Removable Hydrofoils Which Permit Surface And Bottom Sampling With A Single Otter Trawl
A rapidly installable and removable hydrofoil permits a single otter trawl to be used for both surface and bottom sampling. The hydrofoil is airplane-wing shaped in cross section and is three feet long, ten inches wide with a two inch maximum thickness. It is mounted on a fifteen degree wedge and secured to the top edge ofeach otter board. Conversion of doors from one mode of sampling to the other can be done in about one minute. As part of the Maryland anadromous fish studies, I young-of-the-year c1upeids and other species were collected by otter trawling on the bottom and surface of...
