The first GCC Marine Biotechnology Symposium: Emerging Opportunities and Future Perspectives.

With its diverse, living marine resources and rapidly growing educational and research infrastructure, the Sultanate of Oman is well-positioned to take advantage of the commercial opportunities presented by marine biotechnology. In recognition of potential development, an international symposium, Marine Biotechnology-Emerging Opportunities and Future Perspectives, was held in Muscat, November 12-13, 2013. Three keynote addresses were given, 23 oral presentations made, and a poster exhibition held. The final session reviewed national and regional issues, and the delegates agreed informally on a number of future actions. The potential for future development of marine biotechnology was recognized by all delegates, and following the symposium, they were surveyed for their views on how best to sustain and develop new activities. One hundred percent of respondents found the meeting useful and would support future symposia in the region. Fifty-one percent of Omani respondents recognized major organizational challenges and obstacles to the development of marine biotechnology compared with 23 % of overseas respondents. The need for greater collaboration between research institutions within the GCC region was recognized by 98 % of all respondents. The presentations and survey outcomes are reviewed in this paper.

Distribution patterns of toxic metals in the marine oyster Saccostrea cucullata from the Arabian Sea in Oman: spatial, temporal, and size variations.

The variations in size and spatial and temporal variations in concentrations of toxic metals (cadmium, mercury, and lead) in oyster tissues were studied. Samples were collected at monthly intervals over a 1-year period from three locations along the southern coast of Oman (Mirbat, Hadbeen, and Sadah). Cadmium and lead were analyzed using an inductively coupled plasma atomic emission spectrometer, and mercury was analyzed using a direct mercury analyzer. The annual mean concentrations in oyster tissues sampled from the three locations and from different time periods ranged from 2.64 to 3.80 mg kg(-1) for cadmium, 0.009 to 0.02 mg kg(-1) for lead, and 0.01 to 0.02 mg kg(-1) for mercury. The temporal effect on cadmium concentrations was more distinct than the local site-specific effect, with higher concentrations recorded in tissues during the summer season than in the winter season. Moreover, within each site, a significant time-specific dependence on the toxic metal concentration differences was recorded. Lipid content was found to influence mercury concentrations in the oysters; however, there was no relationship between cadmium or lead and moisture or lipid content. No distinct relationships were observed between the size of oysters and metal uptake by the oyster. The results were discussed in relation to those obtained from related species in the seas of Oman and worldwide.

Concentration and exposure assessment of mercury in commercial fish and other seafood marketed in Oman.

The results of this study present analytical data of the mercury levels in several fish and shellfish species to create awareness among individuals of the risks associated with consuming fish contaminated with mercury. Mercury concentrations varied from a mean of 0.02 mg/kg in Indian mackerel to 0.19 mg/kg in shark in both fresh and frozen fish, from 0.02 mg/kg in sardines to 0.18 mg/kg in skipjack tuna in canned fish, and from 0.02 mg/kg in Indian mackerel to 0.79 mg/kg in shark in dried fish. Shellfish contained a slightly higher amount of mercury than fresh or frozen fish with a mean of 0.09 mg/kg. Trophic position, followed by habitat, was the most important factors for variability in mercury concentrations in fish and shellfish. The maximum safe weekly intake (MSWI) values of mercury were significantly higher for herbivores than for carnivores. The MSWI value for total mercury in the case of consuming most (72%) fish species was more than 5 kg; however, the MSWI value was never more than 5 kg in most (66%) shellfish species. Risks were identified upon consumption of 120 g of dried shark when exceeding the provisional tolerable weekly intake threshold (1.6 µg/kg) for methylmercury. Therefore, fish-eating populations should reduce the quantity of dried shark to efficiently diminish the exposure to mercury.

Histamine levels in commercially important fresh and processed fish of Oman with reference to international standards.

Histamine was investigated in fresh (378), frozen (441), canned (290) and dried (24) fish samples of scombroid and non-scombroid species of Oman using a high performance liquid chromatography with a fluorescence detector. Of the 1133 fish samples tested, histamine was detected in 551 samples with a detection rate of about 41.8% among fresh fish, 61.0% of frozen fish, 78.9% of canned fish and 91.6% of dried fish samples and the mean histamine levels were 2.6, 5.8, 3.1 and 104mgkg(-1), respectively. A total of 3.7% and 0.79% of the total samples exceeded the FDA and EU regulatory limits for histamine. Imported dried anchovies contained high histamine levels. The study confirms that post catching and commercialisation practices of seafood are adequate, warranting good quality fish and may not cause histamine risk to consumer in terms of human diet. While necessary monitoring may be done for imported dried fish products.

Comparative pathogenomics of bacteria causing infectious diseases in fish.

Fish living in the wild as well as reared in the aquaculture facilities are susceptible to infectious diseases caused by a phylogenetically diverse collection of bacterial pathogens. Control and treatment options using vaccines and drugs are either inadequate, inefficient, or impracticable. The classical approach in studying fish bacterial pathogens has been looking at individual or few virulence factors. Recently, genome sequencing of a number of bacterial fish pathogens has tremendously increased our understanding of the biology, host adaptation, and virulence factors of these important pathogens. This paper attempts to compile the scattered literature on genome sequence information of fish pathogenic bacteria published and available to date. The genome sequencing has uncovered several complex adaptive evolutionary strategies mediated by horizontal gene transfer, insertion sequence elements, mutations and prophage sequences operating in fish pathogens, and how their genomes evolved from generalist environmental strains to highly virulent obligatory pathogens. In addition, the comparative genomics has allowed the identification of unique pathogen-specific gene clusters. The paper focuses on the comparative analysis of the virulogenomes of important fish bacterial pathogens, and the genes involved in their evolutionary adaptation to different ecological niches. The paper also proposes some new directions on finding novel vaccine and chemotherapeutic targets in the genomes of bacterial pathogens of fish.