Effect of salt on the level of histamine in preserved fish (Herring, Clupea harengus)

Histamine levels in batches of heavily salted (fish:salt ratio 4:1) herring (Clupea harengus) were monitored during ripening at 4°C and 25°C. The batches studied were prepared from both pre-spawning and post-spawning (spent) fish using new and used salt. Salt levels in the flesh, which reached 11 to 14% (wet weight basis) during the ripening period, were found to retard histamine formation. During normal spoilage of ice chilled fish, histamine levels had been reported to exceed 50mg/100g flesh as it approached the limit of edibility whilst, in the heavily salted fish, levels remained below 20mg/100g flesh throughout the ripening periods of 18 months for the 4°C batches and 3 months for the 25°C batches. This was the case when the samples were set up and the salt allowed penetrating the flesh at 4°C. When, however, the samples were set up and initially stored at ambient (10-15°C) temperature the histamine levels in the flesh rose above 20mg/100g before enough salt had penetrated to inhibit its generation. The gradual rise in levels which, nevertheless, occurred over the ripening periods followed significantly (5% level of significance) different trends, being greater in the batches prepared from pre-spawning than those from spent fish.

Effects of natural gas pipeline condensate and crude oil spills, and comments on remediation, with emphasis on south Louisiana salt marshes: a review

This report reviews some of the natural ecological processes at work within a salt marsh as they relate to a spill of natural gas condensate - a mixture of aliphatic hydrocarbons, n-hexane, benzene, toluene, and xylene. It also reviews the environmental impacts of some of the components of natural gas condensate as well as related compounds (crude oil, higher molecular weight hydrocarbons, polycyclic aromatic hydrocarons - PAHs, linear alkyl-benzenes - LABs, etc.) on salt marsh ecosystems in southern Louisiana and elsewhere in the world. The behavior and persistence of these compounds once they have entered the environment is also considered.

Salt and water balance in the Mundel Lake: a strongly choked coastal lagoon

The Mundel Lake is an extremely shallow lagoon on the west coast of Sri Lanka. It is connected to the Puttalam Lagoon through 15 km long Dutch Canal. Salinity measurements and daily sea level data were obtained fortnightly from January 1993 to March 1994 and they were used to quantify the salt and water budget along with precipitation, evaporation and freshwater runoff. Extreme fluctuations of salinity and sea level are striking features of the system. Salinity of the Mundel Lake and Dutch Canal varied from 5-46.5 and 6 61 ppt respectively while the sea level ranged from -0.25 to +1.2 m. Tidal variations were not seen in the lagoon due to its long narrow canal system. Salt budget showed that the deposition of salt on the lagoon bottom during periods of decreasing water level. During increasing water level, salt is dissolved again. Flow of water through the Dutch Canal between the Puttalam Lagoon and Mundel Lake is driven by the changes in sea level. These changes are mainly due to seasonal changes of net freshwater supply and, to a lesser degree, to seasonal changes in sea surface height. As the flow rates are small due to the long and narrow canal, the residence time ranges between two months and several months in the Mundel Lake, except during season of high freshwater supply. As the water exchange is weak, the Mundel Lake becomes hyper saline with strong fluctuations in salinity. This implies a stress to all lagoon dwelling aquatic organisms and also to aquaculture practices in the area.

Evaluation of biochemical characteristics of a traditional salt fermented fish product of northeast India with special reference to its flavour components

'Lona ilish', is a traditional salt fermented fish product, widely consumed and very popular in north-east part of India and Bangladesh. It is prepared exclusively from a high fat fish, Hilsa (Tenualosa) ilisha. 'Lona ilish' was prepared in the laboratory following traditional process. After 150 days of fermentation, a better quality 'lona ilish' was obtained. Biochemical characteristics of market sample was estimated and compared with the laboratory prepared one. A variation in biochemical composition was observed. Sensory quality of the final product of laboratory prepared 'lona ilish' was compared with the market sample and found that the laboratory prepared product scored better than the market sample. The moisture (49.89%) and salt (15.48%) of the final product was found to be satisfactory for stability of the 'lona ilish' at ambient temperature. Analysis of volatile compounds of 'lona ilish' was done using GC-MS. It was concluded that, aldehydes, ketones and esters may possibly contribute characteristic aromas to the overall flavour of the salt fermented hilsa.