Protocol Details for Monitoring Aquatic Nuisance Species

Protocol Details for Monitoring Aquatic Nuisance Species Protocol Details for Monitoring Aquatic Nuisance Species

Fish - Sea Lamprey

Rivers and Creeks - non-wadable

Qualitative:

Quantitative:

Yes

Rapid Assessment:

Specs:

Quantitative sampling

Distance:

Plot size is standardized by the area sampled by the hood of the deep water electrofisher (.61 m2 ). Since 4 plots are sampled at each site, the area sampled by the Deep Water Electro Fisher at each site equals 2.44 m2 (4 X .61). Care must be taken not to overlap plots on successive drops at a site.

Frequency:

Gear:

electroshock boat

Method:

Larval density sampling with the deep water electrofisher is achieved by electrofishing at sites spaced equidistantly along transects. Four drops are made at each of 80 sites resulting in a total of 320 drops (4 drops X 80 sites) in each survey area.

After the transect is measured, the DWEF boat is navigated to the first sampling location. The vessel is anchored, habitat is classified, and the following procedures are followed:

1. The deep water electrofisher is lowered by one of the two crew members. The electrofisher is energized for 30 seconds during each of the four drops. Each time the electrofisher is energized the voltage gradient in the bell is adjusted to 0.7 volts/cm as measured on a digital display on a volt meter attached to the AbP-II electrofisher. The catch of larvae for the plot is recorded as the sum of the 4 drops.

2.GPS coordinates are recorded and the vessel moves to the next sampling location along the transect.

DWEF surveys will be conducted using the values for the parameters listed in Table 2. These settings will be used without exception until the Assessment Task Force recommends a change based on further study.

Table 2. Standardized Deep Water Electrofisher Settings

Slow Pulse

Burst

Volt Range

Rate

Duty Cycle

DWEF

3pps

10%

2:2

To achieve 0.6 to 0.8 V/cm

MDEF

3pps

10%

2:2

To achieve 2.5 to 3.0 V/cm

Comments:

Reference 1

author	Larval Assessment Work Group of the Sea Lamprey Management Program
Date	2003
Title	Larval Assessment Sampling Protocol for Non-wadable Waters of the Great Lakes and its Tributaries
pages	15 pp

Reference 2

Reference 3