Sedimentary chemistry of a small polluted lake,Gallträsk,S. Finland

Macro nutrients N, P, K, Ca, Mg, Na and S as well as heavy metals Pb, Cu, Zn, Co, Cr, Ni, Fe and Mn were analysed from a sediment core representing a 7000-year long history of a lake including the preceding brackish (Litorina Sea) and freshwater (Ancylus Lake) stages. Sediments were also analysed for sedimentary pigments, algal growth potential (AGP) of the interstitial water, phosphorus fractions, pH, specific conductivity and redox potential. The annual accumulation values of several chemical elements were interpreted in light of other paleolimnological data from the same core. In the uppermost sediment stratum the influence of sewage pollution is clearly reflected by increases in total electrolyte content, pH, AGP and sedimentary pigments including myxoxanthophyll. Nickel, copper and manganese only slightly increase in the recent sediment, whilst other heavy metals (especially Cr and Zn) and sulphur, phosphorus, nitrogen and total organic matter are heavily concentrasted in the polluted surface sediment. The interpretation of the chemostratigraphy of the lake accords with evidence of lake development based on biological analyses.     

The food and parasites of fish in some deep basins of northern L. Päijänne

The composition of the fish stock, food and macroparasites were studied in eleven basins (22–100 m) of Lake Jyväsjärvi and North Päijänne in August–September 1976. The fishing was done by means of a series of nets (meshes 15, 21 and 35 mm) laid on the bottom overnight. No fish were found in the two northernmost basins owing to bad oxygen conditions caused by waste waters. Smelt and burbot were the most abundant fish in the catches in other basins but the vendace was rare. Relict crustaceans and some deep water copepods (e.g. Heterocope borealis) played an important role in the food of fish in all basins.Parasites spreading via relict crustaceans were abundant in smelt and burbot, but absent in vendace and ruffe. The most common parasite in smelt was Cystidicola farionis, in burbot Echinorhynchus borealis, in ruffe Triaenophorus nodulosus and in vendace the gill parasite Ergasilus sieboldi. Females of a relatively rare copepod Salmincola lotae were found in the oral cavity of five burbot (at depths of 50 and 100 m).     

The recovery of L. Vesijärvi following sewage diversion

For 60 years the sewage of the City of Lahti was discharged into L. Vesijärvi. The eutrophication of the lake was observed as early as the 1920s but in the 1960s the pollution became obvious. The sewage was completely diverted in 1976. As a result of the diversion the bacteriological defects were eliminated within one year, restoring the recreational value of the lake. The recovery of water quality was rapid during the first two years. The oxygen content increased markedly but hypolimnetic oxygen depletion persisted. The phosphorus content decreased about 60% and the nitrogen content about 30%. After that period the recovery slowed down. The biomass of phytoplankton decreased but the abundance of heterocystous blue green algae increased causing blooms in July and August. The primary production has lately been reduced despite the lack of improvement in chemical water quality. Hypolimnetic aeration was started in order to accelerate the recovery. The results during winter stagnation have been encouraging.     

The taxonomy of the family Paramphistomidae Fischoeder, 1901 with special reference to the morphology of species occurring in ruminants. III. Revision of the genus Calicophoron Näsmark, 1937

Summary The genus Calicophoron N?smark, 1937 is redefined. Only the following species originally assigned by N?smark to the genus are considered valid: C. calicophorum (Fischoeder, 1901) N?smark, 1937 (type species); C. papillosum (Stiles & Goldberger, 1910) N?smark, 1937; and C. raja N?smark, 1937. The following species previously assigned to the genus Paramphistomum Fischoeder, 1901 are considered valid but moved to the genus Calicophoron N?smark, 1937 in new combinations: C. bothriophoron (Braun, 1892); C. microbothrium (Fischoeder, 1901); C. papilligerum (Stiles & Goldberger, 1910); C. clavula (N?smark, 1937); C. microbothrioides (Price & McIntosh, 1944); C. sukari (Dinnik, 1954); C. phillerouxi (Dinnik, 1961); C. daubneyi (Dinnik, 1962) and C. sukumum (Dinnik, 1964). The genus Bothriophoron (Stiles & Goldberger, 1910) Grétillat 1958 is synoymized with Calicophoron N?smark, 1937. Paramphistomum crassum Stiles & Goldberger, 1910, P. cauliorchis Stiles & Goldberger, 1910, P. ijimai Fukui, 1922, P. (Cauliorchis) skrjabini Popova, 1937, P. erschovi Davydova, 1959, Calicophoron orientalis Mukherjee, 1966, C. wuchengense Wang, 1979 and Cotylophoron skrjabini Mitskevich, 1958 in part are considered synonyms of Calicophoron calicophorum (Fischoeder, 1901) N?smark, 1937. C. zhejiangense Wang, 1979 is regarded a synonym of C. papillosum (Stiles & Goldberger, 1910) N?smark, 1937. P. vangrembergeni Van Strydonck, 1970 and P. togolense Albaret, Bayssade-Dufour, Guilhon, Kulo & Picot, 1978 are considered synonyms of Calicophoron phillerouxi (Dinnik, 1961) n. comb. and Ceylonocotyle petrovi Davydova, 1961 is synonymized with Calicophoron microbothrioides (Price & McIntosh, 1944) n. comb. The species considered valid under the genus are redescribed and illustrated and scanning electron photomicrographs of the tegumental surfaces of some species are provided. A key to the species is given. Part of a thesis approved by the University of London for the award of the Ph.D. degree.