Estimation of starvation and diet variation of the RNA/DNA ratios in field-caught Sardina pilchardus larvae off the north of Spain

The aim of this study was to analyse the general larval condition, to determine the lncidence of starvation and to investigate the effect of time of day on RNA/DNA ratios among field-caught Sardina pilchardus (L.) larvae. The larvae were collected during 4 research cruises off northern Spain, during March, April, May and June 1992. A highly sensitive fluorometric method for nucleic acid quantification was applied to larvae of S. pilchardus. The means of the RNA/DNA ratio were relat~vely high, so the larvae collected off northern Spain were generally in good condition. Low percentages of starving larvae (RNA/DNA ratio less than 1.3), ranging from 0 to 3.23%, were found over the 4 mo. The RNA/DNA ratios were significantly correlated with zooplankton biomass. Larvae collected at night revealed higher RNA/DNA ratios compared to larvae caught during the day. This seems to indicate that there is some endogenous rhythm in the production of RNA. It would then follow that, if there are die1 changes in RNA concentrations, average RNA Indices can be unrepresentative if there IS any day/night bias in sampling

Farmers’ management of functional biodiversity goes beyond pest management in organic European apple orchards

Supporting functional biodiversity (FB), which provides natural pest regulation, is an environmentally sound and promising approach to reduce pesticide use in perennial cultures such as apple, especially in organic farming. However, little is known about farmers’ practices and motivations to implement techniques that favor FB, especially whether or not they really expect anything from FB in terms of pest regulation. In fact, FB-supporting techniques (FB-techniques) are massively questioned by practitioners due to inadequate information about their effectiveness. An interview survey was performed in eight European countries(i) to describe farmers’ practices and identify promising FB-techniques: (ii) to better understand their perceptions of and values associated with FB; and (iii) to identify potential drivers of (non-)adoption. Fifty-five advisors and 125 orchard managers with various degrees of experience and convictions about FB were interviewed and a total of 24 different FB-techniques which can be assigned to three different categories (ecological infrastructures, farming practices and redesign techniques) were described. Some were well-established measures (e.g., hedges and bird houses), while others were more marginal and more recent (e.g., animal introduction and compost). On average, farmers combined more than four techniques that had been implemented over a period of 13 years, especially during their establishment or conversion period. In general, it was difficult for farmers to evaluate the effectiveness of individual FB-techniques on pest regulation. They considered FB-techniques as a whole, targeting multiple species, and valued multiple ecosystem services in addition to pest regulation. The techniques implemented and their associated values differed among farmers who adopted various approaches towards FB. Three different approaches were defined: passive, active and integrated. Their appraisal of FB is even more complex because it may change with time and experience. These findings provide empirical evidence that the practical implementation of promising techniques remains a challenge, considering the diversity of situations and evaluation criteria. Increased cooperation between researchers, farmers and advisors should more effectively target research, advisory support and communication to meet farmers’ needs and perceptions

О некоторых тенденциях, осложнивших в начале ХХI века перспективы курортно-рекреационного развития Крыма

Целью работы явился анализ взаимовлияния различных факторов, сужающих потенциал туристско-рекреационной привлекательности Крыма, для уточнения возможностей объективного прогнозирования его перспективного развития

Developing fencing policies in dryland ecosystems

The daily energy requirements of animals are determined by a combination of physical and physiological factors, but food availability may challenge the capacity to meet nutritional needs. Western gorillas (Gorilla gorilla) are an interesting model for investigating this topic because they are folivore-frugivores that adjust their diet and activities to seasonal variation in fruit availability. Observations of one habituated group of western gorillas in Bai-Hokou, Central African Republic (December 2004-December 2005) were used to examine seasonal variation in diet quality and nutritional intake. We tested if during the high fruit season the food consumed by western gorillas was higher in quality (higher in energy, sugar, fat but lower in fibre and antifeedants) than during the low fruit season. Food consumed during the high fruit season was higher in digestible energy, but not any other macronutrients. Second, we investigated whether the gorillas increased their daily intake of carbohydrates, metabolizable energy (KCal/g OM), or other nutrients during the high fruit season. Intake of dry matter, fibers, fat, protein and the majority of minerals and phenols decreased with increased frugivory and there was some indication of seasonal variation in intake of energy (KCal/g OM), tannins, protein/fiber ratio, and iron. Intake of non-structural carbohydrates and sugars was not influenced by fruit availability. Gorillas are probably able to extract large quantities of energy via fermentation since they rely on proteinaceous leaves during the low fruit season. Macronutrients and micronutrients, but not digestible energy, may be limited for them during times of low fruit availability because they are hind-gut fermenters. We discuss the advantages of seasonal frugivores having large dietary breath and flexibility, significant characteristics to consider in the conservation strategies of endangered species

The Photodetector Array Camera and Spectrometer (PACS) on the Herschel Space Observatory

The Photodetector Array Camera and Spectrometer (PACS) is one of the three science instruments on ESA's far infrared and submillimetre observatory. It employs two Ge:Ga photoconductor arrays (stressed and unstressed) with 16x25 pixels, each, and two filled silicon bolometer arrays with 16x32 and 32x64 pixels, respectively, to perform integral-field spectroscopy and imaging photometry in the 60-210\mu\ m wavelength regime. In photometry mode, it simultaneously images two bands, 60-85\mu\ m or 85-125\mu\m and 125-210\mu\ m, over a field of view of ~1.75'x3.5', with close to Nyquist beam sampling in each band. In spectroscopy mode, it images a field of 47"x47", resolved into 5x5 pixels, with an instantaneous spectral coverage of ~1500km/s and a spectral resolution of ~175km/s. We summarise the design of the instrument, describe observing modes, calibration, and data analysis methods, and present our current assessment of the in-orbit performance of the instrument based on the Performance Verification tests. PACS is fully operational, and the achieved performance is close to or better than the pre-launch predictions

Sublittoral soft bottom communities and diversity of Mejillones Bay in northern Chile (Humboldt Current upwelling system)

The macrozoobenthos of Mejillones Bay (23°S; Humboldt Current) was quantitatively investigated over a 7-year period from austral summer 1995/1996 to winter 2002. About 78 van Veen grab samples taken at six stations (5, 10, 20 m depth) provided the basis for the analysis of the distribution of 60 species and 28 families of benthic invertebrates, as well as of their abundance and biomass. Mean abundance (2,119 individuals m-2) was in the same order compared to a previous investigation; mean biomass (966 g formalin wet mass m-2), however, exceeded prior estimations mainly due to the dominance of the bivalve Aulacomya ater. About 43% of the taxa inhabited the complete depth range. Mean taxonomic Shannon diversity (H', Log e) was 1.54 ± 0.58 with a maximum at 20 m (1.95 ± 0.33); evenness increased with depth. The fauna was numerically dominated by carnivorous gastropods, polychaetes and crustaceans (48%). About 15% of the species were suspensivorous, 13% sedimentivorous, 11% detritivorous, 7% omnivorous and 6% herbivorous. Cluster analyses showed a significant difference between the shallow and the deeper stations. Gammarid amphipods and the polychaete family Nephtyidae characterized the 5-mzone, the molluscs Aulacomya ater, Mitrella unifasciata and gammarids the intermediate zone, while the gastropod Nassarius gayi and the polychaete family Nereidae were most prominent at the deeper stations. The communities of the three depth zones did not appear to be limited by hypoxia during non-El Niño conditions. Therefore, no typical change in community structure occurred during El Niño 1997–1998, in contrast to what was observed for deeper faunal assemblages and hypoxic bays elsewhere in the coastal Humboldt Current system

Amphiura chiajei Forbes, comensal de Maldane glebifex Grube, en la Ría de Muros (Galicia)

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Contribution of infauna and mussel-raft epifauna to demersal fish diets

The contribution of infauna and mussel-raft epifauna to the diet of 3 dominant species in the demersal fish community of the Ria de Arosa, N. W. Spain - Lesueurigobius friesii (Gobiidae), Callionymus lyra (Callionymidae) and Trisopterus luscus (Gadidae) - was determined. Intense raft mussel culture in the Ria de Arosa supports a rich epifauna which constitutes the main food resource for the fishes studied. In contrast, infauna density is low and contributes only a small proportion to fish diets. Prey consumed was similar in the 3 fish species. Gut contents consisted mainly of the small crab Pisidia longicornis. This decapod is a dominant component of the raft epifauna, and electivity indices indicate that it is selected by the fishes. In the Ria de Pontevedra, which contains fewer mussel rafts, these fish fed on infauna. Thus, one effect of intense mussel aquaculture has been to change the food habits of these 3 fishes from predominantly infauna to raft epifauna diet.versión del edito

Upwelling and outwelling effects on the benthic regime of the continental shelf off Galicia, NW Spain

The benthic regime off the Galician coast of NW Spain was surveyed to assess biogenic enrichment from coastal upwelling and detritus outwelling from the rías, large coastal embayments: the Rías Altas along the northern and the Rías Bajas along the western coast, which have intense mussel aquaculture. Sediment samples were collected from 1984 to 1986 and used for geological, microbiological, and macrofaunal studies. Sub-bottom acoustic profiler records and grab and core samples identified two main mud deposits on the western shelf that were aligned north to south and parallel with the coastline. The major axis of the mud deposit, which extended south to the Portuguese border, is associated with the three most southern rías (Arosa, Pontevedra and Vigo) along the western shelf. Sediment particle size analysis showed that sediments on the western shelf were heterogeneous, and grain size increased from the inner shelf to the shelf break. On the northern shelf, sediments exhibited a more homogeneous textural distribution. Sediment organic matter followed a similar pattern with that of particle size. The highest organic matter values, 10%, occurred on the western shelf nearest the Rías Bajas, but these values decreased offshore to between 2 and 4%. On the northern shelf organic matter content was generally less than 4% but with patches of higher organic content. The composition and structure of macroinfauna on the northern shelf, where seasonal coastal upwelling results in benthic enrichment, showed mainly small, surface feeding, and fast growing polychaetes. In contrast, macroinfauna on the western shelf showed more subsurface, deposit-feeding polychaetes. A main difference between the two shelves is that off the rías Bajas, besides coastal upwelling, outwelling from the highly productive rías Bajas, with their intense mussel aquaculture, also enriches the coastal sediment regime with a steady source of organic matter. Although seasonal and interannual variations occurred in the benthic bacteria, their general density distribution followed the pattern of organic matter content and particle grain size seasonally and interannually. The highest numbers of bacteria occurred in the upwelling region off the northern shelf and nearest the Rías Bajas on the western shelf. Both coastal upwelling and organic outwelling from the rías Bajas support benthic production alongthe western Galician shelf. The main commercialdemersal finfishalongthis coast is hake, Merluccius merluccius and blue-whiting, Micomesistius poutassou. The norwegian lobster, Nephrops norvegicus is also an important crop, and is more abundant off the rías Bajas in the finer and organic-richsediments where there are abundant prey resources of benthic infauna

Coastal upwelling off the Rías Bajas, Galicia, Northwest Spain. II. Benthic studies

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