Trap nets

Key details

• Features: proven globally, cover a small area, support local fisheries
• Benefits: low bycatch, minimal contact with habitat, low mammal interactions
• Locations: shallow waters, rivers and semi-enclosed bays
• Species: javelin fish, mullet, jewfish, bream, barramundi
• Existing commercial fisheries: Europe (e.g. Sweden, Germany) and North America (fish survey)

Design

The trap nets are comprised of the trap section, wings on either wide, and a lead net. Floats and lead core ropes are used to support the structure.

There are 2 wings on either side, typically 100 metres or less in length. They are made of thick visible mesh to prevent entanglement.

The leader or lead net guides fish toward the trap.

The trap section holds the catch and must never go dry to keep the catch alive. It has a surface float attached to the top of the trap, providing access to airspace at the top of the trap. The front of the trap has a metal grid with bar spacings that allow fish to enter the trap but exclude larger animals.

Passive gear, active fish

Trap nets are a passive fishing gear that guide fish into a funnel-shaped system of nets.

Fish swim along the lead net, entering the funnel and eventually reaching the final trap chamber.

Trap nets are anchored to the seabed and stretch toward the shore or coastline, often set in shallow bays or large river systems. The gear is usually set in place for single- tide cycle or multiple-tide cycles (up to 3 days) before live fish are harvested.

Trap nets cover a small spatial area and are operationally limited to relatively shallow waters. Depending on where and how trap nets are set they can be a labour-intensive gear type.

Old gear, new to Australia

Trap nets have been used for centuries in Europe and are particularly common in Finland’s Archipelago Sea and the Baltic Sea, where they support small-scale, seasonal fisheries for herring and other coastal species.

In addition to their commercial use, they are a gear type regularly used by researchers across North America to survey fish populations as well as being a common gear type employed as an alternative to gillnets.

Live catch and sorting

Trap nets allow for live catch and sorting. Fishers can release non-target species and undersized fish immediately with high survival rates.

In Finland’s Archipelago Sea, studies show that herring trap nets effectively target schooling fish with minimal bycatch and stable catch rates.

The design of trap nets enables fishers to make decisions about what to keep or release, reducing waste and improving stock management.

Low environmental impact

Trap nets are stationary and not towed so they have minimal contact with the seabed. The gear is typically seasonal and removed between uses, making this method compatible with sensitive marine habitats.

Research from the Baltic Sea confirms that trap nets provide low-impact fishing, especially when modern materials and construction are used.

Efforts to address mammal interactions, like using seal-resistant mesh and the development of a floated system known as a pontoon trap, have also been used in overseas applications of this gear type.

Supports local fisheries

Trap nets support sustainable small-scale fisheries that are economically and culturally significant.

In Finland, they are commonly used in seasonal herring fisheries during spawning migration. The fisheries are typically run by family businesses or cooperatives, and the gear is adapted for easy maintenance and long-term use. The simplicity and adaptability of trap nets make them well-suited for regional fisheries in Australia.

More information

Fish-LIGHT is led by the Department of Primary Industries, and co-funded by the:

• Queensland Government
• Fisheries Research and Development Corporation.

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