OIMB Theseshttps://scholarsbank.uoregon.edu/xmlui/handle/1794/10442024-03-28T20:53:30Z2024-03-28T20:53:30ZMERCURY IN THE ENVIRONMENTTsuneyoshi, Kuniohttps://scholarsbank.uoregon.edu/xmlui/handle/1794/272372022-07-07T07:25:31Z1971-09-01T00:00:00ZMERCURY IN THE ENVIRONMENT
Tsuneyoshi, Kunio
The chances of us being exposed to mercury and its compounds are significant. During the past, farmers, miners, and manufacturers have used millions of pounds of mercury annually. Mercury containing agricultural chemicals are used widely because of their antifungal activity and mercury is used extensively in the manufacturing of many inorganic and organic chemicals, pulp, felt, and electrical appliances. The pollution resulting from these applications eventually finds its way into our food and water supply. The different forms of mercury which get into the environment can be converted to the more dangerous methylmercury by microorganisms. The ingestion of polluted freshwater and saltwater fish is probably the main route by which mercury enters the human body. In heavily polluted water the mercury level in fish can be very high.
75 pages
1971-09-01T00:00:00ZReview of factors contributing to the settlement and recruitment of barnaclesTrainer, Jameshttps://scholarsbank.uoregon.edu/xmlui/handle/1794/272362022-07-07T07:25:29Z2007-03-01T00:00:00ZReview of factors contributing to the settlement and recruitment of barnacles
Trainer, James
Barnacles are popular study organisms for a variety of reasons. As adults, they are sessile, and they are often small and numerous, making them easy to manipulate in ecological experiments. A researcher can be sure that an adult barnacle that disappears between observations has died, and has not moved away. As larvae, they develop through a series of six naupliar instars in the plankton. Nauplii are easy to identify in plankton samples, and are easy to collect from the egg lamellae of adult barnacles and culture in the laboratory. Nauplii metamorphose into the non-feeding cyprid stage, at which point they attempt to contact and stick to hard substrata. Depending on condition of the substrate, cyprids metamorphose into juvenile barnacles or return to the water column. A juvenile barnacle feeds and grows at its site of metamorphosis until it dies.
33 pages
2007-03-01T00:00:00ZThe High Nutrient Low Chlorophyll (HNLC) Phenomenon and the Iron HypothesisStenn, Erik Strickerhttps://scholarsbank.uoregon.edu/xmlui/handle/1794/272352022-07-07T07:25:28Z1996-04-01T00:00:00ZThe High Nutrient Low Chlorophyll (HNLC) Phenomenon and the Iron Hypothesis
Stenn, Erik Stricker
With rising CO2 levels in the atmosphere it becomes increasingly more important to understand the nature of the oceans as a sink for CO2 as well as the mechanisms that transport carbon from the atmosphere to the oceans. Regions of ocean in the subarctic Pacific, eastern equatorial Pacific and the southern Ocean have been recognized as being abnormally low in total biomass and yet they maintain high levels of available macronutrients. Due to the characteristic high nutrient low chlorophyll content of these regions, they have been dubbed HNLC. The 'biological pump' concept is a proposed mechanism serving as a carbon sink and was assumed to be limited by nitrogen. Early shipboard container experiments demonstrated that iron might be the limiting nutrient and not nitrogen. The data from the early experiments proved to be inconclusive due to imprecise methodology. In the late 1980' s there was renewed interest in HNLC areas championed by J.H. Martin. He maintained that HNLC regions exhibit Leibig limitation by iron, where, standing crops of phytoplankton are constrained by availability of iron: if iron were available, the standing crops of phytoplankton would increase and nitrate would be depleted despite grazing. Others argue that HNLC regions are a manifestation of active grazing in a steady state ecosystem. An intermediate camp claims that HNLC regions are a result of combined physical and biological processes that prevent the utilization of the surface macronutrients. The debate surrounding this issue prompted Martin and colleagues to perform the IronEx experiment: the in situ use of iron to enhance an HNLC patch in the Galapagos region of the Pacific. The ecosystem demonstrated an unequivocal response to iron; however, macronutrients were still relatively abundant after the experiment. Subsequent studies have revealed that iron impacts all cell size groups of phytoplankton and constrains new production in HNLC areas. What remains unclear is the effect of grazing within these ecosystems.
47 pages
1996-04-01T00:00:00ZThe Ecology of the Dall Porpoise (Phocoenoides dalli) and Interaction With Japanese Fisheries in the North Pacific OceanStark, Kimberle Annhttps://scholarsbank.uoregon.edu/xmlui/handle/1794/272342022-07-07T07:25:27Z1988-06-01T00:00:00ZThe Ecology of the Dall Porpoise (Phocoenoides dalli) and Interaction With Japanese Fisheries in the North Pacific Ocean
Stark, Kimberle Ann
The Dall porpoise (Phocoenoides dalli True) is a small, deep-bodied and easily identifiable cetacean found in the northern North Pacific Ocean and adjacent waters including the Gulf of Alaska, Bering Sea, Sea of Okhotsk, and the Sea of Japan.
90 pages
1988-06-01T00:00:00Z