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author Zellmer, Iris D
Arts, M
Abele, Doris
Humbeck, Klaus
author_facet Zellmer, Iris D
Arts, M
Abele, Doris
Humbeck, Klaus
collection Datos científicos de ciencias marinas y ambientales
contents Daphnia was collected from five subarctic ponds which differed greatly in their DOC contents and, consequently, their underwater light (UV) climates. Irrespective of which Daphnia species was present, and contrary to expectations, the ponds with the lowest DOC concentrations (highest UV radiation levels) contained Daphnia with the highest eicosapentaenoic acid (EPA) concentrations. In addition, EPA concentrations in these Daphnia generally decreased in concert with seasonally increasing DOC concentrations. Daphnia from three of the ponds was also tested for its tolerance to solar ultraviolet radiation (UVR) with respect to survival. Daphnia pulex from the clear water pond showed, by far, the best UV-tolerance, followed by D. longispina from the moderately humic and D. longispina from the very humic pond. In addition, we measured sublethal parameters related to UV-damage such as the degree to which the gut of Daphnia appeared green (as a measure of their ability to digest algae), and whether their guts appeared damaged. We developed a simple, noninvasive scoring system to quantify the proportion of the gut in which digestive processes were presumably active. This method allowed repeated measurement of the same animals over the course of the experiment. We demonstrated, for the first time, that sublethal damage of the gut precedes mortality caused by exposure to UVR. In a parallel set of experiments we fed UV-exposed and non-exposed algae to UV-exposed and non-exposed daphnids. UVR pretreatment of algae enhanced the negative effects of exposure to natural solar UV-irradiation in Daphnia. These UV-related effects were generally not specific to the species of Daphnia.
format Dataset Open Access
id pangaea_https___doi_org_10_1594_PANGAEA_858495
institution PANGAEA
language en
publishDate 2004
publisher PANGAEA
record_format pangaea
spellingShingle (Table 1) Dissolved organic carbon, water temperature and conductivity in three subarctic ponds near Kilpisjärvi, North Finland
Zellmer, Iris D
Arts, M
Abele, Doris
Humbeck, Klaus
Carbon, organic, dissolved; Carbon, organic, dissolved, standard deviation; Conductivity, electrolytic; Conductivity, standard deviation; DATE/TIME; Depth, bottom/max; Description; Finland; Kilpisjärvi; Lake; Priority Programme 1158 Antarctic Research with Comparable Investigations in Arctic Sea Ice Areas; SPP1158; Temperature, water; Temperature, water, standard deviation; Water sample; WS
Daphnia was collected from five subarctic ponds which differed greatly in their DOC contents and, consequently, their underwater light (UV) climates. Irrespective of which Daphnia species was present, and contrary to expectations, the ponds with the lowest DOC concentrations (highest UV radiation levels) contained Daphnia with the highest eicosapentaenoic acid (EPA) concentrations. In addition, EPA concentrations in these Daphnia generally decreased in concert with seasonally increasing DOC concentrations. Daphnia from three of the ponds was also tested for its tolerance to solar ultraviolet radiation (UVR) with respect to survival. Daphnia pulex from the clear water pond showed, by far, the best UV-tolerance, followed by D. longispina from the moderately humic and D. longispina from the very humic pond. In addition, we measured sublethal parameters related to UV-damage such as the degree to which the gut of Daphnia appeared green (as a measure of their ability to digest algae), and whether their guts appeared damaged. We developed a simple, noninvasive scoring system to quantify the proportion of the gut in which digestive processes were presumably active. This method allowed repeated measurement of the same animals over the course of the experiment. We demonstrated, for the first time, that sublethal damage of the gut precedes mortality caused by exposure to UVR. In a parallel set of experiments we fed UV-exposed and non-exposed algae to UV-exposed and non-exposed daphnids. UVR pretreatment of algae enhanced the negative effects of exposure to natural solar UV-irradiation in Daphnia. These UV-related effects were generally not specific to the species of Daphnia.
title (Table 1) Dissolved organic carbon, water temperature and conductivity in three subarctic ponds near Kilpisjärvi, North Finland
topic Carbon, organic, dissolved; Carbon, organic, dissolved, standard deviation; Conductivity, electrolytic; Conductivity, standard deviation; DATE/TIME; Depth, bottom/max; Description; Finland; Kilpisjärvi; Lake; Priority Programme 1158 Antarctic Research with Comparable Investigations in Arctic Sea Ice Areas; SPP1158; Temperature, water; Temperature, water, standard deviation; Water sample; WS
url https://doi.org/10.1594/PANGAEA.858495