The trays were essentially shallow metal boxes laid upside down on the bottom, in which rotenone poison was applied. Fig. 9 gives details of the construction of a tray. Fig. 10 shows the trays ready for use on the deck of the vessel "Cottus". The trays were set over the stern of the vessel "Cottus" in as near a straight line as possible. When set on the bottom, S.C.U.B.A. (Self-Contained Underwater Breathing Apparatus) divers were employed to turn the trays with the open side against the sand and to bed them down to seal the bottom edge to the sand. Trays were left on the bottom for 24 hours; they were then revisited by S.C.U.B.A. divers who carefully inverted them and collected any dead animals from underneath. FoLlowing this, the trays were hauled aboard and re-set at the next location. Repeating this technique, 4 strings or 40 trays could be conveniently examined and re-set each day. The trays were used along the 20 ft and 30 ft isobaths.

Most deep water sampLing was carried out using an anchor dredge designed especially for the purpose. This dredge, shown on the deck of the "Cottus" in Fig. 12, consists essentially of a sharpened steeL plate which is dragged at an angle to the bottom and which scoops substrate into a bag behind. The effective width of the dredge was two feet, its length 9 feet three inches, and its weight 208 lbs. It was used at depths from 6 to 124 feet. Physical data for the bottom at each haul was recorded and collections of all fauna captured in the dredge were made.