Pairovet Net Tow

Pairovet Net Recovery

The Pairovet Net is towed vertically through the water column to collect fish egg samples from the upper euphotic zone.

The Pairovet Net consists of paired 25 cm diameter 150 μm mesh nets. The nets are 1.5 m in length; a 0.8 m cylindrical portion joined to 0.6 m conical portion, tapering to a 0.1 m codend. The ratio of mesh aperture area to mouth area is about 8:1. 

The net is towed from 70 meters to the surface, depth permitting. With the survey ship holding a stationary position, 70 m of towing cable are paid out, the net is held at depth for 10 sec, and then retrieved vertically at a rate of 70 m/min. All tows with wire angles exceeding 15 degrees during the ascent are repeated. A 45 kg weight is attached to the end of the towing cable, a few meters below the sampler. 

The starboard sample is preserved in formaldehyde and port sample preserved in ethanol. Back on land, the samples are sorted for ichthyoplankton and archived at the NOAA SWFSC Ichthyoplankton Collection.

Pairovet Net tows are performed at all stations inshore of and including station 70 (weather permitting), except for 20 m SCCOOS stations.