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Unlock This CourseWelcome back to our leatherback turtle journey! In Part 1, we explored how these amazing creatures begin life on beaches. Now we'll dive into the incredible ocean adventures that follow. Adult leatherbacks are some of nature's greatest travellers, crossing entire ocean basins in search of food and mates.
Imagine swimming from the UK to Canada - that's the kind of distance leatherbacks cover regularly! These ocean giants can weigh up to 900kg and travel over 10,000 miles in a single year. Their migrations are amongst the longest of any marine animal.
Key Definitions:
Leatherbacks possess incredible navigation abilities. They use Earth's magnetic field like a built-in GPS system, detecting tiny changes in magnetic intensity to find their way across vast oceans. Young turtles imprint on their birth beach's unique magnetic signature, helping them return decades later to nest.
Adult leatherbacks undertake some of the most impressive migrations in the animal kingdom. These journeys aren't random wandering - they're carefully planned expeditions following food sources and ocean currents.
In the Atlantic, leatherbacks follow a figure-of-eight pattern. They nest on beaches in places like Costa Rica, then swim north following the Gulf Stream current. Some travel as far as Nova Scotia in Canada, covering over 6,000 miles. The warm Gulf Stream acts like an oceanic motorway, carrying both turtles and their jellyfish prey northward.
Major nesting sites include Costa Rica, Trinidad, French Guiana and Florida. Females return to these beaches every 2-3 years to lay eggs.
Rich feeding areas off Canada, Ireland and the UK where cold waters create jellyfish blooms during summer months.
Warmer waters near the Caribbean and West Africa where turtles spend winter months when northern waters become too cold.
Scientists have attached satellite transmitters to leatherbacks, revealing incredible journeys. One turtle named "Yawkey" was tracked swimming 12,774 miles from a nesting beach in Costa Rica to feeding grounds off Nova Scotia and back - equivalent to swimming halfway around the world! The data showed she spent 647 days at sea, diving up to 1,200 metres deep in search of jellyfish.
Once leatherbacks leave coastal waters, they become true ocean nomads. The open ocean might seem empty, but it's full of challenges and opportunities for these remarkable reptiles.
Leatherbacks are jellyfish specialists, consuming up to 200kg of jellyfish daily - that's equivalent to eating about 400 large pizzas! Their throats are lined with backward-pointing spines that prevent slippery jellyfish from escaping. They particularly love lion's mane jellyfish, which can have tentacles over 30 metres long.
Leatherbacks are ambush predators, using their excellent eyesight to spot jellyfish from below. They approach slowly, then use powerful suction to draw prey into their mouths. Their flexible necks allow them to strike quickly at moving targets.
Unlike other sea turtles, leatherbacks can survive in surprisingly cold water. They're the only reptiles that can maintain their body temperature above the surrounding water - a ability called gigantothermy.
Their secret weapons include:
Leatherbacks have a sophisticated heating system in their flippers. Warm blood flowing out to the flippers passes close to cold blood returning to the heart. This heat exchange system, called counter-current flow, prevents heat loss and keeps their core body temperature 8°C warmer than the surrounding water - even in near-freezing conditions!
Life in the open ocean is dangerous for leatherbacks. These ancient mariners face both natural predators and human-created hazards during their epic journeys.
Young leatherbacks face predation from seabirds, large fish and sharks. Adults are generally too large for most predators, though killer whales and large sharks occasionally attack them. However, the biggest natural challenge is finding enough food in the vast ocean.
Unfortunately, human activities create serious dangers for migrating leatherbacks:
Plastic bags look remarkably similar to jellyfish underwater. Turtles often mistake them for food, leading to internal blockages and death.
Leatherbacks can become entangled in fishing nets and lines, or accidentally caught by fishing boats targeting other species.
Large vessels can strike turtles at the surface, causing serious injuries or death, especially in busy shipping lanes.
Climate change is altering ocean conditions in ways that affect leatherback migrations. Rising sea temperatures are shifting the distribution of jellyfish, forcing turtles to travel further to find food.
Warmer waters are pushing jellyfish populations towards the poles, meaning leatherbacks must swim further north to reach their feeding grounds. This increases energy costs and may affect their ability to return to nesting beaches.
Ocean acidification, caused by increased CO₂ absorption, is also affecting jellyfish populations and the entire marine food web that leatherbacks depend upon.
Scientists studying leatherbacks off the coast of Nova Scotia have noticed changes in arrival times over the past 30 years. Turtles are arriving earlier in the year as waters warm sooner, but jellyfish blooms are also shifting, sometimes creating a mismatch between predator and prey timing.
Despite the challenges, there are encouraging conservation efforts helping protect leatherback migration routes and feeding areas.
Multiple countries now work together to protect leatherback migration corridors. Fishing regulations in key areas reduce accidental captures, whilst shipping lanes have been adjusted to avoid important turtle habitats.
Satellite tracking data helps identify critical areas that need protection, leading to the establishment of marine protected areas along migration routes.
The Inter-American Convention for the Protection and Conservation of Sea Turtles brings together 16 countries to coordinate leatherback protection efforts across their entire range.
Understanding leatherback migration helps us appreciate their complete life cycle. From tiny hatchlings racing to the sea, through decades of ocean wandering, to mature adults returning to nest - each stage is perfectly adapted to ocean life.
These incredible journeys connect distant ecosystems and demonstrate how marine conservation requires international cooperation. Protecting leatherbacks means protecting entire ocean systems that benefit countless other species.
The leatherback's story reminds us that our oceans are interconnected highways where ancient mariners continue their timeless journeys - if we give them the chance to survive and thrive.