Use of aerial survey and aerophotogrammetry methods in monitoring manatee populations

We evaluated the use of strip-transect survey methods for manatees through a series of replicate aerial surveys in the Banana River, Brevard County, Florida, during summer 1993 and summer 1994. Transect methods sample a representative portion of the total study area, thus allowing for statistical extrapolation to the total area. Other advantages of transect methods are less flight time and less cost than total coverage, ease of navigation, and reduced likelihood of double-counting. Our objectives were: (1) to identify visibility biases associated with the transect survey method and to adjust the counts accordingly; (2) to derive a population estimate with known variance for the Banana River during summer; and (3) to evaluate the potential value of this survey method for monitoring trends in manatee population size over time. (51 page document)

20th annual meeting of the WEFTA Working Group on Analytical Methods in Fish and Fishery Products and 3rd annual meeting of the WEFTA Working Group on Microbiology. A retrospect on 20 years

After 20 annual meetings it is worth to have a look back and to see how it has started. There has been very little collaboration on research projects between member institutes under the auspices of WEFTA, co-operation in more neutral areas of common interest was developed at an early stage. The area which has proved very fruitful is methodology. It was agreed that probably the best way to make progress was to arrange meetings at each laboratory in turn where experienced, practising scientists could describe in detail how they carried out analyses. In this way, difficulties could be demonstrated or uncovered, and the accuracy, precision, efficiency and cost of the methods used in different laboratories could be compared.

Methods of sensory evaluation of quality and application of statistical methods in sensory evaluation problems with special reference to fishery products

The quality of raw and processed fishery products depend on several factors like physiological conditions at the time of capture, morphological differences, rigor mortis, species, rate of icing and subsequent storage conditions. Sensory evaluation is still the most reliable method for evaluation of the freshness of raw processed fishery products. Sophisticated methods like Intelectron fish tester, cell fragility technique and chemical and bacteriological methods like estimation of trimethylamine, hypoxanthine, carbonyl compounds, volatile acid and total bacterial count have no doubt been developed for accessing the spoilage in fish products.

Study of the relative effectiveness of extension methods in educating fisherwomen

Three experimental groups from three different fishing villages were selected and administered with three extension treatments on two messages, namely, production of fish wafers and fish pickles. There was a significant knowledge gain in the subjects taught through different extension methods. It was observed that lecture aided with slides induced maximum knowledge followed by lecture aided with charts and lecture alone. Among all, the young and highly educated women gained maximum knowledge.

Fishing gear and methods of the river Brahmaputra in Assam

Potentially the inland fishery resources of the country are of very high order. But the present level of their exploitation is far from optimum, mainly because of the inadequacies of the existing fishing gear and methods. There is vast scope for increasing the fish production from inland waters by improving the existing gear and methods. This would require a thorough study of the fishing gear and methods in vogue, of which very little is known at present. In the present communication the authors discuss the fishing gear and methods of the river Brahmaputra, in Assam, based on a survey carried out by them during January-February 1964. The survey covers a 640 km stretch of the Brahmaputra River, its important tributaries and connected bheels, from Dhubri to Dibrugarh. As a result of the survey about 19 types of fishing nets, which could be grouped into eight classes, were identified. The salient technological features of the gears and their methods of operation are discussed class-wise. The characteristics of the individual types are shown in tables. The materials used for gear and gear accessories, are briefly discussed. The classification and relative importance of different types of gear are examined. Besides, the influence of the ecological and topographical features of the river on the development of different types of fishing gears, is also discussed.

The effect of artisanal preservation methods on nutritional security of “Mukene” Rastrineobola argentea caught from Lakes Victoria and Kyoga in Uganda

The artisanal fish preservation methods in Uganda are characterized by extreme operating conditions. Consequently, vital nutritional components diminish in value and quantity which renders fish consumer nutritionally insecure. To establish the magnitude of nutritional loss, duplicate samples of Mukene Rastrineobola argentea were collected from Kiyindi landing site on L. Victoria and Moone landing site on L. Kyoga. Each set of duplicate samples was divided into five portions and kept on ice. For each preservation method a portion was processed into respective products at Food Bioscience and Agri-Business Laboratories aside from the control (fresh) sample. Both preserved and control samples were analysed for nutrient loss at Department of Chemistry, Makerere University using AOAC methods. The composition of fatty acids was determined by methanolysis gas chromatography and Mass spectrophotometry of the resultant methyl esters. The results indicate that nutrients of all preserved samples did not vary significantly from the control except for some fatty acids. The Eicosapentaenoic acid (EPA) in fresh samples declined from 6.72% to 1.08% in deep-fried samples constituting 83.93% nutrient loss. The sum ratio w3:w6 as well as EPA: DHA (Docosahexaenoic) ratio in fried samples also varied significantly (p<0.5) lower than 0.668 and 0.20 for the average of either preservation methods and experts recommended ratio respectively. Further research has been recommended to ascertain the causative factor, since Mukene frying is being promoted in the Great lakes region as alternative method to sun-drying. In conclusion, regular consumers of fried Mukene do not benefit much from the nutritional and health attributes of Omega 3 and 6.

Wirkungsbezogene Detektion von toxischen Substanzen in Fisch und Umwelt

The detection of unknown and the quantification of known toxic substances is a challenge for the modern chemical and biological analysis. Effect-related in vitro methods, e.g. AH-receptor or estrogene-receptor mediated, offer some advantages compared to the classical chemical analysis. It could be shown that two cell lines exhibit different sensitivities to 2,3,7,8-tetrachlorodibenzodioxin (TCDD), although the cells contain the identical dioxin-receptor. The application and limitations of these methods in envi-ronmental analysis are discussed.

Texture measurement on gutted cod during storage in ice using a hand-held instrument

Fish muscle as food is to be seen as highly perishable. In unfrozen fish, freshness is considered the most important quality attribute. It is well known that there are several biochemical changes that can affect dramatically the texture of fish muscle. Immediately after death the fish texture is soft and elastic. In connection with rigor mortis the fish texture changes markedly. It becomes harder during rigor and after its resolution it becomes softer. This softness increases due to proteolysis during further storage at refrigerated conditions. Texture is a very important indicator for evaluating the quality of fish. Barroso et al. (1997) have recently reviewed mechanical methods in use for texture measurements on fresh fish. Further reviews on texture measurement performed on fish muscle were recently published underlining the importance of texture as quality attribute (Hyldig et al 2001, Coppes et al. 2002). The position along the fish can influence the results and was investigated by several authors (Sigurgis-ladottir et. al. 1999). Different methods have been compared for their ability to differentiate between recently killed salmon and salmon stored on ice for up to 24 days (Veland et al. 1999).

Use of Fish Corrals in the Seine Fishery of the Virgin Islands

Although selected aspects of the commercial fishery in the Virgin Islands have been documented since the early 1930's (Fiedler and Jarvis, 1932; Idyll and Randall, 1959; Hess, 1961; Swingle et al. 1970; Brownell, 1971; Brownell and Rainey, 1971; Sylvester and Dammann, 1972, and Olsen et al., 1978), fish corrals and their use have not been described. This account, based on personal observations made during 1985-86, summarizes commercial fishing methods in the Virgin Islands (U. S. and British), documents the use of fish corrals, and serves as an introduction to the methodologies of this harvesting technique. Interviews of commercial fishermen about how and when fish corrals are used provided information not available from direct observation. Local common names for gear type and fish species are shown in parentheses.

Effects of Zataria multiflora Boiss essential oil and nisin on the growth of Staphylococcus aureus in light salted silver carp fillet (Hypophthalmichthys molitrix)

There is an increasing demand in developing newer and safer methods in preserving food products.Among which herbal additives seem to attract evermore attention recently.the major advantage of herbal additives is due to their favorable aroma besides their antimicrobial effects and less expensive than chemical additives. Zataria multiflora Boiss is a native Iranian herb which is used vastly as a food preserver essential oils and also medical usage. Metabolites of harmless bacteria, such as Nisin are also known to be safe preservatives that have antimicrobial activity. However to establish the usefulness of natural antimicrobial preservatives, they must be evaluated alone and in combination with other preservation factors to determine whether there are synergistic effects in rigid media . In this study were evaluated the effects of different concentrations of Zataria multiflora (EO 0, 0.005, 0.015, 0.045, 0.135, 0.405 ,0.810 %) and Nisin(0, 0.15, 0.25, 0.75 μg/ml) and Storage time (up to 21 days) on growth of Staphylococcus aureus ATCC 6538 in a food model system(light salted fish of silver carp, Hypophthalmichthys molitrix). The results on growth of S. aureus were evaluated using SPSS 15.0 statistical software (SPSS 15.0 for windows, SPSS Inc.) and analyzed the logarithm of total count of the bacteria by Tukey Test. Results were considered statistically significant when P≤0.05. The growth of Staphylococcus aureus was affected significantly(P<0.05) by EO and Nisin and also combinations of EO and Nisin. Samples treated with 0.135, 0.405 and 0.810% of thyme essential oil showed a significant decrease on the growth of the bacteria compared with an treated samples(P<0.05). No significant difference was seen on the growth of S.aureus in samples treated with lower concentrations of Z.multiflora(below 0.045%) and untreated group(P>0.05). The most inhibitory effects were seen in samples treated with 0.405% and 0.810% of thyme essential oil until 9 and 12 days after storage,respectively. Also there was significant inhibtory effect(P<0.05) in different concentration of nisin on the organism compared with an treated samples. The synergism effects of the Eo and nisin on the growth rate of the bacteria was significant (P<0.05) compared with untreated samples and samples treated with the Eo or nisin, only. Synergismic effects was observed at concentration of 0.405 and 0.810% of Z. multiflora essential oil with 0.25 μg/ml Nisin, respectively until 15 days after storage. As expected it is preferred to apply the least possible amounts of additives in food preserving that not only are effective and safe but are economically justifiable.