Why Are Ghost Nets a Problem - Dynamic Earth Lesson Plans

WHAT IS A GHOST NET?

A ghost net is a type of fishing net that has been lost or intentionally left at sea. Ghost nets are a big problem in our oceans.

EFFECTS OF GHOST NETS ON THE OCEAN

Ghost nets are a global problem. The world’s oceans are full of old fishing nets that have been left behind. These nets have a negative effect on marine biomes in a number of ways.

Ghost Fishing

A type of fishing called “ghost fishing” happens when fishing nets, traps, lines, and other equipment that has been left in the ocean by fishermen still catch fish. It a big problem for the animals that live in the water.
These nets can catch any animal that swims in the sea. Sea turtles, sharks, whales, seals, crustaceans, manatees, dolphins, and more are some of the animals that are most at risk. Nets can also trap seabirds.
The abandoned gear can continue to catch and kill marine animals for years, even decades. The trapped animals are unable to escape and may die from starvation, exhaustion or suffocation.
Ghost nets can cut down on the number of animal species in the ocean and cause declines in fish populations
It is estimated that ghost fishing accounts for up to 10% of all plastic pollution in the ocean.

Dispersal of Invasive Species

When fishing gear is lost or abandoned, it can trap animals and then drift with ocean currents to transport non-native species to new locations. These species may then establish themselves in the new environment and outcompete native species for resources.
Ghost nets can act as a platform for the growth of algae, barnacles and other organisms. This can create a microhabitat that attracts small fish and invertebrates, which are then eaten by larger predators. If these predators are not native to the area, they may introduce non-native species into the ecosystem.
Ghost nets can also damage habitats such as coral reefs and seagrass beds, which can create opportunities forinvasive species to take hold. For example, if a net becomes entangled in a coral reef, it may break off pieces of coral and create spaces where invasive algae or other organisms can grow.

Damage to Coral Reefs

Ghost nets can smother and suffocate coral by covering them entirely or partially. Coral requires sunlight for photosynthesis, which is essential for their survival. If a net covers a part of the reef, it blocks sunlight from reaching the coral beneath it, causing them to die.
Ghost nets can also attract predators like fish that feed on small organisms living on or near the reef. These predators may accidentally damage the corals while feeding or swimming around the net.
Corals are very important because they are some of the most biologically diverse ecosystems on the planet, supporting an estimated 25% of all marine species despite covering less than 1% of the ocean floor. Coral reefs provide habitat and shelter for countless organisms, including fish, invertebrates, and even sea turtles.

WHAT ARE GHOST NETS MADE OF?

Rope was used to make most of the fishing nets that people used to catch fish in the past. They’re also made of nylon, which is a plastic that’s meant to last. Nylon is used a lot in the net-making business because it is very strong. It is very durable and almost completely resistant to saltwater (Research from the Oliver Ridley Project).

Unfortunately, these nylon nets are less biodegradable than robe. They can stay in the sea for a long time. If they aren’t removed, they will just keep interfering with the lives of aquatic animals. Nylon is also very light. This makes it easy for nylon nets to move with the waves in the ocean.

GHOST NETS STATISTICS

Recent scientific data shows that there has been a steady rise in the number of ghost nets in the world’s oceans over the last few years. Hundreds of fishing nets are lost at sea every year.
There are about 6.4 million tonnes of foreign trash that enter the ocean each year.
Ten percent of this amount is made of old fishing gear and other plastics, like nets.
Between 500,000 and 1 million tonnes of nets are thrown into the ocean each year.
Marine scientists say that there are about 2.7 miles (4.4 kilometers) of old fishing nets per square kilometer in each fishing ground.
The nets hurt a lot of fish and other aquatic animals when they come into contact.
A lot of fishing nets often end up in open water after they are thrown away in the sea. The animals in the sea are at risk because they can easily get stuck.

A link to more news about ghost nets is here.

HOW MANY GHOST NETS ARE IN THE OCEAN?

They don’t know exactly how many ghost nets are in the ocean. But, the estimated number is getting bigger each year. Experts say that the ocean holds about 640,000 tonnes of nets.

In the ocean, the nets are mostly found on the bottom. This makes them even more dangerous because most marine mammals get their food from the bottom of the ocean.

International waters are the most affected. This is because they have a larger amount of boat traffic.

WHERE DO GHOST NETS COME FROM?

Different ways lead ghost nets to the ocean. Most of the time, fishing nets are intentionally thrown into the ocean:

Accidental Snags

-Some fishing practices, like trawling, can make nets get caught on the bottom of the ocean. This can be dangerous. They can tear and drift away with the currents if they get caught in something.

Catch Overload

When a lot of fish are caught, nets get overfilled. This could cause the fishing net to tear. Fishermen also often throw fishing nets overboard to make room for more fish on the boat.

Harsh Weather Conditions at Sea

During storms, nets can fall off trawl boats. Dislodged fishing nets may drift away before they are found and brought back.

Illegal Fishing Practices

People who fish illegally may throw their nets into the sea when they are caught by the authorities.

High Retrieval Cost

There is a lot of money that goes into getting ghost nets out of the ocean. It also takes a lot of time and is risky. Fishermen who have lost their fishing nets may want to buy a new one instead of trying to find the one they lost instead.

GHOST NETS SOLUTIONS: HOW TO REDUCE FISHING NETS IN THE OCEAN

Ghost nets damage marine habitats, and they are not good for the sea. They damage coral reefs, kill aquatic animals, and harm marine biomes, which are places that live in the sea:

(i) Recycling Worn Out Fishing Nets

Fishermen should be encouraged to reuse old fishing nets in order to keep the oceans clean.

(ii) Creating Awareness

People who live near the ocean should be taught how to keep marine biomes safe and healthy.

(iii) Making Donations

People can donate to marine conservation groups that work to remove nets from the sea.

GHOST NETS SHOULD BE RETRIEVED FROM THE WORLD’S OCEANS

Abandoned fishing nets have a negative effect on the ocean. They are bad for marine animals and can also lead to the death of important species. Fishermen leave tonnes of fishing gear in the ocean each year, which only makes the problem worse. Government agencies should try to stop the increasing number of harm-causing nets in the ocean. Overall, the world needs healthy oceans to survive.