Field teams collect fish by overnight sets of trap nets, minnow traps and gill nets as well as seining after sunset.  Fish sampling is stratified by habitat and random within habitat. 

Both littoral and midlake gill nets are used in this protocol.  Gill nets are set overnight and retrieved the next morning.  Gill net specifications (e.g., length, mesh size) are not given.

This long (55 pg) document describes these methods in detail.

This method employs three separate gears:  gill nets, Fyke nets and electrofishing.

Gill nets:

1)  Should be set in the evening before electrofishing starts and retrieved the next morning

2)  Should be set perpendicular to shore

3) Smallest mesh size should be closest to shore

4)  Although net-nights will be the unit of interest, set time and pick up time are recorded

 The purpose of this sampling is ruffe removal; however, this protocol can also be used to survey fish populations.  Used in early April through the end of May.

A 30.5 XZ 1.8 m small mesh gill net (3.8 cm stretch mesh monofilament twine) is the primary gear used to remove adult spawning ruffe.  A minimun of 4 nets are set per night (week nights) at four locations during the reduction effort.  Overnight sets are used.  Effort is measured as a lift and catch is measured as catch is measured as catch per lift.  Specifications on the gear and protocol are as follows:

Protocol:

1.  Bridles, anchor lines, anchors, buoy lines, and buoys are attached to the gill net.

2.  The net is deployed at the sampling location perpendicular to shore.

3.  Data sheet is completed.

4.  Fish are removed from the net, placed in a basin of water, and sorted by species.

5.  The net is either reset if during the week or removed for the weekend.

Total lenth (mm), weight (g), and sex are recorded for each ruffe captured.  Aging structures (otoliths, dorsal spines, or scales) are removed from all ruffe captured.  Ruffe are then labeled and frozen for future studies or needs.

The total catch per species is recorded for all non-target species and returned to the water alive when possible.

A minimum of 4 lifts per week night is desired per location.  When four locations are fished each week, the total effort is approximately 16 lifts per week.