PENGAMATAN ASPEK BIOLOGI REPRODUKSI IKAN KAKAP MERAH (LUIJANUS MAIAbAT\CUS) DARI PERAIRAN SAPE DAN KUPANG

Pengamatan aspek biorogi reproduksi ikan kakap merah (Lutjanus marabaricus) dari perairan Kupang telah dilakukan pada sampel ikan yang diambil setiap bulan mulai desember 2000 sampai dengan Nopember 2001 di perairan sape dan Januari sampai Desember 2001 di perairan Kupang. Analisis yang dilakukan meliputi hubungan panjang berat, tingkat kematangan gonad, indeks kematangan gonad, fekunditas, dan diameter telur pada ikan kakap mlrah sebanyak 389 ekor dari sape dan 35b ekor dari Kupang

Ecological sustainability of bycatch and biodiversity in prawn trawl fisheries

Prawn trawl fisheries are under increasing public and legislative pressure to manage their by-catch sustainably, but by-catch cannot be managed without knowing what and how much is caught. This project focused on the Northern Prawn Fishery (NPF), the Torres Strait Prawn Fishery (TSPF) and the Queensland Banana Prawn Fishery. The objectives of this study were: to undertake a literature review of prawn trawl by-catch and of methods for estimating and monitoring by-catch of prawn trawl fisheries from published information to add to the already substantial literature database on by-catch reduction devices; to compile a detailed description of the by-catch in the NPF and TSPF (tiger and banana prawns) and Queensland East Coast banana prawn fisheries to provide a reference against which future assessment can be made; to measure the impact of prawn trawling on the sustainability of important vertebrate by-catch species, particularly those that may be vulnerable or endangered, and for those by-catch species for which no significant reductions can be achieved; to assess the effects of prawn trawling on the biodiversity of key fish and other vertebrate communities; and to develop cost-effective, accurate and feasible methods of describing and monitoring prawn trawl by-catch that would be acceptable to all stakeholders. The high diversity of by-catch of these tropical prawn fisheries, and the fact that most species are rare, means that managing the sustainability of the by-catch is a significant challenge

The emergence of a theta social brain network during infancy

Infants’ socio-cognitive ability develops dramatically during the first year of life. From the perspective of ontogeny, the early development of social behavior allows for parent-child attachment, which in turn enhances survival. Thus, it is theorized that the development of social behavior, driven by social brain networks, forms the core of developmental acquisitions during this period. Further, understanding the maturation within the neural networks during social development is crucial to obtain a better grasp of the development of social developmental disorders. Therefore, we performed a longitudinal study in 854 infants measured at around 5 and 10 months to map the development of functional networks in the brain when infants were processing social and non-social videos. Using EEG, we focused on the frequency bands most commonly connected to social behavior: theta and alpha. We found that alpha networks remained relatively stable over the first year of life and showed no selectivity for social versus non-social stimuli, theta networks, showed strong global reconfigurations. The development o

Understanding the effects of marine debris on wildlife

This study of marine debris finds that Australia\u27s coastal rubbish is mainly plastic from Australian sources. Summary Marine debris is a global environmental issue of increasing concern. Marine ecosystems worldwide are affected by human-made refuse, much of which is plastic. The potential impacts of waste mismanagement are broad and deep. Marine debris comes from both land and sea-based sources and can travel immense distances. It can pose a navigation hazard, smother coral reefs, transport invasive species and negatively affect tourism. It also injures and kills wildlife, can transport chemical contaminants and may pose a threat to human health. Marine debris includes consumer items such as glass or plastic bottles, cans, bags, balloons, rubber, metal, fibreglass, cigarettes and other manufactured materials that end up in the ocean and along the coast. It also includes fishing gear such as line, ropes, hooks, buoys and other materials lost on or near land, or intentionally or unintentionally discarded at sea. The Australian government has recognised marine debris as a key threatening process, because of the potential harm it poses to wildlife. In 2003, ‘injury and fatality to vertebrate marine life caused by ingestion of, or entanglement in, harmful marine debris’ was listed as a key threatening process under the Environmental Protection and Biodiversity Conservation Act 1999 (EPBC Act). A key threatening process is defined as one that ‘threatens or may threaten the survival, abundance or evolutionary development of a native species or ecological community’. Under the EPBC Act, the Australian government implemented the Threat Abatement Plan (TAP) which focuses on strategic approaches to reduce impacts and injuries to marine fauna and ecological communities. CSIRO’s national marine debris project set out to address knowledge gaps identified in the TAP. The project engaged with young Australians while collecting robust, scientific data relevant to the global marine litter problem. To understand the patterns and sources of marine debris and assess the potential harm posed to Australia’s marine fauna, our research sought to address four questions: 1) What are the sources, distribution, and ultimate fate of marine debris? 2) What is the exposure of marine wildlife to debris? 3) When wildlife are exposed to debris, what factors determine whether animals ingest or are entangled by debris? 4) What is the effect of ingestion or entanglement on marine wildlife populations

Integrating Size-structured Assessment and Bioeconomic Management Advice in Australia's Northern Prawn Fishery

Three species in Australia's northern prawn fishery (Penaeus semisulcatus, P. esculentus, and Metapenaeus endeavouri) are assessed using a size-structured population model that operates on a weekly time-step. The parameters of this multispecies population model are estimated using data on catches, catch rates, length frequency data from surveys and the fishery, and tag release-recapture data. The model allows for the technical interaction among the three species. The results from the multispecies stock assessment are used to calculate the time-series of catches and levels of fishing effort that maximize net present value. The bioeconomic model takes into account costs which are proportional to catches and those which are proportional to fishing effort, as well as fixed costs. The sensitivity of the results is examined by changing the assumptions regarding the values for the economic parameters of the bioeconomic model as well as those on which the assessment are based. The results suggest that fishing effort needs to be reduced in the short term to achieve economic goals, although most stocks are estimated currently to be above the stock size corresponding to maximum sustainable yield. Short-term catches and effort levels are sensitive to model assumptions, and in particular, to trends in prices and costs

Integrating size-structured assessment and bioeconomic management advice in Australia's northern prawn fishery

Three species in Australia's northern prawn fishery (Penaeus semisulcatus, P. esculentus, and Metapenaeus endeavouri) are assessed using a size-structured population model that operates on a weekly time-step. The parameters of this multispecies population model are estimated using data on catches, catch rates, length frequency data from surveys and the fishery, and tag release-recapture data. The model allows for the technical interaction among the three species. The results from the multispecies stock assessment are used to calculate the time-series of catches and levels of fishing effort that maximize net present value. The bioeconomic model takes into account costs which are proportional to catches and those which are proportional to fishing effort, as well as fixed costs. The sensitivity of the results is examined by changing the assumptions regarding the values for the economic parameters of the bioeconomic model as well as those on which the assessment are based. The results suggest that fishing effort needs to be reduced in the short term to achieve economic goals, although most stocks are estimated currently to be above the stock size corresponding to maximum sustainable yield. Short-term catches and effort levels are sensitive to model assumptions, and in particular, to trends in prices and costs