Problems associated with the over protection of fishing trawlers against sea water corrosion and fouling

Some presently used anti-fouling materials contain metals and other compounds, which are toxic in the environment. Coating products are not always stable, and there is a resulting pollution hazard. In particular if surfaces are poorly prepared and manufactures' instructions are not closely followed the application of anti-fouling substances becomes pointless and dangerous. In addition the salinity, constant biological activity and suspended particles make seawater a highly corrosive material in its own right.

Studies on preservation of fish in refrigerated sea-water

Storage characteristics of oil sardine (Sardinella longiceps), mackerel (Rastrelliger kanagurta) and seer (Scomberomorus guttatus) in refrigerated sea-water (RSW) were studied in comparison with their storage in crushed ice. Oil sardine stored in RSW was found to be comparable to iced ones only during the initial stages (up to 2 days) of storage and on further storage the former was found to be inferior to the latter. RSW can be advantageously employed for preservation of mackerel and seer. Mackerel and seer could be stored in RSW in acceptable condition for 4 to 6 days and 12 to 14 days respectively.

An analytical study of the sea water slime with reference to bacterial flora

A detailed study of the primary film of slime with reference to the bacterial flora, its quality and quantity, as observed on different material surfaces exposed to sea water is carried out. A correlation has been established between bacteria and slime deposited on different surfaces.

Effect of chilled sea water storage of oil sardine (Sardinella longiceps) on quality changes during frozen storage

The shelf-life of frozen oil sardine (Sardinella longiceps) can be improved by preserving the fish immediately after catch in chilled sea water before freezing. Delayed icing caused considerable deterioration in quality and reduced frozen shelf-life. Oil sardine preserved in chilled sea water were found to be suitable for freezing up to 5 days whereas iced samples could be frozen only up to 2 days.

Article: Overview of Analytical Methodologies for Sea Water Analysis: Part I-Metals

A comprehensive, critical and up-to-date review of analytical methods developed during the last decade for metals present in sea water is presented. Separate sections are devoted to singular and multimetal determinations. Furthermore, a critical comparison of relative merits or demerits of a particular procedure is made in terms of sensitivity, selectivity and precision. Various aspects of analysis of sea water samples for metals are summarized, and the future trends are discussed.

Flow-through room temperature phosphorescence optosensing for the determination of lead in sea water

The chelates formed between the heavy metal ion Pb(II) and the reagents 8-hydroxy-5-quinolinesulphonic acid, 8-hydroxy-7-quinolinesulphonic acid and 8-hydroxy-7-iodo-5-quinolinesulphonic acid exhibit strong room temperature phosphorescence (RTP) if retained on the surface of anion exchange resin beads. Based on the on-line formation, in a flow-injection system, of such RTP lead chelates and their transient immobilization on an anion exchange resin, three flow-through optosensing systems are investigated for lead in sea water. Optimum experimental conditions and the analytical performance characteristics of the three optosensors are discussed. Relative standard deviations (RSDs) of the order of 3% are typical at 100 ng ml−1 Pb(II) and the active sensing phases can easily be regenerated by passing 500 μl of 6 M hydrochloric acid. A lead(II) detection limit of 0.1 ng ml−1 (3×background SD, for 2 ml sample injection volumes) was achieved for the optosensor based on 8-hydroxy-7-quinolinesulphonic acid. Possible interferences present in sea water, including cations and anions which could affect the sensor response, are discussed in detail. Finally, the selected RTP flow-through optical sensor has been successfully tested for the determination of lead in sea water at a few ng ml−1.

Automated voltammetric system for shipboard determination of metal speciation in sea water

An automated and semi-intelligent voltammetric system is described for trace metal analysis. The system consists of a voltammeter interfaced with a personal computer, a sample changer, 2 peristaltic pumps, a motor burette and a hanging mercury drop electrode. The system carries out fully automatically approximately 5 metal determinations per hour (including at least 3 repetitive scans and calibration by standard addition) at trace levels encountered in clean sea water. The computer program decides what level of standard addition to use and evaluates the data prior to switching to the next sample. Alternatively, the system can be used to carry out complexing ligand titration with copper whilst recording the labile copper concentration; in this mode up to 8 full titrations are carried out per day. Depth profiles for chromium speciation in the Mediterranean Sea and a profile for copper complexing ligand concentrations in the North Atlantic Ocean measured on board-ship with the system are presented. The chromium speciation was determined using a new method to differentiate between Cr(III) and Cr(VI) utilizing adsorption of Cr(III) on silica particles.

Nanostructured thin-film WO3 photoanodes for solar water and sea-water splitting

This article charts the development of the use of thin films of nanoparticulate WO3 and how they have been used to overcome problems associated with other photocatalytic materials and bulk WO3. Current technology is described and the authors' views on the outlook for future development is suggested.