Negative effects of commercial fishing

Many unregulated and unregulated commercial fishing affects the health of Victoria’s oceans, fisheries, communities and economies.

Bycatch of Vulnerable Species

The animals are sorted from the lucrative catch and discarded back into the water, often dead or injured. While populations of these bycatch species may not be threatened, the accidental killing of individual animals in some fisheries can be significant, with implications for marine food webs.

What is


Bycatch can be fish, but also includes other animals such as dolphins, whales, sea turtles, and seabirds that become hooked or entangled in fishing gear.

Diver trying to rescue a leatherback turtle caught in a net.

It is estimated that over 300,000 small whales, dolphins, and porpoises die from entanglement in fishing nets each year, making this the single largest cause of mortality for small cetaceans. Species such as the vaquita from the Gulf of California and Maui’s dolphin from New Zealand face extinction if the threat of unselective fishing gear is not eliminated.
Hundreds of thousands of endangered loggerhead turtles and critically endangered leatherback turtles drown annually on longlines set for tuna, swordfish, and other fish. Incidental capture of turtles by longlines, trawls and gillnets is the single greatest threat to the survival of most populations.

Habitat destruction

Heavy or large gear can harm the environment when fishing. Some fishing methods, such as dredging and bottom trawling, affect bottom habitats. In areas where benthic species such as deep-sea corals are sensitive, fishing gear can cause long-term damage.

How to impact?


Dredging is a practice commonly used to harvest clams and employs a large metal scoop that drags along the seafloor to pick them up. The process also churns up sediments along the seafloor, causing them to become suspended in the water column, decreasing water quality.

Seafloor trawling

Seafloor trawling, in which equipment is pulled across the seafloor to catch bottom-dwelling fish, decreases the biomass and production of benthic species.

Get to know how to reduce the negative impact