Ed. Edwards et Ad. Huryn, ANNUAL CONTRIBUTION OF TERRESTRIAL INVERTEBRATES TO A NEW-ZEALAND TROUT STREAM, New Zealand Journal of Marine and Freshwater Research, 29(4), 1995, pp. 467-477
Whole-stream drift from stream reaches enclosed by 1 mm mesh barriers
was sampled to estimate the potential contribution of terrestrial inve
rtebrates to trout production in a high-country pasture stream in New
Zealand. Invertebrates were classified into two activity groups: winge
d or wingless. Biomass of winged insects was significantly related to
temperature but not discharge. Biomass of wingless invertebrates was n
ot related to temperature or discharge; however, abundance was signifi
cantly related to discharge but not temperature. These results suggest
that mode of entry differed between activity groups. Winged insects a
pparently entered the stream as a function of overall activity, wherea
s wingless invertebrates entered the stream passively-possibly a-resul
t of fluctuations in discharge. An empirical model based on these rela
tionships indicated that total input of terrestrial invertebrates may
support as much as 5% of annual production by resident brown trout.