Purse seine fishing is mainly used to catch fish species that swim in large schools near the ocean surface.
The main species fished with purse seine gear are southern bluefin tuna, Australian sardine, blue mackerel and jack mackerel.
How purse seine works
In a purse seine the top of the net is floated at the ocean’s surface and the bottom of the net has weights attached that pull the walls of the net downwards.
The bottom of the net has a wire threaded through it which is pulled and tightens the net like a purse trapping the fish inside.
The net is then pulled in toward the boat and the catch is either pumped or lifted out with small nets or the whole net is brought aboard.
The size of purse seine nets can be varied, depending on what species is being targeted.
Environmental impacts and management
The purse seine method of fishing is very selective as it usually targets only one species at a time. This means that there is very little impact from purse seine fishing on other marine species. Purse seine nets are set near the ocean surface and do not touch the sea floor, so their impact on the marine environment is also very small.
In some countries, purse seine nets may be set around a floating object such as ocean debris. These objects are called Fish Aggregating Devices (FADs) and large numbers of fish are often attracted to these. This means that if a purse seine net is set around a FAD, many other marine species may be caught. The use of FADs for purse seine fishing is not allowed in Australia.