Ecology of the Young-of-the-Year Emerald Shiner (Notropis Atherinoides) in the Upper Niagara River, New York: Growth, Diversity, and Importance as a Forage Species
The emerald shiner (Notropis atherinoides) is a relatively understudied Cyprinid that fills a major keystone role in the Niagara River. Little is known about the emerald shiner’s early life history, such as the ecology of their larval and juvenile stages, which is the focus of this study. In the upp...
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Digital Commons at Buffalo State
2017
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| Online Access: | https://digitalcommons.buffalostate.edu/greatlakes_theses/3 https://digitalcommons.buffalostate.edu/context/greatlakes_theses/article/1003/viewcontent/Cochran_Thesis_DigiCommons_Revised_2.pdf |
| Summary: | The emerald shiner (Notropis atherinoides) is a relatively understudied Cyprinid that fills a major keystone role in the Niagara River. Little is known about the emerald shiner’s early life history, such as the ecology of their larval and juvenile stages, which is the focus of this study. In the upper Niagara River, larvae first recruited into sampling gear in early July at a mean water temperature of 23oC, with larvae appearing into August. Young-of-the-year (YOY) emerald shiners grew an average of 1.5 mm and 31.5 mg a week throughout the growing season with condition peaking during warm water months (August-September). Increased catches of larvae in gyre areas of the river suggest that spawning may occur in these locations with eggs and hatchlings becoming entrapped during early development. However, juvenile stages were most frequently encountered in natural habitats. These natural habitats (marshes, islands, and creek-mouths) also displayed a significantly more diverse YOY fish community when compared to developed habitats (i.e. marinas/seawalls) (F (3,66) = 9.639, p-value < 0.05). Developed habitats, comprised of little structure and typically lacking vegetation, often times only housed emerald shiners and no other YOY species. Emerald shiners are an essential forage species for native piscivorous fish and birds such as walleye (Stizostedion vitreus), steelhead trout (Oncorhynchus mykiss), and the New York State threatened common tern (Sterna hirundo). Juvenile and adult emerald shiners comprise over half of the diet of walleye and steelhead trout in the river (57% and 59% respectively). Emerald shiners were also the top ranked prey item for walleye (71%) and steelhead (85%) as suggested by the Index of Relative Importance (% IRI). In the Niagara River, the combined effects of YOY fish habitat loss, invasive species, and degraded water quality require that this native forage fish becomes a priority for scientists and fishery managers in order to maintain the ecological integrity of the aquatic food web ... |
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