Study on resistance and intact stability behavior of patrol boat using axe bow hull form to support surveillance activities in the Indonesia territorial sea

As a sovereign maritime country, Indonesia has an obligation to protect, maintain, and manage marine and fishery resources. Patrol boats as the primary means of monitoring marine and fishery resources are needed in response to several problems and threats that may occur, such as illegal fishing, destructive fishing, violations of zoning in fisheries conservation areas and others. Apart from having to be adequate on the number of units, the patrol boats must also have suitable technology to support pursuit operations and suppress violations. The main objective of this research is to investigate the total resistance and intact stability behavior of the developed axe bow hull geometry for the patrol boat hull. The preliminary design is started with the determination of the principal dimension of the patrol boat. Then the hull geometry configurations were made with the variation of the depth of bow and the water line spline type. In the case of the depth of bow, the bow with the additional depth of 30%, 40% and 50% of the draft was investigated. Otherwise, the water line spline type was configured as convex spline, concave spline and straight spline. According to the numerical analysis, the axe bow hull with the depth of bow of 30% and the straight spline type was presented the smallest total resistance performance. However, in the case of intact stability performance, all developed axe bow hull presented a similar righting moment lever arm (GZ curve). It is indicated that the total resistance of the axe bow hull is influenced by the depth of bow and water line spline type. Furthermore, those variables have a slight influence on intact stability performance.

Rethinking sustainability in seafood

Sustainability is a common goal and catchphrase used in conjunction with seafood, but the metrics used to determine the level of sustainability are poorly defined. Although the conservation statuses of target or nontarget fish stocks associated with fisheries have been scrutinized, the relative climate impacts of different fisheries are often overlooked. Although an increasing body of research seeks to understand and mitigate the climate forcing associated with different fisheries, little effort has sought to integrate these disparate disciplines to examine the synergies and trade-offs between conservation efforts and efforts to reduce climate impacts. We quantified the climate forcing per unit of fish protein associated with several different U.S. tuna fishing fleets, among the most important capture fisheries by both volume and value. We found that skipjack tuna caught by purse seine, a gear type that is often associated with relatively high bycatch of nontarget species, results in lower climate forcing than all other sources of proteins examined with the exception of plants. Conversely, skipjack tuna caught by trolling, a gear type that is often associated with relatively low bycatch of nontarget species, generates higher climate forcing than most other protein sources with the exception of beef. Because there is a range of selectivity and climate forcing impacts associated with fishing gears, examining the trade-offs associated with bycatch and climate forcing provides an opportunity for broadening the discourse about the sustainability of seafood. A central goal of more sustainable seafood practices is to minimize environmental impacts, thus mitigation efforts—whether they target conservation, habitat preservation, or climate impacts—should consider the unintended consequences on fisheries conservation.

Information processing in the European Union’s Common Fisheries Policy

The policy studies literature is divided on how information processing takes place in policy processes. Punctuated equilibrium theory claims that policymakers tend to process information disproportionately, giving more weight to some incoming signals than to others. By contrast, thermostatic models of policymaking argue that policymakers respond in a more proportionate way. In this paper, we analyse information processing in the adoption of Total Allowable Catches (TACs) under the European Union’s (EU) Common Fisheries Policy. Based on a novel measure for the proportionality of information processing, it shows that over time TACs have become more closely aligned with incoming signals about fish stocks. This development can be explained through a combination of changing discourses around fisheries conservation and institutional adjustments in EU fisheries policy. This analysis has implications for the debate between punctuated equilibrium and thermostatic models of policymaking and our understanding of the effectiveness of EU fisheries policies.