In conclusion, the number of hammerhead sharks left is uncertain. Estimates range 100,000 to 500,000 with regional variations. Conservation efforts implemented protect these species.
An 100 million sharks killed per year. The number of sharks in oceans plunged 71% over half a century, mainly due to over-fishing. Three-quarters of species studied now threatened with extinction.
8,000 tigers kept in captivity, 5,000 living in wild. 13,000 tigers left. Most live in captivity.
Seventeen of 39 pelagic shark species threatened with extinction. Overfishing by far biggest threat to larger reef sharks. Damage to reefs also having an impact.
Estimated 100 million sharks killed every year. Out of over 350 shark species known today, scientists managed to mark only 30. So a lot to do and find out in this field.
Sharks considered incredibly dangerous by public, with many scared just to look. Sharks certainly among most diverse and populous aquatic creatures. They varied in terms of species.
The northern river shark extremely rare. No more than 250 mature individuals estimated to exist in wild, with no more 50 in any subpopulation.
There could be a billion or more sharks in all oceans. Up until 16th century, mariners called sharks “sea dogs.” Today, over 400 different shark species.
Some shark species reduced due to overfishing and habitat loss. Shark fin trade another threat. Sharks often hunted for fins used for soup, delicacy in some cultures. Finning involves removing fins, discarding body. Led to decline in populations, some species facing extinction. Habitat degradation also a factor.
At least 500 shark species in oceans. Sharks range 40-foot Whale sharks to seldom-seen Dwarf Lantern sharks less than human hand length! 75% now endangered due to human activity.
Up until 16th century, mariners referred to all sharks as “sea dogs.” The Greenland shark longest vertebrate lifespan, 300–500 years. Among largest sharks. Generalist feeder, eats available foods.
Research indicates over 100 million sharks die each year. Mostly killed by humans, some natural causes. Others die as prey or cannot be in captivity, become suicidal. Lifespan in wild 20 – 30 years.
Highly unlikely great white shark will attack any given individual swimming. Florida shark attack hotspot. New Smyrna Beach largest number of attacks. Other risky areas: Dyer Island, South Africa; New South Wales, Australia; Hawaii.
Over 400 shark species. Some estimates over a billion in ocean. Declines since 2014, more threatened.
Overfishing large predators past 40 years left oceans out of balance. Could result in disappearance by 2050.
Around 100 million sharks killed worldwide each year.
Prefer deep 500-1500 meters. Feed on squid, fish, smaller sharks. Embryos develop inside eggs in mother’s body. Gestation estimated 3.5 years! Conservation status.
What animals eat sharks?
Killer whales, giant groupers, some shark species, seals, sea lions, crocodiles, and humans eat sharks. Humans eat shark fins, but this harms sharks.
Nature balances species by interdependence in the food chain. What courageous animals attack sharks? Killer whales are the biggest shark predators. Other sharks attack smaller sharks. Seals, sea lions, groupers, crocodiles, and osprey also eat small sharks. Humans threaten sharks by catching them for fins and meat.
Orcas prey on sharks in packs. Their intelligence, sharp teeth and strong jaws overcome sharks. Crocodiles ambush sharks entering their territory, crushing them with powerful bites.
Bull, great white, hammerhead and tiger sharks eat smaller sharks when possible. As predators, sharks eat diverse marine animals. Though fierce, sharks have natural enemies. Orcas attack sharks, even large ones, to eat nutritious livers. Unfortunately, sharks’ greatest enemy is humans. We fish sharks for food and products like leather and oil. Our actions now threaten shark survival.
How many colors of sharks are there?
Some sharks jazz up basic color schemes with added stripes, spots or patterns. In the sea’s depths, certain sharks transform blue light into bright green that only their kind sees. Researchers identified what causes the sharks’ bright hue. Sharks are solitary while dolphins travel in protective pods. Whenever a dolphin is in shark danger, pod-mates defend it, even protecting humans. Counter-shading helps sharks blend into murky or clear water to surprise prey.
Lore claims sharks are most attracted to yellow. This birthed “Yum Yum Yellow.” But is it true? Sharks are least attracted to red, most to yellow. High contrast colors like yellow, orange and red are most visible. So some sharks are drawn to them, especially in dim water. The bright yellow of safety gear is easy for sharks to see. Researchers jokingly call it “yum yum yellow.”
A shark’s appearance varies widely on species. Most range from white to black. Some like goblin sharks are bright pink. Not only varying in color but also shape and size. As predators, their colors are usually not flashy. A great white’s name reflects its white belly.
Sharks lack orientation to swim backwards. Their fins move them forward only. Of 440 species across 8 orders, some better known ones are:
Angel sharks resemble stingrays. Great whites are feared predators. Nursery sharks reach over 6 feet. Tiger sharks have stripes. Bull sharks swim in fresh and saltwater. Leopard sharks have dark spots. Whale sharks are gentle giants.
Are sharks in danger of extinction?
Over 37% of the world’s sharks, rays and chimaeras are facing extinction. As many as 220 rays are threatened, followed by sharks (167) and chimeras (four). Shark lovers can support efforts to curb the threat. Sharks keep the marine food chain in balance. Without sharks other predatory fish and marine animals will thrive, depleting food fishes. They’ve survived five mass extinctions, including the asteroid wiping out 75% of life. But many aquatic apex predators now risk extinction. “Sharks are in crisis globally,” says WWF. Hunting them before reproduction along with getting caught in gear and climate change are big threats. Scientists use this to inform conservation plans. Advocates recommend policy to officials. Research educates future generations inheriting Earth.
One main decline cause is overfishing – targeted, bycatch and finning. Habitat destruction like coastal construction and pollution has also affected populations. Some species suffer population decline and extinction risk. We play a large part. Reef sharks help maintain healthy prey fish populations by killing sick fish and keeping numbers in check. But they also risk extinction. A study warns three quarters of oceanic sharks and rays are endangered, like 4 hammerhead and 4 angel shark species and the giant manta ray.
Administering one COVID-19 vaccine dose worldwide requires killing 250,000 sharks, doubling with two doses. In 2020, 31 species officially became extinct. Over 300 shark and ray species are endangered. Their population has decreased 50% in 75 years. Overfishing is the main threat. Their meat is consumed. This imbalance exists because the overall population nears extinction. Their unborn offspring eat each other. They cannot replenish fast enough. Multiple stressors like bycatch and climate change put great white sharks at extinction risk. Despite calls to protect them, a study reveals their abundance has declined over 70% largely from fishing pressure. Sharks are a ‘keystone’ species. Removing them could collapse the food chain.