|
Hi,
According to my experience, the point method is useful, when the fish
feed on a variety of different thing, or things, which are hard to quantify (like
detritus or makrophytes). I used it with slides of gut contents from cyprinids
by looking through the slide on a microscope.I estimated the amount of area
within the slide covered by a certain food category.
It is essential to have only few food categories (2-4 categories with items
occuring frequently and another 3-5 categories occuring less frequently in
one slide).
You also have to be familiar with the remains, so that putting the remains
into groups is no big mental exercise (otherwise you will forget your
estimations while trying to figure out what is what).
With some experience it is possibel to get reproducable results, especially
when only one person is doing the analysis.
Between-person differences can be large and if several people have to do
the work, it is useful to train them through analysing the same slides.
Hope, this helps!
kind regards
Irene
-------------------------------------------------------
Dr. Irene Zweimüller phone: ++43 1 4277 54343
Inst. f. Ecology and FAX: ++43 1 4277 9542
Nature Conservation
Dept. Limnology e-mail: [log in to unmask]
Althanstr. 14
A-1090 Vienna
Austria - Europe
----------------------------------------------------------
|
