Cephalopod fisheries: A future global upside to past overexploitation of living marine resources? Results of an international workshop, 31 August – 2 September 1997, Cape town, South Africa

Management strategies for cephalopod fisheries present similar challenges to those encountered in fisheries for finfish. Peculiarities of cephalopod life cycles and the fact that cephalopod fisheries can benefit frommanagement experiences gained in other fisheries may help to preclude mistakes and management failures. During a three-day workshop, features of cephalopod biology, recommended areas of research and key conclusions for management were identified and points of differences between cephalopods and fish were highlighted. Among these, life-cycle understanding, spatial distribution, stock-recruitment relationship and agedetermination/growth studies were identified as key priorities for research. Physiological and genetic approaches to understanding basic aspects of the life cycle, and their importance for understanding populationdynamics, were stressed. Similarly, theoretical ecology has a role to play in management, e.g. the role of a spatial distribution strategy in survival. Environmental studies are also emerging as being important in thepossible prediction of population trends through links that operate at the level of spawning biology. In the interim, cephalopods can be managed using similar principles to those applied to short-lived fish species.Among these, constant proportion harvest strategies were identified as the most effective

Spatial patterns in the biology of the chokka squid, Loligo reynaudii on the Agulhas Bank, South Africa

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 characterization between adults from different spawning areas across the Agulhas Bank

Ruthenium oxide-carbon-based nanofiller-reinforced conducting polymer nanocomposites and their supercapacitor applications.

In this review article, we have presented for the first time the new applications of supercapacitor technologies and working principles of the family of RuO2-carbon-based nanofiller-reinforced conducting polymer nanocomposites. Our review focuses on pseudocapacitors and symmetric and asymmetric supercapacitors. Over the last years, the supercapacitors as a new technology in energy storage systems have attracted more and more attention. They have some unique characteristics such as fast charge/discharge capability, high energy and power densities, and long stability. However, the need for economic, compatible, and easy synthesis materials for supercapacitors have led to the development of RuO2-carbon-based nanofiller-reinforced conducting polymer nanocomposites with RuO2. Therefore, the aim of this manuscript was to review RuO2-carbon-based nanofiller-reinforced conducting polymer nanocomposites with RuO2 over the last 17 years

The self-organizing fractal theory as a universal discovery method: the phenomenon of life

A universal discovery method potentially applicable to all disciplines studying organizational phenomena has been developed. This method takes advantage of a new form of global symmetry, namely, scale-invariance of self-organizational dynamics of energy/matter at all levels of organizational hierarchy, from elementary particles through cells and organisms to the Universe as a whole. The method is based on an alternative conceptualization of physical reality postulating that the energy/matter comprising the Universe is far from equilibrium, that it exists as a flow, and that it develops via self-organization in accordance with the empirical laws of nonequilibrium thermodynamics. It is postulated that the energy/matter flowing through and comprising the Universe evolves as a multiscale, self-similar structure-process, i.e., as a self-organizing fractal. This means that certain organizational structures and processes are scale-invariant and are reproduced at all levels of the organizational hierarchy. Being a form of symmetry, scale-invariance naturally lends itself to a new discovery method that allows for the deduction of missing information by comparing scale-invariant organizational patterns across different levels of the organizational hierarchy

Developing a policy and operational protocol for the formation of new commercial fisheries in South Africa

The development of new fisheries is one of the few options open to support the demands of South Africans for increased commercial access to their marine resources. Globally, the development of most new fisheries has been far from sustainable. Typically, it has been fast and unrestrained, with an inevitable collapse following soon after it commences. Although these failures can be ascribed to a number of factors, the lack of an adequate institutional framework and a misunderstanding of the role of experimental fishing have played a major role. Using available international policies and the unique challenges facing fisheries in South Africa, a policy and framework is proposed for developing new fisheries in South Africa. A three-phased management system is proposed, which is general in nature and could be applied to any new fishery. Keywords: biological feasibility, experimental fisheries, management framework, policy, socio-economicAfrican Journal of Marine Science 2007, 29(3): 393–40

Spawning aggregations of squid (Sepioteuthsis australis) populations: a continuum of 'microcohorts'

The aim of this study was to determine how size, age, somatic and reproductive condition, abundance and egg production of southern calamary spawning aggregations changed during the spawning season in each of 2 years. During the spawning period in at least one of the years there was a decline as much as 20% in average size, 50% in somatic condition, 28–34% in size-atage, 26–29% in reproductive status, as well as abundance and reproductive output of the stock declining during the spawning season. However, this change was not a function of the population becoming reproductively exhausted, as the aggregation was composed of different individuals with different biological characteristics. In each month the average age of individuals was ca. 6 mo, indicating that squid that had hatched at different times had entered the spawning aggregations, suggesting that the aggregation was made-up of a succession of microcohorts. Currently, management of many squid populations assumes that there is a single cohort in the aggregation. Therefore, estimating stock biomass at the start of the spawning season cannot be used as the population is constantly changing as microcohorts move into the aggregation. An instantaneous estimate of the spawning biomass, independent of fishing activity may be obtained by quantifying the density of deposited eggs. The strategy of individuals with a diversity of life history characteristics coming together in a single spawning aggregation may ensure the phenotypic and genetic diversity required to guarantee successful recruitment of this short-lived species. Therefore, temporally structured protection from harvest throughout the spawning season will ensure maintenance of this population diversity