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Whole-catchment liming at Tjønnstrond, Norway: An 11-year record
1997
Traaen, T. S. | Frogner, T. | Hindar, A. | Kleiven, E. | Lande, A. | Wright, R. F.
In June 1983 a whole-catchment liming experiment was conducted at Tjønnstrond, southernmost Norway, to test the utility of terrestrial liming as a technique to restore fish populations in remote lakes with short water-retention times. Tjønnstrond consists of 2 small ponds of 3.0 and 1.5 ha in area which drain a 25-ha catchment. The area is located at about 650–700 meters above sea-level in sparse and unproductive forests of spruce, pine and birch with abundant peatlands. A dose of 3 ton/ha of powdered limestone were spread by helicopter to the terrestrial area. No limestone was added to the ponds themselves. The ponds were subsequently stocked with brown and brook trout.Liming caused large and immediate changes in surface water chemistry; pH increased from 4.5 to 7.0, Ca increased from 40 to 200μeq/L, ANC increased from −30 to +70μeq/L, and reactive-Al decreased from about 10 to 3μmol/L. During the subsequent 11 years the chemical composition of runoff has decreased gradually back towards the acidic pre-treatment situation. The major trends in concentrations of runoff Ca, ANC, pH, Al and NO₃ in runoff are all well simulated by the acidification model MAGIC. Neither the measured data nor the MAGIC simulations indicate significant changes in any other major ion as a result of liming.The soils at Tjønnstrond in 1992 contained significantly higher amounts of exchangeable Ca relative to those at the untreated reference catchment Storgama. In 1992 about 75% of the added Ca remains in the soil as exchangeable Ca, 15% has been lost in runoff, and 10% is unaccounted for.The whole-catchment liming experiment at Tjønnstrond clearly demonstrates that this liming technique produces a long-term stable and favourable water quality for fish. Brown trout in both ponds in 1994 have good condition factors, which indicate that the fish are not stressed by marginal water quality due to re-acidification. The water quality is still adequate after 11 years and >20 water renewals. Concentrations of H⁺ and inorganic Al have gradually increased and approach levels toxic to trout, but the toxicity of these are offset by the continued elevated Ca concentrations. Reduced sulphate deposition during the last 4 years (1990–94) has also helped to slow and even reverse the rate of reacidification. The experiment at Tjønnstrond demonstrates that for this type of upland, remote terrain typical of large areas of southern Norway, terrestrial liming offers a suitable mitigation technique for treating acidified surface waters with short retention times.
اظهر المزيد [+] اقل [-]Mollusc and sediment contaminant levels and trends in south Florida coastal waters
1997
Cantillo, A.Y. | Lauenstein, G.G. | O'Connor, T.P. (Office of Ocean Resources, Conservation and Assessment, NO AA/National Ocean Service, 1305 East West Hwy, Silver Spring, MD 20910 (USA))
Contamination of the deep-sea
1997
Ballschmiter, K.H. | Froescheis, O. | Jarman, W.M. | Caillet, G. (Universitat Ulm, Analytische Chemie, Postfach 4066, D-7900 Ulm (Germany))
Organochlorines in sea otters and bald eagles from the Aleutian Archipelago
1997
Estes, J.A. | Bacon, C.E. | Jarman, W.M. | Norstrom, R.J. | Anthony, R.G. | Miles, A.K. (National Biological Service, A-316 Earth and Marine Sciences Building, University of California, Santa Cruz, CA 95064 (USA))
Increase of organochlorines and mercury levels in common guillemots Uria aalge during winter in the southern North Sea
1997
Joiris, C.R. | Tapia, G. | Holsbeek, L. (Laboratory for Ecotoxicology and Polar Ecology, Free University of Brussels (VUB), Pleinlaan 2, B-1050 Brussels (Belgium))
Isomer-specific analysis of polychlorinated biphenyls in harbour porpoise (Phocoena phocoena) from the Black Sea
1997
Tanabe, S. | Madhusree, B. | Ozturk, A.A. | Tatsukawa, R. | Miyazaki, N. | Ozdamar, E. | Aral, O. | Samsun, O. | Ozturk, B. (Department of Environment Conservation, Ehime University, Tarumi 3-5-7, Matsuyama 790 (Japan))
Distribution patterns of polychlorinated biphenyl congeners in water, sediment and biota from midway atoll (North Pacific Ocean)
1997
Hope, B. | Scatolini, S. | Titus, E. | Cotter, J. (Ogden Environmental and Energy Services Company, Inc., 680 Iwilei Road, Suite 660, Honolulu, HI 96817 (USA))
Distribution and abundance of meiofauna in a subtropical coastal lagoon in the south-eastern gulf of California, Mexico
1997
Noguera, S.E.G. | Hendrickx, M.E. (Estacion Mazatlan, Instituto de Ciencias del Mar y Limnologia, Universidad Nacional Autonoma de Mexico, Ap. Postal 811, 82000, Mazatlan, Sinaloa (Mexico))
Metals, petroleum hydrocarbons and organochlorines in inshore sediments and waters of Mombasa, Kenya
1997
Williams, T.M. | Rees, J.G. | Ferguson, A. | Herd, R.A. | Kairu, K.K. | Yobe, A.C. (British Geological Survey, Keyworth, Nottingham (United Kingdom))
Concentrations of Cd, Pb, Zn and Cu in contaminated wetlands of the Russian Arctic
1997
Zhulidov, A.V. | Headley, J.V. | Robarts, R.D. | Nikanorov, A.M. | Ischenko, A.A. | Champ, M.A. (Hydrochemical Institute-Federal Services of Russia for Hydrometeorology and Environmental Monitoring, Stachki Ave. 198, Rostov-on-Don 344104 (Russian Federation))