Measuring Fish Assemblages in Great Lakes Coastal Wetlands, Les Cheneaux, Michigan: A Program Assessment

Fishes;Lake Huron;Coastal Wetlands;Sampling Methods;Natural Resources and Environment

Florence, LauraDiana, James ;

University of Michigan

关键词: Fishes;    Lake Huron;    Coastal Wetlands;    Sampling Methods;    Natural Resources and Environment;   

Others  :  https://deepblue.lib.umich.edu/bitstream/handle/2027.42/64480/LWFlorence_MSthesis2009.pdf?sequence=1&isAllowed=y

瑞士|英语

来源: The Illinois Digital Environment for Access to Learning and Scholarship

【 摘 要 】

Les Cheneaux Islands constitute an archipelago along the shoreline of Michigan’seastern upper peninsula, containing coastal wetlands that provide key supports for fishesin the Laurentian Great Lakes. This thesis reports unpublished 1996 survey data used toevaluate fish assemblages in Les Cheneaux coastal wetlands. It is also a programassessment of fish survey methods in Les Cheneaux marshes from 1996-2004, growingfrom the 1996 survey recommendations. In 1996, I sampled larval and adult fishassemblages from ice-off to ice-on in four bays: Cedarville, Mackinac, Mismer, and St.Martin. From 1997-2004, larval and adult fishes were sampled in Cedarville, Mackinac,Mismer, McKay, and Prentiss bays. The 1996 survey focused on open water and whatproved to be seasonal marsh areas. Visual surveys identified more diverse zonations,from permanent marsh through seasonal marsh to open water. Subsequent years focusedon the seasonal and permanent marsh. I found that electroshocking and seining wereineffective for sampling these marsh habitats. Gill nets were highly effective but onlyaccurate when nets with variable mesh sizes were used. Fyke nets and minnow trapsproved most useful, accurately sampling fishes in densely vegetated marsh. The key foreffectively sampling all areas of the marsh is to deploy multiple methods with goodoverlap across zones, testing and validating methods. Fish assemblages were typical oflacustrine habitats and varied among methods, habitats, bays and with time. Results ofthe 1996 survey showed July and August were key sampling times because richness andabundance were highest. Subsequent surveys demonstrated that extended samplingprotocols are preferable to short surveys when evaluating habitat utilization of marshfishes. Overall, this thesis and subsequent research in Les Cheneaux Islands supportstudies showing that conservation of Great Lakes shoreline habitats will be important forthe success of fish populations that depend on them.