Sharks have been swimming in Earth’s oceans since before the time of the dinosaurs. In recent years, however, many shark populations have dropped fast, and a growing number of species are now considered at risk. To protect sharks properly, it helps to understand two things:
- Why sharks matter for the ocean ecosystem
- What’s actually driving the decline in shark numbers
Why Sharks Are Crucial To The Ocean’s Ecosystem
Sharks are a crucial part of the ocean’s ecosystem. As apex predators, they help keep the marine food chain in balance. When shark populations collapse, the ripple effects can be serious: other predators can overgrow, key food fish can drop, algae can spread, coral reefs can suffer, and the entire system can shift in unhealthy directions.
Sharks are also described as being part of broader ocean processes that affect the planet, so protecting sharks isn’t only about sharks, it’s about keeping oceans stable.
What Are The Causes Of Shark Population Declines?
There are many factors leading to the decrease in shark populations. Almost all are tied to human activity, which means they can be reduced with the right choices and enforcement.
Here are the most damaging causes of shark population decline:
1) Shark Fishing (Targeted Fishing)
An estimated 100 million sharks are killed every year. Much of this comes from commercial fishing. Sharks are caught for meat, oils, and cartilage, but a major driver is the demand for shark fin soup.
2) Commercial Fishing (Food Depletion)
Commercial fishing can reduce the ocean’s fish populations, which are the main food source for many sharks. Less food can also reduce successful breeding and survival of pups.
3) Commercial Fishing Bycatch
Sharks are often caught accidentally in nets meant for other species. They can become tangled, injured, and die as a result.
4) Pirate Fishing
Pirate fishing ignores rules and protected areas. Even where finning or shark fishing is banned, illegal operations can keep pressure high and wipe out local populations.
5) Baited Drum Lines
Used near popular beaches to deter sharks, drum lines can still kill sharks, including younger individuals, which makes population recovery harder.
6) Shark Nets
Shark nets can trap and entangle sharks (and other marine animals). They are responsible for the death of many sharks worldwide.
7) Chemical Pollution
Industrial pollutants (for example DDT, mercury, oil spills) can be toxic to marine life, including sharks, and contribute to illness and death.
8) Garbage and Plastic
Large amounts of garbage enter the ocean every year. Sharks can mistake debris for food, swallow it, and suffer internal damage that can lead to death.
9) Habitat Loss
As human activity expands, sharks can lose important hunting, mating, and nursery habitats. When those areas degrade, reproduction and survival drop.
Which Sharks Are Most Endangered?
Many species are endangered to some degree. Some are considered critically endangered due to a combination of heavy fishing pressure, habitat threats, and low reproductive rates.
Examples of critically endangered sharks include:
- Pondicherry Shark
- Ganges Shark
- Natal Shark
- Daggernose Shark
- Striped Smooth-Hound
- Smalltooth Sawfish
- Sawback Angelshark
- Angel Shark
- Sand Tiger Shark
- Porbeagle
- Spiny Dogfish
A Closer Look: Critically Endangered Angel Sharks
Angel sharks (genus Squatina) are unusual sharks with flattened bodies that can look a bit like rays. They often live near the seabed and hunt by hiding in sand and ambushing passing prey.
There are 21 recognized species of angel sharks, and three are described as critically endangered: the Angel Shark, the Smoothback Angelshark, and the Sawback Angelshark.
Why Are Angel Sharks Endangered?
The main threat is fishing, especially bottom fishing. As fishing for bottom-feeding fish increased, angel sharks were increasingly caught in nets. This has been especially severe in the Mediterranean Sea, where these species used to be common but are now heavily depleted.
More Critically Endangered Examples
Striped Smooth-hound Shark
A smaller shark with a slender shape and vertical stripes. It lives near the bottom and has been depleted largely due to net fishing, with young sharks especially at risk in shallow breeding areas.
Natal Shyshark
A small catshark with a very limited habitat near South Africa. It’s threatened by coastal development and shrimp fishing bycatch.
Daggernose Shark
A small requiem shark with a long pointed snout. It lives in shallow muddy coastal waters and is threatened mainly by fishing and bycatch.
Pondicherry Shark
An extremely rare requiem shark from the Indo-Pacific. No specimen has been recorded since 1979, and unregulated fishing is a major concern.
River Sharks
Several river sharks are listed as critically endangered (including the Ganges River Shark and others). They are threatened by fishing, pollution, and habitat changes like dam construction.
Case Study: Are Great White Sharks Endangered?
The Great White shark is one of the world’s most iconic sharks. Because it’s so famous, people often ask a specific version of the bigger question: are Great White sharks endangered?
Great White sharks are apex predators that hunt fish, other sharks, rays, and marine mammals. They live in many coastal regions worldwide and are often found near shorelines and offshore in deeper waters.
How many Great White sharks are left?
The exact number is uncertain, but estimates suggest there are between 3,000 and 5,000 individuals in the wild.
So, are Great White sharks endangered?
It depends on definitions and criteria. Some sources describe Great Whites as vulnerable, while others list them as near threatened. Some scientists argue their numbers are still too low in parts of their range and that stronger protections are needed.
Why are Great White sharks at risk?
Great Whites face a mix of human-driven threats: pollution, climate-related changes, and especially issues related to fishing. They can be caught as bycatch or become entangled in nets, and overfishing can reduce the prey they depend on.
Support Comprehensive Shark Conservation
One of the best ways to protect sharks is to support comprehensive conservation efforts. Not just protecting one species, but reducing the major drivers across the board: commercial and pirate fishing, finning, harmful beach-control methods, chemical pollution, and ocean dumping, while also protecting key habitats.
Final Thoughts
Sharks are endangered because of a wide mix of threats, mostly caused by human activity. The good news is that what humans cause, humans can change. Understanding the threats is the first step toward protecting sharks and keeping the ocean ecosystem healthy.
