MEPS 445:53-63 (2012)  -  DOI: https://doi.org/10.3354/meps09470

ABSTRACT: The effects of marine reserves on the growth and mortality rates of 2 commonly exploited (Helcion concolor and Scutellastra longicosta) and 2 rarely exploited (Cellana capensis and Scutellastra granularis) limpets were investigated at 2 reserve and 2 non-reserve sites in South Africa. Two hypotheses were tested: (1) growth of commonly exploited species would be reduced in reserves due to higher densities and stronger intraspecific competition, with no effect for rarely exploited species; (2) commonly exploited species would show higher mortality rates outside than inside reserves, with no effect for rarely exploited species. Both the exploited H. concolor and C. capensis (sometimes mistaken for H. concolor by harvesters) exhibited faster growth at non-reserve sites where their densities were generally lower. No effect of reserve status was detected for the growth rates of S. granularis (rarely exploited) or S. longicosta (commonly exploited). S. longicosta showed no reserve effect on growth because it is territorial, and density has no effect on territory size. Reserve effects were only observed for the survival probability of S. longicosta, the most commonly exploited species, and the probability of capture (but not survival) of the 2 rarely exploited species. The results indicate that the effects of reserves on growth and mortality are species-specific and are difficult to generalize even within the categories of commonly and rarely exploited limpets. 

KEY WORDS: Helcion concolor · Cellana capensis · Scutellastra longicosta · Scutellastra granularis · Growth rate · Mortality rate