Assessment of wild spiny lobster stocks on the Brazilian continental shelf

Abstract

The red spiny lobster Panulirus argus (Latreille, 1804) and the green spiny lobster Panulirus laevicauda (Latreille, 1817) are the most abundant and commercially valuable lobster species on the Brazilian continental shelf. Though sold on the domestic market, the painted spiny lobster (Panulirus echinatus Smith, 1869) and the slipper lobster (Scyllaridae) are of little economic importance and have been the object of very little research. Brazilian spiny lobster fisheries have been in decline for many years due to growth overfishing, including the capture of undersized specimens (>50%). Furthermore, fishing berried females and older lobsters from deeper waters (≥50 m), compromising the reproductive potential of the species and increasing the risk of low recruitment and fishing collapse. The setting of quotas on catches is in itself insufficient to protect Brazilian lobster stocks. Management efforts should instead focus on the enforcement of control measures in order to increase lobster stocks. In this study we make several recommendations: (i) lobster traps should be furnished with escape gaps for undersized lobsters, (ii) the use of undersized lobsters (decoys) in traps should be avoided, (iii) gillnets (“cacoeira”) and artificial shelters (“marambaia”) should be eliminated, (iv) an optimal minimum legal size should be established (80 mm CL for all spiny lobster species and 85 mm CL for slipper lobsters), (v) a maximum legal size should be established (135 mm CL for P. argus and 100 mm CL for P. laevicauda of both sexes), (vi) the capture of berried females should be prohibited, (vii) a closed season should be instituted to protect ovigerous females and ensure recruitment, (viii) establishment of marine reserves or a total closed season to protect the juveniles in nursery areas, (ix) a monitoring program collecting catch and effort data should be implemented to help assess lobster stocks adequately, and, (x) stratified random sampling must be implemented.