Ocean and Marine Life Quiz: 12 Great Underwater Questions

The coelacanth fish, nicknamed a “living fossil,” can live for 100 years, a study published Thursday, June 17, 2021, in Current Biology found.

Coelacanth Fish Facts:

Coelacanth females don’t reach sexual maturity until their late 50s, while male coelacanths are sexually mature at 40 to 69. Researchers figure pregnancy in the fish lasts about five years.

Red tides are the discoloration of the sea surface caused by harmful algal blooms.

The Gruesome Florida Red Tide

A harmful “red tide” was killing hundreds of tons of fish in Florida in the summer of 2021. At least 600 tons of marine life have been washed up on the shores of southern Florida in late June 2021. The media also reported waves of dead fish in South Tampa and St Petersburg. Environmental activists said industrial waste poured into Tampa Bay in March 2021 has worsened the annual algae bloom, killing hundreds of tons of fish and ruining Florida’s waters.

Coral bleaching happens when corals, under stress from warmer water, expel the colorful algae living in their tissues, making them turn white.

What’s killing the world’s corals?

A study released on Oct. 5, 2021, by the Global Coral Reef Monitoring Network (GCRMN), a U.N.-supported global data network, showed that the world already lost 14% of its coral on reefs between 2009 and 2018, an area of about 2.5 times the size of Grand Canyon National Park. The study attributes the loss mainly to coral bleaching. The hardest-hit regions are South Asia, Australia, the Pacific, East Asia, the Western Indian Ocean, and Oman.

Australia’s Great Barrier Reef is the world’s most extensive coral reef system, composed of over 2,900 individual reefs and 900 islands, stretching over 2,300 kilometers over an area of about 344,400 square kilometers.

Is The Great Barrier Reef “In Danger”?

On Friday, July 23, 2021, Australia was able to defer an attempt by the United Nations’ cultural organization UNESCO to downgrade the Great Barrier Reef’s World Heritage status to “in danger” because of damage caused by climate change. The reef has suffered significantly from coral bleaching caused by hot ocean temperatures in 2016, 2017, and 2020. The bleaching damaged two-thirds of the coral.

Poseidon’s ribbon weed, or Posidonia australis, found in Shark Bay, off the western end of Australia, is the world’s largest plant. The seagrass — not to be confused with seaweed and algae — spreads at least 180 km (77 square miles), about the size of Cincinnati. A new study published on June 1, 2022, in Proceedings of the Royal Society, shows that Shark Bay’s Poseidon’s ribbon weed colony is one giant organism that has been cloning for about 4,500 years, the largest known example of a clone in any environment on Earth.

Is it the largest organism on Earth?

Utah’s Pando, a clonal colony of 40,000 aspen trees connected by their roots, is the former “heaviest known organism.” covering an area of about 500 square meters (0.16 square miles) and weighing 6,000 tonnes. But the Humongous Fungus is probably even more enormous, weaving a web of mycelial tendrils (the root network of mushrooms) covering 3.7 square miles (9.6 square km) of Oregon’s Malheur National Forest. Scientists calculate it could weigh at least 7,500 tons and maybe up to 35,000 tons, making it the world’s most massive living organism.

Orcas, known as killer whales, are, in fact, members of the same family as dolphins (the toothed whales family of oceanic dolphins). The Blue, the Gray, and the Fin whales belong to the family Balaenidae, AKA the right whales.

Can orcas make a meal out of an adult blue whale?

In a paper published Jan. 21, 2022, in the journal Marine Mammal Science, scientists confirm for the first time through firsthand observation the first three records of groups of killer whales killing and eating blue whales near Southwestern Australia. While Blue whales are commonly between 70 and 80 feet and weigh up to 150 tons, Orcas can reach lengths of 30 feet and weigh up to four tons.

Jonah’s icefish is an antarctic deep water fish. The name Jonah refers to the Old Testament whale story, alluding to how this type of icefish was discovered (in the stomach of a whale). Icefish absorb the oxygen-rich Antarctic waters through their skin. They thrive in temperatures just above freezing temperatures with massive hearts and transparent blood because they lack hemoglobin and red blood cells.

What is the largest fish breeding colony ever discovered?

A breeding colony of Jonah’s icefish (Neopagetopsis ionah) globally unprecedented in scale has been discovered in the southern Weddell Sea, Antarctica. In a paper published Jan. 13, 2022, in Current Biology, scientists estimated the colony of Jonah’s icefish stretches across 92 square miles (240 square km), totaling 60 million active nests — the largest fish breeding colony ever discovered.

The immortal jellyfish and the turritopsis nutricula (a type of hydra) are the only two biologically immortal animal species known to science.

How Come?

Scientists at the Spanish University of Oviedo mapped the genetic sequence of the immortal jellyfish, able to repeatedly revert to an immature stage after reproduction. The study, published on Aug. 29, 2022, in the Proceedings of the National Academy of Sciences, found that the immortal jellyfish genome may be better at copying and repairing DNA and maintaining the ends of chromosomes intact.

How is that different from human DNA?

In humans and other species, the ends of chromosomes become so short with age that the cell can no longer divide successfully and dies.

A hydra is a freshwater-dwelling cnidarian no more than a half-inch long that eats mostly insect larvae and crustaceans. It is equipped with the ability to regenerate its body — even its head – deeming it essentially immortal (unless starved.) Researchers at the University of California, Irvine, pinpointed the genetic machinery behind some of these tiny creatures’ powers of regeneration, which practically make them immortal. Their research was published in Genome Biology and Evolution on Dec. 8, 2021.

Ocean snow is a shower of usually biological debris that falls from higher in the water – sometimes for weeks – before reaching the ocean’s bottom. For millions of years, the debris has delivered flecks from plant and animal remains mucus, dust, microbes, and the ocean’s carbon to the seafloor.

What’s wrong with marine snow?

An April 4, 2022, report in the New York Times identifies marine snowfall as increasingly being contaminated by microplastics, eventually settling on the seafloor in a layer of plastic that might affect Earth’s cooling process.

The Coca-Cola Company is ranked as the world’s top plastic polluter for the 4th consecutive year, according to the 2021 Break Free From Plastic report. In each year since 2019, Brand Audit found Coca-Cola branded products represent more pollution than the next two top polluters, PepsiCo and Unilever, combined. Claims about plastic packaging being eco-friendly made by big brands, including Coca-Cola and Unilever, are misleading greenwashing, according to a report by the Changing Markets Foundation. Case on point: The world’s largest plastic polluter, Coca-Cola, has spent millions promoting the notion that its bottles are 25% marine plastic.

Aurora of the sea is a natural phenomenon where plankton blooms glow in blue and green after nightfall. The light is activated by the movement of waves, swimming fish, and even footprints in the wet sand. The phenomenon is caused by plankton and phytoplankton species blooms, some of which use bioluminescence to distract predators.