k iss ), ▁il leg ally ▁released ▁in ▁its ▁range ▁in ▁the ▁ 1 9 9 0 , ▁probably ▁by ▁ang lers . ▁However , ▁as ▁these ▁rivers ▁have ▁strong ▁spring ▁flo ods ▁and ▁high ▁summer ▁temper atures , ▁neither ▁bl u eg ills ▁nor ▁tr out ▁fare ▁as ▁well ▁there ▁as ▁they ▁do ▁elsewhere . ▁Add itional ▁thre ats ▁include ▁habitat ▁destruction ▁by ▁humans ▁due ▁to ▁water ▁poll ution ▁and ▁over use , ▁and ▁clear ing ▁of ▁rip arian ▁for ▁orch ards . ▁This ▁is ▁especially ▁harm ful , ▁as ▁it ▁dep riv es ▁the ▁young ▁fish ▁( which ▁are ▁especially ▁under ▁pressure ▁by ▁the ▁introduced ▁species ) ▁of ▁their ▁shelter , ▁and ▁allows ▁surface ▁run off ▁carrying ▁p estic ides ▁and ▁fert il izers ▁to ▁poll ute ▁the ▁rivers . ▁ ▁It ▁is ▁also ▁listed ▁as ▁End anger ed ▁by ▁the ▁Nature ▁Conserv ation ▁Ord in ance ▁of ▁Western ▁Cape ▁Province . ▁It ▁is ▁illegal ▁to ▁kill ▁Twe e ▁River ▁re df ins ▁and ▁for ▁the ▁time ▁being , ▁it ▁may ▁only ▁be ▁caught ▁for ▁super vised ▁transfer ▁tri als ▁to ▁other ▁habitat . ▁Land own ers ▁are ▁being ▁educated ▁about ▁the ▁uniqu eness ▁of ▁the ▁rivers ' ▁e cos ystem ▁and ▁the ▁threat ▁pos ed ▁by ▁adv ancing ▁cultiv ation ▁right ▁to ▁the ▁river bank . ▁As ▁mentioned ▁above , ▁some ▁trans loc ations ▁of ▁this ▁species ▁to ▁pres umably ▁secure ▁areas ▁have ▁been ▁started , ▁and ▁capt ive ▁bre eding ▁studies ▁are ▁being ▁undert aken ▁at ▁the ▁University ▁of