Crocodiles play an important role in wetland ecosystems around the world. Picture: Brendan Magaar/African News Agency(ANA)
Crocodiles play an important role in wetland ecosystems around the world. Picture: Brendan Magaar/African News Agency(ANA)

Why we need crocodiles

By Dominic Naidoo Time of article published Jun 18, 2021

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Durban - Did you know that crocodiles are vital to maintaining a healthy aquatic population? This is partly because they eat sick and old fish, allowing healthy fish to reproduce and grow without competition or the risk of contracting diseases.

This vital role they play in the ecosystem just one of the many advantages of having them in our waters.

Thursday marked World Crocodile Day, which has been celebrated annually since 2017.

The day highlights the importance of crocodiles within our ecosystems and aims to raise awareness around endangered crocodiles and alligators around the world.

Read the latest Simply Green magazine below:

Crocodiles, like their old cousins, the dinosaurs, are reptiles which appeared around 320 million years ago. They evolved from amphibians, which like crocodiles, are cold-blooded. Mammals and birds evolved from reptiles some 140 to 180 million years later.

The first clearly recognisable crocodilian fossils are about 200 million years old and it is estimated all were most likely to have lived on dry ground for a good 20 million years before they invaded the seas, lakes, and swamps, according to the International Union for the Conservation of Nature’s Crocodile Specialist Group (IUCN-SCG) .

Today, crocodiles are found in Africa, Asia, the Americas, and Australia. The IUCN-SCG recognises 24 different species grouped into three “families”, Alligatoridae, Crocodylidae and Gavialidae.

There are five naturally occurring species of crocodile in Africa with only one native to South Africa, the Nile Crocodile.

These prehistoric reptiles have undergone minimal evolutionary change and still display the same skills, habits, and physical features as they did millions of years ago.

WorldAtlas says crocodiles play an important role in wetland ecosystems around the world.

They maintain a healthy aquatic population by eating sick and old fish, allowing healthy fish to reproduce and grow without competition or the risk of contradicting diseases. Crocodiles also regulate fish populations, preventing the dominance of a single fish species.

Numerous studies have shown that by preying and consuming old and sickly fish, crocodiles increase the number of fish in water bodies and river systems. Fish that are healthy and stronger would go on to produce larger clutches of eggs and hatch healthier offspring. Their droppings serve as nutritious food for fish and crustaceans. Caimans and crocodiles in the Amazon Basin damage gill fishing nets, enabling fingerlings and smaller, younger fish to escape while allowing fishermen to catch large, mature fish.

Of the five species in Africa, West African Slender-snouted crocodile is classified as Critically Endangered with the African Dwarf crocodile classified as vulnerable to threats. Hunting by local people for meat and skins, depletion of food sources and habitat destruction have led to the steep decline in these species. The Nile Crocodile is the most common member of the species found in Africa and carries a “Least Concern” status.

Support these important creatures by visiting a local reptile conservation centre or donating to your local wildlife rescue organisation.

Like all reptiles and animals in general, crocodiles largely avoid contact with people and will only become aggressive if approached or cornered. Still, best to admire these beautiful creatures from a safe distance.

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