Blue Planet II

Starfish, such as the common starfish, are quick to respond to the arrival of spring sunshine in Bergen, Norway, sensing changes in the water with the tips of its tube feet. They race to the highest point among the sea floor to spawn. This annual event triggers a feeding frenzy among various marine creatures, such as sea cucumbers and sea pens, who compete to claim their share of the food source.

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In the spring, sea cucumbers, such as Psolus phantapus, emerge in the cold waters off Bergen, Norway, with only their mouths exposed to take advantage of spawning starfish. They actively collect as many starfish eggs as they can, using all ten of their arms for efficient collection. This annual banquet is a crucial opportunity for sea cucumbers to feed.

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The orange-footed sea cucumber is another species that opportunistically feeds on the eggs of spawning starfish each spring in the waters off Bergen, Norway.

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In the spring, sea pens take advantage of the abundance of starfish eggs brought about by the seasonal changes. They rise up from the sea floor to claim their share of this annual feast, competing with other marine creatures such as sea cucumbers.

The common octopus is an adept ambush hunter that patiently waits for prey, such as crabs. It shares its habitat in the rich kelp forests off the coast of South Africa with various predators, including fur seals, pyjama sharks, and other sharks that feed on octopuses if they can locate them. The octopus displays remarkable survival skills, such as slipping its tentacles into a shark's gills to prevent it from breathing and forcing it to let go. Additionally, it employs a unique and extraordinary tactic of camouflaging itself with shells, hiding in plain sight and confusing a prowling pyjama shark.

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A Cape rock crab finds itself as the unsuspecting prey for a common octopus, an ambush hunter in the kelp forests of South Africa.

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Cape fur seals are one of the many predators in the waters off South Africa. These seals are known to prey on common octopuses.

One of the many predators of the common octopus in the nutrient-rich Cape waters is the broadnose sevengill shark.

Predatory pyjama sharks share the Cape waters with other marine creatures such as fur seals, other sharks, and octopuses, on which they prey. These fish are better suited than the larger sharks in their habitat because their small size allows them to get deep into crevices where octopuses may be hiding. In a never-before-recorded behaviour, a common octopus is observed using a protective armor of shells to hide in plain sight from a hunting pyjama shark.

The Garibaldi fish is a diligent farmer in California's kelp forests, tending to its patch of seaweed and feeding on the tiny creatures within. This hardworking fish faces constant challenges, such as removing snails and other grazers that threaten its algae. One of its most formidable pests is the sea urchin, which can devour all the algae on a rock. The Garibaldi fish must also hide from nocturnal predators like the Pacific electric ray, leaving its farm vulnerable to urchin attacks during the night.

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The Crowned sea urchin is a persistent and troublesome pest for the Garibaldi fish, as it feeds on algae and can strip rocks clean of vegetation. Its needle-sharp spines make the urchin difficult to remove. The swarming behavior of sea urchins can be disastrous not only for the Garibaldi but also for the entire kelp forest ecosystem.

The Pacific electric ray, also known as the torpedo ray, emerges is one of the nocturnal hunters of the Garibaldi fish. It can deliver a powerful 45-volt electric shock to stun its prey.

Urchins, such as the purple sea urchin, are a plague on kelp forests along the Pacific Coast of North America. Amassing in great numbers, they cut through kelp fronds, leaving vast barren areas in their wake. Sea otters play a crucial role in controlling the urchin population.

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Urchins, such as the red sea urchin, are a plague on kelp forests along the Pacific Coast of North America. Amassing in great numbers, they cut through kelp fronds, leaving vast barren areas in their wake. Sea otters play a crucial role in controlling the urchin population.

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Sea otters play a crucial role in maintaining the balance of the Pacific Coast's kelp forests by feeding on sea urchins, which can otherwise devastate these ecosystems. Unlike other otters, sea otters spend most of their lives in water and have a voracious appetite, consuming up to 50% of their body weight daily in shellfish, including urchins. Historically, sea otters were hunted to near extinction for their fur, leading to a decline in kelp forests. However, with current protective measures in place, sea otter populations are gradually recovering, resulting in the resurgence of kelp forests and the return of large gatherings of sea otters, groups of which now gather in huge rafts on the water. Mother otters spend hours grooming their pups' fur to make it buoyant, since newborn pups are not yet capable swimmers.


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Green sea turtles feed almost exclusively on sea grass, consuming up to two kilograms per day. Where they graze in the marine grasslands in the Tropics, they are preyed upon by tiger sharks.

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Tiger sharks patrol the extensive marine grasslands in the Tropics. They have powerful crushing jaws and prey on green turtles. By keeping the turtles on the move, tiger sharks prevent overgrazing of sea grass, maintaining a healthy ecosystem. These sharks indirectly contribute to the fight against climate change, as sea grass can absorb and store 55 times more carbon dioxide than rainforests.

Giant spider crabs in Australia undergo an incredible annual transformation in a specific meadow during the first full moon of winter. Hundreds of thousands of these crabs gather together to molt, breaking out of their old shells to allow their soft, new shells to expand. During this vulnerable period, they face threats from predators like the smooth stingray, which seeks out freshly molted crabs for an easy meal. By assembling in large numbers and forming mounds, the crabs find safety in the middle of the pile, ensuring the majority of them successfully molt and return to the depths to continue their solitary search for food.

A massive short-tail stingray is on the hunt for an easy meal. It targets soft, freshly moulted crabs, which are more vulnerable and easier to consume. In an attempt to catch its prey, the stingray disturbs a group of crabs, causing them to scatter. Newly moulted crabs struggle to keep up with the rest with their as-yet-unhardened legs, making them an even easier target for the stingray.

The giant cuttlefish, the largest of its kind, gathers in an Australian bay to breed as summer ends. With over 100,000 males competing for females, a smaller male resorts to trickery to mate. He displays a white stripe on his side, mimicking a female's appearance, in order to deceive and placate a dominant male and get within reach of the female. The female cuttlefish, having mated with multiple partners, ensures the greatest genetic diversity for her offspring. In the world of giant cuttlefish, size isn't everything, as clever adaptations and behaviors can lead to successful reproduction.

Seahorses, such as the common seadragon found in Australia's green seas, exhibit a unique parental role. During mating, the male collects and attaches the eggs to his underside. When the eggs are close to hatching, he ventures into open waters. Despite the elevated danger from predators, this is also where a favorite food source for seadragons, minute mysid shrimp, form in dense clouds. After the young hatch, the fathers return to the safety of seaweed thickets, where their elaborate camouflage makes them nearly invisible. The young sea dragons remain in open waters, growing quickly due to the abundance of the shrimp.

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Mysid shrimp are a favourite food source for common sea dragon hatchlings. Their abundance in Australia's green seas allows the young sea dragons to grow quickly.

The zebra mantis shrimp is a deadly assassin in the green seas of Northern Australia's mangrove forests. In these waters, the male shrimp hunts for food not only for itself but also for its mate, with whom it may have partnered for 20 years. The female shrimp relies on the male to provide food while she focuses on producing eggs. However, this strategy is risky, as the female could starve if her male partner absconds with a rival female. One male is lured out of his burrow by signals sent by a larger female shrimp. Though she may produce more eggs with him, she will also demand more food from the male.

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The Common dolphins are rushing towards Monterey Bay, California, drawn in by an explosion in the population of anchovies, fueled by algal blooms and an abundance of phytoplankton. The dolphins herd the anchovies towards the surface, making it easier for them and other marine animals to feed.

California sea lions join the massive feast in Monterey Bay, where algal blooms have led to an explosion in plankton feeders, such as anchovies.

Anchovies are small, plankton-feeding fish that play a crucial role in marine ecosystems, as they serve as a primary food source for many larger marine animals. In Monterey Bay, California, algal blooms lead to a massive increase in anchovy populations, attracting various predators such as common dolphins, sea lions, and humpback whales.

Humpback whales also participate in the massive achovy feast in Monterey Bay, California. These whales showcase their unique feeding behavior by lunging upwards to sieve out up to 100 kilos of fish in a single attempt.

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