(MENAFN– The Conversation)
In the popular imagination, estuaries don’t have the prestige or the romanticism of their two constituent parts: the rivers that feed them with freshwater from one side, the ocean that injects salty water from the other.
But as the go-between between river and ocean, estuaries nonetheless deserve more credit. Their dull, brackish appearance belies the abundance of life that they hold. Considered as, pound for pound, among the most productive environments on earth, they are said to produce more organic matter than forests or grasslands of the same size. With little of the violent movements of water associated with oceans and rivers, they hold few predators. As a result, they shelter and offer respite to countless species of birds, fish and mammals.
They are economic powerhouses, too. They’ve been described as“super” ecosystems. And, in the case of South Africa, although they comprise less than 2% of the country’s territory, they’re estimated to contribute R4.2 billion per annum (around US$4.2 million) to the country’s economy.
A 2020 report pointed out that as many as 80 species caught in linefishery rely on South Africa’s nearly 300 estuaries for their feeding, refuge and reproduction.
In addition, estuaries are valued for their capacity as“blue carbon” sinks . This refers to the ability of coastal mangrove forests, salt marshes and seagrasses to store carbon dioxide and other greenhouse gases from the atmosphere, mitigating the effects of climate change.
However, estuaries are vastly understudied which means that we know little of the harm that we as humans are doing to them.
To help make up for this gap in our knowledge about the nearly 300 estuaries in South Africa, we have increasingly begun to look at microplastic pollution in a selection of these estuaries. Our work is in collaboration with colleagues from University of KwaZulu Natal.
Our findings in a recent study show that…