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l()0 90 HO 70 60 50 40 JO 20 10 0

(ontrol I    5    10    50    100    500    1000

Glyphosate conccntrations (pg/l)

A)

□    Chloro phyceae H Cryptophyceae

□    Euglenophyceae D Bacillariophyceae

■    Chrysophyceae

□    Cyanobactcria

B)

□    Ali other species

B Uroncma clongatum B Synura uvella 3 Synedra ulna

□    Synedra acus B Spirogyra sp

□    Nit/schia palca

□    Nitzschia acicularis B katablepharis ovalis

□    Chromulina elegans

K Chlamydomonas dinobryoni

■    Carteria cordiformis

Figurę 3.4. Rclativc biomass of the six major phytoplankton classcs (A) and major phytoplankton species (morę than 5% of total biomass) (B) in an agricultural stream phytoplankton community after a 96 hours exposure to various conccntrations

of glyphosatc-bascd herbicide.

Figurę 3.4 (B) shows the shift in the composition of the phytoplankton species when exposed to different concentrations of glyphosate for 96 hours. We detected five dominant species for the contro! {Carteria cordiformis [35%], Nitzchia palea [16%], Synedra uvella [9%], Nitzchia acicularis f8%] and Synedra acus [%%\). With glyphosate concentrations equal or above 5 pg I'¹, N. acicularis biomass decreased below 5%. Similar results were obtained for S. uvella_y for glyphosate concentrations equal or above 10 pg I*¹. When glyphosate concentrations reached 500 pg I*¹ and above, S. acus proportion in the community was also