Sea turtles have been swimming in the world’s oceans and nesting on its seashores for over 120 million years. They even survived mass extinction occasions, together with the one which noticed the tip of the big dinosaurs.
All through human historical past sea turtles have performed key roles within the tradition and eating regimen of coastal populations worldwide. However, on fashionable occasions, over-exploitation of sea turtle meat, eggs, cartilage, oil, and physique components, triggered inhabitants’ declines and even native extinctions. Additionally, they face threats from plastic ingestion and local weather change.
Among the many seven species of sea turtles, the inexperienced turtle was traditionally essentially the most exploited for human consumption. Inexperienced turtles are a key aspect of West Africa’s biodiversity heritage and contribute to the well-being of coastal marine ecosystems within the area. However defending them is troublesome, partly as a result they carry out a number of the longest migrations recognized within the animal kingdom.
These grand actions pose a serious conservation problem: how can we defend animals that cross worldwide borders and may subsequently expertise various ranges of safety and human-caused threats?
We performed analysis across the small island of Poilão off the coast of Guinea-Bissau. The island is a part of the Bijagós archipelago which hosts one of many largest inexperienced turtle populations on this planet. The core nesting website for these inhabitants is Poilão island a place around 25,000 turtles make their nests yearly.
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In our current research, we glued monitoring gadgets to the shells of inexperienced turtles to check their actions. These gadgets transmitted their places to orbiting satellites, permitting us to know the place they’re in close to real-time.
We used the turtles’ positions to map the marine areas they occupy and estimate how a lot of time they spent inside marine protected areas.
We discovered that the inexperienced turtles from Poilão join no less than 5 West African nations. Some turtles remained year-round within the waters of Guinea-Bissau or close by in Guinea, to the south. Others travelled some 400 km north to feed in Senegal and The Gambia, and even so far as 1000 km northwards to the Bay of Arguin, in Mauritania.
Usifo Omozokpea / Frontiers in marine science
We concluded from our findings that assembly the problem of defending the ocean turtles requires worldwide cooperation for conservation coupled with an understanding of the geographic connectivity that they create.
The life-cycle of inexperienced turtles
When newly hatched inexperienced turtles emerge from the nest, they rapidly crawl to the ocean and shortly disappear from sight.
They spend the primary three to 5 years within the huge open ocean,
after which they strategy the coast to settle in areas wealthy in meals.
For an inexperienced turtle, beds of seagrass and macroalgae are the everyday habitats they search for nourishment.
Feminine inexperienced turtles solely attain maturity at about 20 years previous, at which level they return to put their eggs on the identical sandy seaside the place they emerged as hatchlings all these years in the past.
After breeding, they return to their feeding grounds and take a lot of wanted breaks from travelling, mating, making and laying eggs, which often lasts about three years.
The seaside at Poilão is patrolled by conservation groups throughout the peak of the nesting season (August to November), granting safety to the turtles that come ashore to nest. However, turtles don’t keep lengthy on the seaside. Within two hours they laid their eggs and returned to the ocean.
All through the course of a breeding season, females lay between three and 6 clutches of eggs, at 12-day intervals, after which they migrate to their feeding grounds.
As inexperienced turtles are recognized to emigrate generally 1000’s kilometres between nesting and feeding areas, figuring out their whereabouts is important to assess what threats they could face alongside the way in which. For instance, if turtles had been closely captured for his or her meat at faraway feeding areas, the efforts in place on the nesting seashores of Poilão could be fruitless.
Learning the actions of turtles from the Bijagós Archipelago was subsequently mandatory to grasp what degree of safety the inhabitants have whereas at sea.
Revelations from satellite tv for pc monitoring
The analysis was performed in partnership with biodiversity managers from Guinea-Bissau, Senegal and Mauritania, and gives a scientific foundation for decision-making on efficient conservation measures.
Primarily based on the actions of the turtles, we had been capable of presenting suggestions for conservation managers on how they might enhance the safety of necessary websites.
For instance, we present for the primary time that many of the coastal waters of the Bolama-Bijagós Biosphere Reserve in Guinea-Bissau are used as feeding grounds by these inhabitants. This can be a sturdy argument for implementing fishing rules on this reserve to scale back the danger of turtles being captured in fishing gear.
Miguel Varela
Our findings additionally present that the Regional Community of Marine Protected Areas of West Africa encompasses many of the habitats utilized by these necessary inhabitants. Turtles spent over 90% of their time contained in the boundaries of the realm throughout breeding, and 78% of their time when foraging.
Nevertheless, we additionally recognized places, significantly throughout the migration, the place safety could possibly be improved.
Our findings even have relevance for native communities within the area. For the Bijagós folks, it’s a matter of satisfaction that inexperienced turtles journey from so many alternative locations to nest on their pristine seashores. Likewise, the Imraguen folks, the only residents of the Banc d’Arguin Nationwide Park, take satisfaction in sustaining productive waters with huge seagrass beds, the place inexperienced turtles can flourish.
Moreover, wholesome sea turtle populations can promote eco-tourism by way of turtle watching actions, suggesting that the profitable conservation of these globally necessary inhabitants could also be economically helpful to folks throughout the area.
