The South African commercial rock-lobster industry employs an average soak
time of 22 h for traps. Experiments were undertaken to test
(1) the rate of bait loss with soak time and the effect
that protection of the bait has on bait loss, (2) the
relationship between catch rate (numbers per trap) and soak time for traps
with either protected or unprotected bait, and (3) the
effect of two bait types (whole maasbanker and hake heads) on the catch of
rock lobsters. There were substantial losses of unprotected bait within 6 h;
substantially less weight loss was observed from protected bait even after a
48-h soak time. The numbers of rock lobsters caught in traps with unprotected
bait were low relative to the capture rate with protected bait. The highest
capture rate occurred after 6 h for unprotected bait and 6–12 h for
protected bait. There was no significant effect of bait type (maasbanker
v. hake heads) on the number or size of rock lobsters.
To optimize catch efficiency, the commercial industry should use protected
bait and soak times as short as 6–12 h.
Lance van Sittert explores the historical records concerning the exploitation of marine resources along the West Coast of Africa, using them to provide evidence of the commerical importance of the West Coast over the East or South. The date demonstrates a boom-bust cycle along the West Coast, pertaining to whales, snoek, guano, rock lobster, hake, and pilchard.
Climate change impacts on working people (the HOTHAPS initiative): findings of the South African pilot study
