A regionalized IO-model to value seasonal recreational ecosystem services in a mountain National Park in Spain

Recreational Ecosystem Services (RES) are among the most frequently evaluated ecosystem services.RES are seen as a major opportunity for sustainable development...     

Korea's fisheries industry and government financial transfers

The Korean fisheries industry has long played a role as a national food industry with agriculture. Fisheries products supply about 39.2% of animal proteins that Korean people need. The industry, however, is facing great challenges including international arguments for reduction or abolition of fishery subsidies. Therefore, it is urgent for us to review the characteristics of fishery subsidies according to WTO, OECD, FAO and UNEP. This paper examines the status of Korean fishery industry, and to tackle the problems of the currently supported fishery policy funds, whose total amount in 1999 was more than 1 trillion Korean won with 77 fishery projects.     

Spatial and temporal aspects of phytoplankton blooms in complex ecosystems off the korean coast from satellite ocean color observations

Complex physical, chemical and biological interactions off the Korean coast created several striking patterns in the phytoplankton blooms, which became conspicuous during the measurements of ocean color from space. This study concentrated on analyzing the spatial and temporal aspects of phytoplankton chlorophyll variability in these areas using an integrated dataset from a Sea-viewing Wide Field-of-view Sensor (SeaWiFS), Advanced Very High Resolution (AVHRR) sensor, and Conductivity Temperature Depth (CTD) sensor. The results showed that chlorophyll concentrations were elevated in coastal and open ocean regions, with strong summer and fall blooms, which appeared to spread out in most of the enclosed bays and neighboring waters due to certain oceanographic processes. The chlorophyll concentration was observed to range between 3 and 54 mg m^-3 inside Jin-hae Bay and adjacent coastal bays and 0.5 and 8 mg m^-3 in the southeast sea offshore waters, this gradual decrease towards oceanic waters suggested physical transports of phytoplankton blooms from the shallow shelves to slope waters through the influence of the Tsushima Warm Current (TWC) along the Tsushima Strait. Horizontal distribution of potential temperature (θ) and salinity (S) of water off the southeastern coast exhibited cold and low saline surface water (θ<19°C; S<32.4) and warm and high saline subsurface water (θ>12°C; S>34.4) at 75dBar, corroborating TWC intrusion along the Tsushima Strait. An eastward branch of this current was called the East Korean Warm Current (EKWC), tracked with the help of CTD data and satellite-derived sea surface temperature, which often influenced the dynamics of mesoscale anticyclonic eddy fields off the Korean east coast during the summer season. The process of such mesoscale anticyclonic eddy features might have produced interior upwelling that could have shoaled and steepened the nutricline, enhancing phytoplankton population by advection or diffusion of nutrients in the vicinity of Ulleungdo in the East Sea.     

Production of <Emphasis Type="Italic">Acartia steueri</Emphasis> (Copepoda: Calanoida) in Ilkwang Bay,Southeastern Coast of Korea

Production of the marine calanoid copepod Acartia steueri was measured from 2 October 1991 to 8 October 1992 at a station in Ilkwang Bay, on the southeastern coast of Korea. Phytoplankton standing stock ranged over 1.0 to 9.3 mg chl.a m⁻³, and annual primary productivity (by the C-14 method) at three stations was estimated at 200 gC m⁻² yr⁻¹. Acartia steueri (nauplii + copepodids + adults) were present in the plankton throughout the year, with seasonal variation in abundance. Biomass of A. steueri, excluding the NI stage, was 0.01–4.55 mgC m⁻³ (mean: 0.68 mgC m⁻³) with peaks in November, February, May and July-early August, and relatively low biomass in September– January. Instantaneous growth rates of the nauplius stages were higher than the copepodid stages. Annual production of A. steueri was 25.1 mgC m⁻³ yr⁻¹ (or 166 mgC m⁻² yr⁻¹), showing peaks in November, May and July–August with a small peak in February, and low production in December–April and September–October. There were no significant relationships between the daily production rate of A. steueri and temperature or chlorophyll a concentration, indicating that unknown other factors might be related to the variation of the production rate.     

Two‐dimensional waveform inversion of multi‐component data in acoustic‐elastic coupled media

In order to account for the effects of elastic wave propagation in marine seismic data, we develop a waveform inversion algorithm for acoustic‐elastic media based on a frequency‐domain finite‐element modelling technique. In our algorithm we minimize residuals using the conjugate gradient method, which back‐propagates the errors using reverse time migration without directly computing the partial derivative wavefields. Unlike a purely acoustic or purely elastic inversion algorithm, the Green's function matrix for our acoustic‐elastic algorithm is asymmetric. We are nonetheless able to achieve computational efficiency using modern numerical methods. Numerical examples show that our coupled inversion algorithm produces better velocity models than a purely acoustic inversion algorithm in a wide variety of cases, including both single‐ and multi‐component data and low‐cut filtered data. We also show that our algorithm performs at least equally well on real field data gathered in the Korean continental shelf.     

2D acoustic‐elastic coupled waveform inversion in the Laplace domain

Although waveform inversion has been intensively studied in an effort to properly delineate the Earth's structures since the early 1980s, most of the time‐ and frequency‐domain waveform inversion algorithms still have critical limitations in their applications to field data. This may be attributed to the highly non‐linear objective function and the unreliable low‐frequency components. To overcome the weaknesses of conventional waveform inversion algorithms, the acoustic Laplace‐domain waveform inversion has been proposed. The Laplace‐domain waveform inversion has been known to provide a long‐wavelength velocity model even for field data, which may be because it employs the zero‐frequency component of the damped wavefield and a well‐behaved logarithmic objective function. However, its applications have been confined to 2D acoustic media. We extend the Laplace‐domain waveform inversion algorithm to a 2D acoustic‐elastic coupled medium, which is encountered in marine exploration environments. In 2D acoustic‐elastic coupled media, the Laplace‐domain pressures behave differently from those of 2D acoustic media, although the overall features are similar to each other. The main differences are that the pressure wavefields for acoustic‐elastic coupled media show negative values even for simple geological structures unlike in acoustic media, when the Laplace damping constant is small and the water depth is shallow. The negative values may result from more complicated wave propagation in elastic media and at fluid‐solid interfaces. Our Laplace‐domain waveform inversion algorithm is also based on the finite‐element method and logarithmic wavefields. To compute gradient direction, we apply the back‐propagation technique. Under the assumption that density is fixed, P‐ and S‐wave velocity models are inverted from the pressure data. We applied our inversion algorithm to the SEG/EAGE salt model and the numerical results showed that the Laplace‐domain waveform inversion successfully recovers the long‐wavelength structures of the P‐ and S‐wave velocity models from the noise‐free data. The models inverted by the Laplace‐domain waveform inversion were able to be successfully used as initial models in the subsequent frequency‐domain waveform inversion, which is performed to describe the short‐wavelength structures of the true models.     

Benchmarks for validating range-dependent seismo-acousticpropagation codes

The availability of fast and relatively low-cost computing power has resulted in radical changes to the role of seismo-acoustic modeling. With the increase in the number of models available, there is the inevitable question of how can one go about validating all these numerical schemes. Recently, the issue of establishing reference solutions for range dependent ocean acoustic problems was addressed within the Acoustical Society of America. This has resulted in a set of well-defined benchmarks for range-dependent fluid problems. However, to date, there is no consistent set of benchmarks for the range-dependent seismo-acoustic codes. In this paper, we present a collection of problems intended for general use by the modeling community for validation of new computational schemes. A number of new seismo-acoustic codes are applied to produce reference solutions for these benchmarks     

Provenance of recycled palynomorph assemblages recovered from surficial glaciomarine sediments in Bransfield Strait, offshore Antarctic Peninsula

Glaciomarine surficial sediments in cores taken from Bransfield Strait, adjacent to the Antarctic Peninsula, have yielded abundant recycled and contemporaneous (Pleistocene–Holocene) palynomorphs. The former are derived principally from Late Cretaceous–Palaeogene sediments and provide information on glaciomarine depositional conditions and sediment source areas. The composition of the assemblages suggests that they reflect vegetation that was endemic to the Weddellian Biogeographic Province, which includes what is now Seymour Island, James Ross Island and other parts of the Antarctic Peninsula region. The sediments concerned are considered to have accumulated as a result of ice-rafting and discharge of subglacial meltwater.     

Winter distribution of diatom assemblages along the coastline of R. O. Korea in 2010

Diatoms are a globally successful and eukaryotic photosynthetic organism with an ornamented silica external wall. The relationship between their valve morphology and habitat means that diatoms can be used as bioindicators to characterize the aquatic environment. To estimate the differential distribution and diversity of diatom assemblages along the coastal line, we collected phytoplankton samples from 114 coastal sites of waters of R. O. Korea. We applied the unweighted pair-group technique usin...