© Getty Images

Blast fishing -

This type of fishing involves the use of explosives in order to stun or kill fish, which causes extensive damage to coral reefs and marine habitats.

© Getty Images

Cyanide fishing - Fishermen who use this method tend to spray a sodium cyanide mixture in a desired fish’s habitat, which incapacitates the fish. But it also severely damages coral reefs and disrupts marine ecosystems.

© Shutterstock

Bottom trawling -

While trawling alone uses large nets that are dragged along to catch fish, bottom trawling involves dragging these nets along the ocean floor. This inevitably destroys seabed habitats and results in the capturing of non-target species.

© Getty Images

Trawling in sensitive habitats -

Trawling and fishing in sensitive areas such as seagrass beds and coral reefs leads to irreversible damage to these ecosystems.

© Shutterstock

Trawling with explosives -

Sometimes, fishermen attempt to increase their catch while trawling, and so they attach explosives to their nets to accomplish this. But while trawling is already a destructive practice, the additional use of explosives makes it even worse.

© Getty Images

Trawling in nursery areas -

Fishing in nursery areas (locations designed to assist in the growth of marine life) can disrupt the life cycle of fish species and cause the collapse of entire fish populations.

© Shutterstock

Bottom longlining -

Longlines with dozens of baited hooks are laid on the seabed in the hopes of catching aquatic life along the ocean floor. However, these hooks can sometimes catch on debris and coral, dragging them along and causing habitat damage for potentially endangered marine life.

© Shutterstock

Ghost fishing -

When fishermen lose or abandon their fishing gear in the ocean, the gear continues to trap and kill marine life, which contributes to debris and habitat destruction. In fact, derelict fishing gear is one of the primary types of debris affecting the ocean today.

© Getty Images

Electrofishing -

Electrofishing involves the use of a direct electric current to shock fish, which tends to be done by biologists in a way that is non-destructive. But this isn’t always the case. When electrofishing is performed incorrectly, it can drastically impact not only target species, but also other aquatic organisms.

© Getty Images

Poison fishing -

Various toxins–taken from fish or plants–are used to kill fish by paralyzing them for easy capture. A massive consequence of this method, however, is that waterways tend to be contaminated, and non-target organisms are killed as well.

© Shutterstock

Muro-ami fishing -

This technique is most often used in Southeast Asia. It involves the dropping of large stones onto coral reefs to scare fish into nets. Coral reefs are irreversibly damaged, and many associated species die off.

© Getty Images

Dredging -

With dredging, large scoops or nets are dragged along the seabed, destroying habitats and disrupting marine ecosystems.

© Shutterstock

Bycatch -

Sometimes, fishermen capture non-target species that they do not want or cannot sell, resulting in the unnecessary death of large numbers of marine animals. Tragically, bycatch is often tossed back into the ocean.

© Shutterstock

Gillnetting -

A gillnet is a wall of netting that hangs in the water, with holes large enough for a fish’s head but not its body. As the fish tries to retreat, its gills get caught in the net. These nets are known to entangle and kill many unintended species, leading to bycatch and ecosystem imbalance.

© Shutterstock

Drift netting -

A majorly negative side effect of using large nets in fishing is that they drift off once they are pulled into open water. This tends to result in large quantities of bycatch, which can include marine mammals, turtles, and seabirds.

© Shutterstock

Overfishing -

When fishermen excessively capture aquatic life in a single place, which often happens in dams, it causes fish stocks to be irreparably depleted. As a result, food chains are disrupted and entire ecosystems could collapse.

© Shutterstock

Illegal fishing gear -

Use of illegal gear such as fine mesh nets and explosives intensifies environmental degradation and threatens marine biodiversity.

© Getty Images

Agrochemical pollution -

While farmers use fertilizers and pesticides to increase plant and animal crop production, rain can carry these chemicals away and introduce them into water bodies, which harms fragile ecosystems.

© Shutterstock

Bacterial blooms -

Nutrient pollution from agrochemicals can lead to excessive growth of bacteria, which creates incredibly toxic blooms that harm aquatic life.

© Shutterstock

Coastal development -

When mangroves, wetlands, and other critical habitats are cleared for the purposes of coastal development, they disrupt breeding grounds and diminish biodiversity.

© Shutterstock

Dams -

Unsurprisingly, dams have hugely negative consequences on vast areas of wildlife. Blocking rivers with dams disrupts fish migration, alters habitats, and reduces spawning grounds.

© Getty Images

Noise pollution -

Noise from shipping, drilling, and construction disrupts marine life behavior, navigation, and communication. In fact, sound travels further in and over water, which can heavily impact aquatic species.

© Shutterstock

Plastic pollution -

Discarded plastics accumulate in oceans, entangling marine life and releasing toxins that can destroy ecosystems. Marine animals also tend to mistake plastics for food, which can cause them to die after ingestion.

© Getty Images

Oil spills - The accidental or deliberate release of oil can result in the deadly contamination of marine habitats. Scientific studies have shown that long-term destruction is caused to ecosystems that come into contact with oil spillages.

© Getty Images

Industrial waste dumping -

Industrial factories located near water bodies often dump industrial waste inside. Habitats are contaminated as a result, and marine life can be poisoned to the point of collapse in the local ecosystems.

© Shutterstock

Climate change -

As pollution around the planet causes sea temperatures to rise and also results in the increase of the ocean's acidity, entire marine ecosystems and species are threatened to the point of extinction.

© Getty Images

Illegal, unreported, and unregulated (IUU) fishing -

Laws and regulations for marine wildlife are typically put in place to ensure the safety of aquatic ecosystems in certain areas. But unregulated and illegal fishing practices can destroy these protected zones, especially if they use destructive fishing methods.

© Shutterstock

Lack of regulation and enforcement -

In other places, there are not enough laws and enforcement put in place to prevent destructive fishing practices. These methods then go unchecked, creating a snowball effect that creates irreversible environmental damage.

Sources: (Turtle Island Restoration Network) (4Ocean) (Marine Conservation Institute) (The Pacific Community) (NOAA’s National Ocean Service)

See also: Can reindeer help fight climate change?

© Shutterstock