Seabird bycatch by tuna longline fisheries off southern Africa, 1998–2000

The incidental mortality of seabirds in tuna longline fisheries is estimated for the continental South African Exclusive Economic Zone (EEZ). Fishery observers accompanied 13 fishing trips and observed 108 sets (143 260 hooks) during the period 1998–2000. Despite most lines being set at night, seabird bycatch rates were high, with a mean of 1.6 birds killed per 1 000 hooks. Japanese vessels (1% effort observed) had a higher bycatch rate (2.6 birds per 1 000 hooks, range per trip 0.1–5.4) than South African vessels (0.8, range 0.0–4.3; 17% effort observed), possibly as a result of gear differences. Bird bycatch differed regionally in relation to the numbers of birds attending vessels. In international waters off the Northern Cape and southern Namibia, where there are few birds, only one bird was caught on 93 600 hooks (0.01 birds per 1 000 hooks). Shy Thalassarche cauta, black-browed T. melanophris and yellow-nosed T. chlororhynchos albatrosses, and white-chinned petrels Procellaria aequinoctialis were killed most frequently. Based on 1998–1999 fishing effort, simple extrapolation suggests that 19 000–30 000 seabirds are killed annually in South Africa's EEZ, of which 70% are albatrosses. Confidence in these estimates is low, given the small proportion of effort observed, but it is clear that urgent steps are needed to reduce seabird bycatch within South African waters.     

Yield and catch changes in a Mediterranean small tuna trap: a warming change effect?

Since the 17th century, the Tonnarella of Camogli, a small tuna trap, has been used to catch pelagic fish along the western coast of the Portofino Promontory (Ligurian Sea, Northwestern Mediterranean). The availability of long‐term datasets on fish yields (1950–1974 and 1996–2011), with information related to the seawater temperatures and the North Atlantic Oscillation (NAO), has allowed us to study the qualitative and quantitative changes in fish yields in the last decade and the possible relationships with the seasonal anomalies of temperature that have occurred in the Ligurian Sea. In 1950–1974, yields remained relatively constant over time (average of 35.6 ± 8.7 t·year^?1). From 1996 through 2011, yields were high (42.9 ± 15.9 t·year^?1) but inconsistent with strong annual variability in catches. The primary catches are Seriola dumerili, Auxis rochei, Trachurus spp. and Sarda sarda. Changes in species composition have occurred as well: S. dumerili, Sardinella sp. and Belone belone have appeared recently. Moreover, a significant decrease in the boreal scombroid (Scomber scombrus) and an increase of warm‐temperate carangids and other typically Southern Mediterranean species such as Coryphaena hippurus and Sphyraena viridensis, appear to be linked to the warming of the surface water layer, particularly evident in the Ligurian Sea, for the last 10 years. The analysis of this kind of trend may be a powerful tool for assessing structural changes of the pelagic fish community in the Ligurian Sea (Northwestern Mediterranean).     

Is there a need for a new governance model for regionalised Fisheries Management? Implications for science and advice

Over the years, the breadth and depth of EU marine policy has increased with revisions of the Common Fisheries Policy (CFP) and new legislation like the Marine Strategy Framework Directive (MSFD), Integrated Maritime Policy (IMP) and the Framework for Marine Spatial Planning Directive in Europe (FMSP). Not only do these different policies have different remits and hence scope, they also present a multitude of modes of implementation. Although the CFP and MSFD have many common goals when it comes to conservation and sustainable use of living marine resources, they differ substantially in governance set up and implementation modalities, including the underlying scientific advisory processes and structures. Regional cooperation and coordination is foreseen, but there is no governance model in place to coordinate requests for scientific advice, nor institutions coordinating the activities of advice providers, either across policies or across regions. This results in an increase in uncoordinated requests for scientific advice yet the pool of experts fuelling the advisory system is limited. As a result the European marine scientific advisory system is increasingly under pressure. In this paper the consequences of this problem are analysed and a redesign of the institutional governance setting to accommodate these challenges and make the science and advice system ready for the future is explored.     

Dynamic Load Analysis for Towlines

- Based on the curve equation of towline in towing, this paper introduces the new concepts of the coefficient of shape extension and comprehensive extension of towline, infers related calculation formulas, and then gives some quantitative analyses on the magnitude of dynamic loads acting on the towline and the measures to increase the capacity of towline against the dynamic loads.     

Research on the risk-based model for regional emergency resource allocation for ship-source oil spill

The key point for rational allocation of emergency resources is to match the oil spill response capacity with the risk of oil spill. This paper proposes an innovative risk-based model for quantitative regional emergency resource allocation, which comprehensively analyzes the factors such as oil spill probability, hazard consequences, oil properties, weathering process and operation efficiency, etc. The model calculates three major resources, i.e., mechanical recovery, dispersion and absorption, according to the results of risk assessment. In a field application in Xiaohu Port, Guangzhou, China, and the model achieved scientific and rational allocation of emergency resources by matching the assessed risk with the regional capacity, and allocating emergency resources according to capability target. The model is considered to be beneficial to enhancing the resource efficiency and may contribute to the planning of capacity-building programs in high-risk areas.     

Asymptotic Analysis Methods for Structural Reliability

- Applying Laplace asymptotic approximation of integral, asymptotic analysis methods of structural reliability are proposed in generalized and orthogonal random space. Analytic results show that the proposed methods are simple in calculation and accurate enough for problems of continuous random variables.     

New Eulerian-Lagrangian Method for Salinity Calculation

A difference scheme in curvilinear coordinates is put forward for calculation of salinity in estuaries and coastal waters, which is based on Eulerian-Lagrangian method. It combines first-order and second-order Lagrangian interpolation to reduce numerical dispersion and oscillation. And the length of the curvilinear grid is also considered in the interpolation. Then the scheme is used in estuary, coast and ocean model, and several numerical experiments for the Yangtze Estuary and the Hangzhou Bay are conducted to test it. These experiments show that it is suitable for simulations of salinity in estuaries and coastal waters with the models using curvilinear coordinates.     

Can management effort be predicted for marine protected areas? New considerations for network design

This study examined the level of management complexity (simultaneously occurring licensed human activities) within the currently designated Marine Protected Areas (MPAs) in Scottish waters and through modelling and statistical analysis determined which variables play an important role in defining the level of management effort required for each MPA. This study utilised surveyed distribution data for Priority Marine Features and modelled distribution data showing potential “Most Suitable” Priority Marine Feature habitat through the species distribution model, Maxent. Prediction indicators were developed through Spearman׳s Rank coefficients and a linear regression model. Results showed that, (1) there was a significant negative correlation between the management complexity score within 5 km of a MPA and the number of casework events (defined as any work or statutory consultation associated with an MPA, such as planning applications, discharges or new fisheries); and (2) a significant positive correlation between the number of casework events and location, number of features, and the type of features and most suitable scores. Calculations showed that Lochs Duich, Long and Alsh, Loch Sunart, Loch Sween and Loch Creran may potentially require most effort to manage once they are designated as MPAs. This study showed that it is possible to evaluate options within an MPA network to achieve cost effective options for the biodiversity and socio-economic objectives of MPA networks and that some MPAs are likely to be more efficient than others in terms of management time.     

Artificial Neural Networks for the analysis of spread⿿mooring configurations for floating production systems

This work presents the development of Artificial Neural Networks for the analysis of any arbitrarily defined spread-mooring configuration for floating production systems (FPS), considering a given scenario characterized by the water depth, metocean data, characteristics of the platform hull, and the riser layout. The methodology is applied to recent designs of deepwater semi-submersible platforms connected to a large number of risers with asymmetrical layout. In such cases, the design variables may include values for the azimuthal spacing and mooring radius varying along the corners of the platform, besides the pretension and material of the lines. The results of the case study indicated that, given any mooring configuration characterized by the combination of all these design variables, the ANNs provide fairly accurate values for the parameters of the response that are required for the design of mooring systems (typically platform offsets and line tensions).     

Acceptance of the international compensation regime for tanker oil pollution – And its implications for China

The international compensation regime for tanker oil pollution has been successful in providing adequate and prompt compensation to pollution victims in its member states. Nevertheless, the attitudes of different countries toward acceptance of this regime have varied considerably. This paper aims to explain three main factors in the acceptance of the regime, including: (1) The level of economic development; (2) the risk of exposure to tanker oil spills; and (3) the financial burden associated with adherence to the International Oil Pollution Compensation Fund (IOPC). Using both fuzzy-set Qualitative Comparative Analysis and an Ordered Probit model, this study found two patterns causing upper-middle and high income countries to have a high acceptance level: (a) Those facing a medium risk of oil spills and having a low financial burden; and (b) those facing a high risk of oil spills. The study reveals that, for a country with a high risk of exposure to tanker oil spills, such as China, with its improvement in economic status it is far better for it to join the IOPC Fund, so as to provide better protection both for potential pollution victims and for the marine environment. The results of this study can also be applied to other countries that are considering whether or not to accept the international compensation regime for tanker oil pollution.     

The Boundary Element Method for Pile-Soil Interaction

In this paper, several mathmatical models for the pile- soil interaction are outlined. The Boundary Element Method is one of the very effective methods for the reasonable models of elasticity and elastoplasticity. The major of this paper is concerned with the Boundary Element Method for the pile-soil interaction, including general methods and calculating formulation of static and dynamic analysis of the pile and pile groups. Some results of analysis are also given.     

Lifetime Prolonging Algorithms for Underwater Sensor Networks

1.IntroductionRecent advances in acoustic communication,sensor networks and ad hoc networks have motivatedthe development of UASNs which are generallyformed by a surface station,autonomous underwater ve-hicles(AUVs)and sensor nodes that possess sensing,si…     

Dynamic Analysis for Structures Isolated with Dampers

- In this paper, mathematical models and dynamic analyses for both SDOF and MDOF structures isolated with dampers are established and performed, and a comprehensive computation method is provided. The shock absorbing effect is illustrated through an example of a two DOF damper-isolated system excited by sinusoidal waves and actual ground acceleration input recorded in earthquakes. It is shown that most of the responses of the structure with dampers reduce greatly near the resonant zone, but acceleration is enlarged in the lower or higher frequency zone; among various parameters, the influence of frictional coefficient n is the most significant, that of damping ratio of the dampers , is the second, and that of stiffness coefficient of the dampers k, is the slightest.