Arctic and Antarctic Scleractinian Corals: Comparisons—Similarities and Differences

Oceanology - Fauna of the circumpolar Arctic and Antarctic regions was compared based on the example of cold-water Scleractinia corals. In similar subzero temperatures of surrounding waters, not...     

Coral reef ecological pump for gathering and retaining nutrients and exporting carbon: a review and perspectives

How coral reefs with high productivity and biodiversity can flourish in oligotrophic tropical oceans has inspired substantial research on coral reef ecosystems. Increasing evidence shows that similar to water in an oasis in the desert, there are stable nutrient supplies to coral reefs in oligotrophic oceans. Here, with emphasis on the fluxes of organic matter, we summarize at the ecosystem level(1) the multiple input pathways of external nutrients,(2) the storage of nutrients in reef organisms,(...     

The long and bumpy journey: Taiwan׳s aquaculture development and management

This paper presents an overview of Taiwan׳s aquaculture development and management, focusing on the transition of the industry and the current management measures that particularly address environmental effects, ecolabels and diversification into tourism and ornamental fish business. Since the late 1980s when Taiwan׳s aquaculture in its heyday was pounded by emergent environmental problems, a policy was established on enhancing governance over aquaculture, in seeking to transform it towards an environmentally, economically and socially sustainable industry. The paper shows that positive outcomes have been achieved after the policy measures have been implemented over the past two decades. However, potential challenges of ongoing environmental impacts, conflicts regarding multiple sea uses, concerns on seafood safety, lack of management of “black” farms, low market penetration of ecolabeled products and lack of participative management were identified. It argues for the need to encourage ICZM programs to solve sea use conflicts and minimize environmental impacts, reduce “black farms” to fill the management gap, enhance market shares of ecolabeled products and a transition to a more participative mode of governance.     

Wave Energy Study in China: Advancements and Perspectives

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Repair and revitalisation of Australia׳s tropical estuaries and coastal wetlands: Opportunities and constraints for the reinstatement of lost function and productivity

Tropical fisheries are in decline around world as a result of diverse anthropogenic threats. These threats are intimately linked to biodiversity and conservation values because of the heavy dependence of both fisheries and high value marine and coastal wetlands on coastal ecosystem health. Consequently, if the widespread degradation of coastal ecosystems can be halted and remediated, there are substantial benefits to fisheries output, ecosystem resilience, food security, livelihoods, recreation and the protection of ecological assets of national and global significance. The extent, intactness and quality of Australia׳s tropical coastal ecosystems has declined markedly since European settlement, due to the cumulative impact of many small encroachments and local barrier construction on the extent and productivity of coastal wetlands, mangroves and seagrass meadows. Additionally, coastal ecosystem dependent biota has been excluded from large areas of critical habitats. Despite these changes, coastal fisheries show no clear declines that could not be explained by changes in effort. This lack of detectable decline is probably partly attributable to the short history of available fisheries catch data. However, it is also likely that it reflects the offsetting of lost natural productivity by greatly increased anthropogenic nutrient loads; a substantial problem as governments are committed to large scale, long term efforts to reduce discharges of nutrients to coastal waters. This possibility underlines the importance of rejuvenating lost coastal productivity. Evaluation of past remediation efforts show that documented success is rare, due to a complex of factors including ineffective prioritisation, a lack of necessary knowledge and resources, and inefficient monitoring and evaluation. Past experiences from Australia׳s tropics and around the world, together with current ecological understanding, suggests some generally desirable characteristics to enhance the likelihood of successful remediation and repair actions.     

New regulations in Chilean Fisheries and Aquaculture: ITQ’s and Territorial Users Rights

The large industrial fishery development that turn Chile into the third fishing nation in the world is described, and recent regulatory innovations introduced by new Fishery and Aquaculture legislation are reviewed. In addition to classical Fishery management tools, different types of limited entry systems are now defined in the law and applicable to Chilean fisherie. These for the first time include allocation of resources in the form of Individual Fishing Quotas and Individual Transferable Quotas (IFQs and ITQs). Territorial User’s Rights in Fisheries (TURF’s) were incorporated in the law to enhance self-regulatory practices among artisanal fishermen. Among them, the Areas for Management and Exploitation for Benthic Resources (AME) represent an associative assignment of TURFs. Large-scale zoning is used to re-define Aquaculture Grants and to ritualise the conflicts between Artisanal and Industrial fishermen by establishing the Artisanal Reserve in which small-scale coastal fishermen have Priority Access. Performance of the new management instruments are documented with case studies, for the following fisheries: the loco (Concholepas concholepas) a carnivorous snail, keyhole limpets (Fissurella spp.), langostino or squat lobster (Cervimunida johni), Black hake (Dissostichus eleginoides) and the Yellow prawn (Pleuroncodes monodon).     

‘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.     

AltiKa Radiometer: Instrument Description and In–Flight Performance

On 25 February 2013, the Satellite for Argos and AltiKa (SARAL) was launched from the Indian Sriharikota launch site. The AltiKa payload consisted of an altimeter and a radiometer. This paper describes the AltiKa radiometer. This instrument has been studied for several years by CNES, TAS-F, ASTRIUM-F and a set of science laboratories, and AltiKa is the first compact instrument embedding simultaneously the altimeter and radiometer functions. AltiKa radiometer is a dual frequency instrument working in K (23.8 GHz) and Ka band (37 GHz), it is based on the total power principle, with direct detection receivers. On-ground acceptance tests exhibited a very high level of performance: less than 0.2 dB has been estimated for both sensitivity and absolute accuracy in both frequencies. This paper focuses on the in-flight performances that have been observed since the launch. All the instrument observable characterizations are nominal, and in-flight sensitivity has been estimated lower than 0.2 K.     

Wave‐induced instability of seabed: Mechanism and conditions

Abstract

The instability of the seabed constitutes an important consideration in the planning and design of various offshore facilities. The stresses and the pore water pressure in the sediments, induced by the action of waves during a storm, may cause them to fail, leading to seabed instability. In this article the possible mechanism of such failures are discussed and the conditions necessary for them are formulated through simplified analyses. These provide the combinations of wave, site, and sediment parameters likely to cause instability, which may be used to identify potentially unstable sediments in a given offshore region during a storm. The numerical results are presented in convenient graphical form. Some illustrative field studies are also presented.     

Bivalves,Tributyltin and Green Tides: Ecosystem-Level Impact?

Filter feeders such as bivalves are increasingly being shown to control phytoplankton blooms in eutrophic estuaries. The possibility of such a top-down effect on macroalgae, however, has not been considered previously even though most green tide algal species reproduce by pelagic swarmers that are equivalent to phytoplankton. This work presents circumstantial evidence from an oyster-culturing French embayment where, despite eutrophication since the mid-1970s, macroalgae did not proliferate until 1982. This was also the year when tributyltin pollution from antifouling paints dropped substantially following a world-wide prime ban that was implemented to save the shellfish industry. From the recorded evolution of the oyster stock, it is shown how tributyltin reduced the bivalve filter capacity within those years and resulted in Enteromorpha swarmers being much more likely to germinate and bloom. This suggests that the green tides had been successively contained by the biological activity and the chemical pressure. The effects of the latter on the former would thus have cascaded to ecosystem-level changes, and so the functional role of bivalves should be evaluated and preserved wherever relevant.     

Nitrous oxide and methane in the Atlantic Ocean between 50°N and 52°S: Latitudinal distribution and sea-to-air flux

We discuss nitrous oxide (N₂O) and methane (CH₄) distributions in 49 vertical profiles covering the upper ∼300 m of the water column along two ∼13,500 km transects between ∼50°N and ∼52°S during the Atlantic Meridional Transect (AMT) programme (AMT cruises 12 and 13). Vertical N₂O profiles were amenable to analysis on the basis of common features coincident with Longhurst provinces. In contrast, CH₄ showed no such pattern. The most striking feature of the latitudinal depth distributions was a well-defined “plume” of exceptionally high N₂O concentrations coincident with very low levels of CH₄, located between ∼23.5°N and ∼23.5°S; this feature reflects the upwelling of deep waters containing N₂O derived from nitrification, as identified by an analysis of N₂O, apparent oxygen utilization (AOU) and NO₃⁻, and presumably depleted in CH₄ by bacterial oxidation. Sea-to-air emissions fluxes for a region equivalent to ∼42% of the Atlantic Ocean surface area were in the range 0.40–0.68 Tg N₂O yr⁻¹ and 0.81–1.43 Tg CH₄ yr⁻¹. Based on contemporary estimates of the global ocean source strengths of atmospheric N₂O and CH₄, the Atlantic Ocean could account for ∼6–15% and 4–13%, respectively, of these source totals. Given that the Atlantic Ocean accounts for around 20% of the global ocean surface, on unit area basis it appears that the Atlantic may be a slightly weaker source of atmospheric N₂O than other ocean regions but it could make a somewhat larger contribution to marine-derived atmospheric CH₄ than previously thought.     

Exploitation and conservation of coastal and marine fisheries in Bangladesh: Do the fishery laws matter?

The present study analysed the major features of two important acts and an ordinance in Bangladesh that govern coastal and marine fishery exploitation and conservation. The problems with the implementation of these regulations were identified, and the level of compliance among fishers and reasons for their noncompliance were assessed. Based on two case studies on coastal and marine ecosystems, the findings revealed that the level of noncompliance is highly prevalent, particularly in hilsa sanctuaries in the Meghna River estuary. The study identified coastal poverty, the inadequate and improper distribution of incentives, insufficient logistic support, limited alternative occupations, political interference and a lack of awareness regarding fishery regulations as the major limitations in the implementation. The drawbacks of proper implementation and the noncompliance of fishery regulations lead to fishery degradation, directly affect the sustainability of the coastal and marine ecosystem of Bangladesh and may be barriers to achieving Goal 14 of the Sustainable Development Goals (SDGs). Establishing a co-management mechanism for sanctuary management, creating economic opportunities outside of fishery sectors, declaring more protected areas in the coastal and marine ecosystem, enhancing logistic support to the enforcing agencies and building awareness are critical to improving the compliance level among fishers. Finally, the study submits that understanding the fishers’ reasons for compliance and noncompliance of the regulations is important for devising fishery policies through the consultation and engagement of stakeholders at all levels.     

The air–water sloshing problem: Fundamental analysis and parametric studies on excitation and fill levels

The problem of liquid sloshing has gained recent attention with the proliferation of liquefied natural gas (LNG) carriers transporting liquids in partially filled tanks. Impact pressures caused by sloshing depend on the tank fill level, period and amplitude of oscillation of the tank. In this paper, we first present the rudiments of a linear potential theory for sloshing motions in a two-dimensional rectangular tank, due to small amplitude sway motions. Although this topic is fundamental, we clarify inconsistencies in the published literature and texts.Numerical investigations were carried out on the sloshing motions in a two-dimensional tank in the sway excitation. The fluid domain was modeled using a finite volume approximation, and the air–water interface was tracked using a volume-of-fluid (VOF) technique. Computational results for free surface elevation and impact pressure are found to be in good agreement with theory and published data. The fill levels were varied from 10% to 95%, and the excitation time periods were varied from 0.8 to 2.8 s for a constant sway amplitude of 0.25 m (peak–peak) at 1:30 scale. The results of the parametric study are compared with theoretical predictions and suggestions are made on incorporating sloshing effects in standard seakeeping analysis for LNG carriers.     

Institutionalizing environmental reform with sense-making: West and Central Africa ports and the ‘green port’ phenomenon

Harmonizing economic activities with environmental considerations has emerged as a new globalizing phenomenon for ports. The phenomenon is labelled as ‘green port’. There is however no canonical way of turning green port into business reality. Some advanced ports have adapted it and African ports are also beginning to follow. The Freeport of Monrovia in West and Central Africa had its process of incorporating environmental considerations into its operational practices in an environmental reform labelled as ‘going green’, akin to the green port phenomenon. The process interrupted routinized port activities and behavior. Employees of Freeport of Monrovia and stakeholders could not foresee the meaning and consequences of such reform. The uncertainty triggered a process for employees and stakeholders to collectively make sense of and react to their new situation. This paper integrates Weick's sense-making properties with Weber and Glynn's institutional mechanisms affiliated to sense-making as a conceptual tool to analyze and understand the process by which meaning was assigned to Freeport of Monrovia's environmental reform and also how it became institutionalized. The analysis is based on hands-on empirical research on an environmental capacity strengthening project executed in 2013 in the Freeport of Monrovia as part of its institutional reform from a service port into landlord port. Findings bring to light the dynamic interplay of institutions and sense-making in the greening of Freeport of Monrovia.     

“Blue competition” in China: Current situation and challenges

The current study analyzes the competitiveness of marine economies in provinces/districts along the eastern coast of China. The current work reviewed the development of marine economy in China over the past decade, and analyzed strategies of each regional economy regarding natural resource endowment and policy priorities in five major coastal provinces of China. Through comparative study of local marine policies and industrial priorities, it is found that the Chinese marine economy is largely oriented towards heavy industry. Local governments focus on land reclamation and often neglect environment protection, which resulted in similar dysfunctional structures of regional industrial policies in these provinces. Based on these findings several policy suggestions are proposed.     

In-situ detection equipment for radon-in-water:unattended operation and monthly investigations

Radon is recognized as a powerful tracer of certain geophysical processes in marine and aquatic environments. In the past few decades, the instruments and methods for measuring radon concentration in water have been developed to some extent but still lack underwater in-situ measurements. Here we present an in-situ detection equipment for radon-in-water(pulsed ionization chamber(PIC)-radon) to measure dissolved radon in ocean and groundwater settings. The equipment has been successfully deployed ...     

Recreational fishing and boating: Are the determinants the same?

The research uses household survey data collected from 656 people in Townsville (adjacent to the Great Barrier Reef, Australia) within a hurdle model to investigate key factors influencing both the probability of participating and the frequency of (a) boating trips which involve fishing; (b) boating trips which do not involve fishing; and (c) land-based fishing trips. The findings suggest that there are differences in determinants, highlighting the importance of disaggregating the fishing/boating and boat/land-based experience (an uncommon practice in the literature) if wishing to obtain information for use in the design of monitoring programs, policy and/or for developing monitoring and enforcement strategies relating to fishing and boating.