Salmonid Field Protocols Handbook: Techniques for Assessing Status and Trends in Salmon and Trout

Fyke Nets (in Lentic Habitats and Estuaries)

Jennifer S. O’Neal

doi: https://doi.org/10.47886/9781888569926.ch20

Fyke netting is a passive capture method used for sampling juvenile salmon and steelhead Oncorhynchus mykiss that use lentic habitats and estuary areas and, in some cases, stream habitats. Fyke nets are large hoop nets with wings (and/or a lead) that are attached to the first frame and act as funnels to direct swimming fish into the trap (see Figure 1). The second and third frames each hold funnel throats, which prevent fish from escaping as they enter each section. The opposite end of the net may be tied with a slip cord to facilitate fish removal. These nets are typically used in shallow water (where the first hoop is less than 1 m under the water’s surface), although some lake studies have used fyke nets where the water was as deep as 10 m over the first frame. This deep-set approach has resulted in comparable data to shallower sets, except for 0-age fish where the deeper sets had lower catch values.

The net is set so that the leads intercept moving fish. When the fish try to get around the lead, they swim into the enclosure. Leads and wings are held in place by poles or anchors. Modified fyke nets have rectangular frames to enhance their stability. The square or rectangular frames prevent the net from rolling on the bottom substrate (Hubert 1996). Fyke nets are suspended between buoyant and weighted lines much like a gill net.

Fyke nets have their origins in salmon wing nets and have been used in river fisheries for hundreds of years. According to Kustaa Vilkuna, a Finnish academic, large fyke nets were used in Finnish sea regions to catch herring, whitefish, and salmon. The size of the catch determined the mesh size of the netting used. The first version of this fyke net was used in Finland before anyone registered the invention of a new gear. From that area, it was adopted in the Vaasa archipelago to be used as a herring trap in the 1860s. On the coasts of Sweden, the gear was first called “finnryssja” meaning “the Finnish trap net.”