The requirement to rebuild US fish stocks: Is it working?

The Magnuson–Stevens Fishery Conservation and Management Act (MSA) was amended in 1996 to require that overfished stocks be rebuilt in as short a time period as possible, not to exceed 10 years, with limited exceptions. This comment examines the basic but important question of whether the implementation of rebuilding plans under the 1996 amendments has in fact been associated with biomass recovery. Specifically, for each of the 44 stocks examined, this analysis compares the biomass trend before rebuilding plan implementation to the trend after rebuilding plan implementation using a linear trend-break model. The analysis demonstrates a statistically significant positive association between the implementation of rebuilding plans and standardized biomass in 19 of 44 stocks. None of the 44 stocks examined showed a statistically significant negative association. The analysis showed a strong temporal relationship between the implementation of the policy and rebounds in fish stocks.     

Compromise in the IWC: Is it possible or desirable?

It is widely assumed that a compromise position must be reached between pro- and anti-whaling groupings within the International Whaling Commission. This assumption is based on the belief that the Commission will collapse in the absence of any such compromise, and has been the driving force behind a number of compromise proposals in recent years. This paper argues that the fundamental positions of the two groups are so different, and that both groups are getting enough from the current position as to make it unattractive to either group to make any serious concessions toward a compromise position.The suggested solution is for the two groups to “agree to disagree”; using the resulting improvement in goodwill between them to focus on cooperation on those aspects of whale conservation on which they can agree.     

Rights based fishing on the high seas: Is it possible?

The high seas fisheries are troubled by overcapacity and lax enforcement of management rules. The idea has emerged that these problems could be dealt with by property rights solutions such as ITQs. Such management tools only emerged after the 200-mile EEZ was established. This made it possible to apply the sovereign state's legislative, enforcement and judiciary apparatus to regulate fisheries. It is argued that without the EEZ such solutions would have been unlikely to emerge, and that a further extension of the EEZ is necessary to apply rights-based regulations to high seas fisheries. The current management regime of high seas fisheries lacks the necessary enforcement apparatus, which makes it necessary to apply trade sanctions, port measures and blacklisting to support regulations of high seas fisheries. It is argued that such measures are likely to be the second best, compared to further extending coastal state jurisdiction. Finally a bioeconomic model is applied to analyze potential gains from cooperation in high seas fisheries.     

The LUSI mud volcano triggering controversy: Was it caused by drilling?

Following the Yogyakarta earthquake on May 27th, 2006, the subsequent eruption of a mud volcano has been closely observed and analyzed by the geological community. The mud volcano, known as LUSI, began erupting near the Banjarpanji-1 exploration well in Sidoarjo, East Java, Indonesia. LUSI offers a unique opportunity to study the genesis and development of a mud volcano.     

‘The Hare and the Tortoise’: Lessons from Baltic Sea and Mediterranean Sea governance

Commonly, the Baltic Sea is pictured as a proactive region with a long-standing tradition for cooperation and surrounded by the “greenest” EU countries. In contrast, southern countries often suffer from the “Mediterranean Syndrome” in which the heterogenous socio political situation is given as the “proof” that cooperation would not work. The Marine Strategy Framework Directive adopted by European Union in 2008 is an important step towards ecosystem-based marine management and provides a legal document suggesting marine regions as a scale for cooperation. In this paper, we aim to explore stakeholders׳ perspectives on key factors for good governance at the regional sea level covering the Eastern Baltic States and the south of France. We targeted a broad panel of professionals from different sectors with a political, economic or societal importance in the respective seas. We suggest that Baltic and Mediterranean stakeholders are going through very different stages of governance adjustment fitting the purpose of ecosystem-based marine management. Baltic institutions are well established, which in some way prevents structural analysis of whether the current governance model is the most appropriate reaching GES. In the Mediterranean, the EU strategies faces institutional challenges, which is leading stakeholders to think “out of the box” about what is really needed for implementing ecosystem-based marine management for this sea. It is suggested that a golden opportunity exists at present in the Mediterranean to create a regional platform of cooperation, not only to fit the MSFD implementation, but also to improve governance of the Mediterranean Sea and its environmental status.     

Good luck or good governance? The recovery of Celtic Sea herring

The herring stock in the Celtic Sea collapsed in 2004. The stock is managed under the European Union's (EU) Common Fisheries Policy (CFP), but with a large measure of local stakeholder involvement through the Pelagic Advisory Council and a local Irish stakeholder committee. An iterative process, initiated by the local committee culminated in a formal rebuilding plan, which ran until 2012, by which time, the stock had fully recovered. Subsequent analyses of stock development over this period suggest that the stock was already recovering by the time the final plan was implemented. Did the stock rebuild by good fortune or did the governance measures put in place achieve their aims? This question is answered by way of examination of stock trends over time, analyses of the main elements of the rebuilding measures, including a management strategy evaluation (MSE) along with analyses of the legal and institutional arrangements in Ireland and in the EU CFP, including the development of the Pelagic Advisory Council. Important innovations in the CFP are revealed as having been crucial for the rebuilding process.     

Is stress-insensitive chemical compaction responsible for high overpressures in deeply buried North Sea chalks?

Chalk compaction is often assumed to be controlled by a combination of mechanical and effective stress-related chemical processes, the latter commonly referred to as pressure solution. Such effective stress-driven compaction would result in elevated porosities in overpressured chalks compared with otherwise identical, but normally pressured chalks. The high porosities that are frequently observed in overpressured North Sea chalks have previously been reported to reflect such effective stress-dependent compaction.However, several wells with deeply buried chalk sequences also exhibit low porosities at high pore pressures. To investigate the possible origins of these overpressures, basin modeling was performed in a selected well (NOR 1/3-5) offshore Norway. This modeling was based on both effective stress-driven mechanical porosity reduction, which enables modeling of disequilibrium compaction, and on stress-insensitive chemical compaction where the porosity reduction is caused by thermally activated diagenesis.The modeling has demonstrated that the present day porosities and pore pressures of the chalks could be successfully replicated with mechanical porosity loss as the only process leading to chalk porosity reduction. However, the modeled porosity and fluid pressure history of the sediments deviated significantly from the porosity and pore pressure versus depth relationships observed in non-reservoir North Sea chalks today. To the contrary, modeling which was based on thermally activated porosity loss due to diagenesis (as a supplement to mechanical compaction), resulted in modeled chalk histories that are consistent with present day observations.It was therefore inferred that disequilibrium compaction could not account for all of the pore pressure development in overpressured chalks in the study area. The observation that modeling including temperature-controlled diagenetic porosity reduction gave plausible results, suggests that such porosity reduction may in fact be operating in chalks as well as in clastic rocks. If this is correct, then improved methods for pore pressure identification and fluid flow analysis in basins containing chalks should be developed.     

Characteristics of Tide in The South China Sea

Based ourself mainly on the harmonic constant in the tide table (English-edition), we acquire data from 320 tidal observatories, calculate the different tidal ranges and cotidal hours of the South China Sea, and by the contour line method, draw the M_2, S_2. K_1, O_1 constituent charts, thus better showing the tide distribution in the South China Sea and presenting tide characteristics in the area more accurately.     

The South China Sea thermohaline structure and circulation

In this study, we used the Navy' s Master Oceanographic Observation Data Set(MOODS), consisting of 116019 temperature and 9617 salinity profiles, during 1968- 1984 to investigate the temporal and spatial variabilities of South China Sea thermohaline structures and circulation. For temperature, profiles were binned into 204 monthly data sets from 1968 to 1984 (17 years). For salinity, profiles were binned into 12 climatological monthly data sets due to the data paucity. A two-scale optimal interpolation method was used to establish a three-dimensional monthly-varying gridded data set from MOODS, covering the area of 5°-25°N and 105° - 125°E and the depth from the surface to 400 m. After the gridded data set had been established, both composite analysis and the Empirical Orthogonal Function (EOF) analysis (for temperature only) were used to identify the major thermohaline fratures including annual mean, monthly anomalies, and interannual thermal variabilities. The inverted monthly circulation pattern     

Resilience: What is it and what does it mean for marine policymakers?

Marine policymakers are facing increasing calls to consider the resilience of communities that rely on coastal and marine ecosystem goods and services, and the resilience of natural systems themselves. These calls are in response to increasing threats to coastal communities from external factors such as coastal hazards, possibly associated with climate change, reductions in natural capital often caused by over-fishing and invasive species, and drivers that act to change local and regional economic conditions leading to changes in employment and inequality. However, most communities have had little experience in explicitly managing for resilience. Similarly, our understanding of the factors that make a natural or social system resilient is also somewhat limited. Furthermore, there is a lack of consensus-based definitions and performance measures for assessing resilience. These factors, along with other barriers, will need to be overcome before effective resilience-based management can be implemented.     

The circulation in the southern Huanghai Sea and northern East China Sea in June 1999

On the basis of hydrographic data and current measurement (the mooring system, vessel-mounted ADCP and toward ADCP) data obtained in June 1999, the circulations in the southern Huang-hai Sea (HS) and northern East China Sea (ECS) are computed by using the modified inverse method. The Kuroshio flows northeastward through eastern part of the investigated region and has the main core at Section PN, a northward flow at the easternmost part of Section PN, a weaker anti-cyclonic eddy between these two northward flows, and a weak cyclonic eddy at the western part of Section PN. The above current structure is one type of the current structures at Section PN in ECS. The net northward volume transport (VT) of the Kuroshio and the offshore branch of Taiwan Warm Current (TWCOB) through Section PN is about 26.2×106m3/s in June 1999. The VT of the inshore branch of Taiwan Warm Current (TWCIB) through the investigated region is about 0.4×106m3/s. The Taiwan Warm Current (TWC) has much effect on the currents over the     

A re-assessment of the “Neogene” deposits of the south Irish Sea and Nymphe Bank

Recent studies carried out in the Nymphe Bank area of the north Celtic Sea and in the south Irish Sea have prompted a re-assessment of the deposits formerly described as Neogene. Comparison between seismic profiles and borehole results show that the Neogene unit which underlies a boulder clay, correlates with marine sands and gravels and an earlier boulder clay. This, along with other evidence has led us to propose a Pleistocene age for this unit. The approximate extent of these deposits in the south Irish Sea and the north east Celtic Sea is indicated.     

The Manila clam population in Arcachon Bay (SW France): Can it be kept sustainable?

The venerid clam Ruditapes philippinarum is the most prominent suspension-feeding bivalve inhabiting muddy intertidal seagrass beds in Arcachon Bay (SW France). It is exploited by fishermen, and Arcachon Bay ranks number one in France in terms of production and total biomass of this species. Previous studies revealed a decrease in the standing stock of R. philippinarum since 2003 and unbalanced length–frequency distributions with a lack of juveniles and of adults > 40 mm. Consequently, the population dynamics of this bivalve were studied at four intertidal sites and one oceanic site in Arcachon Bay. As clam size structure did not allow classical dynamics computations, field monitoring was coupled with field experiments (tagging–recapture) over two years. Monitoring of condition index and gonadal maturation stages highlighted a high variability in spawning number and intensity between sites. Recruitment events in the exploited area varied spatially but with uniformly low values. Von Bertalanffy Growth Function (VBGF) parameters (K, L_∞) were determined using Appeldoorn and ELEFAN methods. In the exploited sites in the inner lagoon, K was relatively high (mean = 0.72 yr^? 1) but L_∞ was low (mean = 41.1 mm) resulting in a moderate growth performance index (Φ′ = 2.99). Growth parameters were not correlated with immersion time and L_∞ was different between sites. Comparison of mortality coefficients (Z) between cage experiments and field monitoring suggested that fishing accounts for 65–75% of total adult mortality. Low recruitment, a low growth rate and a normal mortality rate led to low somatic production (4.1 and 8.7 g Shell-Free Dry Weight (SFDW) m^? 2 yr^? 1) and an annual P/B ratio from 0.44 to 0.92 yr^? 1. Under current conditions, the possibility of a sustainable population in Arcachon Bay will strongly depend on recruitment success and fishing management.     

The carbonate system in the central South China Sea

The Clements of the carbonate system (HCO3- , CO32-, CO2, ·CO2 and Pco2) in the central South China Sea have been calculated by determining the pH values and total alkalinity of the seawater samples collected at 42 stations, combining simultaneously with the data of the temperatures, salinity and depths. The distributions of their characteristics have been briefly described and discussed. The saturation degrees (Ω) of calcite and aragonite in the studied area have also been evaluated. The ΩcaIc- and Ωarag. in the surface waters are about 5.8 and 3.9, respectively. The saturation depth is about 2200m for calcite and 1200m for aragonite. The lysocline in the studied area probably lies between 3000 m and 4000 m where the saturation degree of calcite is approximately 0.78.     

The role of the marine sector in the Irish national economy: An input–output analysis

Recent research in Ireland has estimated both the national and regional economic value of the marine sector. However, economic activity does not exist in a vacuum. Activities in the marine sector not only directly affect the industries in the sector but also influence other sectors through inter-sectoral linkages. This paper uses an input–output (IO) methodology to examine the linkages and production effects of the Irish marine sector on the national economy. Disaggregating the Irish IO table for 2007 to include 10 additional marine sectors, this paper represents the first effort to quantify the inter-industry linkage effects, production-inducing effects and employment multipliers in the marine sector. This analysis found that a number of marine sectors, notably the maritime transportation sector, have an important economic role within the wider Irish economy.     

Is the Northern Sea Route attractive to shipping companies? Some insights from recent ship traffic data

While the media vigorously propagates historic Northern Sea Route (NSR) transits and researchers demonstrate the viability of the NSR, current usage by the shipping industry has been neglected thus far. This study aims to analyse the current ship traffic at NSR using transit data and port call data. The results show that navigation season lasts for five months, and Arc4 and Arc5 vessels are used extensively. Some Asian countries are active participants in the transit activities. NSR seems to be more appealing to liquid, bulk and general cargo transportation. Currently, most activities are still domestic and destinational in nature. The paper provides real statistics that can add value to the viability analysis. It identifies key players of the transits, exhibits trade pattern at NSR, and presents facts that interest shipping companies.     

The Gulf of Suez—northern Red Sea neogene rift: a quantitive basin analysis

Subsidence analysis (backstripping) was carried out on a series of wells from the Gulf of Suez and northern Red Sea region of Egypt in order to examine the interplay between tectonic events, basin subsidence, sedimentation and sea level changes in a young, developing ocean basin and continental margin. Using constraints on chronostratigraphy and paleodepth from various sources combined with stratigraphic and structural information from industry wells and other geophysical sources it has been possible to compile the data necessary to perform geohistory analyses throughout the region.Major subsidence due to crustal thinning began ∼25 Ma with sedimentation initially occurring in isolated sub-basins. These earliest sediments record the transition from continental to marine depositional environments. Subsequently during early and middle Miocene times subsidence was rapid and uniform along and across the entire rift basin. Open marine sedimentation occurred across all structural regimes. The mid-Clysmic tectonic event (16.5 Ma) resulted in structural rearrangement of the rift basin and uplift of the rift shoulders. Rapid subsidence continued as global sea level fell, producing a series of prograding, siliciclastic fan-deltas at the rift margins. At ∼15.5 Ma, opening of the Suez rift was terminated, tectonic subsidence decreased dramatically in the southern rift and ceased entirely in the northern rift. Tensional plate motion probably was transferred from the Gulf of Suez to sinistral strike-slip movement on the Dead Sea transform at this time. The quiescence in subsidence combined with a lowered global sea level resulted in the deposition of a thick (up to 4 km) series of evaporites within the central trough of the rift from the middle to latest Miocene. The accumulation of such a thick sequence of sediments during a phase of decreased tectonic subsidence is interpreted as a ‘filling-in’ of the rift topography which developed during the earlier period of rapid subsidence and rift-shoulder uplift and continued compaction.A rapid global sea level rise concomitant with a subsequent pulse of increased tectonic activity in the latest Miocene—earliest Pliocene returned the rift to dominantly marine conditions.     

The “Tegnue de Ciosa” area: Patch reefs in the northern Adriatic Sea

Exposures of both living and dead biogenic rock built by calcarous algae, madreporaria and serpulids are present in the northern Adriatic Sea. These asymmetrical patch reefs, which project up to 4 m above the present sea floor, are best developed off Chioggia, Italy, in water depths ranging from 17 to 24 m. Side-scan sonar traverses showed that individual reef exposures are areally irregular and ranged in size from roughly 1 to 100,000 m².     

Sea,freshwater or saltpans? Foraging ecology of terns to assess mercury inputs in a wetland landscape: The Ebro Delta

The Ebro catchment, the largest river basin in Spain, includes various heavily industrialized areas. Among these is the Flix site, where a chemical plant has been operating since the beginning of the 20th century. This extended operational period, together with the construction of a dam next to the factory around 1960, resulted in the accumulation of large amounts of heavily polluted sediments in the adjacent riverbed, many of which are contaminated by mercury. Pollutants from Flix are carried downstream by the Ebro River to its delta. In order to assess the transfer of mercury to the complex river estuary ecosystem, we studied the ecology of the tern community living there as these birds segregate into a range of habitats. For this purpose, first we used stable isotope analysis (SIA) (δ³⁴S, δ¹³C, δ¹⁵N) of eggs to determine the trophic ecology and habitat partitioning of several tern species (Common, Sandwich, Little, Gull-Billed and Whiskered Tern) breeding sympatrically, in order to link their foraging ecology with habitat types. Next we measured mercury concentrations in eggs to monitor the input of this metal into the diverse habitats. With the exception of the Little Tern, the other terns used a restricted habitat range in the Ebro Delta, as shown by C and S isotopes; the Gull-Billed and Whiskered Tern foraged in freshwater habitats, while the Common and Sandwich Tern used marine habitats. This restricted feeding behavior of the Gull-Billed and Common Tern contrasts with previous reports in other breeding sites. The Little Tern, which showed a wide range of isotopic values, was found to be an opportunistic forager but fed mainly in saltpans, a feeding habitat not reported previously for this species in this area. We found that mercury concentrations are related to foraging habitat and diet, and are unexpectedly higher in species feeding on demersal prey in marine habitats and also higher in birds feeding in saltpans than in those feeding in freshwater habitats. The mercury concentrations found in the Little and Common Tern eggs sampled in “Punta de la Banya” may be sufficiently high to endanger breeding success.