Breverton, T. (2013). Breverton’s Nautical Curiosities. Quercus.

• The Bloop was an ultra-low frequency underwater sound detected multiple times in 1997

  • The source remains unknown

  • It was detected by machines built to detect submarines

  • The sound ‘rises rapidly in frequency over about one minute and was of sufficient amplitude to be heard on multiple sensors, at a range of over 5000km’, according to the US National Oceanic and Atmospheric Administration

  • The sound was far more powerful than any call made by an animal we know

• Fish tail fins are vertical, to propel them forwards, however 3 major groups of mammals left the sea in prehistoric times and returned to it millions of years later. These mammals developed horizontal tail flukes for propulsion. These mammals were:

  • Whales and dolphins

  • Seals, sea lions and walruses

  • Dugongs and manatees

• Types of sea animals

  • Arthropods

    • Jointed legged animals

    • Crustaceans – crabs, lobsters, shrimps

    • Barnacles

  • Chordates

    • Animals with a notochord

    • Lampreys, hagfishes, sharks, skates, rays, eels, barracudas and other fish

  • Reptiles

    • Sea snakes, turtles, alligators, crocodiles

  • Mammals

    • Whales, dolphins, sea lions

  • Molluscs

    • Animals with a mantle

    • Snails, bivalves, chitons, tusk shells and cephalopods (octopuses, squids)

  • Echinoderms

    • Spiny skinned animals

    • Sea stars, brittle stars, sea urchins, crinoids, etc

  • Cnidarians

    • Stinging animals

    • Jellyfish, corals, hydroids, cubomedusa

  • Sponges

    • 5000 species plus comb jellies and worms

• Apex predators

  • Megalodon ruled the seas in prehistoric times

  • Billfish

    • Feed on other fish

    • Fast and graceful

    • Includes marlin, sailfish and swordfish

  • Electric ray

    • Feeds by stunning fish and small sharks

    • Grows up to 91kg

    • Produces a powerful electric shock of up to 220 volts

  • Leopard seal

    • Top predator in the Antarctic

  • Orca

    • Largest species of dolphin

    • Incredibly fast – can get up to 35mph

    • Hunt in pods and have different methods for different prey

    • Prey on whales, seals, sea lions and walruses

  • Sperm whale

    • Second largest animal in the world

    • Largest brain of any animal we know

    • Feed on squid, octopus, deep-water fish, sharks and skate

    • Can dive incredibly deep for a whale (1100m)

  • Tiger shark

    • Can go up to 20mph

    • Solitary

    • Will attack and eat anything

• Beluga whales communicate with whistles and pulsed calls

• The blue whale is the largest animal to have ever lived on Earth – up to 28m

  • Loudest animals on Earth – calls can go up to 188 decibels

    • Can be heard from hundreds of miles away

• Dolphins

  • Dolphins are extremely intelligent

  • In 2008 a sperm whale and its calf were stuck in shallow waters and called out. After some time a dolphin, named Moko, arrived and escorted them out. This was the first time humans had seen dolphins and whales communicate

  • A Risso’s dolphin, named Pelorus Jack, escorted ships across Admiralty Bay in New Zealand between 1888 and 1912

    • The area was dangerous because of rocks and Jack would sometimes stay with ships for up to 20 minutes to guide them through

    • Sailors would often wait for him to arrive before travelling through the French Pass, which was the most dangerous part

    • A ‘pelorus’, which Jack was named after, was used to help when travelling with inaccuracies with compass

    • A shipmate on the attacked Jack, by shooting him, and he took several weeks to recover. Jack never escorted the again and later it was found shipwrecked on the French Pass

• The archerfish is the accurate marksman in the sea and sprays water jets to stun fish

• The megamouth shark, which is newly discovered, is another large shark which swims with its mouth wide open to catch plankton and jellyfish

  • Deepwater shark

  • Discovered in 1976

  • Can grow up to 5.5m

• The giant squid is a huge predator that lives in the deep sea

  • It can grow up to 20m

  • Its only threat is the sperm whale, which dives great depths just to catch them

  • The giant squid pulls prey towards it with the suckers on its 2 longest tentacles. It pulls the prey into its beak and uses its toothed tongue to lacerate the prey

  • The giant squid has the biggest eyes, up to 50cm, of any known animal

• Sea otters are one of the few animals to use tools

  • They place a rock upon their chests when eating and use the rock as an anvil, smashing shells against it to get to what’s inside

• The swordfish is the fastest fish in the world for short sprints and can reach up to 72mph

• Manta rays

  • Can reach 7.6m

  • Has the biggest brain to body ratio of all sharks and rays

  • Is commonly preyed on by sharks who attack from behind, their blind spot

• Whaling

  • Whaling is the act of hunting whales, usually for meat and oil and bone, and it is the primary cause for most whales being endangered

  • It began in the 11th century but picked up momentum in the 19th, with the rise of fast steam-powered ships and explosive harpoons

  • Whale oil was used to light homes, in oil lamps or candles, before electricity

  • In the 20th century almost all products, such as perfume and soaps, contained whale in some capacity

  • In 1986 rules were put in place to restrict whaling

    • Norway and Japan continue to hunt whales, against restrictions put in place, and they quote that it is for ‘scientific purposes’ but no findings have been published

    • Japan now regularly hunts in Antarctica waters, which was originally the only safe place for whales as steam-ships would rarely go that far

  • The right whale – named because it was the easiest to hunt – is the most endangered. Right whales are easy to hunt because they become buoyant when they die; other whales sink immediately