Depth, temperature and salinity preferences of newly recruited penaeid shrimps in Kuwait waters

Associations between catches and depth, temperature and salinity data obtained from the 1994–97 preseason shrimp trawl surveys in Kuwait waters were analysed using cumulative distribution functions and overlap coefficients. No single environmental factor had a controlling influence on shrimp distribution. Shrimp associations with the joint distributions of two environmental variables were stronger and more consistent over time than those with any single environmental factor. All three shrimp species examined in this study were significantly associated with the joint distributions of depth and temperature, and depth and salinity, indicating depth as the most influential factor in structuring the shrimp distributions during the surveys. Metapenaeus affinis and Parapenaeopsis stylifera were distributed at similar ranges of depth (8–15 m), temperature (26–31°C) and salinity (35–41‰), and had very high overlap coefficients. These two species can be categorized as co-occurring species in the sampled area. Penaeus semisulcatus had the widest range of the three environmental variables investigated in this study, particularly depth (8–32 m) and temperature (24–32°C).     

Characterization of β-haemolytic Group B Streptococcus agalactiae in cultured seabream, Sparus auratus L., and wild mullet, Liza klunzingeri (Day), in Kuwait

Streptococcus agalactiae was isolated from cultured gilthead seabream, Sparus auratus L., and diseased wild Klunzinger's mullet, Liza klunzingeri (Day), in Kuwait Bay, Arabian Gulf. Isolates were catalase negative, β‐haemolytic, Gram‐positive cocci and serogroup B. Experimental infectivity trials with mullet and seabream brain isolates in Nile tilapia, Oreochromis niloticus L., caused 100 and 90% mortality, respectively, within 7 days post‐inoculation indicating virulent S. agalactiae as the bacterial pathogen responsible for the epizootic in Kuwait Bay.     

Use of Mass Vaccination with a Reduced Dose of REV 1 Vaccine for Brucella melitensis Control in a Population of Small Ruminants

Mass vaccination with reduced dose 1/50 Rev 1 strain live vaccine (1–2 109 colony forming units), administered subcutaneously, over a four and a half year period reduced the prevalence of Brucella melitensis in Kuwait's small ruminant population from 5.8% in 1993 to 2.02% in 1997.Serological test results using the Rose Bengal Plate Test, Rivanol Agglutination Test and Complement Fixation showed no evidence of persistence of positive serology in animals nine or more months after vaccination. Questionnaires and post-vaccination flock inspections found that the effects on gestation (abortions) were minimal – and not proven to be due to the vaccine.The conclusion from these findings is that mass vaccination with reduced dose Rev 1 administered by the subcutaneous route is a practical field strategy for control of Brucella melitensis.     

Autochthonous Dirofilaria (Nochtiella) repens infection in dogs in Kuwait

Human dirofilariasis caused by Dirofilaria repens is a rare but increasingly reported zoonosis in the Middle East. However, eligible animal reservoirs seldom have been investigated in the area until now. Seven (1.8 percent) out of 381 dogs examined in Kuwait carried D. repens microfilariae showing compatible cutaneous clinical signs and positive response to the adulticide and microfilaricide therapies. This study indicates that dogs from Kuwait are natural hosts of D. repens and therefore act as an animal reservoir for the zoonotic condition.     

A CASE ASSESSMENT OF THE MECHANISMS INVOLVED IN HUMAN‐INDUCED LAND DEGRADATION IN NORTHEASTERN KUWAIT

Soil degradation and vegetation deterioration in contrasting areas (open desert versus protected desert) in the northeastern part of Kuwait were investigated, using field measurements, and laboratory methodologies. The average infiltration rate of compacted soils studied was found to be 52 per cent lower than that of the undisturbed soils we investigated. The bulk density of the compacted soils was 19 per cent higher than that of the non‐compacted soils. The average topsoil resistance of severely compacted soils was 13 per cent greater than that of undisturbed soils and is mainly due to overgrazing, and off‐road vehicle use. We found that the overall vegetation cover status of open areas investigated was approximately 70 per cent less than for the protected areas studied. As a consequence of soil compaction and vegetation deterioration, sand deflation processes, and sand movement prevail in open areas. The total average percentages of course grain sizes in unprotected soils and heavily disturbed soils by vehicles (off‐road) are 51 and 103 per cent greater, respectively. The annual rate of sand transport during the last 20 years, from the prevailing wind direction (NW) in the area has increased by 81 per cent. The delicate balance between soil and natural vegetation cover is easily disturbed by off‐road vehicle use associated with overgrazing and recreation activity. A restoration plan is needed in order to reduce land degradation and to allow natural vegetation recovery. Copyright © 2011 John Wiley & Sons, Ltd.