EARLY HEARING DETECTION AND INTERVENTION VIRTUAL CONFERENCE
MARCH 2-5, 2021
(Virtually the same conference, without elevators, airplane tickets, or hotel room keys)
5/21/2019 | 10:00 AM - 10:15 AM | A COMPARISON OF MACROINVERTEBRATE DRIFT IN A 4TH ORDER REACH OF THE AU SABLE RIVER, MI. | 250 DE
A COMPARISON OF MACROINVERTEBRATE DRIFT IN A 4TH ORDER REACH OF THE AU SABLE RIVER, MI.
The Au Sable River (MI) is a 4th order blue ribbon trout stream that has experienced an array of changes during the past 50 years, including diversion of sewage effluent and removal of a low-head dam. We evaluated invertebrate drift for 24 hours at 3 sites on 3 dates to replicate drift studies conducted in 1969 and 1996. Drift typically peaked between midnight and 5 am and was dominated by mayflies. Drift was lowest during day light hours. Total drift abundance at a single sample location was reported to be 8,489 organisms day?¹ net?¹ before the sewage diversion (1969) and 4,535 organisms day?¹ net?¹ after effluent diversion (1996). In comparison, we estimated drift in 2018 to be 11,418 organisms day?¹ net?¹ at the same site. Although effluent diversion significantly reduced nutrient loading, 2018 invertebrate drift exceeded previous drift abundance suggesting that nutrient reductions have not diminished invertebrate drift.
- Bioassessment
- Monitoring
- Secondary Production
Presentation:
This presentation has not yet been uploaded.
Handouts:
Handout is not Available
Transcripts:
CART transcripts are NOT YET available, but will be posted shortly after the conference
Presenters/Authors
Barney Boyer
(), Grand Valley State University, boyerb@mail.gvsu.edu;
ASHA DISCLOSURE:
Financial -
Nonfinancial -