Aquatic Food Resources Research Articles

Chemically Contaminated Aquatic Food Resources and Human Cancer Risk: Retrospective

Chemically Contaminated Aquatic Food Resources and Human Cancer Risk: Retrospective

Epidemiologic approaches to assessing human cancer risk from consuming aquatic food resources from chemically contaminated water.

Epidemiologic approaches to assessing human cancer risk from consuming fish from contaminated waters must confront the problems of long latency and rarity of the end point (cancer). The latency problem makes determination of diet history more difficult, while the low frequency of cancer as an end point reduces the statistical power of the study. These factors are discussed in relation to the study designs most commonly employed in epidemiology. It is suggested that the use of biomarkers for persistent chemicals may be useful to mitigate the difficulty of determining exposure, while the use of more prevalent and timely end points, such as carcinogen-DNA adducts or oncogene proteins, may make the latency and rarity problems more tractable.

Epidemiologic Approaches to Assessing Human Cancer Risk from Consuming Aquatic Food Resources from Chemically Contaminated Water

Epidemiologic Approaches to Assessing Human Cancer Risk from Consuming Aquatic Food Resources from Chemically Contaminated Water

Chemically contaminated aquatic food resources and human cancer risk: retrospective.

Chemically contaminated aquatic food resources and human cancer risk: retrospective.

Specializations and limitations in the utilization of food resources by the carp, Cyprinus carpio: a study of oral food processing

The wide variety of aquatic food is considered to be instrumental for the diversification in fish species. Yet their abilities and inabilities of handling food are poorly known. For these reasons the food processing and feeding repertoire of the adult carp, Cyprinus carpio, fed on a variety of food types, were analyzed by light and X-ray cinematography of the head parts and by electromyography of the head and body muscles during feeding. Nine stereotyped movement patterns (particulate intake, gulping, rinsing, spitting, selective retention of food, transport, crushing, grinding and deglutition) compose the feeding process, their sequence and frequency were adjusted to the type of food. Following quantitative morphological analysis at macroscopic, light- and electronmicroscopical level, the relations between the functioning and architecture of the feeding apparatus were established. The structure and dimensions of the mouth opening, the protrusible upper jaw, the slit-shaped pharyngeal cavity, the palatal and postlingual organ, the branchial sieve, the pharyngeal masticatory apparatus and the distribution of taste buds, mucous cells and muscle fibers along the oropharyngeal surface were the directive structural characters used for estimating the abilities in food processing. The specializations for utilizing food items and its limitations, derived from structural and functional data, are compared with diet data found in the literature in order to evaluate the relative position of the carp in competition for food in the aquatic environment. It is established that the ‘omnivorous’ carp is specialized in effective handling of several categories of aquatic food, even when these are mixed with non-food (bottom invertebrates 250 μm). The carp is at the same time very limited in processing long and struggling prey (e.g. fish) as well as vegetable matter, due to the lack of oral teeth and the specialized morphology of its pharyngeal chewing apparatus. These feeding abilities agree with diet data from literature. The reported herbivorism of carp illustrates its opportunism in feeding behaviour. Specialization in feeding is discussed and the necessity to take into account the total series of post-capture feeding actions for a more complete view on trophic specialization. Food intake and the intra-oral food processing of carp are bound to the structures of its sensory, central processing and effector apparatus and to the plasticity in their functioning. These together determine its feeding efficiency in exploiting the available aquatic food resources. Next to ethological and ecological studies functional morphology is another important tool to explain the trophic interactions of fish.

Effect of a long-term release of plutonium and americium into an estuarine-coastal sea ecosystem--I. Development of an assessment methodology.

A method is developed for the assessment of the distribution and the associated hazard due to a long-term release of long-lived alpha-emitting radionuclides into surface waters of a marine ecosystem. The methodology is designed to identify various environmental compartments and the processes occurring within them, which are of importance in affecting the behaviour and thus the distribution of actinide elements in such systems. The compartment model system (box model) chosen is applied to an imaginary coastal area. Various processes in the environmental compartments are considered separately and then assembled to show their combined interactions. Using the concept of critical nuclide-pathway-group analysis, an attempt has been made to define a number of the most important pathways by which actinides released into the aquatic environment could return to man, and especially those related to the exploitation of aquatic food resources. The concentration levels for the conditions used as an example for the critical group considered in the present work produce rather low dose rates to man of less than 3% of the maximum permissible intake. The development of the present methodology indicates that the low dose levels strongly depend upon the concentration factors of the various biological species, as well as upon source-term activities. The concentration factors used for the biological transfer of actinides relate to the water activity only. In the case where highly radioactive sediments or sedimentary-associated material were closely involved in the uptake pathway, actinide transfer to man could become more relevant. The present study shows that sedimentation and bottom sediment absorption represent the major reconcentration processes for actinides released into surface waters. In parallel to improvements of the assessment methodology, there is a need of continued radiological research with special emphasis on the benthic zone in order that the significances of the long-term sediment-biota interactions (sink-source role of sediments) on the transfer of actinides to man may be understood.

Mercury, DDT, and PCBs in aquatic food resources

Mercury, DDT, and PCBs in aquatic food resources

The Utilization of Aquatic Food Resources

The Utilization of Aquatic Food Resources