This is a presentation of my undergraduate senior thesis project at LSSU. This study focused on the effects of spawning Pacific salmon on benthic algal biomass via nutrient enrichment and bioturbation
Disturbance of benthic algae by spawning Pacific salmon in Thompson Creek, MI
1. Disturbance of benthic algae by spawning Pacific salmon in Thompson Creek, MI Jessica Kosiara School of Biological Sciences Lake Superior State University
8. The Big Picture Salmon Nutrients Disturbance Competition Pollutants Water Chemistry Algae Consumers (inverts, fish) Objective: to assess overall impact of Pacific salmon in Great Lakes tributaries
9. Research objective Salmon Nutrients Disturbance Competition Pollutants Water Chemistry Algae Consumers (inverts, fish) To assess impact of salmon on algal biomass through nutrient enrichment and disturbance
When someone mentions exotic species in the GL these are some of the species that come to mind Sea lamprey, zebra mussels, purple loosestrife, round goby But most neglect to remember P. salmon
Pacific salmon introduced in 60’s-control alewife pop Recent concerns over Asian carp in GLs lead to speculations on value of GL fishery-7 bil$ Despite this tremendous economic importance, little is know about how they impact the great lakes ecosystem
Insert pic of spawners What we know is based on studies in native range that demonstrate ecological impacts of Pacific salmon are related to life history Ecological role as nutrient subsidy-bring nutrients from ocean
At the same time spawning activities displace sediments/biota thru construction of redds (or nests) Spawner uses tail to move/dig out substrate. Once eggs are deposited, move forward and fan substrate to cover eggs (left pic) Tell tale sign=clean substrate (right pick)
This leads us to question which role is more important/dominant? Nutrient subsidy vs bioturbator Results from previous study give varying results Meta-analysis showed that effects were site dependent. As confusing as these results can be, even less is know about P salmon effects in GL
expect different response based on diff environent
87, 126, 187
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Think about adding treatments Purpose of exclosure: keep salmon out=control Purpose of reference reach: account for effects of exclosure on algae
update
Purpose of exclosure: keep salmon out=control Purpose of reference reach: account for effects of exclosure on algae