Pesticides Research, 85 – Effects of Pesticides on Bombina bombina in Natural Pond Ecosystems

Effects of Pesticides on Bombina bombina in Natural Pond Ecosystems

5 Effects of pesticides

Analysis of variation

There was significantly less variation between the cages within ponds than between ponds in all three years for metamorphosis time and weight and for growth rate in the first week but not in the second week (table 5.1). Growth rate in the second week can therefore not be used for evaluation of pesticide effects.

Table 5.1
Statistical test (ANOVA) of variation in growth parameters of tadpoles between cages within ponds, and between ponds. Significance imply that variation between ponds was larger than variation between cages within the respective ponds. In 1993 and 1994 there was no variation in metamorphosis time between cages within ponds and therefore an ANOVA could not be conducted.

Statistisk test af variation i vækstparametre mellem bure indenfor vandhuller og mellem vandhuller. Signifikans betyder at variationen mellem vandhuller var større end variationen mellem bure i de enkelte vandhuller. I 1993 og 1994 var der ingen forskel i metamorfosetid mellem bure inden for vandhuller og en ANOVA kunne derfor ikke udføres.

	Metamor-phosis time	Metamor- phosis weight	Growth rate 1st week	Growth rate 2nd week
1993	-	p<0.05	p<0.03	p<0.5 n.s.
1994	-	p<0.001	p<0.001	p<0.2 n.s.
1995	p<0.001	p<0.02	p<0.04	p<0.5 n.s.

All correlations tested

All growth and survival parameters of tadpoles in the individual years were tested for correlations with contamination of herbicides, insecticides, fungicides and pesticides. Only a few significant correlations were found.

Survival to metamorphosis was significantly negatively correlated with contamination with herbicides in 1995 (r_s=-0.781, p<0.05).

Contradictory correlations

In 1993 there was a significant negative correlation between contamination with insecticides (r_s=-0.869, p<0.02) and fungicides (r_s=-0.741, p<0.05) and metamorphosis weight (figure 5.1). The opposite connection, a significant positive correlation between fungicide (r_s=0.751, p<0.05) and pesticide contamination (r_s=0.721, p<0.05) and metamorphosis weight, was found in 1995.

In 1995 there was a significant negative correlation between survival of the small tadpoles from week 2-4 and fungicide contamination (r_s=-0.835, p<0.02). In 1994 the growth rate of tadpoles in the first week was significantly negatively correlated with contamination with fungicides (r_s=-0.723, p<0.05).

Food Quality Index was not correlated with any pesticide contamination.

Figure 5.1 Spearman Rank correlations between weight at metamorphosis and insecticide (rs=-0.869, p<0.02), as well as fungicide (rs=-0.741, p<0.05) contamination in 1993. Pesticides are ranked with the highest number assigned to the highest concentration/heaviest exposure

Figure 5.1
Spearman Rank correlations between weight at metamorphosis and insecticide (r_s=-0.869, p<0.02), as well as fungicide (r_s=-0.741, p<0.05) contamination in 1993. Pesticides are ranked with the highest number assigned to the highest concentration/heaviest exposure.

Spearman Rank korrelationer mellem metamorfose vægt og insekticid-rank (r_s=-0,869, p<0,02) og fungicid-rank (r_s=-0,741, p<0,05) i 1993. Pesticiderne er rangordnet med største værdi til højeste koncentration/største eksponering.