towing 

 points 







towing 

 points 



tow 

 direction 



51cm -• 



p— 47 cm - — h 





/ 



PLAN VIEW FLOAT 



6.3mm holes 

 10 cm centres 



float bolts to 

 top of box 



63mm x 25mm 

 stainless bolts 



SIDE ELEVATION 



6.3 x 25mm 

 stainless bolt 



1.2 x 3cm 

 alum, channel 



net collar with 

 rope sewn in 



6.3mm rope 

 stainless nut 



I5cm 



47 cm 

 51 cm 



NET ATTACHMENT DETAIL 



L.SIDE ELEVATION FLOAT 



to accept standard 1/4 m 2 

 (184 cm circum) plankton net 



EF 



46cm 



-46cm 



B- 



15x5 x 0.5cm 

 reinforcing pads 

 welded both 

 sides 



9.5mm x 25mm 

 stainless bolt 



5cm — ► 



wing 



depressor 



^ 



32mm marine alum, 

 folded a welded at 

 one corner. 



9.5mm x 38mm 

 stainless bolt 



6.3mm holes 

 19mm o.c. 



09.5 mm 

 holes 



61cm 



2.5cm 



06.3mm 

 holes 



BOX - FRONT ELEVATION 



R=IOcm- 



BOX- L.SIDE ELEVATION 



Figure 2.— Scale drawings of the sampler body and float, and net attachment detail. 



Flowmeter 



A General Oceanics meter is attached inside the 

 body by means of a hinged strut which folds forward 

 to facilitate reading the meter (Figs. 1, 3). The meter 

 is free-pivoting in the horizontal plane and offset 17 

 cm from the center of the mouth opening. 



Evaluation 



This modified version of the otter neuston sampler 



has been used extensively since 1981, offshore to 

 Station Papa (Mason et al. 1983) and in inside waters 

 under all weather conditions, including a full gale. 

 It performs best when towed into or across the wave 

 direction at 4-6 knots. At higher speeds, disturbance 

 due to backsplash from the fins and bridal may 

 cancel out potential advantage of further increase 

 in tow speed. Sampling efficiency is deemed to be 

 relatively high when using a 500 pjm mesh net at 

 night. Catches of juvenile fishes in the Strait of 

 Georgia are quantitatively comparable with those 



482 



