When Nutrients Become Pollution
Growing up in a Caribbean household one will often hear the phrase ‘too much of a good thing, is a bad thing.’ Children have also been encouraged to eat things that may taste particularly bad, with the promise that it is good for them. As we gets older, we find ourselves examining nutrition labels and slowly we come to the realisation that our parents were right! So now when one hears the word ‘nutrient’, surely, you may be tempted to think, we can’t have too much of it, not so?
The term Nutrient typically refers to a substance or ingredient that promotes growth, provides energy, and maintains life. Humans need it, so do plants and animals. Even the environment needs nutrients to maintain its cycles and its ecosystems. The key, here is a balance or equilibrium. When nutrients enter the environment faster than they can be fully utilised, they become pollutants. Nutrient pollution leads to a number of negative impacts that can occur vast distances away from where it originated; each impact snowballing to a number of formidable challenges that makes it difficult to regain the required environmental balance. It seems the old adage is infallible!
The nutrients of interest are nitrogen and phosphorus, which are naturally present in soil and water. Nitrogen is also present in the atmosphere as a component of the air we breathe. However, nutrient pollution occurs when surplus nitrogen and phosphorus enter bodies of water such as rivers and lakes, increasing the content to such extreme levels that it severely affects water quality. The sustained over-abundance of these nutrients leads the unsustainable growth of aquatic plant life, particularly algae. When this proliferation of algae eventually dies, the process of decomposition consumes almost completely any oxygen dissolved in the water. This leaves insufficient oxygen to support the lives of fish and other aquatic life. The result? A severely compromised and damaged ecosystem.
Seemingly simple, algae perform many functions and are a part of a delicate marine ecosystem that must remain in balance in order to sustain marine life. Nutrients act like fertilizer for aquatic plants which accelerates their growth at an abnormal rate, which is harmful for the aquatic life.
So, where does the excess of nutrients come from? Three words; indiscriminate human activity! One of the main causes of nutrient pollution is synthetic agricultural fertilizers, which have a high nitrogen and phosphorus content. The overuse of fertilizers coupled with the low absorption of those nutrients by crops, followed by heavy rainfall is the simple sequence of events that leads to excess nitrogen and phosphorus compounds entering nearby waterways. When used in home gardens or lawns, excess fertilizer carried away by rainfall as runoff into drains and rivers, eventually finds its way to our aquifers, catchment areas, and oceans.
Additional sources of nutrient pollution are organic fertilizers such as manure, untreated sewage from domestic and/or animal livestock, the industrial discharge of chemical effluents and domestic wastewater that is soaps and detergents. It is a long-standing global issue negatively affecting regional marine ecosystems and human health.
As much as 70% of the Caribbean population live in or nearby coastal areas. Coastal waters surrounding islands and by extension, the Caribbean Sea, offer many economic opportunities such as tourism, shipping, fisheries and aquaculture. The World Bank has in 2016 estimated regional revenues from these activities to be well over US $400 billion. However, nutrient pollution continues to degrade the water quality and often directly impacts the economic activity that occurs on beaches, within and around coastal areas and in sensitive marine ecosystems.
With the need to improve and protect our marine habitat and preserve human health at the core, the United Nations Environment Programme (UNEP) in 1983 spearheaded The Convention for the Protection and Development of the Marine Environment of the Wider Caribbean Region (WCR). The Cartagena Convention, as it is commonly referred to, is a regional legal agreement for the protection of the Caribbean Sea by United Nation Member States, including Trinidad and Tobago. The Convention is supported by three technical agreements or Protocols on Oil Spills, Specially Protected Areas and Wildlife (SPAW) and Land Based Sources of Marine Pollution (LBS).
The LBS Protocol was adopted in 1999 and specifically attempts to mitigate the effects of nutrient pollution across the region by identifying sources of contamination and establishing standards for reduction, control and ultimately prevention. In addition, it encompasses a holistic approach requiring countries that are signatories to the Protocol (contracting parties) to develop plans at a national level to help prevent and reduce nutrient pollution, as well as stage concurrent monitoring programmes for water quality. More importantly, contracting parties are encouraged to build their institutional and policy framework capacity to strengthen regional implementation capabilities.
One can appreciate the complexity of the issue and the probable solution – a harmonised multinational and multilevel approach is required. This support comes in the form of Regional Activity Centres (RAC). These are organisations designated to aid contracting parties with technical support to coordinate and execute activities toward the implementation of the Cartagena Convention Protocols. The Institute of Marine Affairs (IMA) serves as the LBS Protocol designate for contracting parties of the English-Speaking Caribbean. The IMA has a strong history of marine research and water quality monitoring and is well poised to serve as a Regional Activity Centre.
UNEP, the Regional Activity Centres, contracting parties and civil society must work together to fight nutrient pollution in our region. Collaboration is a key focus of the Regional Nutrient Reduction Strategy recently developed by UNEP and the RACs. The Regional Nutrient Reduction Strategy together with its attending Action Plan is geared towards building an institutional and policy framework to improve the capacity of contracting parties to develop initiatives to mitigate nutrient pollution and so promote and sustain economic activity. Though nutrient pollution poses an ongoing threat with complicated challenges, the path towards a better and balanced environment begins with cooperation.
By: Dr. Maurice Narcis, Nutrient Chemist – Institute of Marine Affairs