Sea Spider

Sea spiders belong to a group of arthropods called the pycnogonids, so they are technically not true spiders, although they are just as creepy-looking. These bizarre animals have organs in their legs, since they don’t have much of a body. Deepwater species can grow to nearly three feet.

“Sea Spider” is licensed under CC BY-NC-SA 2.0. Courtesy of the NOAA Office of Ocean Exploration and Research.

Ghost Shark (Chimera)

These ghostly cartilaginous fishes, also known as chimeras, roam the ocean floors down to 8,500 feet. Their bodies are soft to withstand the extreme pressure at these depths.

“Chimaera” is licensed under CC BY-NC-SA 2.0. Courtesy of NOAA Okeanos Explorer Program.

Deep-Sea Dragonfish

Deep-sea dragonfishes live between 1,600 and 15,000 feet deep, far below where any light reaches. They have special light-producing organs called photophores that they use to illuminate and attract their prey. They have huge, fang-like teeth and two sets of jaws to swallow large prey.

“Ocean Exploration 2020: Deep-sea Fish” is licensed under CC BY-NC-SA 2.0. Courtesy of the NOAA Office of Ocean Exploration and Research. Modified from the original version.

Giant Isopod

Unlike pill bugs, their tiny terrestrial relatives, these giant crustaceans can grow to 30 inches long and can weigh nearly four pounds. These animals exhibit deep-sea gigantism, which is the tendency for deep-sea animals to reach a larger size than their shallow-water relatives. The colder temperatures in the deep ocean are associated with increased cell size and life span, which lead to an increase in maximum body size.

“Ocean Exploration 2020: Isopod” is licensed under CC BY-NC-SA 2.0. Courtesy of the NOAA Office of Ocean Exploration and Research. Modified from the original version.

Colossal Squid

The colossal squid is the largest invertebrate on Earth, reaching lengths of up to 46 feet long and weights of up to 1,650 pounds. Its limbs are covered in toothed suckers and sharp hooks for capturing prey and fighting off predators. Its eyes are the largest of all animals, even bigger than those of blue whales.

“Squid” is licensed under CC BY-NC-SA 2.0. Courtesy of the NOAA Office of Ocean Exploration and Research.

I hope you enjoyed learning about these spooky sea creatures. Happy Halloween!

1. Sea turtles use the Earth’s magnetic field as a compass. This adaptation helps them return to the exact spot where they were born to lay eggs after spending years migrating thousands of miles at sea.
   

   Scientists study the movements of sea turtles using satellite tracking. Photo courtesy of USGS.

2. They are one of the few animals that eat jellyfish. Leatherback turtles can consume twice their own body weight in jellies and other soft-bodied animals per day. They have sharp points on their jaws to pierce jellies and spines in their throat to prevent jellies from slipping out before they can swallow them! Plastic pollution in the ocean is especially dangerous for leatherback turtles, who often confuse plastic bags for their favorite food.
3. Sea turtles survived the mass extinction event that killed the dinosaurs. 65 million years ago, an asteroid crashed into Earth, changing the planet’s climate and wiping out most life on Earth. Sea turtles, however, have many adaptations that helped them survive what other species couldn’t. They have a slow metabolism, requiring very little energy, so they can get by when resources are scarce. They can hibernate when it’s too cold, or burrow into the sand when it’s too hot. Turtles are tough­—it’s no wonder they’ve been around for over 120 million years!
   

   Sea turtles have lived on Earth for over 120 million years!

4. Only one in a thousand turtle hatchlings will make it to adulthood. It’s a treacherous journey from the nest to the water—birds, dogs, racoons and fish all prey on turtle hatchlings, and human disturbances make the voyage even more dangerous. Baby turtles use the natural light horizon over the ocean to find the water, and unnatural light from buildings, cars, and fires leads turtles in the wrong direction.
   

   It’s hard out there for a sea turtle hatchling.

5. Temperature determines the sex of baby turtles. The sex of turtle hatchlings depends on the temperature of the environment surrounding the eggs. More female hatchlings are born in warmer temperatures, while males are born in cooler temperatures. Sand that is too hot can even prevent the eggs from hatching at all. Increased sand temperatures due to climate change will affect sea turtle populations by changing natural sex ratios and decreasing hatch rates.
   

   Temperature determines the sex of baby turtles. Photo by Elise Peterson.

6. Sea turtles need our help. Six out of the seven species of sea turtles are threatened or endangered thanks to entanglement in fishing gear, pollution, habitat loss, climate change, and demand for their eggs, meat and shells. Here are some easy ways you can help sea turtles:
   • Never buy turtleshell products.
   • Reduce your use of plastic. Bring reusable straws when dining out and reusable bags while shopping. Read up on some easy ways to reduce your plastic footprint here. (Clicking on affiliate links and making a purchase will earn CurrentSea a small commission at no extra cost to you. Thank you for supporting CurrentSea!)
   • Reduce your carbon footprint by cutting back on meat.
   • Only buy sustainable, turtle-friendly seafood.
   • Protect sea turtles during nesting season.
   • Contact your government representatives to tell them to protect the Endangered Species Act.
   • Support sea turtle conservation organizations like Sea Turtle Conservancy.

The sea turtles will thank you!

A sea turtle escapes a net equipped with a turtle exclusion device (TED). Photo courtesy of NOAA.

1. The largest mountains and deepest valleys on Earth are in the ocean.
Hawaii’s Mauna Kea is the tallest mountain in the world measured from base to summit. Its base begins 19,700 feet below the surface of the Pacific Ocean, making its total height 33,500 feet, almost a mile taller than Mount Everest. The Mariana Trench is the lowest point on Earth’s surface at 36,000 feet deep in the Pacific Ocean. Amazingly, it’s full of life.

The mid-ocean ridge is a 40,000 mile mountain range that extends through all major ocean basins. It is the single largest feature on Earth and the longest continuous mountain chain known to exist in the universe.

This beautiful jelly was spotted during the Deepwater Exploration of the Marianas expedition on April 24, 2016. Courtesy of NOAA Ocean Exploration & Research.

2. The ocean controls our climate.
The ocean plays the largest role in the global water cycle and provides most of the rain that falls on land. It regulates Earth’s temperature by absorbing and storing heat and carbon dioxide, a greenhouse gas.

The ocean has absorbed over 90% of the excess heat trapped in Earth’s atmosphere by greenhouse gas emissions, temporarily slowing global warming.

3. We wouldn’t be here without the ocean.
Life on Earth began in the ocean. Most of the oxygen we breathe comes from photosynthetic organisms in the ocean. Billions of people depend on the ocean for their primary source of food.

Most of the oxygen we breathe comes from photosynthetic organisms in the ocean, like these diatoms. Courtesy of Carolina Biological Supply Company.

4. Most of the ocean remains unexplored.
The ocean contains 99% of the habitable space on Earth, but we have only explored less than 5% of it. Scientists estimate that we have yet to describe 91% of species in the ocean.

Scientists use remotely operated vehicles (ROVs) to explore the deep ocean. Courtesy of NOAA Photo Library.

5. No matter where on Earth you live, you are connected to the ocean.
“Even if you never have the chance to see or touch the ocean, the ocean touches you with every breath you take, every drop of water you drink, every bite you consume. Everyone, everywhere is inextricably connected to and utterly dependent upon the existence of the sea.” ― Sylvia Earle, The World Is Blue: How Our Fate and the Ocean’s Are One

We can’t survive without the ocean. We once believed the ocean was so vast that human actions could not affect it. Now we know that as we overfish, pollute, warm and acidify the ocean, we threaten our own life support system. Our future depends on restoring our ocean while we still can.