioned above, there are other ecological ramifications that have to be considered. Several immediately spring to mind, including the effects on fish and other aquatic creatures that live in these rivers and the wildlife that use them as watering sources, as well as the natural native vegetation. These may appear to be minor deviations in the scheme of larger things, like rice production for instance. However, it has been well documented that every naturally occurring plant, tree and creature has a definitive role in an area’s ecological system. It is to our detriment that we constantly refuse to acknowledge this, which sadly, is a universal problem driven by ignorance and/or greed; it is difficult at times to say which is worse.