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Subsurface video footage can be used as a successful identification tool for various marine organisms; however, processing of such information has proven challenging. This study tests the use of automated software to assist with photo-identification of the great white shark Carcharodon carcharias in the region of Gansbaai, on the south coast of South Africa. A subsurface photo catalogue was created from underwater video footage. Single individuals were identified by using pigmentation patterns. From this catalogue, two images of the head for each individual were inserted into automated contour-recognition software (Interactive Individual Identification System Beta Contour 3.0). One image was used to search the database, the other served as a reference image. Identification was made by means of a contour, assigned using the software to the irregular border of grey and white on the shark's head. In total, 90 different contours were processed. The output provided ranks, where the first match would be a direct identification of the individual. The method proved to be accurate, in particular for high-quality images where 88.24% and 94.12%, respectively, were identified by two independent analysts as first match, and with all individuals identified within the top 10 matches. The inclusion of metadata improved accuracy and precision, allowing identification of even low-quality images. 相似文献
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Belcheva NN Zakhartsev M Silina AV Slinko EN Chelomin VP 《Marine environmental research》2006,61(4):396-409
Seasonal and age-specific variations of cadmium (Cd) concentration in the digestive gland were investigated in the Japanese scallop Patinopecten yessoensis from Peter the Great Bay, Sea of Japan, with different degrees of Cd pollution. The seasonal changes in Cd concentrations of the digestive gland were inversely proportional to the dry weight of the gland. Concentrations of Cd and total Cd content (mug Cd per organ) increased with age (age-specific) to the same extent in contaminated and uncontaminated areas. There was also a strong positive correlation between Cd content in the whole digestive gland and shell weight and it is proposed that this relationship can be used as a new criterion for comparative evaluation of Cd levels in scallops from different areas We hypothesize that Cd is uptaken into scallops in proportion to the amount of calcium that absorbed through ion channels, and in addition, Cd in the digestive gland is in immobile forms (e.g. metal-rich granules) that accumulate with age. Moderate environmental pollution has no effect on the relationship between Cd content and shell size and the observed decrease in growth performance of the scallops from polluted areas may be due to other factors. 相似文献
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The trophic relationships in the association of the Yeso scallop Mizuhopecten yessoensis and its dominant endobiontic polychaete Polydora brevipalpa, which burrows into the scallop??s shell, and their potential food sources were studied using the method of fatty acid biochemical markers. It is shown that the differences in the diet of the scallop and the polychaete allow them to coexist in a close association. The trophic role of the association in the benthic community was revealed. The association selectively utilizes the food sources of the environment. It almost does not consume organic matter of bottom sediments, which allows it to coexist with other species in the community of higher order. There is minimal food competition between the association and detritivorous species; however, association can limit the development of species mostly foraging on diatom algae. 相似文献
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Izvestiya, Physics of the Solid Earth - Abstract—Anomalous variations in radon emissions from the soil are sometimes observed before and after strong earthquakes. In this paper, we... 相似文献
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Alla V. Silina 《Ocean Science Journal》2006,41(4):211-219
A comparison was made of population of the economically important cockleAnadara (=Scapharca)broughtoni (Bivalvia, Arcidae) inhabiting different areas of the Razdolnaya River estuary at the head of Amurskii Bay (Peter the Great
Gulf, East Sea). Also, changes in cockle population density and structure, as well as in cockle growth rates during the last
20 years were studied. In all years of investigation, the morphometrical parameters and growth rates of cockles were smaller
at the sites located close to the River mouth than farther down-estuary. The differences can be attributed to higher concentration
of suspended particulate matter, decreased salinity and water temperature, as well as a longer exposure to these unfavorable
environmental factors at sites located close to the River mouth, compared to farther sites. For two decades, cockle population
density had decreased by almost 30 times at some sites in the River estuary. The main reason for this population decline is
commercial over-fishing of the cockle. Besides, for the last 20 years, linear parameters of the cockles in the population
decreased approximately by 30% and weight parameters, almost two times. Cockle growth rates also decreased for this period.
Evidently, these facts are due to the damaging effect of dredging. 相似文献
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Oceanology - In the study area, located in the coastal waters of Amur Bay off Vladivostok, which is exposed to industrial and domestic sewage effluents, the population of the Yesso scallop... 相似文献
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The community of the Japanese scallop Mizuhopecten yessoensis with its dominant endobiont polychaete Polydora brevipalpa, which bores into the scallop’s shell, was studied. It was established that the bulk of the scallop’s food ration consists of diatom algae and, to a lesser extent, flagellates and small invertebrates. The polychaete species considered mainly assimilates diatom algae and, to a significant degree, bacteria. Thus, the elements of the community enter competitive food relations. In the process of feeding, the scallop excretes detritus with its pseudofeces and this way increases the concentration of food available for polychaetes. In the course of its motion and filtration, the scallop enhances the water flow around the polychaete, which also favors the feeding of the latter. Meanwhile, negative relations between the degree of the population of the scallop’s shell by polychaetes and the volume of its internal cavity were recognized; this indicates a decrease in the potential for water filtering and, correspondingly, for food procuring by the host mollusk. With the increase in the polychaete-related bioerosion of the shell, the linear sizes and weight parameters of the scallop fall together with the rate of its growth. 相似文献
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Association of the scallop Patinopecten yessoensis and epibiotic barnacle Balanus rostratus: inter‐specific interactions and trophic relationships determined by fatty acid analysis 
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下载免费PDF全文 Marine mollusks provide shelter to epibiotic organisms which settle on the outer surface of their hard shells. Epibionts can exert beneficial or detrimental effects on the host mollusk. In this study, the ecology of the association of the commercially valuable marine mobile scallop Patinopecten (=Mizuhopecten) yessoensis with its epibiotic barnacle Balanus rostratus was investigated. Fatty acid analysis was performed to determine the trophic relationships between these species. The distribution of fatty acid markers in this scallop species suggests an important contribution of diatoms, flagellates and animal material in its diet. The fatty acid analysis indicated a predominance of diatoms in the diet of the adult barnacles and some detrital input into the diets of young individuals. It was found that adult barnacles may compete with the scallops for food sources such as diatoms and zooplankton. It was revealed that with a negligible biomass of epibionts, the interactions between the barnacle and scallop may be regarded as commensalisms. An increase in the weight of epibiotic barnacles resulted in decreases in the weights and shell heights of the scallops, testifying to the adverse influence of a high biomass of epibionts on their host. 相似文献
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