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Full-Text Articles in Life Sciences

Algal Blooms Reduce The Uptake Of Toxic Methylmercury In Freshwater Food Webs, Paul C. Pickhardt, Carol L. Folt, Celia Y. Chen, Bjoern Klaue, Joel D. Blum Jan 2002

Algal Blooms Reduce The Uptake Of Toxic Methylmercury In Freshwater Food Webs, Paul C. Pickhardt, Carol L. Folt, Celia Y. Chen, Bjoern Klaue, Joel D. Blum

Dartmouth Scholarship

Mercury accumulation in fish is a global public health concern, because fish are the primary source of toxic methylmercury to humans. Fish from all lakes do not pose the same level of risk to consumers. One of the most intriguing patterns is that potentially dangerous mercury concentrations can be found in fish from clear, oligotrophic lakes whereas fish from greener, eutrophic lakes often carry less mercury. In this study, we experimentally tested the hypothesis that increasing algal biomass reduces mercury accumulation at higher trophic levels through the dilution of mercury in consumed algal cells. Under bloom dilution, as algal biomass …


Seasonal Variations In The Biomass Of Macro-Algal Communities From The Gulf Of Antalya (North-Eastern Mediterranean), İsmai̇l İbrahi̇m Turna, Ö. Osman Ertan, Mario Cormaci, Giovanni Furnari Jan 2002

Seasonal Variations In The Biomass Of Macro-Algal Communities From The Gulf Of Antalya (North-Eastern Mediterranean), İsmai̇l İbrahi̇m Turna, Ö. Osman Ertan, Mario Cormaci, Giovanni Furnari

Turkish Journal of Botany

In this study, the seasonal variations in the macro-algal biomass in the Gulf of Antalya (north-eastern Mediterranean) were investigated. The seasonal variations of the macro-algal biomass were found to be related to the biology of the abundant species during less favourable seasons. These variations occurred usually as a result of a significant reduction in algal density [Padina pavonica (L.) J.V.Lamour., Dasycladus vermicularis (Scopoli) Krasser, Chondrophycus papillosus (C.Agardh) Garbay & Harper] or loss of major part of their thallus [Cystoseira spp., Liagora distenta (Mertens ex Roth) J.V.Lamour., Liagora viscida (Forssk.) C.Agardh]. The highest values of biomass were found to be in …


Fungi And Diseases Associated With Cultivated Switchgrass In Iowa, C. E. Gravert, G. P. Munkvold Jan 2002

Fungi And Diseases Associated With Cultivated Switchgrass In Iowa, C. E. Gravert, G. P. Munkvold

Journal of the Iowa Academy of Science: JIAS

Switchgrass (Panicum virgatum L.) is a native perennial prairie grass that is now cultivated as a forage crop and a biomass crop for renewable energy. Biomass yields of switchgrass in southern Iowa have recently dropped significantly in some fields and the reduction has been attributed to disease. A disease survey was conducted in 1999 to assess the prevalence of major diseases in Chariton Valley switchgrass production. There were disease symptoms present on switchgrass plants in each field and thirteen fungal species were identified from leaf, stem, and root samples. Two pathogenic fungi, Tilletia maclaganii and Colletotrichum graminicola, were present in …


A Preliminary Study On The Population Dynamics Parameters Of Whiting (Merlangius Merlangus Euxinus) In Turkish Black Sea Coastal Waters, Ali̇ İşmen Jan 2002

A Preliminary Study On The Population Dynamics Parameters Of Whiting (Merlangius Merlangus Euxinus) In Turkish Black Sea Coastal Waters, Ali̇ İşmen

Turkish Journal of Zoology

Some population parameters of the whiting (Merlangius merlangus euxinus) distributed along the Turkish Black Sea coast, were determined by using age-length data. The mean annual growth rate in length was found to be 3.7 cm. The maximum age group was determined as IX for females and VI for males. The seasonalized von Bertalanffy growth parameters in length were estimated to be L_o=39.1 cm, K = 0.15 year^{-1}, t_o = -1.53 year, C=0.23, t_s=0.48. There was a difference in growth rate between male and female fish. The females grow faster than males and reach a greater maximum length. Total mortality and …


Influence Of Forest Composition On Understory Cover In Boreal Mixedwood Forests Of Western Quebec, Sonia Legare, Yves Bergeron, David Pare Jan 2002

Influence Of Forest Composition On Understory Cover In Boreal Mixedwood Forests Of Western Quebec, Sonia Legare, Yves Bergeron, David Pare

Aspen Bibliography

Forest overstory composition influences both light and nutrient availability in the mixed boreal forest. The influence of stand composition on understory cover and biomass was investigated on two soil types (clay and till deposits). Four forest composition types were considered in this study: aspen (Populus tremuloides Michx.), paper birch (Betula papyrifera Marsh.), jack pine (Pinus banksiana Lamb.) and a mixture of balsam-fir (Abies balsamea (L.) Mill.) and white spruce (Picea glauca (Moench) Voss). The cover of all understory species was recorded while the biomass of two important and ubiquitous species was measured: mountain maple (Acer spicatum Lam.) of the shrub …