Age-Dependent Bioaccumulation of Organochlorine Compounds in Fish and their Selective Biotransformation in Top Predators from Lake Maggiore (Italy)

Abstract

Fish and piscivorous bird eggs collected in 2003 from Lake Maggiore (Italy), were analysed for PCB and DDT contamination. Lake Maggiore has been severely polluted by DDT through production of the pesticide within its catchment. Although agricultural application of DDT was banned in Italy in the 1978, industrial production continued until 1996, with enough contamination of water and soil for serious bioaccumulation in the lake biota. PCB and DDT concentrations in a whitefish (Coregonus macrophthalmus Nusslin 1882) were seen to be dependent on season and fish age, but not on sex. The average increase of the lipid-normalised concentration of DDTs and PCBs was two-fold across season and also across age, resulting in an overall increase of four fold. The seasonal variation was related to the ecophysiological cycle of the fish and to the contamination dynamic of the lake, while the effect of the fish age was explained on the base of biomagnificationrelated mechanisms. A fugacity model was applied to predict the age-dependent bioaccumulation potential of PCBs, whose concentrations were rather stable in recent years in the lake. Predicted values for compounds with negligible biotransformation were in good agreement with experimental data (calculated vs. experimental mean difference of 14%), and a relationship between the increase of experimental agedependent concentration and K ow was observed. The good correspondence between the predicted and the measured values for most PCB congeners confirmed the general inability of fishes to biotransform these compounds. On the contrary, the importance of biotransformation processes was recognised in birds; eggs of a fish eating bird (Podiceps cristatus) from the same area selectively bioaccumulated p,p′-DDE. For PCBs, congener 149 appears to be completely metabolized by the bird species, and congeners 95, 101, 132, 151 and 174 were reduced as well. The role of the meta-para free position on at least one phenyl ring of PCB congeners in biotransformation processes was confirmed.

Impacts of climate warming on the long-term dynamics of key fish species in 24 European lakes

“…Ambrosetti and colleagues (2006) have shown an increase of short and very intense rain 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 events coupled with long drought periods, and increased pollutant loads from the catchment (Galassi et al, 2006;Volta et al, 2009;Guilizzoni et al, 2012), due to changes in hydrology and precipitation regimes, have been also identified. Furthermore, an increase in the duration of the thermal stratification and stability of the water column was observed, probably triggering cyanobacteria blooms (Morabito, 2007).…”

The recent invasion of Rutilus rutilus (L.) (Pisces: Cyprinidae) in a large South- Alpine lake: Lago Maggiore

“…During the last 50 years, Italian lakes have been heavily affected by anthropogenic pressures such as organic (Mosello & Giussani 1997) and chemical pollution (Galassi et al 1981;Volta et al 2008) but also by erroneous fish management and stocking practices often characterized by the introduction of alien species. After the 1950s the presence of exotic species in Italy increased rapidly and the adverse effect of these invaders is now a major problem for the local fish fauna (Bianco 1998;Bianco & Ketmeier 2001;Gherardi et al 2008).…”

Contamination of Fish and Sediments from the Vistula River by Organochlorine Pesticides and PCBs

“…According to the available literature, the presence of residues of some persistent organic pollutants in tissues of freshwater fish is still found in many countries [3,6,[9][10][11][12]. The problem with DDT and PCB contamination of food and environment in the areas of their former manufacture still occurs.…”

“…The bioaccumulation of contaminants such as DDTs (mainly as DDE), PCBs, dioxins, and heavy metals by fish represents a potentially significant risk to piscivorous wildlife [11,12,17]. Fish often comprise a substantial dietary portion of mammalian and avian species, and therefore represent a significant route of contaminant exposure.…”