A cloudy/milky emulsion commonly noticed in Northern Rivers creeks has been analysed by the Qld Dept of Health, and found to contain PBO (piperonyl butoxide), an insecticidal synergist that is believed to make trace-soluble camphor in freshwater even more active as an insect repellant/killing agent, along with camphor's "sister narcotics" from camphor laurel: napthalene, benzene and vanillin.
During
the course of field experimentation confirming in Australia, that camphor
kills frogs (see Fact sheet 2) observations were made of ephemeral streams
in the worst affected, smaller streams near The Channon. Close studies
of medium-large pondages in small ephemeral streams, particularly the old
water supply reservoir at The Channon, proves that over two wet seasons
water pollution under the invasive camphor trees - which in places choke
the stream bed - was so serious that only Mosquito larvae could be observed
living there (often for up to five months at a time).
A wide range of Water beetles, including Water boatmen and Water striders
(Family: Getridae) are absent from Camphor-impacted waterways and appear
to be most heavily affected, sterilized or killed by camphor.