Effects of haul duration on the physical condition of sprat larvae

Abstract

A BIOMOC (BIOlogical Multiple Opening Closing) plankton net was used to collect Baltic sprat Sprattus sprattus larvae at discrete depths of the Bornholm Basin, central Baltic Sea. This stratified sampling regime revealed haul-time-dependent damage of the larvae as defined by the absence/presence of eyes and guts and the overall degree of damage, resulting in significant weight differences between larvae with different degrees of damage. Additionally, long haul durations were found to compromise the retention of gut contents. Our findings suggest revision of current standard catching procedures with respect to the investigation of the feeding ecology and the nutritional condition of larval fish. © Inter-Research 2007.