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153 pages, 97 figures, 10 tables, 2 appendixes, Recent studies have shown that coastal and shelf cephalopod populations have increased globally over the last six decades. Although cephalopod landings are dominated by the squid fishery, which represents nearly 80% of the worldwide cephalopod catches, octopuses and cuttlefishes represent ∼10% each. Total reported global production of octopuses over the past three decades indicates a relatively steady increase in catch, almost doubling from 179,042 t in 1980 to 355,239 t in 2014. Octopus fisheries are likely to continue to grow in importance and magnitude as many finfish stocks are either fully or over-exploited. More than twenty described octopus species are harvested from some 90 countries worldwide. The current review describes the major octopus fisheries around the globe, providing an overview of species targeted, ecological and biological features of exploited stocks, catches and the key aspects of management, IGG has been supported by the Japan Science and Technology Agency (Grants J130000263 and AS2715164U). RV has been supported by the Spanish Ministry of Education and Culture (Grant PRX17/00090), Spanish Ministry of Science, Innovation and Universities (OCTOSET project, RTI2018-097908-B-I00, MCIU/AEI/FEDER, EU) and by the Direcció General de Pesca i Afers Marítims, Generalitat de Catalunya. FAFA was supported by a predoctoral fellowship of the MINECO (BES-2013-063551) and an Irish Research Council - Government of Ireland Postdoctoral Fellowship (Ref. GOIPD/2019/460)

Climate change is projected to cause significant reductions in global fisheries catch during the 21st Century. Yet, little is understood of climate change impacts on tropical fisheries, which support many livelihoods, as is the case in the Western Indian Ocean region (WIO). Here, we focus on two central WIO countries ― Kenya and Tanzania ― and run a multi-species fish model (Size Spectrum Dynamic Bio-climate Envelope Model; SS-DBEM) for 43 species of commercial and artisanal importance, to investigate the effects of climate change. We include both national Exclusive Economic Zones (EEZs) as domains. The model was forced by data from a biogeochemical model (NEMO-MEDUSA), run under the high emissions scenario Representative Concentration Pathway (RCP) 8.5, until the end of the 21st century. Impacts of fisheries and climate change were investigated by running SS-DBEM under five scenarios of fishing pressures to predict a range of possible future scenarios. Fishing pressure was represented as the Maximum Sustainable Yield (MSY), expressed as MSY0, MSY1, MSY2, MSY3 and MSY4 representing fishing mortality of 0, 1, 2, 3 and 4 times MSY, respectively. Large reductions in average fish biomass were projected over the 21st Century, with median reductions of fish species biomass of 63–76% and 56–69% for the Kenyan and Tanzanian EEZs respectively across the fishing scenarios. Tunas were particularly impacted by future climate change, with the six modelled species exhibiting biomass reductions of at least 70% in both EEZs for all fishing scenarios during the 21st Century. Reductions in fish biomass were much more severe during the second half of the 21st Century, highlighting the benefits to tropical fisheries of global action on climate change.

The marine fisheries sector is one of the most important income sectors in South Africa and plays an important role in food security for small-scale and subsistence fishers. Climate-driven impacts have resulted in distribution shifts and declines in abundance of important fisheries targets, with negative consequences to the users dependent on these resources. The sustainability of the sector depends on its readiness to adapt to climate change. The inclusion of climate change impacts and adaptation in fisheries management documents in South Africa is essential to ensure adequate climate adaptation responses are implemented at the short- and long-term. This study aims to 1) determine if the relevant fisheries national management documents address climate change and adaptation, 2) determine if the relevant national climate change documents address climate change and adaptation in the fisheries sector and 3) evaluate the extent to which fisheries management documents address climate change and adaptation. A content analysis of fisheries management and climate change documents was carried out to determine if they incorporated information on climate change impacts and adaptation and marine fisheries respectively. Fisheries management documents were then screened against nine pre-determined criteria (or themes) based on climate change adaptation to determine the level of inclusion of best practice for climate change adaptation. Results indicate that climate change impacts and adaptation are rarely incorporated in the main fisheries management documents, except for the Climate Change Adaptation and Mitigation Plan for the agriculture, fisheries and forestry sectors. However, this document is still waiting to be adopted. The only direct reference identified in all the fisheries documents that supports climate change adaptation was ‘conservation and sustainable management of biodiversity’. With regards to indirect references to climate change adaptation, ‘equity,’ ‘participatory management,’ and ‘capacity building’ were most frequently incorporated in fisheries management documents. There is a need to explicitly incorporate information on climate change impacts and adaptation in South African fisheries management documents and increase the human and financial capacity at national institutions to ensure that the fisheries sector can adequately adapt to climate change.

While acoustic telemetry (AT) has become the dominant technique for understanding patterns of fish migration, catch rate (CR) and conventional tagging (CT) techniques still play a major role, particularly in developing countries. Understanding the potential biases of each technique is important for fish migration research. We compared these techniques for understanding the migration patterns of two coastal fishery species (Argyrosomus coronus and Lichia amia) in southern Angola. Seasonal fluctuations in the catchability of A. coronus led to incorrect conclusions about migration patterns using CR and CT and we recognised “cryptic residency” during the austral summer. This was attributed to a fine-scale offshore movement that was detected using AT. The AT data provided evidence for partial migration in L. amia, and while supported by the CR and CT data, these did not provide direct evidence for this intraspecific behavioural diversity. Range test results indicated that the optimal placement of nearshore AT receivers is essential, especially when migratory routes proceed along noisy, nearshore pathways. These limitations should be addressed during the design phase of fish migration experiments.

Small pelagic fish, including anchovies, sardines and sardinellas, mackerels, capelin, hilsa, sprats and herrings, are distributed widely, from the tropics to the far north Atlantic Ocean and to the southern oceans off Chile and South Africa. They are most abundant in the highly productive major eastern boundary upwelling systems and are characterised by significant natural variations in biomass. Overall, small pelagic fisheries represent about one third of global fish landings although a large proportion of the catch is processed into animal feeds. Nonetheless, in some developing countries in addition to their economic value, small pelagic fisheries also make an important contribution to human diets and the food security of many low-income households. Such is the case for many communities in the Zanzibar Archipelago and on mainland Tanzania in the Western Indian Ocean. Of great concern in this region, as elsewhere, is the potential impact of climate change on marine and coastal ecosystems in general, and on small pelagic fisheries in particular. This paper describes data and information available on Tanzania's small pelagic fisheries, including catch and effort, management protocols and socio-economic significance. Then, incorporating the rapidly improving understanding of the region's oceanography resulting from the application of remote sensing and oceanographic modelling, the paper undertakes the most complete assessment to date of the potential impacts of climate change on the small pelagic fishery of the Pemba Channel. Pathways of climate change impact are explored and crucial knowledge gaps, both in terms of the fishery itself and the wider ecosystem, are identified in order to guide future research activities. Although we analyse small pelagics in the specific context of the Pemba Channel, the key challenges identified in the analysis are likely to be relevant to many small pelagic fisheries in coastal nations heavily dependent on living marine resources.

The South African squid fishery is based on a single species, Loligo reynaudi, locally referred to as chokka and commonly found around the Agulhas Bank and West Coast shelf of South Africa. The existing long term rights for participation in the fishery expire at the end of 2013 and a new set of rights will have to be issued. Progress made to date in achieving the objectives of the South African Marine Living Resources Act of 1998 (MLRA), including progress towards greater equity, will be an important consideration in allocation decisions. The draft Small-Scale Fisheries Policy, scheduled to be adopted in 2013, could also influence the criteria to be used. This study updates the information on the current structure and functioning of the squid jig sector and considers the likely performance of two alternative access allocation scenarios against the current and evolving policy goals. The study reaffirms that the squid fishery is an important contributor to human well-being in South Africa and particularly in the Eastern Cape Province but there is scope for improvement in the extent of transformation and equity. The study concludes that, as a result of a common lack of experience and capital amongst potential new entrants, the risks associated with transformation in this fishery are likely to be high, especially if the option of allocating rights to community-based legal entities was to be used. The risks could be reduced by ensuring that a number of pre-conditions were met. These include, amongst others, not allowing total effort in the fishery to increase; ensuring effective management by the responsible government authorities; adequate capacity building of new entrants, whether individuals or cooperatives; and ensuring new entrants have viable business plans.

The skipjack tuna, Katsuwonus pelamis, inhabits tropical and subtropical oceans the world over, and contributes substantially to total tuna catches. Both fishing pressure and anthropic influences affect skipjack populations, impacting on economic returns and investment. The present study analyses and compares spatial time series of catch and catch per unit effort (CPUE), of pole-and-line fishing of skipjack tuna from Brazil, South Africa and the Maldives. Both regional and inter-regional analyses were conducted for the period 1970-2014 in order to ultimately investigate potential associations between these fisheries, climatic conditions and the El Niño Southern Oscillation (ENSO). Correlation tests and spatial mapping tools were used. From 2004 to 2011, South African skipjack catches correlated positively with Brazilian ones and negatively with Maldivians. CPUEs from the Brazilian and Maldivian skipjack fisheries showed a significant positive correlation in the period 1982-1993. Yearly catches from all regions were strongly associated with the Northern Oscillation Index (p < 0.001), an ENSO index. This study reflects an effort to articulate an inter-regional appraisal of skipjack pole-and-line fisheries embedded in the context of a globally changing climate, in the face of which emerging economies are the most vulnerable. Evidence of common patterns influencing these fisheries should encourage international South-South cooperative management and understanding of the resource.

With ocean warming predicted globally, one of the mechanisms driving distributional shifts and changes in the abundance of resident fishes is reproductive output. The relationship between sea surface temperature and the reproductive activity of a eurythermic, resident coastal species, blacktail seabream Diplodus sargus capensis, was examined in the “ocean warming” hotspot of the northern Benguela. Reproductive activity was found to be restricted to periods when the water temperature dropped below 20 °C. A metadata analysis conducted on the D. sargus sub-species complex similarly showed that reproductive activity was restricted to temperatures between 15 and 20 °C, regardless of the range in ambient water temperature. Based on these findings and using satellite derived SST information, we examined D. s. capensis’s total and seasonal “reproductive scope” that is defined as either the area suitable for spawning each year or the duration of its potential spawning season at a fixed geographical locality, respectively. Trends were examined over the last three decades. Reproductive scope by area was found to be shrinking at a rate of 7 % per decade in southern Angola and expanding at a rate of 6 % per decade in northern Namibia. Reproductive scope by season decreased by 1.05 months per decade in Namibe, southern Angola and increased by 0.76 months per decade in Hentiesbaai, northern Namibia. Changes in reproductive scope may be a driving mechanism of distributional shifts in resident fishes, although the rate of the shifts is likely to be slow. More importantly, changes in reproductive scope will not be uniform throughout fish distributions and will most likely result in heterogeneous variations in fish abundance.

Roberts, M. J., Downey, N. J., and Sauer, W. H. 2012. The relative importance of shallow and deep shelf spawning habitats for the South African chokka squid (Loligo reynaudii). – ICES Journal of Marine Science, 69: 563–571. It is well known that the spawning grounds of chokka squid Loligo reynaudii lie along the shallow inshore regions of South Africa's south coast. However, egg masses have been found in deeper water on the Agulhas Bank, and hydroacoustic targets deemed to be large aggregations of spawning squid have been identified. The aim of this study was to investigate the extent, depth range, and importance of deep spawning. Trawl data collected during demersal research surveys between Port Nolloth on the west and Port Alfred on the south coast were examined for egg capsules. No spawning was found on the west coast. Data showed that chokka squid preferred the eastern Agulhas Bank for spawning. Spawning occurred not only inshore but also on the mid-shelf extending to depths of 270 m near the shelf edge. Squid egg biomass markedly decreased beyond 70 m, suggesting delineation between the inshore and offshore spawning grounds. Total egg biomass calculations for depths shallower and deeper than 70 m indicated the coastal area to be strongly favoured, i.e. 82 vs. 18%. These results contest the commonly accepted notion that L. reynaudii is an inshore spawner and redefine the spawning grounds to extend across the shelf.

The effects of fishing on the population structure and life history of roman Chrysoble- phus laticeps, a protogynous hermaphroditic seabream from South Africa, were investigated by com- paring 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 age- at-sex-change were lower in the exploited area. The shift in age-at-sex-change maintained a con- stant 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.

Observers aboard commercial trawlers collected data on the total catch composition of 614 and 479 hauls made by vessels operating off the south and west coasts of South Africa, respectively. On the south coast, four fishing areas were identified on the basis of target species and fishing depth. On the west coast, hauls were separated into those targeting hake Merluccius spp. in four depth ranges (0–300, 301–400, 401–500, and >500 m) and those targeting monkfish Lophius vomerinus . For each area, the catch composition was calculated and the species assemblages were investigated using cluster analysis and multi-dimensional scaling. Finally, for each coast, the weight of fish discarded annually was estimated. On the south coast, although hake dominated, between 21% and 47% of the catch was not hake, depending on the fishing area. In comparison, hake dominated west coast catches, the proportion of hake increasing with depth. For each fishery investigated, approximately 90% of the catch was processed and landed. However, estimates of annual discards indicate that the south and west coast fisheries may annually discard 9000 or 10,000 t and 17,000 or 25,000 t, of undersized and unutilizable fish and offal, respectively, depending on the estimation method used. When developing strategies to limit or enhance utilization of bycatch, cognisance should be taken of the differences in catch composition between the south and west coasts and of the importance of bycatch revenue to south coast fishing companies.

Although migration patterns for various life history stages of the chokka squid (Loligo reynaudii) have been previously presented, there has been limited comparison of spatial variation in biological parameters. Based on data from research surveys; size ranges of juveniles, subadults and adults on the Agulhas Bank were estimated and presented spatially. The bulk of the results appear to largely support the current acceptance of the life cycle with an annual pattern of squid hatching in the east, migrating westwards to offshore feeding grounds on the Central and Western Agulhas Bank and the west coast and subsequent return migration to the eastern inshore areas to spawn. The number of adult animals in deeper water, particularly in autumn in the central study area probably represents squid spawning in deeper waters and over a greater area than is currently targeted by the fishery. The distribution of life history stages and different feeding areas does not rule out the possibility that discrete populations of L. reynaudii with different biological characteristics inhabit the western and eastern regions of the Agulhas Bank. In this hypothesis, some mixing of the populations does occur but generally squid from the western Agulhas Bank may occur in smaller numbers, grow more slowly and mature at a larger size. Spawning occurs on the western portion of the Agulhas Bank, and juveniles grow and mature on the west coast and the central Agulhas Bank. Future research requirements include the elucidation of the age structure of chokka squid both spatially and temporally, and a comparison of the statolith chemistry and genetic characterisation between adults from different spawning areas across the Agulhas Bank.

Some 290 species of squids comprise the order Teuthida that belongs to the molluscan Class Cephalopoda. Of these, about 30–40 squid species have substantial commercial importance around the world. Squid fisheries make a rather small contribution to world landings from capture fisheries relative to that of fish, but the proportion has increased steadily over the last decade, with some signs of recent leveling off. The present overview describes all substantial squid fisheries around the globe. The main ecological and biological features of exploited stocks, and key aspects of fisheries management are presented for each commercial species of squid worldwide. The history and fishing methods used in squid fisheries are also described. Special attention has been paid to interactions between squid fisheries and marine ecosystems including the effects of fishing gear, the role of squid in ecosystem change induced by overfishing on groundfish, and ecosystem-based fishery management.

Walmsley, S. A., Leslie, R. W., and Sauer, W. H. H. 2007. Managing South Africa's trawl bycatch. – ICES Journal of Marine Science, 64: 405–412. Over the past few decades, it has become widely recognized that the management strategies of world fisheries must ensure sustainability of bycatch as well as of target species. South Africa implemented a pilot observer programme from 1995 to 2000 to collect data on the levels and patterns of bycatch and discards in the demersal trawl fishery. Here, the results of that programme are used in conjunction with information on bycatch value and compliance to assess the issues and problems regarding bycatch and discarding in the fishery. In general, bycatch components can be placed into one of three categories (discarded bycatch, retained bycatch, and processing waste), each of which present different management problems and require different management approaches. The results were used to formulate a bycatch management plan for the demersal trawl fishery in South Africa. Given the need to continue monitoring bycatch, the performance of the pilot observer programme is reviewed, and the levels of sampling effort required for a national programme are discussed.

Human activities have substantially changed the world’s oceans in recent decades, altering marine food webs, habitats and biogeochemical processes. Cephalopods (squid, cuttlefish and octopuses) have a unique set of biological traits, including rapid growth, short lifespans and strong life-history plasticity, allowing them to adapt quickly to changing environmental conditions. There has been growing speculation that cephalopod populations are proliferating in response to a changing environment, a perception fuelled by increasing trends in cephalopod fisheries catch. To investigate long-term trends in cephalopod abundance, we assembled global time-series of cephalopod catch rates (catch per unit of fishing or sampling effort). We show that cephalopod populations have increased over the last six decades, a result that was remarkably consistent across a highly diverse set of cephalopod taxa. Positive trends were also evident for both fisheries-dependent and fisheries-independent time-series, suggesting that trends are not solely due to factors associated with developing fisheries. Our results suggest that large-scale, directional processes, common to a range of coastal and oceanic environments, are responsible. This study presents the first evidence that cephalopod populations have increased globally, indicating that these ecologically and commercially important invertebrates may have benefited from a changing ocean environment, SI

The interaction of a suite of predators with mating and spawning chokka squid (Loligo vulgaris reynaudii) was studied at inshore (

To study their migratory movements, Chokka squid ( Loligo vulgaris reynaudii ) were tagged on their inshore spawning grounds in early summer: 1748 in November 1992 and 4335 in November 1993. Squids were captured by hand jigging in depths of 24–35 m. Diving observations revealed that the behaviour pattern of recently tagged individuals was similar to that of untagged squid on the spawning grounds. Recaptures from commercial jigging vessels subsequent to tagging were 33 (1.89%) in 1992 and 387 (9.04%) in 1993. The longest tag-recapture duration was 32 days. Loligo. v. reynaudii moved to other spawning sites within the general spawning area, up to 207 km within 18 days. In 1993, mean speed was calculated as 3.0 km/day and mean distance travelled 42.8 km in a mean time of 14 days. Squids dispersed predominantly eastward from those tagged on the westward limit of their inshore spawning grounds. Those tagged towards the centre appeared to move randomly between spawning sites, possibly influenced by environmental conditions and food availability. Loligo v. reynaudii may be considered an uniseasonal-iteroparous species, maximising their reproductive potential by depositing eggs over an extended period in a number of spawning sites.

The net emigration from a spawning concentration of the loliginid squid, Loligo vulgaris reynaudii d’Orbigny, 1845, was investigated quantitatively using a combination of tagging and hydroacoustic techniques, midwater trawling, purse seining and SCUBA diving. Aquarium experiments were used to supply additional information on tag loss and mortality from tagging. The number of squid in a concentration containing T tagged individuals was assessed hydroacoustically and then c squid were caught by means of a midwater trawl or purse seine. It was assumed that the tn tagged squids in these catches were the result of natural mortality, tagging mortality and net stability of the concentration (the result of emigration and immigration) n days after tagging. The average net emigration was then calculated to be 0.2 per day for 7.5 days of observations. This result is a first attempt to solve the so-called ‘‘Hilborn’s problem’’, i.e. the problem of how to measure the aggregation dynamics of nektonic organisms in the sea (instead of modelling). ? 1998 International Council for the Exploration of the Sea

This first description of behavioural interactions between benthic pyjama sharks Poroderma africanum (Chondrichthyes: Scyliorhinidae) and spawning squids Loligo vulgaris reynaudii (Cephalopoda: Loliginidae) was made from underwater video recordings. The behaviours are described and illustrated to show that the sharks searched for squids in egg beds, then rested there partially hidden and immobile. The pyjama sharks at-tempted to ambush the squids when they approached to lay their eggs after they had apparently habituated to the predators. Although normally nocturnal, the pyjama sharks had emerged by day from caves and cracks in the rocky reef to attack the spawning squids, thereby benefiting from an occasionally available resource.

This paper explores effects of environmental variability on the life cycle of the chokka squid, Loligo vulgaris reynaudii in South Africa, particularly the effect of physical and chemical influences on adult distribution, and the availability of spawning aggregations to the local jig fishery. The following hypotheses are presented: 1) temperature, dissolved oxygen and currents have a direct effect on the demersal distribution of adult chokka on the feeding grounds, but this is restricted to the west coast where environmental conditions are more extreme relative to the south coast, 2) chokka catches increase in proportion to the extent of coastal upwelling, 3) spawning behavior along the inshore regions (

Roving creel surveys and aerial surveys of shore-angling were undertaken as part of a national investigation into linefishing in South Africa. Shore patrols utilized a random stratified sampling procedure to collect catchand-effort data, and a questionnaire provided information on fishing effort, angler demographics, economics and attitudes towards current regulations. A total of 1 677 patrols, covering 19 616 km, was conducted betweenApril 1994 and February 1996, during which period 9 523 anglers had their catches checked and 4 490 were interviewed. A further 16 497 km were covered by aerial surveys, when 22 609 anglers were counted. Fromthe aerial surveys, angler densities were highest on the KwaZulu-Natal coast (4.65 anglers.km–1), followed by the Southern Cape coast (2.29 anglers.km–1), the Eastern Cape coast (0.36 anglers.km–1) and the WestCoast (0.12 anglers.km–1). Catch rates varied from 1.5 kg.angler –1.day–1 on the Southern Cape coast to 0.45 kg.angler–1.day–1 on the KwaZulu-Natal coast. Total effort was estimated at 3.2×106 angler days.year–1 and the total catch was estimated at 4.5×106 fish.year–1 or 3 000 tons.year–1. Targeted species varied regionally, with elf Pomatomus saltatrix (29%) being the most sought after species on the KwaZulu-Natal coast, kob Argyrosomus japonicus (18%) on the Eastern Cape coast and galjoen Dichistius capensis on the Southern Cape coast (30%) and along the West Coast (50%). The catch composition by mass was dominated byP. saltatrix on the KwaZulu-Natal coast (29%), the Eastern Cape coast (26%), and on the Southern Cape coast (56%) and by white stumpnose Rhabdosargus globiceps (40%) on the West Coast. Although anglersgenerally supported the regulations currently governing the linefishery, the questionnaire results showed that knowledge and compliance of them was poor. A low level of law enforcement was found, except for inKwaZulu-Natal. Management of the linefishery is discussed in relation to the findings of this study.

(1) Dalhousie University, 1355 Oxford St., Halifax, Nova Scotia Canada B3H 4J1, Email: rodor@oceanleadership.org (2) IRD HEA, BP 5045, 34032 Montpellier Cedex 1, Montpellier, France, Email: dagorn@ird.fr (3) Hawaii Institute of Marine Biology, University of Hawaii, P.O. Box 1346, Coconut Island, Kaneohe, Hawaii 96744, USA, Email: kholland@hawaii.edu (4) Bedford Institute of Oceanography, 1 Challenger Drive, P. O. Box 1006, Dartmouth, Nova Scotia, Canada, B2Y 4A2, Email: JonsenI@mar.dfo-mpo.gc.ca (5) POST, Vancouver Aquarium, P. O. Box 3232, Vancouver, British Columbia, Canada, V6B 3X8, Email: jcpayne@u.washington.edu (6) Rhodes University, Grahams Town, South Africa, Email: w. sauer@ru.ac.za (7) Marine Research Laboratories, Tasmanian Aquaculture & Fisheries Institute, University of Tasmania, Private Bag49, Hobart, Tasmania 7001, Australia, Email: Jayson.Semmens@utas.edu.au (8) Faculty of Science, Dalhousie University, Halifax, Nova Scotia, B3H 4J1, Canada, Email: mstokesb@dal.ca (9) Bedford Institute of Oceanography, 1 Challenger Drive, P. O. Box 1006, Dartmouth, Nova Scotia, Canada, B2Y 4A2, Email: SmithPC@mar.dfo-mpo.gc.ca (10) The Atlantic Salmon Federation, P. O. Box 5200, St. Andrews, New Brunswick, Canada, E5B 3S8, Email: FWhoriskey@Dal.ca

Goukamma Marine Protected Area (MPA) on the South African temperate South Coast has been shown to be effective in maintaining a spawning stock of roman, Chrysoblephus laticeps (Sparidae). The larval ecology and the oceanographic conditions in the area suggest a good potential for the enhancement of roman stocks outside the reserve through larval dispersal. A high rate of illegal fishing just inside the seaward boundary of the MPA could severely compromise its function. We suggest that a change of the seaward boundary of the reserve to coincide with a latitudinal line could increase its function as a harvest refuge for resident reef fishes such as roman, facilitate voluntary compliance and monitoring and prosecution of illegal fishing without a significant negative impact on the commercial linefishing fleet in the area. Simple adjustments such as the one proposed here could be attempted at a number of South African MPAs as they would be beneficial to achieve fishery and conservation goals alike.

The location of spawning grounds of the squid Loligo vulgaris reynaudii (D'Orbigny) was investigated in the years 1988–1990. At least 39 spawning sites were found during this period along the inshore areas of the Eastern Cape coastline between Algoa Bay and Plettenberg Bay. The substrate chosen for egg laying was mostly fine sand or flat reef, frequently in large and relatively shettered bays. Spawning was found to occur sporadically throughout the year, and some spawning sites were used repeatedly within a particular year and in subsequent years. Squid migrate in discrete schools separated by sex in the vicinity of the spawning sites; these schools mix during spawning. Mating and egg deposition behaviour is described from observations made on the spawning grounds. Cannibalism was seen on a number of occasions, but no post-spawning mortality was recorded. Egg beds consisted mostly of large concentrations of egg strands (>3 m in diameter), with smaller aggregations of one to ten egg strands surrounding these, with single strands in the immediate vicinity. Three basic patterns of echotraces were identified and interpreted according to diving observations. These patterns were classified as loose patches, dense patches, and complex patterns. The first two represent non-spawning schooling patterns and the third, mating and egg laying behaviour. This observation led to the general classification of squid aggregations: schools (non-spawning mode) and concentrations (spawning mode). Concentrations as far as Loligo vulgaris reynaudii was concerned were further divided into two patterns: suprabenthic and benthic (spawning) squid.

Contemporary patterns of genetic diversity and population connectivity within species can be influenced by both historical and contemporary barriers to gene flow. In the marine environment, present day oceanographic features such as currents, fronts and upwelling systems can influence dispersal of eggs/larvae and/juveniles/adults, shaping population substructuring. The Benguela Current system in the southeastern Atlantic is one of the oldest upwelling systems in the world, and provides a unique opportunity to investigate the relative influence of contemporary and historical mechanisms shaping the evolutionary history of warm-temperate fish species. Using the genetic variation in the mitochondrial DNA Control Region and eight nuclear microsatellite DNA loci, we identified the presence of two highly divergent populations in a vagile and warm-temperate fish species, Atractoscion aequidens, across the Benguela region. The geographical distributions of the two populations, on either side of the perennial upwelling cell, suggest a strong correlation between the oceanographic features of the system and the breakdown of gene flow within this species. Genetic divergence (mtDNA φ ST = 0.902, microsatellite F ST = 0.055: probability of genetic homogeneity for either marker = p

A mass spawning of squid resembles, at first glance, a chaotic "nuptial dance" (1). But for the first time, we have applied 3-D, radio-linked acoustic positioning (RAP) to this confusing process, and our early results now reveal a choreography that is, in fact, well organized in time and space. Remote tracking with RAP of individual Loligo vulgaris reynaudii off South Africa has provided insights into the daily sequence of behaviours that lead these animals to aggregate for sexual selection. Each dawn, the squid navigate for several kilometers, towards the shore, to small, well-defined zones near egg beds on the substrate. After several hours of circling above the egg beds, a pelagic, 3-D lek-like aggregation of large males forms: females are drawn in, and the aggregation condenses as the females and males pair, mate, and lay eggs. Smaller "sneaker males" remain on the periphery of the mating arena and, from this station, attempt extra-pair copulations (EPCs). The mating system of squids is thus unexpectedly complex, rivaling those of mammals and birds (2, 3). Commercial squid-jigging fishermen in South Africa have recently been attracted to the spawning grounds, and they have been successful. Moreover, their activities may be selective for large males. Thus, attention should be devoted to ensuring that such targeted fishing does not alter the characteristics of squid population genetics. Remote tracking and video observations, in combination with genetic analyses, may offer a new opportunity to monitor mating effort and reproductive success, and thus to manage the fishery.