Potential fishery benefits of Marine Protected Areas (MPAs) are widely acknowledged, yet seldom demonstrated, as fishery data series that straddle MPA establishment are seldom available. Here we postulate, based on a 15-year time series of nation-wide, spatially referenced catch and effort data, that the establishment of the Goukamma MPA (18 km alongshore; 40 km 2 ) benefited the adjacent fishery for roman (Chrysoblephus laticeps), a South African endemic seabream. Roman-directed catch-per-unit-effort (CPUE) in the vicinity of the new MPA immediately increased, contradicting trends across this species' distribution. The increase continued after 5 years, the time lag expected for larval export, effectively doubling the pre-MPA CPUE after 10 years. We find no indication that establishing the MPA caused a systematic drop in total catch or increased travel distances for the fleet. Our results provide rare empirical evidence of rapidly increasing catch rates after MPA implementation without measurable disadvantages for fishers.

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The dispersal of the surf-zone teleost galjoen (Coracinus capensis) from the De Hoop Marine Reserve, South Africa, was investigated. Over a period of 5.5 yr, 11 022 galjoen were tagged in the centre of the reserve. Most of the 1008 recoveries were at the site of release, while the remainder covered a distance of up to 1040 km. There was no difference with respect to age, sex, or season between those that dispersed and those that did not. Six models were developed to test the hypotheses that (1) galjoen are polymorphic with respect to dispersal behaviour, (2) nonreporting of tags masks a random dispersal process, and (3) the recovery distribution is the result of unequal movement rates in different areas. It is inferred from the likelihoods of the various models that the tagged population was polymorphic, with fish displaying either resident or nomadic behaviour. This conclusion is unaffected by a large uncertainty in the extent of nonreporting of recoveries, or by spatial variability of movement rates. The estimate of emigration from the reserve implies that the unharvested reserve population is restocking adjacent exploited areas with adult fish.

A discrete, space-time, age-structured model of a fishery was developed to test the effect of marine reserves on yield of fish to recreational angling. The model was applied to three sympatric surf-zone species commonly targeted by shore-anglers. Movement rates of white steenbras Lithognathlls litllOgnatlrlls and galjoen Diclristius ('(/pensis, both of which are nomadic, were estimated from tag-recovery data. Because post-recruit blacktail Diploe/us SUl~~uScapensis are resident. a coefficient of passive larval diffusion was estimated from drogue-separation rates. Marine reserves cannot increase the yield-per-recruit of white steenbras, although the spawnerbiomass-per-recruit responds positively. A "recruitment-spawner-biomass" function was applied to galjoen and blacktail. The yield of galjoen increased sharply as the size of area conserved increased. Small reserves, closely spaced, appeared to be optimal for blacktail. A range of reserve size and spacing combinations satisfied management criteria for the three fisheries. Because of the assumption of a uniform coastline, and the unknown extent of effort displacement by reserves, the results are too general to be of specific value, but they do suggest that management of multi species fisheries by the use of marine reserves is a viable option. With the availability of site-specific data, the model can be applied to evaluate the effect of existing or proposed marine reserves.

This study was designed to establish whether populations of fish species important in the catches of rock and surf anglers increased following the proclamation of the De Hoop Marine Reserve on the southern coast of South Africa Catch per unit effort (CPUE) and size frequency distributions of angling species were monitored approximately monthly by angling from the shore at 2 sites in the reserve. At one site sampling commenced 2 yr before the reserve was established and continued 4.5 yr thereafter, allowing comparisons of periods of exploitation and protection. The other site had a long history of minimal exploitation and data collected there 2 . 5 to 4.5 yr after complete protection was considered to represent an unexplolted condition. Ten species accounted for 99% of the catch. Following establishment of the reserve. CPUE increased for 6 of these (galjoen Coracinus capensis, dassie Diplodus sargus, wildeperd D. cervinus, white steenbras Lithognathus lithognathus, Cape stumpnose Rhabdosargus holubi and musselcracker Sparodon durbanensis) The catch rates of 2 species (C. capensis and D. sargus) improved 4 to 5 fold within 2 yr of protection and remained at these high levels, which were similar to the unexploited catch rates. Recoveries were slower amongst the other 4 species, their catch rates reaching 30 to 60% of the unexploited level after 2 . 5 to 4.5 yr of protection This study provides evidence of general stock recoveries of exploited fish species in a shallow marine habitat following protection within a marine reserve.

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The effects of fishing on the population structure and life history of roman Chrysoblephus laticeps, a protogynous hermaphroditic seabream from South Africa, were investigated by comparing fish from protected and exploited areas. Experimental (controlled) fishing and underwater visual census were used to sample roman and to measure population parameters inside and outside the Goukamma Marine Protected Area. Sites chosen for comparisons were adjacent and physically similar to reduce environmental influences on the comparison. Both methods revealed that roman had a higher density and mean size inside the protected area than outside. Age-at-maturity and ageat-sex-change were lower in the exploited area. The shift in age-at-sex-change maintained a constant sex ratio between the exploited and unexploited areas. The condition factor of roman from the protected area was lower than that of roman from the exploited area.KEY WORDS: Fishing effects · Life history · Population structure · Chrysoblephus laticeps · Sparidae · Marine protected area · Sex change Resale or republication not permitted without written consent of the publisherMar Ecol Prog Ser 362: [245][246][247][248][249][250][251][252][253][254][255][256][257][258][259] 2008 demographic differences between areas (Robertson et al. 2005). As Hilborn & Ludwig (1993) point out, this makes the research in this area of science more difficult, and progress is largely determined by how many replicates can be performed, the difficulty or impossibility of obtaining controls, and whether environmental treatments can be randomized. Despite these difficulties, we have chosen this approach to study the effects of fishing on reef fish in South Africa for 2 reasons.Temperate reef fish are the most heavily exploited of marine fishes in South Africa, a predicament that is exacerbated by their slow growth, longevity and hermaphroditic life-styles (Buxton 1993). With the collapse of many species (Griffiths 2000, Griffiths & Lamberth 2002) the line fishery has been declared to be in a state of emergency. The absence of suitably archived data or long-term data series on catch-at-age and ageat-maturity prevents us from analyzing temporal changes in reef fish life-history and production traits. The only realistic option, therefore, is contemporary comparison between areas that have been subjected to different rates of fishing.Sex-change in some coral reef fish is known to be density dependent (Collins et al. 1998), yet this characteristic is one of the least well-known agents of density-dependent population regulation (Rose et al. 2001). Sánchez-Lizaso et al. (2000) review studies examining density-dependent changes in life-history traits of exploited populations. They suggest that Marine Protected Areas (MPAs) should be a useful tool for testing the common hypotheses; however, definitive results from comparative studies have been unclear. Two such studies on reef fish that reported some effects that were opposite to what one might expect are of importance here:(1) Lloret ...