Marine Sci Research Articles

Catch and yield trends of the Portuguese purse seine fishery (2006-2018)

Catch and yield trends of the Portuguese purse seine fishery (2006-2018)

RETRACTED: Optimization of the energy efficiency operational indicator for M/V NSU JUSTICE 250,000 DWT by grey relational analysis method in Vietnam

At the request of the Journal Editor and the Publisher, the following article has been retracted. Tran TA, Optimization of the energy efficiency operational indicator for M/V NSU JUSTICE 250,000 DWT by grey relational analysis method in Vietnam, Proc IMechE, Part M: J Engineering for the Maritime Environment, First Published December 26, 2017, DOI: 10.1177/1475090217748756 Following investigation into this article, it has been determined that the article includes major overlap with a previously published article by the same author; Tran TA, Optimization of the Energy Efficiency Operational Indicator for M/V NSU JUSTICE 250,000 DWT by Grey Relational Analysis Method in Vietnam, J Marine Sci Res Dev 2017, 7:232, DOI: 10.4172/2155-9910.1000232 [Accessed: 4th January 2018]

The Future Prediction of the One-Dimensional Topography of the Estuary Delta of the Shirakawa River

Predicting the long-term topographical change based on results of a time-slice experiment using a General Circulation Model (GCM) is difficult because actual change is a result of the continuum of events occurring in succession leading from the past to the future. We developed a one-dimensional topographical model of an estuary delta as the first step of assessing climate change effects. Three major effects, i.e. tidal flow, waves and sediment supply from the river, were included in this model. In order to estimate the sensitivity of these effects, simulations with virtual conditions were conducted. These simulations show equilibrium profiles that are close to the results of Roberts et al. [2000] “Predicting the profile of intertidal mudflats formed by cross-shore tidal currents,” Proc. Marine Sci. 3, 263–285.]. The simulation results were validated with observation data from the Shirakawa River delta. As a long-term prediction (about 37 years), the propagation of the rollover point was less than the actual data showed. The gradient of the subtidal zone was gentler than that observed. However, the short-term prediction (about 17 years) agrees with the observation data. These results show that old, unreliable, observation data used as a boundary condition significantly affects the reproducibility of the actual tidal flat profile. Finally, the effect of continuous Sea Level Rise (SLR) over 100 years from the present was investigated. As expected, the simulation results show a shift of the shoreline landward. The water depths in the intertidal and subtidal zones increase compared to a no-SLR condition. Therefore, the topset area grows as a consequence of SLR. Additionally, it was shown that future accumulation in the subtidal zone is reduced with SLR.

Detecting discontinuities in GNSS coordinate time series with STARS: case study, the Bologna and Medicina GPS sites

Global navigation satellite systems (GNSS) data are a fundamental source of information for achieving a better understanding of geophysical and climate-related phenomena. However, discontinuities in the coordinate time series might be a severe limiting factor for the reliable estimate of long-term trends. A methodological approach has been adapted from Rodionov (Geophys Res Lett 31:L09204, 2004; Geophys Res Lett 31:L12707, 2006) and from Rodionov and Overland (J Marine Sci 62:328–332, 2005) to identify both the epoch of occurrence and the magnitude of jumps corrupting GNSS data sets without any a priori information on these quantities. The procedure is based on the Sequential t test Analysis of Regime Shifts (STARS) (Rodionov in Geophys Res Lett 31:L09204, 2004). The method has been tested against a synthetic data set characterized by typical features exhibited by real GNSS time series, such as linear trend, seasonal cycle, jumps, missing epochs and a combination of white and flicker noise. The results show that the offsets identified by the algorithm are split into 48 % of true-positive, 28 % of false-positive and 24 % of false-negative events. The procedure has then been applied to GPS coordinate time series of stations located in the southeastern Po Plain, in Italy. The series span more than 15 years and are affected by offsets of different nature. The methodology proves to be effective, as confirmed by the comparison between the corrected GPS time series and those obtained by other observation techniques.

Second Order Model for Wave Crests Used in Prediction of Green Water Load and Volume on Ships in Random Waves

The probability that a wave crest in a random sea will exceed a specified height has long been recognized as important statistics in practical work, e.g., in predicting green water load and volume on a ship. Nonlinear probability density functions for predicting green water load and volume are presented. The models are based on the parametric model of Ogawa (2003, “Long-Term Prediction Method for the Green Water Load and Volume for an Assessment of the Load Line,” J. Marine Sci. Technol., 7, pp. 137–144) combined with transformation of a second order wave crest height model. The wave crest height model is obtained from second order wave theory for a narrow-banded sea state in combination with transformation of the Rayleigh distribution. Results from the second order models are compared with model tests of a cargo ship presented in Ogawa (2003, “Long-Term Prediction Method for the Green Water Load and Volume for an Assessment of the Load Line,” J. Marine Sci. Technol., 7, pp. 137–144) and the Ogawa models.

A Fishy Future for Oilseed Plants

Polluted farm runoff has been linked to recurrent plagues of the predatory crown-of-thorns starfish (Acanthaster planci) on Australia's Great Barrier Reef. The study, by researchers for the CRC Reef Research Centre at the Australian Institute of Marine Sci? ence (AIMS; Townsville, Queensland) and James Cook University (Townsville, Queensland), sheds new light on a problem that has puzzled scientists and alarmed tourism author?

Acoustic classification of zooplankton

Accurate acoustic characterization of zooplankton species is essential if reliable estimates of zooplankton biomass are to be made from acoustic backscatter measurements of the water column. Work on the forward problem has resulted in the identification of three categories of scatterers, represented by theoretical scattering models [Stanton etal., ICES J. Marine Sci. 51, 505–512 (1994)]: gas-bearing (e.g., siphonophores), fluidlike (e.g., euphausiids), and hard elastic-shelled (e.g., pteropods). If there are consistent differences in the characteristic acoustic signatures of each of these classes of zooplankton, it should be possible to solve the inverse problem by using acoustic backscatter data to mathematically infer the class of scatterer. Two different inversion techniques are applied to a dataset of several hundred pings collected from broadband insonifications (∼350–750 kHz) of live zooplankton tethered and suspended in a large tank filled with filtered seawater. The model-based classifiers depend on comparison of the data with theoretical scattering models, whereas the feature-based classifiers are independent of the models and exploit only the inherent characteristics of the acoustic returns. Preliminary results indicate that the acoustic classification of zooplankton insonifications into categories representing distinct scatterer-types is feasible.

A systematic revision of the mangrove genus Avicennia (Avicenniaceae) in Australasia*

In Australasia (including Australia, New Zealand, New Guinea and other islands in the south-western Pacific) the mangrove genus Avicennia L. consists of five species: A. alba Bl., A. integra N. C. Duke, A. marina (Forsk.) Vierh., A. oficinalis L. and A. rumphiana Hallier f. Based on morphological characters and supported by allele patterns in isozyme studies (reported elsewhere), A. marina is divided into three varieties. Keys, descriptions, brief synonymy, descriptive figures and distribution maps are provided for each of the seven taxa.* Aust. Inst. Marine Sci. Contrib. No. 520.

Morphological variation in the mangrove genus Avicennia in Australasia: Systematic and ecological considerations*

Morphological variation in flowers, fruit and leaves of five Australasian species of Avicennia was assessed using multivariate techniques. Groupings based on 184 herbarium specimens gathered throughout the region showed no intermediates or potential hybrids between species, A. alba, A. integra, A. rumphiana (= A. lanata), A. marina (= A. eucalyptifolia; = A. balanophora) and A. officinalis. The most common and systematically troublesome species, A. marina, was considered further in a regional litter fall survey of 25 Australian sites, and in a detailed field study of eight locations within one estuary. In both studies, morphological variation correlated with environmental factors including air temperature, rainfall, intertidal position and upriver location. Major differences were also observed within individuals, as shown in sun and shade leaves. These observations suggested that many attributes, especially of leaves, were influenced by environmental factors, demonstrating their unsuitability in earlier systematic treatments. Other attributes reflecting putative subspecific genetic variation, included bark character, extent of pubescence on calyx lobes, and stigma position in relation to anthers. These characterise three groupings of A. marina sites, related to major biogeographic zones within this region: southeastern Australia and New Zealand; northern and north-eastern Australia and southern Papua New Guinea; and south-western Australia.* Aust. Inst. Marine Sci. Contrib. No. 489.

Sibling species in the mangrove genus Ceriops (Rhizophoraceae), detected using biochemical genetics*

Starch gel electrophoresis of enzymes from the mangrove trees Ceriops tagal (Perr.) C. B. Robinson var. tagal, Ceriops tagal (Perr.) C. B. Robinson var. australis C. T. White, and Ceriops decandra (Griff.) Ding Hou in northern Queensland, Australia, revealed a uniform genetic structure within taxa, but high levels of genetic divergence among taxa. No more than 20% of enzyme phenotypic characters were shared by any pair of the taxa, and patterns of enzyme phenotypic variation consistent with hybridisation among them were not seen in any samples, including those from areas of spmpatry. This evidence of reproductive isolation is considered sufficient to accord species status to C. tagal var. australis.* Aust. lnst. Marine Sci. Contrib. No. 453.

An endemic mangrove species, Avicennia integra sp. nov. (Avicenniaceae), in northern Australia*

This taxon was recognised in Australian mangrove assemblages as Avicennia oficinalis L., which is commonly found in Indo-Malesia and southern New Guinea. However, it is morphologically distinct, and the major distinguishing character of entire margins for calyx and bracts is unique in the genus. This species, described here as A. integra, occurs only in the Northern Territory of Australia. It therefore has the dual distinction for an Australian mangrove species of not only being endemic, but also being absent from the floristically rich tidal forests of north-eastern Queensland. Notes on its floral phenology, distribution and ecology are also given.* Aust. Inst. Marine Sci. Contrib. No. 417.