When the first Arab explorers in their dhows sailed down through the Sea of Zanj from Arabia they discovered many small islands and, as they explored, they left few traces of their passing and must have been in awe of the absolutely unspoiled nature of the seas they sailed through.
Off the coast of what is now known as northern Mozambique, these early mariners must have taken a special interest as they could sail for 100km in relative safety, sheltered from the often stormy open Mozambique Channel by a long archipelago of sand and coral made visible by two groups of small islands some 30km off the coast.
In the 20th century these island groups (christened the Primeiras and the Segundas by the Portuguese) that lie north of the mouth of the Zambesi River, attracted a considerable amount of attention because of the wealth of valuable marine creatures that inhabited the seas around them and the detritus-rich, shallow waters that lay between them and the mainland coastline.
As a result of being so isolated, the islands still have amazing, extensive and species-rich coral reefs surrounding them but the turtles, alas, have experienced severe declines in numbers and only a handful return during the summer months to lay their eggs in the white coral sand beaches. The reason for this is simple: After the early explorers came, those with a lust for adventure and trade, and coastal indigenous African people gradually moved southwards from near the equator bringing both a fishing technology and a desire to kill and eat sea turtles. From the early 20th century the demand for tortoiseshell, the largest and finest quality being obtained from the hawksbill turtle, surged and hawksbill joined the green turtle as a valuable trade item and the great decline of sea turtles in the western Indian Ocean was well and truly launched.
It is thanks to the invaluable reproductive strategy of sea turtles as a species, that there are any surviving today. Simply put, their technique is to lay large numbers of eggs multiple times during the course of a single nesting season. Each clutch of eggs hatches synchronously after nearly two months in the sand and the bulk of the emerging hatchlings emerge after dark and are attracted to the sea by the light horizon, often assisted by the bright white line of surf breaking over the reef or onto the beach. From there the hatchlings enter hostile territory where, because of their small size, they face a vast array of enemies eager to eat them, a situation that will hardly change until they have reached adulthood many years later.
Not all that many do reach full nesting maturity, and their return to their natal beach is never synchronized so that one single cohort of hatchlings arrives back as adults. Individual returns may be 30 years apart as each hatchling may develop in a different environment as they are swept away from the nesting islands by currents and distributed throughout the southern Indian Ocean. Some lucky ones may remain in the heart of warm, food-filled currents and gyres and develop quickly whilst others may be swept into cooler waters with less available food and may take years longer to mature to the point where they feel the urge to return to their original beach to nest and continue the species. And this is the strategy that explains why small numbers of turtles still return to Fire Island when many before them have been killed and eaten or sold by fishermen.
The good news is that the islands have recently been proclaimed a protected area and the regular visits by itinerant coastal fishermen have been prohibited. What is even more encouraging is that over the last 60 years, in many parts of the world, and especially in the south-western Indian Ocean, many such nesting areas have received dedicated protection efforts from their governments and there are numerous examples of turtles returning in increasing numbers. There are almost totally restored nesting sites where turtles return in the thousands today, up from very limited numbers when protection began.
In South Africa and southern Mozambique, loggerhead turtle nesting numbers have grown five-fold, green turtles nest in large numbers in Europa Island in the southern Mozambique Channel after nearly disappearing from over-exploitation before 1923. Perhaps one of the most amazing recoveries of green turtles are those nesting on Moheli Island in the Islamic Republic of the Comores. Starting in the 1970s, one group of Comorians from Itsamia village on the coast decided that they would protect the last of ‘their’ nesting greens from poachers. They organized their own protective patrols, started their own turtle watching tours and sought donor funding to help them achieve their goals.
From a near-extinct nesting group when they started, over 5000 green turtles now nest annually on the beaches of Itsamia. A truly remarkable achievement.
The goal of the Fire Island development is to emulate these successes and see the return of large numbers of nesting turtles, both green and hawksbill. Not only will this mean the physical protection of the females but perhaps also to rescue eggs and transfer them into hatcheries if the site chosen for laying by the females is unsuitable. The beaches must be kept litter free and the danger of undesirable pollution, plastic or otherwise, must be rigorously guarded against so as not to harm turtles or the hundreds of species of animals and plants of the beautiful reefs that surround Fire Island and many of its sister islands.
There is no reason why the restoration of an astonishing biodiversity reef community and nesting home for the once persecuted turtles cannot be achieved. All help in doing so will be warmly welcomed.
Dr Hughes’ CV will make you sit up and listen. The avid hiker and flyfisherman was born in Scotland, but finished his secondary education in Estcourt and his tertiary qualifications at the then-University of Natal. Once he completed his PhD in Zoology at the Oceanographic Research Institute in Durban, Dr Hughes was: