Interactions among waterfowl, fishes, invertebrates, and macrophytes in four Maine lakes of different acidity

Technical Report · Mon Jul 01 04:00:00 EDT 1985

OSTI ID:5024797

Hunter, Jr, M L; Jones, J J; Gibbs, K E; Moring, J R; Brett, M

This study addresses the influence of low pH waters on community structure and species interactions on two pairs of oligotrophic, headwater ponds that were physically similar but with markedly different acidities. The circumneutral ponds had fish and the acidic ponds were fishless. The results showed macrophyte species was lower in the acidic ponds possibly due to low pH. Density of backswimmers was greater on the acidic ponds. Tests indicated that the large numbers of backswimmers present on the acidic ponds replaced fish as a significant planktivore. Although macroinvertebrate species differed between acidic and circumneutral ponds, Diptera were the most abundant macroinvertebrates on both sets of ponds. Diptera were the principle item in the diet of brook trout in the circumneutral ponds. Because of the absence of fish in the acidic ponds, this study suggests that a potential competitor of ducks for aquatic foods had been eliminated. Ducklings on the acidic ponds grew faster, spent less time searching, and more time feeding and resting than ducklings on the circumneutral ponds. There was substantial overlap in the diet of trout and ducks, supporting the hypothesis that ducklings and fish compete for invertegrates and that, under certain circumstances, the negative effect of acidification on fish may produce a beneficial effect for ducklings. 3 figs., 30 tabs.

• Research Organization: Maine Univ., Orono (USA). Maine Cooperative Fishery Research Unit
• OSTI ID: 5024797
• Report Number(s): FWS/OBS-80/40.20; ON: TI86900147
• Country of Publication: United States
• Language: English

Related Subjects

520200* -- Environment
Aquatic-- Chemicals Monitoring & Transport-- (-1989)
54 ENVIRONMENTAL SCIENCES
ACID RAIN
ANIMAL GROWTH
ANIMALS
AQUATIC ORGANISMS
ATMOSPHERIC PRECIPITATIONS
BIRDS
COMPETITION
DATA
DUCKS
ENVIRONMENTAL EFFECTS
EXPERIMENTAL DATA
FISHES
FOWL
GROWTH
INFORMATION
INVERTEBRATES
LAKES
NUMERICAL DATA
PH VALUE
PLANTS
POPULATION DENSITY
RAIN
SURFACE WATERS
VERTEBRATES