14 research outputs found
Peixes recifais da costa da Paraíba, Brasil Reef fishes from Paraíba, Brazil
<abstract language="eng">The coral reef is an ecossystem which evokes great interest, for its beaury, species diversity and fisheries potential. The coast of Paraíba State, northeast Brazil, possesses several natural reefs and shipwrecks which are inhabited by a rich fish fauna. In order to survey the reef fish fauna of Paraíba State, a total of 118 dives, utilizing SCUBA diving techniques, were carriedoutin 27samplingpoints (depths: 0,5-66m), from February/1995 to May/1996. Specimens were collected whenever underwater identification was precluded. A total of 157 known species belonging to 59 families were found. Four unidentified species, one dasyatid, one haemulid, one scarid, and one labrid were recorded. Haemulidae was the most representative family in number of individuais, whereas Carangidae was the most speciose family. This paper is part of a broader study of the northeast Brazilian reef fishes
Is it really organic? - multi-isotopic analysis as a tool to discriminate between organic and conventional plants
Novel procedures for analytical authentication of organic plant products are urgently needed. Here we present the first study encompassing stable isotopes of hydrogen, carbon, nitrogen, oxygen, magnesium and sulphur as well as compound-specific nitrogen and oxygen isotope analysis of nitrate for discrimination of organically and conventionally grown plants. The study was based on wheat, barley, faba bean and potato produced in rigorously controlled long-term field trials comprising 144 experimental plots. Nitrogen isotope analysis revealed the use of animal manure, but was unable to discriminate between plants that were fertilized with synthetic nitrogen fertilizers or green manures from atmospheric nitrogen fixing legumes. This limitation was bypassed using oxygen isotope analysis of nitrate in potato tubers, while hydrogen isotope analysis allowed complete discrimination of organic and conventional wheat and barley grains. It is concluded, that multi-isotopic analysis has the potential to disclose fraudulent substitutions of organic with conventionally cultivated plants