The spotted gully shark Triakis megalopterus (Triakidae) is a mesopredatory species endemic to southern Africa. It is currently listed as Least Concern on the IUCN Red List in accordance with an estimated increase in population size, general release by recreational linefishers and incidental catches in the commercial linefisheries. Previous research suggests this species to be resident, and as such it is likely to receive protection in coastal marine protected areas (MPAs). However, its ecology and movement behaviour remain poorly studied. This study employed acoustic telemetry to provide information on the species' movements along the coast of the Western Cape Province, South Africa. We used network analyses to investigate movement randomness, associations between individuals, sexual segregation, and the effectiveness of MPAs. Our findings reveal nonrandom movements as well as patterns of co-occurrence between individuals. Spatial network analysis suggested sexual segregation, because areas of high use (Walker Bay and De Hoop) differed between males and females. Co-occurrences were observed exclusively in Walker Bay, chiefly between males, with no co-occurrence found between females. The tagged spotted gully sharks were not detected extensively within existing MPA boundaries, though there was no significant difference between their movements inside and outside protected areas for both sexes.

Haploblepharusis an understudied genus comprising four recognized scyliorhinid species that are endemic to southern Africa. Species identification within this group has historically been problematic due to a high degree of morphological conservatism among congeners, further complicated by the possibility of interspecific hybridization. This study describes the development of two microsatellite panels comprising 10 polymorphic markers for the puffadder shyshark,Haploblepharus edwardsii. The markers were characterized in 35H. edwardsiispecimens and tested for cross-species utility inHaploblepharus fuscus,Haploblepharus pictus, and the more distantly related scyliorhinidHalaelurus natalensis. Genetic diversity statistics were estimated for each species, and the presence of population differentiation was tested for inH. edwardsiiandH. pictus. Furthermore, interspecific genetic differentiation was examined to infer the potential use of these markers for species identification as well as for detecting signatures of admixture amongHaploblepharusspecies. All microsatellite markers were polymorphic in each species, with polymorphism information contents ranging from 0.43 to 0.62. Population differentiation was only evident forH. pictus, where genetic discontinuity was detected among geographically distant sampling sites. Statistically significant differentiation (fixation index between populationsF(ST)= 0.091 to 0.382) was found between all species; however, the level of differentiation betweenH. fuscusandH. pictuswas low in comparison and seemingly at a population level rather than at a species level. Species assignment using Bayesian clustering analysis resulted in approximately 57% of 88 genotyped specimens being unambiguously assigned to a distinct genetic cluster that confirmed accurate taxonomic assignment. Overall, the low levels of differentiation together with the presence of distinct and admixed genetic clusters suggests a recent divergence and possible contemporary hybridization within the genusHaploblepharus.As such, conservation strategies should be focused on the generic level until such a time thatHaploblepharusspecies can be readily identified.

Catch-and-release (C&R) is increasingly popular in recreational fisheries as it is thought to protect target species while still allowing anglers to continue recreational fishing activities. Several studies have highlighted high rates of mortality and many sub-lethal effects which ultimately have a negative impact on fish population viability. With poorly developed handling practices, the fish that are released suffer the consequences of physical and physiological stress and do not always survive, thus making the ethics of catch-and-release fishing questionable. Many studies have contributed to our understanding of the factors that influence the fate of fish released by anglers. Despite this, the few interventions which have relied on the knowledge-attitude-behavioural strategy have had little success in improving angler C&R behaviour. The broader pro-environmental behavioural strategies however hold some potential for improving angler C&R behaviour. To test their potential, we partnered with the South African Rock and Surf Super Pro League (RASSPL Africa), the biggest exclusively C&R competitive shore-based angling league in South Africa. The first two years (2013 and 2014) of the partnership were purely focused on building trust and relationships and making observations on angler behaviour. In 2015, we collected baseline data on angler behaviour and fish health during the RASSPL national fishing competition. This was followed by comparable data collection at the following two national competitions in 2016 and 2017 after the introduction of a combination of pro-environmental behaviour interventions, including rule changes, improving angler knowledge, behavioural modelling, rewards, penalties and feedback to improve C&R behaviour. There was a significant decline in the time taken by an angler to place their fish into a C&R bucket and reduction in total air exposure of the fish during a C&R event. There were also improvements in the health of the fish, with a decline in the blood lactate concentration and mean reflex action mortality predictors (RAMP's) scores for the dominant elasmobranch and teleost species. The findings of this study suggest that pro-environmental strategies hold potential for improving the C&R behaviour of anglers and the health of released fishes. It is suggested that interventions to improve C&R behaviour should aim to develop long-term relationships, and implement a broad range of well communicated strategies based on reliable data and sound rationality.

The tope shark (Galeorhinus galeus Linnaeus, 1758) is a temperate, coastal hound shark found in the Atlantic and Indo-Pacific oceans. In this study, the population structure of Galeorhinus galeus was determined across the entire Southern Hemisphere, where the species is heavily targeted by commercial fisheries, as well as locally, along the South African coastline. Analysis was conducted on a total of 185 samples using 19 microsatellite markers and a 671 bp fragment of the NADH dehydrogenase subunit 2 (ND2) gene. Across the Southern Hemisphere, three geographically distinct clades were recovered, including one from South America (Argentina, Chile), one from Africa (all the South African collections) and an Australia-New Zealand clade. Nuclear data revealed significant population subdivisions (FST = 0.192 to 0.376, p<0.05) indicating limited gene flow for tope sharks across ocean basins. Marked population connectivity was however evident across the Indian Ocean based on Bayesian clustering analysis. More locally in South Africa, F-statistics and multivariate analysis supported moderate to high gene flow across the Atlantic/Indian Ocean boundary (FST = 0.035 to 0.044, p<0.05), with exception of samples from Struisbaai and Port Elizabeth which differed significantly from the rest. Discriminant and Bayesian clustering analysis indicated admixture in all sampling populations, decreasing from west to east, corroborating possible restriction to gene flow across regional oceanographic barriers. Mitochondrial sequence data recovered seven haplotypes (h = 0.216, π = 0.001) for South Africa, with one major haplotype shared by 87% of the individuals and at least one private haplotype for each sampling location except Port Elizabeth. As with many other coastal shark species with cosmopolitan distribution, this study confirms the lack of both historical dispersal and inter-oceanic gene flow while also implicating contemporary factors such as oceanic currents and thermal fronts to drive local genetic structure of G. galeus on a smaller spatial scale.

Chondrichthyans (sharks, skates, rays and chimaeras) are captured in many marine fisheries. Management and research efforts directed at chondrichthyan fishing are often neglected because of low product value, taxonomic uncertainty, low capture rates, and harvesting by multiple fisheries. In South Africa's diverse fishery sectors, which include artisanal as well as highly industrialised fisheries, 99 (49%) of 204 chondrichthyan species that occur in southern Africa are targeted regularly or taken as bycatch. Total reported dressed catch for 2010, 2011 and 2012 was estimated to be 3 375 t, 3 241 t and 2 527 t, respectively. Two-thirds of the reported catch was bycatch. Regulations aimed at limiting chondrichthyan catches, coupled with species-specific permit conditions, currently exist in the following fisheries: demersal shark longline, pelagic longline, recreational line, and beach-seine and gillnet. Limited management measures are currently in place for chondrichthyans captured in other South African fisheries. Catch and effort dataseries suitable for stock assessments exist for fewer than 10 species. Stock assessments have been attempted for five shark species: soupfin Galeorhinus galeus, smoothhound Mustelus mustelus, white Carcharodon carcharias, spotted ragged-tooth Carcharias taurus, and spotted gully Triakis megalopterus. Fishery-independent surveys and fishery observer data, which can be used as a measure of relative abundance, exist for 67 species. Compared with most developing countries, South African shark fishing is relatively well controlled and managed. As elsewhere, incidental capture and bycatch remain challenges to the appropriate management of shark species. In 2013, South Africa's National Plan of Action for the Conservation and Management of Sharks (NPOA-Sharks) was published. Implementation of the NPOA-Sharks should help to improve chondrichthyan management in the near future.

A quantitative analysis of the stomach contents of blue sharks (Prionace glauca) caught in recreational shark fishing tournaments in Nova Scotia, Canada tested for dietary differences based on sex, maturity and tournament location across 3 sampling years (19992001).Of 706 sharks examined, 303 stomachs (43%) were everted, 131 (19%) were empty, 231 (33%) contained food items and 41 stomachs (5%) were not examined.Pelagic teleosts and groundfish were found in 19% and 14% of examined blue shark stomachs, respectively.Stomach fullness did not differ between sexes or maturity category.Differences existed between the diet of immature and mature males as well as between immature females and immature males, suggesting sexual segregation during feeding.The frequency of occurrence of pelagic teleosts and groundfish changed across sampling years.Blue sharks off Nova Scotia appear to be opportunistic predators, consuming a wide range of fish species, mammalian tissues and inanimate objects.