ABSTRACT 



The Gulf -II semiautomatic plankton sampler was developed for study- 

 ing heterogeneous plankton distribution in the Gulf of Mexico . By means of 

 a circular rotating trough, eight consecutive hourly samples are collected 

 on removable disks of bolting silk. The sampler collects continuously re- 

 gardless of sea conditions, the intake being through the hull of the vessel at 

 the lowest point possible. Water flow through the sampler is metered 

 directly. Construction details and specifications are provided. 



