Ecological and socio-economic impacts of invasive mollusks in freshwater ecosystems

Abstract

Širenje invazivnih vrsta danas predstavlja jedan od glavnih uzroka gubitka biološke raznolikosti u svijetu. U ovom radu opisane su štetne posljedice invazivnih vrsta mekušaca, školjkaša i puževa, za autohtone vrste, stanište i ekosustav u cjelini. U pogledu ekoloških i socio-ekonomskih učinaka, Dreissena polymorpha spominje se kao jedna od najrazornijih vrsta u vodenim ekosustavima. Uzrokuje brojne nepovoljne učinke poput ugibanja autohtonih školjkaša, promjene kvalitete vode, izmjene strukture bentosa, obraštanja plovila i cjevovoda. Osim nje, opisane su još tri vrste invazivnih školjkaša: Mytilopsis leucophaeata svojim obraštajima uzokuje veliku štetu industriji, Limnoperna fortunei djeluje pogubno na autohtone školjkaše, reducira zalihe fitoplanktona i zagađuje vodene sustave raznih postrojenja. Corbicula fluminea ima slične ekološke učinke kao D. polymorpha - negativno utječe na autohtone Unionidae i zbog visokih stopa filtracije reducira fitoplankton te obrašta rashladne sustave u elektranama. Četiri vrste puževa također se navode kao vrste sa štetnim učincima: Pomacea canaliculata i P. insularum osim što mogu ugroziti autohtone vrste, uništavaju usjeve riže čime pridonose velikom ekonomskom gubitku tog područja te osim toga mogu biti vektori za bolesti i ugrožavati ljudsko zdravlje. Bithynia tentaculata infestira vodoopskrbne sustave, reducira brojnost nativnih vrsta i prenosi metilje koji infestiraju i ubijaju ptice močvarice. Potamopyrgus antipodarum svojim gustim populacijama istiskuje autohtone mekušce i mijenja primarnu proizvodnju, što ima znatne učinke na ekosustav. Jedan od najvećih problema u suzbijanju širenja invazivnih vrsta je kasno otkrivanje štetnih učinaka nakon introdukcije, stoga je važno na vrijeme otkriti potencijalno invazivne vrste i primjeniti metode smanjivanja njihovog negativnog učinka na autohtonu faunu.The spread of invasive species represents one of the main causes of biodiversity loss in the world. This work describes the harmful effects of invasive molluscs, bivalves and snails, for native species, habitat and ecosystem as a whole. In terms of environmental and socio-economic effects, Dreissena polymorpha is one of the most destructive species in aquatic ecosystems. It causes numerous adverse effects such as deflection of indigenous bivalves, water quality changes, changes in the structure of benthos and fouling vessels and pipelines. Three other species of invasive bivalves have been described: Mytilopsis leucophaeata whose fouling causes great harm to the industry, Limnoperna fortunei who has detrimental acts to the indigenous bivalves, reducing stocks of phytoplankton and polluting the water systems of various plants. Corbicula fluminea has similar environmental effects as D. polymorpha - a negative impact on indigenous Unionidae, by reducing phytoplankton because of the high rate of filtration and by fouling cooling systems in power plants. Four species of snails are also referred as species of harmful effects: Pomacea canaliculata and P. insularum, by threatening native species and destroying rice crops, which contribute to large economic loss of the area, and in addition can be vectors of disease and endanger human health. Bithynia tentaculata infests water supply systems, reduces the number of native species and transmittes trematodes that infest and kill waterfowl. Potamopyrgus antipodarum supersedes native bivalves and changes primary production with dense populations, which has significant effects on the ecosystem. One of the biggest problems in combating the spread of invasive species is late detection of harmful effects after the introduction, and therefore it is important to early detect the potentially invasive species and to apply the methods of reducing their negative impact on the indigenous fauna