The ocean covers over 70% of the Earth and is home to some of the world's largest and most extraordinary sea creatures. From gentle ocean giants to colossal creatures of the deep, we'll explore the ocean's biggest sea creatures (think gigantic blue whales, colossal squid and ten-legged Japanese spider crabs). Read on for our top ten favourite ocean giants…
Blue whales
Blue whales are believed to be not only the biggest sea creature but also the largest animal to ever live on Earth. These ocean giants can reach lengths of up to 100ft and weigh as much as 200 tonnes, which is the same as 20 African bush elephants (the largest elephant species). Their movements often align with seasonal feeding and breeding patterns, and they are found in all oceans apart from the Antarctic. During the spring and summer, they tend to migrate to Iceland, the Azores and Australia, then in early autumn, they frequent the waters of California and Baja California. Sir Lanka and Chilean Patagonia are good locations to see these behemoth blue beauties year-round, with sightings peaking during summer.
Sperm whales
Another whopping whale that's made it onto our list of the world's biggest sea creatures is the sperm whale, the largest-toothed predator, with a single tooth ranging from 1 to 11 inches. Sperm whales can grow up to 67ft in length and weigh as much as 57 tonnes. They can also dive to depths of over 3,000m and unlike other whale species, sperm whales do not migrate frequently, making them easier to spot year-round in regions such as Sri Lanka, the Maldives, the Dominican Republic and the Canary Islands. In summer, they make their way to areas near New Zealand, Chilean Patagonia, Iceland and the Azores and during winter, they can be seen near Norway.
Southern elephant seals
Southern elephant seals are the largest pinniped (seal species) in the world, with males growing up to 20ft and weighing up to 40 tonnes. They are also remarkable divers, capable of going to depths of 2,000m and holding their breath for over two hours while hunting for fish and squid (not bad!). Southern elephant seals prefer colder climates, as their blubber and fur keep them nice and toasty and can be spotted year-round on sub-Antarctic islands like South Georgia, Macquarie Island and the Kerguelen Islands. During the summer months, they are often seen on the Patagonian coast of Argentina and Chile as well as near the Antarctic peninsula.
Whale sharks
Whale sharks (the largest fish species) are the ocean's gentle giants. Despite their impressive size, they are filter feeders, dining on plankton, small fish and other microscopic marine life. They are easily recognised by the distinctive speckled pattern of shimmering spots embellishing their massive bodies. They can be up to 65ft long and weigh up to 20 tonnes. Whale sharks are found in warm, tropical waters. Some of our favourite year-round spots to see these glistening giants are the Philippines, the Maldives and Mafia Island, located in Tanzania. They also migrate seasonally to plankton-rich feeding areas. The spring and summer months bring them to Belize and Australia, particularly Ningaloo Reef, while autumn and winter take them to the Arabian Gulf and the Galapagos.
Basking sharks
Basking sharks probably don't spring to mind when you think of sharks. These docile creatures can measure up to 40ft long and weigh up to 10 tonnes. And they're known for their enormous mouths (up to 3ft wide!) which allow them to filter as much plankton from the water as possible. On average, they filter around four million pounds of water per hour (now that would really put your Brita filter to the test). Basking sharks inhabit temperate waters, typically areas abundant with plankton, and favour the Azores and the Mediterranean Sea due to their year-round plankton buffets. The UK, Ireland, Norway, Iceland and the coast of Eastern Canada are popular spots during spring and summer, while Australia and New Zealand are your best bets of seeing these gentle giants during the winter.
Leatherback sea turtles
Leatherback sea turtles are the largest of all the turtle species, reaching up to 7ft long and weighing up to 2,000lb. These incredible ocean travellers are known for their long migrations across the Atlantic and Pacific, with journeys taking up to 12 months and spanning over 7,000 miles. Leatherbacks can also dive to over 1,300 metres deep in search of their favourite food - jellyfish. They can be spotted year-round near the Caribbean and parts of West Africa. During their nesting season in spring and summer, they can be found along the coasts of Indonesia, Costa Rica, the Philippines and Papua New Guinea.
Colossal squids
We couldn't miss colossal squids off our list of the biggest sea creatures. This deep-sea giant is the largest invertebrate in the world, measuring a total length of 46ft (including tentacles) and weighing up to 1100Ib. They are a deep red colour, unlike many other deep-sea creatures that are pale or colourless, and have the largest eyes in the animal kingdom, with a dimension of 10 inches, making one of its eyes larger than a basketball. Colossal squid inhabits deep waters - anywhere from 1,000 to 2,200m - and are adapted to living in cold and dark conditions. They reside in the southern oceans surrounding the Antarctic, particularly around the Antarctic circumpolar current, and can also be found near subantarctic islands such as South Georgia and waters near New Zealand.
Lion’s mane jellyfish
Lion's mane jellyfish are the oldest recorded jellyfish. They can have up to 1,200 tentacles - divided between 8 clusters, from their heads to the tip of their tentacles - can reach up to 120ft long and weigh up to 440Ib. This stinging species can mostly be spotted in summer and autumn along the coasts of the UK, Ireland and Scandinavia. They can also be found near Canada, Alaska and Japan. During winter, they retreat to deeper waters, so are rarely sighted during these months.
Giant clams
Giant clams made it onto our biggest sea creatures list as they are the largest living bivalve mollusc, measuring 4ft across and weighing up to 500Ib. Clams are sessile organisms, meaning they remain in one location for the duration of their lives. They reside in warm shallow waters of the Indo-Pacific region, commonly found around coral reefs in the Philippines, Indonesia, Fiji and Papua New Guinea, as well as in the coastal waters of Australia, particularly the Great Barrier Reef.
Japanese spider crabs
Japanese spider crabs are the largest arthropods in the world and can live up to 100 years. Despite having 'spider' in their name, they actually have ten legs instead of eight like a true spider and can have a leg span of up to 12ft and weigh up to 40lbs. The spider crab is generally found around Japan in cold, deep waters from 50 to 600m, sheltering among rocks and coral reefs on the ocean floor. Japanese spider crabs become more active between winter and early spring, looking for mates during their breeding season.
If you enjoyed this blog, you may also enjoy Our Creepy Creatures, Our Top Ten Hammerhead Shark Facts or Our Top Ten Mola Mola Facts.
