EVALUATING EMBRYO SURVIVAL OF SURROGATE FISH SPECIES USING MULTIPLE INCUBATORS: CONTINUING EFFORTS TOWARDS REINTRODUCING ARCTIC GRAYLING (THYMALLUS ARCTICUS) INTO LOWER MICHIGAN STREAMS

Arctic Grayling Thymallus arcticus have been successfully reintroduced to the Upper Missouri River Basin of Montana using Remote Site Incubators (RSI). Widespread use of RSIs as part of reintroduction efforts in Michigan is challenged by low gradient streams, which limit deployment success. In this...

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Bibliographic Details
Main Author: Mutchler, Joshua
Format: Other/Unknown Material
Language:unknown
Published: NMU Commons 2024
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Online Access:https://commons.nmu.edu/theses/850
https://commons.nmu.edu/context/theses/article/1843/viewcontent/auto_convert.pdf
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Summary:Arctic Grayling Thymallus arcticus have been successfully reintroduced to the Upper Missouri River Basin of Montana using Remote Site Incubators (RSI). Widespread use of RSIs as part of reintroduction efforts in Michigan is challenged by low gradient streams, which limit deployment success. In this study, I evaluated the utility of an alternative instream rearing device, the Floating Basket Incubator (FBI), by directly comparing the survival of Rainbow Trout Oncorhynchus mykiss, Brook Trout Salvelinus fontinalis, and Walleye Sander vitreus (as Arctic Grayling surrogates) between RSI and FBI in stream and hatchery environments. In addition, I assessed how abiotic and biotic factors influenced survival for rainbow trout within FBIs among three natural streams. Overall, I found that mean survival of rainbow trout was higher than that of brook trout and walleye. My results suggested that FBIs performed similarly to RSIs in most experiments. Linear mixed effect model results suggested that survival of surrogate species was best explained by incubator type and stream location. The proportion of variation explained by the incubator type was low, relative to the random effect of stream location. My results suggest that although surrogates of Arctic Grayling sometimes had lower survival in FBI, the magnitude of this difference was small enough that FBIs should be considered as a tool when reintroducing Arctic Grayling.