Seawater Storage Research Articles

Survival of Infectious Hematopoietic Necrosis Virus Held Under Various Environmental Conditions

Dehydration of infectious hematopoietic necrosis virus (IHNV) from water at 4 and 10 °C resulted in only partial inactivation, but dehydration from Hanks' balanced salt solution (HBSS) and homogenized fish tissue resulted in total loss of virus infectivity within 7 days. Survival was not affected by pH between 6 and 8, but virus infectivity was significantly reduced at pH 5 and 9. Water hardness from 20 to 250 mg/ℓ (as CaCO3) did not significantly reduce virus infectivity. Salinity distinctly affected IHNV survival: storage in artificial seawater, filtered ocean water, HBSS. and Earle's balanced salt solution (EBSS) equally reduced virus titers. The addition of protein to deionized water and EBSS and HBSE resulted in increased survival. Survival of IHNV was inversely proportional to HBSS concentration and was highest when it was frozen in media supplemented with 10% calf serum. Virus survival was good at −70 and −20 °C, but virus infectivity decreased sharply with an increase of temperature above 4 °C; increasingly poor survival occurred at 15. 21, 28, and 32 °C. Freezing and thawing of IHNV had no effect if the media contained 10% protein; however, freezing in deionized water resulted in a significant loss of virus infectivity. Key words: virology, virus survival, laboratory storage, environmental effects

Quantitative and Qualitative Studies of Bacteria Isolated from Sea Water Used in the Laboratory Culture of the American Oyster, Crassostrea virginica

Quantitative and qualitative bacteriological studies were conducted on sea water utilized in laboratory culture of American oyster larvae (Crassostrea virginica).The generic diversity of bacteria isolated from a laboratory seawater storage tank did not change during a 15-day sampling period, although bacterial numbers increased substantially. The mean number of bacteria in ultraviolet light-irradiated sea water was less than that in nonirradiated sea water, although individual samples varied considerably. Over a 10-day sampling period during which oyster larval cultures were sampled repetitively, bacteria were more numerous at 24 h and 48 h than at 0 h.Pseudomonas was the dominant genus present in stored sea water, irradiated sea water, and sea water from oyster larval cultures.

Studies on the determination of inorganic iodine in seawater

Existing methods for the determination of the various forms of iodine present in seawater are laborious or unwieldy in use. This paper describes modified forms of the iodate and total iodine methods described by Barkley and Thompson (1960), a spectrophotometric procedure for iodate determination derived from Johannesson's (1958) work, and an automatic method for total iodine determination. Procedures for iodate and total-iodine determination which are suitable for use aboard ship, are recommended. Both procedures for iodate determination returned a standard deviation close to 0.5 μg/l when several replicate samples of a seawater containing approximately 30 μg/l of iodate-iodine were analysed. The automatic method for total iodine determination yielded a standard deviation of 0.8 μg/l by the repeated analysis of a seawater containing a total of approximately 50 μg/l of iodine. Suitable methods for the filtration and storage of seawater are also described.

TOXICITY OF COPPER TO THALASSIOSIRA PSEUDONANA IN UNENRICHED INSHORE SEAWATER1

SUMMARYToxicity of copper to T. pseudonana (formerly Cyclotella nana, clone 13‐1) wax examined in inshore seawater using a 96‐hr bioassay method. Raw unenriched seawater wax filtered through a 0.22‐μ membrane filter and then pasteurized, for 30 min at 60 C. Following this treatment, samples contained 0.68–1.14 μg Cu/liter. Copper was added as the chloride in 5‐μg increments over the range of 5 to 30 μg/liter (about 0.1–0.5 μM). Population densities, mean cell, volume, and 14C bicarbonate uptake were measured.Population growth, and 14C uptake by T. pseudonana displayed inhibition over the entire range of added copper. Growth rate constant (k) of T. pseudonana decreased with increasing copper concentration and during the course of growth at each concentration. Correspondingly, mean cell volumes increased with copper concentration and time. Copper toxicity varied in different water samples. The presence of decomposed natural plankton and detritus decreased toxicity. In the absence of enrichment, bacteria had little effect on copper toxicity. H exults were influenced by glassware treatment, collection and storage of seawater, and absence of enrichments.

Studies in the maturation of underripe sea urchin eggs

When unripe sea urchin eggs are aged in sea water they become mature. Membrane formation, cleavage and development are improved. The fertilization rate is low in unripe eggs but is increased upon storage in sea water.

OBSERVATIONS ON THE MULTIPLICATION OF BACTERIA IN DIFFERENT VOLUMES OF STORED SEA WATER AND THE INFLUENCE OF OXYGEN TENSION AND SOLID SURFACES

The storage of sea water is accompanied by a great increase in the number of bacteria and a decrease in bacterial species.Appreciably more bacteria per cc. appear in small volumes of sea water than in large volumes of identical water.Although the oxygen content of sea water is a factor which influences the activity of bacteria, it does not account for the denser bacterial populations which appear in the smaller volumes.The favorable influence of small volumes is attributed to the contact of the water with the larger solid surface area in the small receptacles. Between ten and a hundred million bacteria per cc. have been demonstrated in sea water stored in sand which presents an enormous surface area whereas less than three hundred thousand bacteria per cc. appearing similar water stored in 10-liter bottles presenting relatively little surface area.The beneficial effect of small volumes and their large surface areas occurs only in dilute nutrient solutions. Upon the addition of 10 to 100 mgm. of organic matter to sea water, the volume effects disappear. Solid surfaces may serve as a resting place for periphytes, they may help concentrate the nutrients by adsorption or otherwise, or they may favor bacterial enzymatic activity and the absorption of metabolites.