THE RESPONSE OF TROPICAL ATLANTIC DECAPOD CRUSTACEANS TO ARTIFICIALLYLIGHTED TRAWLS

Micronektonic decapod crustaceans were sampled repeatedly at a depth o f 200 +/- 25 m at two positions centred on 20-degrees 30'N, 19-degrees 40'W and 31-degrees 10'N, 21-degrees 05'W to assess their response to an artificial light fitted to an opening/closing rectangular midwater trawl. Of the 20 decapod species identified, the numbers and biomass of the three numerically dominant diel migrants Oplophorus spinosus, S ystellaspis debilis and Acanthephyra purpurea were significantly reduc ed in hauls taken with the artificial light switched on, when compared with catches with it switched off. There was little measurable respon se in the frequently occurring species Gennadas valens or Gennadas bre virostris, or in other less frequently occurring species.