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Checking the Pulse of Lake Erie
126,45 €
+ 252 points
Description
A traditional Chinese physician begins by checking the pulse of his patient. More than merely determining heart rate, he examines various levels of the pulse and its energy balance between the two sides of the patient. From this quick examination he can estimate the overall health of the patient and make some assessments of where potential problems may lie. So too, this monograph of current research on Lake Erie covers a breadth of investigations at various depths. Here we ?re-check" the pulse of Lake Erie? in several ways and examine the overall status of the health of the patient: the Lake Erie ecosystem. This patient was certainly due for a check-up and reappraisal. To that end the volume does include some papers that not merely provide a general compendium of current work. Instead, these papers address specific topics related to current issues and assess potential problems that may unfurl in the foreseeable future. Included here are works from well established research groups, as well as from some of the new investigators in the region. This volume presents reports on the biotic spectrum in Lake Erie, from viruses to fish and birds. The main stressors on the Lake Erie ecosystem appear to be largely due to human-induced activities: Climate Change, loadings of nutrient and toxic materials, release and introduction of aquatic invasive species. Recent reports indicate that the depth-integrated summer temperature of the lake has increased an average of 0.037 ± 0.01oC per year between 1983 ? 2002 (Burns, et al. 2005). In this book, Schertzer et al., and Hamblin and Schertzer show that the thermal structure of Lake Erie can be significantly changed in such a way as to reduce duration and extent of ice cover, earlier onset and longer duration of stratification, and possibly a profound change on winter circulation patterns. Indeed, one of the major changes in climate may be an increase in the variability of storm events and their effects on the lake. Although the total P load to the lake has remained near or below the target loads (11,000 MT) mandated by the Great Lakes Water Quality Agreement (1978 as amended, 1987), recent loading pulses in 1997 and 1998 give cause for concern (Dolan and McGunagle 1995). Here, Dolan and Richards report that loadings in these years exceeded target loads not only because of the frequency and duration of storms, but also due to their unusual winter timing. In addition to loading through storm events, the potential for loading from agricultural runoff following irrigation is addressed in this monograph. Loftus and Richards note that irrigation at this time does not lead to significant impacts on Lake Erie water quality, but the amount of ground water that becomes surface water through this activity may become a concern in the future. The effects of these stressors appear to be far-reaching; indeed it is unclear whether we know the full set of consequences, or even that all consequences of these stressors have yet appeared in Lake Erie. Regular recurrence of increasingly large regions of hypoxia in the central basin, leading to the journalistic hyperbole of ?The Dead Zone,? is the most striking of these ecosystem level effects. The causes and consequences of hypoxia in the central basin are not well understood. In the past, regions of hypoxia occurred because of cultural eutrophication that resulted in excessive growth of poorly grazed phytoplankton, largely cyanobacteria, which in turn died, descended to the bottom waters, and decayed, with consequent consumption of hypolimnetic oxygen by heterotrophic bacterial activities. The current regions of hypoxia are not caused in the same way. Here it is shown that total P-loadings are at or below GLWQA target loads (Dolan and Richards), phytoplankton communities in the central basin do not appear to be dominated by ?eutrophic species? (Munawar, M. et al., Meilander et al.), and phytoplankton in the bottom water
Spécifications
Parties prenantes
- Editeur:
Contenu
- Nombre de pages :
- 640
- Langue:
- Anglais
- Collection :
Caractéristiques
- EAN:
- 9783510652365
- Format:
- Livre broché
- Dimensions :
- 140 mm x 220 mm
- Poids :
- 930 g
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