| Abstract: | The proliferation of the invasive round goby (Apollonia melanostoma) in the Great Lakes has caused shifts in the trophic ecology in some areas. We examined the diet of double-crested cormorants (Phalacrocorax auritas) prior to, and immediately after, round goby population expansion at two colonies, Pigeon and Snake Islands, in eastern Lake Ontario from 1999 to 2007. Cormorant diet was determined from the examination of 10,167 pellets collected over the nine-year period. By the second year round gobies were found in the diet (2002 at Snake Island and 2003 at Pigeon Island) they were the main species consumed by cormorants at each colony. The dominance of round goby in cormorant diets had a significant effect on both daily fish consumption and seasonal trends in fish consumption compared to the pre-goby years. Seasonal differences that were observed during the pre-goby years were lost once gobies became the main diet component of cormorants. The rapid switch to a benthic prey such as round goby, from a largely limnetic fish diet demonstrates the adaptive foraging ability of cormorants. Round goby may act as a buffer for yellow perch and smallmouth bass, two sport fish impacted by cormorant predation in eastern Lake Ontario. |
| Genre: | Article |
| ProdID: | 70041979 |
| Citation Author: | Johnson, James H.; Ross, Robert M.; McCullough, Russell D.; Mathers, Alastair |
| Citation Contributing Office: | Great Lakes Science Center |
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| Citation End Page: | 247 |
| Citation Issue: | 2 |
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| Citation Language: | English |
| Citation Larger Work Title: | Journal of Great Lakes Research |
| Citation LatN: | 44.36 |
| Citation LatS: | 43.17 |
| Citation LonE: | -76.0 |
| Citation LonW: | -80.0 |
| Citation Month: | 6 |
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| Citation Online Only Flag: | |
| Citation Phsyical Description: | 6 p. |
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| Citation Publisher: | International Association for Great Lakes Research |
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| Citation Search Results Text: | Diet shift of double-crested cormorants in eastern Lake Ontario associated with the expansion of the invasive round goby; 2010; Article; Journal; Journal of Great Lakes Research; Johnson, James H.; Ross, Robert M.; McCullough, Russell D.; Mathers, Alastair |
| Citation Start Page: | 242 |
| Citation Volume: | 36 |
| Citation Year: | 2010 |
| Type: | citation/reference |
| Text: | Diet shift of double-crested cormorants in eastern Lake Ontario associated with the expansion of the invasive round goby; 2010; Article; Journal; Journal of Great Lakes Research; Johnson, James H.; Ross, Robert M.; McCullough, Russell D.; Mathers, Alastair |
| URL (DIGITAL OBJECT IDENTIFIER): | http://dx.doi.org/10.1016/j.jglr.2010.02.013 |
| URL (THUMBNAIL): | http://pubs.er.usgs.gov/thumbnails/outside_thumb.jpg |
| Date Other: | Sat, 1 Dec 2012 00:00 -0600 |
| Publisher: | International Association for Great Lakes Research |
