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This article summarizes the main extraction methods for sedimentary phosphorus (P) determination. With sequential chemical extractions, P is supposed to be selectively removed from different compounds in the sediments. Extraction schemes using strong acids and alkaline solutions have been tested on different sediments and found not to extract well-defined fractions. In addition, several systematic errors in these schemes have been detected. Thus, these schemes have been modified and simplified accordingly. The Standards Measurements and Testing Program of the European Commission (SMT) method is a popular modification of these extraction schemes, as it is simple to handle, allows laboratories to achieve reproducible results and could provide a useful tool for routine use by water managers. The SEDEX (sequential extraction method) method, another popular modification, is widely applied in biogeochemical research as it can separate authigenic carbonate fluorapatite from fluorapatite. Other chemical extractions using chelating compounds have attempted to extract P bound with iron and calcium in sediments without disturbing claybound or organic P, the purpose being to determine the algal-available non-apatite, apatite and organic fractions of sediment P. All extraction procedures still yield operationally defined fractions and cannot be used for identification of discrete P compounds. Future modifications of the extraction scheme should aim to achieve better extraction efficiency and selectivity, simple handling techniques and methods that can prevent the extracted P from being re-adsorbed onto Fe(OOH) and CaCO3. Abstract: This paper summarizes the main extraction methods for sedimentary phosphorus (P) determination. With sequential chemical extractions, P is supposed to be selectively removed from different compounds in the sediments. The extraction schemes using strong acids and alkaline solutions have been tested on different sediments, and found not to extract well defined fractions. In addition, several systematic errors in these schemes have been detected. Then these schemes have been modified and simplified accordingly. The SMT (Standards Measurements and Testing Program of the European Commission) method is a popular modification of these extraction schemes, as it is simple to handle, suitable to allow laboratories to achieve reproducible results and could provide a useful tool for water managers on a routine basis. The SEDEX (sequential extraction method) method, another popular modification, is widely applied in the biogeochemical research as it is capable of separating authigenic carbonate fluorapatite (CFAP) from fluorapatite (FAP). Other chemical extractions using chelating compounds have attempted to extract P bound with iron and calcium in sediments without disturbing clay-bound or organic P, the purpose being to determine the algal-available non-apatite, apatite and organic fractions of sediment P. All extraction procedures still yield operationally defined fractions and cannot be used for ide...

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A survey of the safety culture and hazard risk perception has been carried out involving 77 maritime pilots around Australia and New Zealand, representing more than the 20% of the maritime pilots in each country, in proportional geographic distribution. In 82% of the cases, interviews were carried out face to face. Each interview was based on a questionnaire designed to be completed in less than one hour. Questions on four different aspects were asked, relating to each pilot's professional background, safety culture and perception of risks, navigation and pilotage hazards and their perception of the pilot's role. The main responses in addition to the most interesting comments highlighted by the pilots are presented in this paper. Finally, the paper makes recommendations which might be considered for improving operational performance and safety of navigation.