Reproduction and larval distribution of the penaeid prawn Macropetasma africanus (Balss) in Algoa Bay

Breeding adults and larvae of Macropetasma africanus were sampled over a two-year period in Algoa Bay, South Africa. Gonadal macro- and microscopic examination enabled classification of breeding females into four stages of development. Breeding females were present throughout the study with a summer peak of late maturing and mature females. Larvae were present in the plankton throughout the study with peak abundance in summer. Protozoea, mysis and post-larval stages were recorded with the mysis stage most abundant. Significantly higher numbers of the mysis and post-larval stages were taken at shallow stations (5 m) off sandy beaches than at the deeper stations (18 m). The presence of breeding females in the mature stage of ovarian development and the increase in larval abundance in summer indicates spawning throughout the year with peak intensity in summer.S. Afr. l. Zool.1987, 22(3

Determination of moult stage in the South African West Coast rock lobster Jasus Lalandii (H. Milne Edwards) (Crustacea: Decapoda)

Nine stages and substages of post-, inter- and premoult were distinguished in the West Coast rock lobster Jasus lalandii by microscopic examination of the cuticle, epidermal retraction and setal development in the pleopods.The postmoult condition is characterized by progressive thickening of the setal walls and cuticle through to intermoult. Premoult commences with apolysis (Stage D0), followed by setal development (Stage D1’, D1”, D1’”)and culminates with cuticle deposition (Stage D2). The diagnostic features of the stages are generally similar to those of other decapod crustaceans

Changes to regulations and the gear used in the South African commercial fishery for Jasus lalandii

Alterations to the operational fishing gear used in the South African west coast rock lobster Jasus lalandii fishery and their resultant impacts are investigated. The most important developments have been: (i) a change during the 1960s from hand-hauled hoopnets to winch-hauled traps, with a concomitant modification of vessels; (ii) the introduction of deck-grid sorters in 1975; (iii) an increase during 1984 of minimum mesh aperture from 62 to 100 mm (stretched), with a concomitant decrease in the length of the trap codend; (iv) a decrease in the minimum legal size during the early1990s; and (v) the introduction of bottom-grid traps in 1994. Most of these alterations have been driven by a tradeoff between the need for greater operational efficiency and concerns surrounding the issue of how best to deal with the problem of catching and releasing specimens smaller than the minimum legal size.Keywords: fishing gear, fishing regulations, Jasus lalandii, rock lobsterAfrican Journal of Marine Science 2002, 24: 365–36

Converging Prefronto-Insula-Amygdala Pathways in Negative Emotion Regulation in Marmoset Monkeys

BACKGROUND: Impaired regulation of emotional responses to potential threat is a core feature of affective disorders. However, while the subcortical circuitry responsible for processing and expression of fear has been well characterized, the top-down control of this circuitry is less well understood. Our recent studies demonstrated that heightened emotionality, as measured both physiologically and behaviorally, during conditioned fear and innate/ social threat was induced, independently, by excitotoxic lesions of either the anterior orbitofrontal cortex (antOFC) or ventrolateral prefrontal cortex (vlPFC). An important outstanding question is whether the antOFC and vlPFC act on common or distinct downstream targets to regulate negative emotion. METHODS: The question was addressed by combining localized excitotoxic lesions in the PFC of a nonhuman primate and functional neuroimaging ([$^{18}$F]fluorodeoxyglucose positron emission tomography) with a fear-regulating extinction paradigm. Marmoset monkeys with unilateral lesions of either the antOFC or vlPFC were scanned immediately following exposure to a fearful or safe context, and differences in [$^{18}$F]fluorodeoxyglucose uptake were evaluated. RESULTS: [$^{18}$F]fluorodeoxyglucose uptake in the insula and amygdala of the intact hemisphere was significantly increased in response to the fearful context compared with the safe context. Such discrimination between the two contexts was not reflected in the activity of the insula-amygdala of the antOFC or vlPFC-lesioned hemisphere. Instead, uptake was at an intermediate level in both contexts. CONCLUSIONS: These findings demonstrate that the distinct control functions of the antOFC and vlPFC converge on the same downstream targets to promote emotion regulation, taking us closer to a mechanistic understanding of different forms of anxiety.This research was supported by a Medical Research Programme Grant (No. MR/M023990/1) from the Medical Research Council (to ACR) and was carried out within the Behavioural and Clinical Neuroscience Institute supported by a consortium award from the Wellcome Trust and the Medical Research Council

Defining ecologically relevant scales for spatial protection with long-term data on an endangered seabird and local prey availability

This is the author accepted manuscript. The final version is available from Wiley via the DOI in this record.Human activities are important drivers of marine ecosystem functioning. However, separating the synergistic effects of fishing and environmental variability on the prey base of nontarget predators is difficult, often because prey availability estimates on appropriate scales are lacking. Understandi ng how prey abundance at different spatial scales links to population change can help integrate the needs of nontarget predators into fisheries management by defining ecologically relevant areas for spatial protection. We investigated the local population response (number of breeders) of the Bank Cormorant (Phalacrocorax neglectus), a range-restricted endangered seabird, to the availability of its prey, the heavily fished west coast rock lobster (Jasus lalandii). Using Bayesian state-space modeled cormorant counts at 3 colonies, 22 years of fisheries-independent data on local lobster abundance, and generalized additive modeling, we determined the spatial scale pertinent to these relationships in areas with different lobster availability. Cormorant numbers responded positively to lobster availability in the regions with intermediate and high abundance but not where regime shifts and fishing pressure had depleted lobster stocks. The relationships were strongest when lobsters 20–30 km offshore of the colony were considered, a distance greater than the Bank Cormorant's foraging range when breeding, and may have been influenced by prey availability for nonbreeding birds, prey switching, or prey ecology. Our results highlight the importance of considering the scale of ecological relationships in marine spatial planning and suggest that designing spatial protection around focal species can benefit marine predators across their full life cycle. We propose the precautionary implementation of small-scale marine protected areas, followed by robust assessment and adaptive-management, to confirm population-level benefits for the cormorants, their prey, and the wider ecosystem, without negative impacts on local fisheries.The National Research Foundation (NRF) SEAChange Grant 79735 and an incentive grant to R.J.M.C., Leiden Conservation Foundation, Claude Leon Foundation, and our institutions provided funding

Recommendations for the management of subsistence fisheries in South Africa

This paper summarizes recommendations for the management of previously marginalized and neglected subsistence fisheries in South Africa. The recommendations stem from the activities and analyses of a task group appointed by Government and mandated to provide advice about management of the new fishing sector. The following focus areas were identified for attention: planning for implementation; definitions of subsistence fishers and other sectors; assessment and categorization of resources; determination of types of fishing activities; zonation; management systems; training; communication mechanisms; application and allocation procedures; compliance processes; research and monitoring; development of institutional capacity. Subsistence fishers were defined as poor people who personally harvest marine resources as a source of food or to sell them to meet basic needs of food security; they operate on or near to the shore or in estuaries, live in close proximity to the resource, consume or sell the resources locally, use low-technology gear (often as part of a long-standing community-based or cultural practice), and the resources they harvest generate only sufficient returns to meet basic needs of food security. A second group of informal fishers was identified that fishes for profit but cannot be equated to large industrial fisheries, and a new sector was proposed to accommodate these artisanal “small-scale commercial” fishers. Resources were classified for use by these different sectors based on accessibility, fishing methods, cash value and sustainability. In all, 12 different categories of subsistence and small-scale commercial fisheries were identified, and a preliminary list of resource species suitable for different fishing sectors is presented. A multi-tiered institutional management structure is recommended, with the national agency (MCM) controlling issues of national concern, and supporting and coordinating the activities of provincial and local structures. The management agents required for effective implementation were identified and include a dedicated national Subsistence Fisheries Management Unit, provincial management agencies that have the capacity to be delegated authority, Regional Fieldworkers, an independent Advisory Group for Subsistence Fisheries Management, local comanagement structures, and community monitors responsible for observing and recording fishing activities and catches. Co-management, involving both authorities and users in joint management, is advocated in preference to previous top-down approaches, because of its potential to improve communication and compliance.Keywords: coastal zonation, fisheries management, fisheries rights, subsistence fisheriesAfrican Journal of Marine Science 2002, 24: 503–52

The process of developing a management system for subsistence fisheries in South Africa: recognizing and formalizing a marginalized fishing sector in South Africa

Subsistence fishers were first recognized as a formal fishing sector in South Africa when new fishing legislation, aimed at redressing past inequalities, was enacted in 1998. Little information was available about these fishers, their activities, and the resources upon which they rely. Recognizing the imperative to gain an understanding of the fishers and to consult broadly, the national agency responsible for the management of marine living resources, Marine and Coastal Management (MCM) of the Department of Environmental Affairs and Tourism, appointed a Subsistence Fisheries Task Group (SFTG) in December 1998 to provide advice on the implementation of appropriate management systems for subsistence fisheries. This paper describes the process followed to formulate recommendations that were presented by the SFTG to MCM in February 2000. The activities of the SFTG fell into two categories: research aimed at identifying subsistence fishers and gaining an understanding of their activities and socio-economic profiles; and consultation aimed at ensuring that the needs and aspirations of fishers and the experience of local managers were incorporated. Research included both field-based studies and synthesis of information about comparative fisheries elsewhere. Consultation took the form of local interviews and focusgroup discussions, meetings with fishers and a national workshop. A pivotal activity was the development of a clear definition and qualifying criteria for subsistence fishers. A significant outcome was the identification of a separate small-scale commercial sector, previously erroneously lumped with subsistence fishers. Needs of fishers and problems identified during the process provided the basis for recommendations in the following areas: definitions, assessment and categorization of resources, management systems, communication mechanisms, application and allocation procedures, capacity building, compliance, research and monitoring, and funding and staff required for the management of this new sector. An evaluation is made of the opportunities presented by the SFTG process, constraints experienced and lessons learnt, giving important insights that are applicable to other similar processes, yet seldom documented in formal literature. Keywords: management of fisheries, subsistence fisheriesAfrican Journal of Marine Science 2002, 24: 405–42