Effect of Elodea spp. on Fish Performance Mediated Through Food Web Interactions
The aquatic plant Elodea spp. is a potential invader to Arctic and Subarctic ecosystems and is already established at a small suite of locations in Alaska, USA. Elodea spp. can alter ecosystem processes and food web structure; yet, little is known about the impact of Elodea spp. on fish performance. A primary concern is the effect of Elodea spp. on juvenile salmon (Oncorhynchus spp.), an important subsistence resource, because juveniles move into littoral zones of lakes to forage and seek refugeAbstract
Invasive species introductions in high latitudes are accelerating and elevating the need to address questions of their effects on Subarctic and Arctic ecosystems. As a driver of ecosystem function, submerged aquatic vegetation is one of the most deleterious biological invasions to aquatic food webs. The aquatic plant Elodea spp. has potential to be a widespread invader to Arctic and Subarctic ecosystems and is already established at a suite of locations in Alaska, USA. Elodea spp. has been found to alter ecosystem processes through multiple pathways; yet little is known about the impact of Elodea spp. on fish life history. A primary concern is the effect of Elodea spp. on juvenile Pacific salmon (Oncorhynchus spp.), because this invading plant can form dense stands in littoral zones, potentially impacting important freshwater rearing habitats used by juvenile fish for foraging and refuge from predators. We used a field experiment to test the effect of Elodea spp. on juvenile Coho salmon (O. kisutch) growth in an infested lake near Cordova, Alaska, USA. We found that Elodea spp. stands result in reduced growth and a lower trophic position for juvenile Coho salmon over the summer compared to habitats dominated by a native assemblage of aquatic plants. While infested sites were not associated with significant changes in water condition or primary productivity compared to sites dominated by native vegetation, zooplankton densities were reduced, and Elodea spp. height and vegetation richness increased macroinvertebrate densities. Combined, these results indicate that Elodea spp. may alter the flow of energy to juvenile salmon by restructuring space and affecting prey resources for rearing fish. Furthermore, these results suggest that widespread establishment of Elodea spp. may alter the quality of habitat for juvenile salmon, and by affecting juvenile fish growth, could lead to population-level impacts on salmon returns.
Products
| Title | Type |
|---|---|
| Limnological Data from Experimental Exposure of Juvenile Coho Salmon (Oncorhynchus kisutch) to Elodea in a High Latitude Lake | Data |
Contacts
Carey, Michael , 907-786-7197Status: onGoing
Start Year: 2016
End Year: 2022