Diet Analysis of Burbot from Eastern Lake Michigan: 1999-2012

<p>The Lake Michigan fish community has undergone many changes due to introduction of non-native species, climate shifts, and management actions. Managers need to understand the time course of these alterations, including the time-frame of impact on the food web in the lake. I used a collection (1999-2012) of diet samples from burbot from eastern Lake Michigan to evaluate temporal alterations in burbot diet with particular attention to non-native vs. native forage. Catch per unit effort (burbot/net · day) decreased from a high of 5.82 burbot/net · day (± 2.19) in 2001 to a low of 0.750 burbot/net · day (± 0.25) in 2010, which is consistent with declining burbot populations throughout the Great Lakes (Gorman and Sitar 2013; Stapanian et al. 2013). The collective contribution of sculpin (<em>Cottus</em>), alewife (<em>Alosa pseudoharengus</em>), and ninespine stickleback (<em>Pungitius pungitius</em>) to burbot diet decreased from ~80% before 2006 to ~15% in 2012. During the same time span, round goby (<em>Neogobius melanostomus</em>) contribution to burbot diet increased from ~0% before 2006 to greater than 60% in 2012, implying nearly a complete diet shift of burbot in just six years. The diet shift suggests a change in feeding behavior from partially pelagic/benthic to almost entirely benthic, and a change in prey consumption from alewife/sculpin to round goby. This shift may and serve as a potential link to move the benthos from a nutrient sink to a nutrient source by utilizing round gobies and moving nutrients up the trophic web.</p>

Name thesis:degree_name

Master of Science

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Biology

Year dc:date.available

2014

Author dc:creator

• Hares, Casey J

Contributors dc:contributor

• Dr. Jill B.K. Leonard

• burbot
• Lake Michigan
• round goby
• non-native species
• benthic
• diet analysis
• Aquaculture and Fisheries
• Biology

Repository record dc:identifier

https://commons.nmu.edu/theses/10

OAI identifier oai:identifier

oai:commons.nmu.edu:theses-1004