Non-target benthic invertebrates are caught as bycatch in huge volumes, but precise numbers are not available.
These devices are incorporated into trawl nets and are designed to give finfish openings for escape while retaining target shrimp species in the rear (codend) of the net. Examples include “skylights” which consist of a mesh opening located at the top of the codend. ”Skylights” can be combined with guiding funnels that create visual and tactile stimuli to direct finfish towards the “skylight” escape sections. A different but similar type of design is the fisheye (including Gulf and yarrow fisheyes and bigeyes) which are openings typically forming a rigid frame constructed of aluminum or steel rods and placed along the top center portion of the codend. These devices create and area of reduced water flow immediately below them that fish can use for swimming behavioral orientation and escape.


