E. Sosacordero et al., ARTIFICIAL SHELTERS FOR SPINY LOBSTER PANULIRUS-ARGUS (LATREILLE) - AN EVALUATION OF OCCUPANCY IN DIFFERENT BENTHIC HABITATS, Journal of experimental marine biology and ecology, 229(1), 1998, pp. 1-18
In spiny lobster, Panulirus argus (Latreile), fisheries in Cuba, Mexic
o and the Bahamas, artificial shelters (casitas) are successfully used
as fishing gears. However, the mechanisms underlying the operation of
these artificial shelters and their long-term effects on the resource
and benthic communities are unclear. Lowered predation-induced mortal
ity due to casitas has led to the proposal that they be placed in bent
hic habitats with adequate food, but where natural shelter is lacking.
In this study, firstly the availability of natural habitat types was
measured and secondly, habitat features which could influence the occu
pancy of artificial shelters by lobsters were evaluated. Casitas were
placed in benthic habitats differing in the relative availability of s
eagrass and hard bottom. Spiny lobsters and faunal assemblages were mo
nitored from December 1993 to July 1994 at six stations, two for each
benthic habitat type. The study area was a typical spiny-lobster nurse
ry area, with bottom cover dominated by seagrass and macroalgae (79.7%
); while hard bottom, including patch reef, amounted to only 0.2%. Hen
ce, a population bottleneck probably occurred, negatively affecting po
stalgal juveniles and subadult lobsters. The results suggest that seag
rass availability was the key factor determining casitas' occupancy by
lobsters. The lowest occupancy was found where seagrass was scarce an
d hard bottom was available. Given seagrass availability, casitas harb
ored a similar number of lobsters irrespective of the hard bottom avai
lability; allowing to infer that artificial shelters provided critical
habitats (refuges) for postalgal and subadult lobsters. The mean size
of lobsters did not vary among stations, and commercial-sized lobster
s were scarce. An index of predator presence showed a significant vari
ation among stations and with time, with higher values from April to J
une. Sea temperature was positively correlated with lobster abundance
and predator index; the latter two variables were not correlated. Thes
e study results support the use of casitas for the enhancement of prea
dult lobster populations. (C) 1998 Elsevier Science BTV. All rights re
served.