Apparent digestibility coefficients of European grain legumes in rainbow trout (Oncorhynchus mykiss) and Nile tilapia (Oreochromis niloticus)

Two trials were carried out to evaluate the apparent digestibility coefficients (ADCs) of dry matter (DM), crude protein (CP), lipids, starch and gross energy (GE) of six European varieties of grain legumes, namely chickpea‐type Kabuli (CHK), chickpea‐type Desi (CHD), field pea (FP), faba bean (FB), white lupin (WL) and chickling vetch (CV), in rainbow trout and Nile tilapia juveniles. The ADCs were measured using a reference diet and six experimental diets (700 g/kg of the reference diet and 300 g/kg of each raw grain legume) containing 10 g/kg chromic oxide as inert marker. Additionally, grain legumes were analysed for the organic acids profile. In rainbow trout, FP presented the highest ADCs of DM, CP and GE, whereas chickpeas and FB had the lowest DM, GE and starch ADC values. In Nile tilapia, the lowest values of nutrients (except starch) and energy ADCs were found for FP and CV. Nutrients and energy of chickpeas, WL and FB were better digested by tilapia, whereas FP was better digested by trout. Overall results reveal raw grain legumes as promising feed sources for both fish species.     

The completely additive effects of two barley phenology‐related genes (eps2S and sdw1) are explained by specific effects at different periods within the crop growth cycle

We used the ‘Baronesse’/‘Full Pint’ doubled haploid population to analyse the genetic factors controlling flowering date under South American conditions. Both parents have similar heading dates, but the population shows transgressive segregation. Two genes, eps2S on chromosome 2H and sdw1 on chromosome 3H, explained most of the phenotypic variation for anthesis date, with the later allele carried by ‘Baronesse’ and ‘Full Pint’ , respectively. Both effects were completely additive with no interaction. We studied three plant developmental periods: seedling emergence to tillering (Z10–Z20), tillering (Z20–Z30) and end of tillering to anthesis (Z30–Z49) under field conditions at three contrasting planting dates. Z10–Z20 was also measured under semi‐controlled conditions. eps2S controlled Z30–Z49 periods, while sdw1 controlled Z20–Z30. Each of the two genes for the end‐point phenotype—anthesis date—was a determinant of flowering at a different developmental stage. No gene x planting date interactions were detected.     

Economic analysis of cobia (<Emphasis Type="Italic">Rachycentron canadum</Emphasis>) cage culture in large- and small-scale production systems in Brazil

Economic feasibility studies regarding aquaculture systems are relatively scarce, but they are important to potential investors and for the allocation of resources for research and technological development. This study evaluated the economic viability of cobia cage culture from the actual investment and operational costs of a large-scale operation off Recife, northeastern Brazil (industrial system; IS), and a family-run farm located in a near-shore area of Rio de Janeiro (familiar system; FS). The IS had twenty-four 1607 m³ floating cages deployed at a depth of 24 m, while the FS had six 75 m³ wooden cages installed in a sheltered 6- to 7-m-deep area. Analyses of profitability (gross revenue, operational profit, cost price and break-even production) and investment (net present value—NPV; and payback time) were performed. An analysis of sensitivity was also carried out. The IS required an initial investment of approximately US$ 1.5 million dollars and was more sensitive to FCR, selling price and productivity fluctuations than the FS. The FS required a relatively small initial investment (US$ 16,000 dollars), which makes it more flexible to variations in production parameters and market fluctuations. The NPV was positive for both systems, and the payback times were estimated to be 3.88 years for the IS and 2.07 years for the FS. Therefore, given the assumptions of this study, cage culture of cobia in Brazil may be considered economically feasible in offshore production systems and in near-shore, FSs. Governmental support through decreased import taxes is recommended as a way to accelerate the early development of the cage culture of marine fish in Brazil.     

Nutritional and Sensory Quality of the Freshwater Prawn Macrobrachium rosenbergii and the Influence of Packaging Permeability on its Shelf Life

The Malaysian freshwater prawn Macrobrachium rosenbergii was used for nutritional, bacteriological and sensory evaluations. Prawns were refrigerated (0 ± 1°C) and divided into two groups named T1 and T2 corresponding to permeable and impermeable (O₂/CO₂) packaging, respectively, in order to evaluate their shelf life. The percent composition ensured its high nutritional value, and consumer testing showed that acceptability was close to ideal, with good purchase intent. The type of treatment did not significantly influence the parameters assessed, and the shelf life was established as 150 h. The mesophilic bacteria count was the determining factor for quality assessment. Total volatile basic nitrogen and pH were not good parameters for evaluating quality, whereas the biogenic amines, especially agmatine, appeared to be appropriate quality parameters.     

Shifting trophic architecture of marine fisheries in New Zealand: Implications for guiding effective ecosystem‐based management

New Zealand has led the world in restoration of marine fisheries since the introduction of the Quota Management System in 1986, but challenges remain in minimizing the ecosystem‐level effects of industrialized fishing. We analysed existing long‐term fisheries data sets from 1931 to 2015 in New Zealand to resolve trends in important ecological properties of major exploited fish communities. Increases in community dissimilarities of catch composition in 1931 and 1972, followed by increasing total landings, highlight major expansions of fishing grounds and exploited species during these periods. Mirroring global patterns, the remarkable rise in fishing power, demand and generation of new markets in New Zealand have all contributed to this expansion. Marine Trophic Indices (MTIs) of landings have decreased together with total catch after the year 2000, reflecting smaller catches with a higher composition of lower trophic‐level species in recent years. Differences in relative abundance of species estimated between fisheries‐dependent and fisheries‐independent data were observed, where high‐value species displayed better agreement in relative abundance between data sets. Despite being under a Quota Management System, temporal development of MTI values relative to the timing of industrial expansion of fisheries was remarkably similar to those observed in the North Sea and Brazil, with a single expansion and decline. MTI values presented better long‐term stability in the US fisheries analysed. Analysis of long‐term data and the development of well‐resolved ecological baselines will be the first step towards applying EBM to New Zealand fisheries, in keeping with global trends in fisheries management.     

Spatial distribution and abundance of the by‐catch coastal elasmobranch Raja undulata: Managing a fishery after moratorium

The undulate ray Raja undulata Lacepède is a coastal species common along the north‐eastern Atlantic Ocean and Mediterranean Sea and is highly accessible to coastal fisheries. Between 2009 and 2015, the species was under a European Union (EU) fisheries moratorium that hampered the collection of data to assess its stock status in Portuguese waters. After that period, a small experimental EU fishing quota was set for Portugal enabling collection of fishery data under a fishermen self‐sampling scenario. Based on the data collected, R. undulata abundance was estimated along the Portuguese continental coast through the application of a N‐mixture model and incorporating environmental factors. The results support the species coastal and patchy nature across the study area with higher abundances estimated in areas associated with shallow sandy bottoms as the Southwest region. The present work constitutes an important step for the management of this fishery resource, in particular concerns about its abundance trends over time and its spatial distribution and habitat requirements.     

Anti-Phytophthora cinnamomi activity of Phlomis purpurea plant and root extracts

Phlomis purpurea (Lamiaceae), found in Quercus suber and Quercus ilex ssp. rotundifolia forest habitats in southern Portugal, is a non-host for the oomycete Phytophthora cinnamomi, the main biotic factor involved in cork oak and holm oak decline in the Iberian Peninsula. The effect of P. purpurea crude ethanol root extract was evaluated in vitro on P. cinnamomi mycelial growth, sporangial production, zoospore release and germination as well as on chlamydospore production and viability. The protection of cork oak against infection by the pathogen was also evaluated in planta. At 10 mg ml^?1, in vitro inhibition of the pathogen structures was 85–100 %. In addition, P. purpurea plants were shown to protect Q. suber and Q. ilex from P. cinnamomi infection and to reduce the inoculum potential in glasshouse trials, indicating the ability to reduce root infection by the pathogen. The results suggest that P. purpurea has the potential to reduce disease spread and that their root extracts could provide candidate substances for control of the important pathogen, P. cinnamomi.