Great Lakes Fishery Commission

FishPass Updates

Updated June, 2025

Dear partners and stakeholders:

On behalf of the FishPass team, I am pleased to provide an update from June-Aug 2025.

NOTE: A time-lapse camera has now been installed to capture FishPass construction progress. Check it out here.

Construction:

  • FishPass has reached the first major construction milestone in completing Phase 1—arc-labyrinth and low-flow weir installation. Phase 1 of construction saw the demolition of half the existing dam and installation of a new, safe water control structure. The new weirs are an important component of FishPass by providing all the regulatory required flood control and acting as a default sea lamprey barrier (Figure 1). A portion of the upstream cofferdam (connecting from River's Edge Condominiums to river center) has been completely removed and the entire river flow is now passing over the new arc-labyrinth and low-flow weirs (Figure 2). Overall, construction is one-third complete.
  • The contractor has started construction Phase 2, which includes encompassing the north side of the river inside a sheet pile cofferdam. Working within the cofferdam will permit the contractor to work in the dry to remove the remaining portions of the existing Union Street Dam and install the 400 ft L x 30 ft W fish-sorting channel, which will be the primary site of research on selective fish passage. The sheet pile installation is anticipated to be completed by mid-August. Throughout sheet pile installation activities, vibration and settlement at nearby properties continue to be monitored and no thresholds have been exceeded.
Aerial view of the Union Street Dam FishPass construction site in Traverse City, Michigan, taken in September 2025. The image shows cranes and construction equipment working along the Boardman River, with sheet piling and infrastructure forming around the developing fish passage channel. Downtown buildings and West Grand Traverse Bay are visible in the background.

Figure 1. Image from the FishPass time-lapse camera: August 1, 2025 showing flow over the new weirs and into a temporary bypass channel, while the contractor installs the cofferdam around the north bank of the river to start constructing the fish-sorting channels.

View from the river of an active construction site at a dam, where a crane and workers are present above a cascading waterfall. Concrete and steel structures frame the dam, with trees and blue sky in the background.

Figure 2. Rerouting of the Boardman/Ottaway River to pass over the new arc-labyrinth and low-flow weirs. Switching of flow from the old Union Street Dam to the new structures occurred on June 16, 2025.

Research:

  • 26 June - FishPass staff completed seasonal operation of a horizontal submerged screen weir (HSSW) at the MI DNR Traverse City Salmon Weir which began on 25 March 2025. At the conclusion of the 93 days of operation, staff processed over 2100 captured fish (Table 1). The HSSW is positioned two feet off the bottom of the river at the Salmon Weir to not impede river navigation or block free movement of fish. The purpose of the study was to assess the effectiveness of the HSSW to capture sea lamprey and other fishes migrating into the Boardman/Ottaway River.
  • June - FishPass staff conducted an additional four electrofishing surveys in the lower Boardman/Ottaway River (Below Union Street Dam) for a total of 12 "spring" surveys in this section of river. FishPass staff in corroboration with project partners have been conducting four seasonal electrofishing surveys annually (i.e., index surveys) in this stretch of river for the past six years. This increased sampling effort being conducted in 2025 will help further refine shifts in the composition of the spring-time fish community assemblage and will greatly increase the number of tagged fish present in the river in preparation for FishPass operations. As part of this work, staff have implanted over one thousand passive integrated transponder (PIT) tags in fishes of suitable size and condition likely to return to the river in the future and encounter the FishPass facility. These tagged fish will help researchers evaluate the effectiveness of sorting technologies when FishPass becomes operational. Additional information on the results of these surveys is available in Table 1.
  • 15 July - Staff from GLFC, Grand Traverse Band of Ottawa and Chippewa Indians, and Conservation Resource Alliance conducted a two-pass electrofishing survey at the Forks long-term monitoring site. The team counted and measured all fish captured and estimated the population of brook and brown trout and a pooled estimate of slimy and modeled sculpin abundance (Table 2).
  • 29 July - GLFC and Central Michigan University staff completed the second scheduled index electrofishing survey in the lower Boardman/Ottaway River (below Union St. Dam). These surveys are conducted to understand the seasonal diversity and abundance of the Boardman/Ottaway River fishery in this section of river and have been conducted for the past seven years (Table 3).
Table showing fish species detected at a fish passage facility with counts from different detection methods. Columns include species name, total count (n), and counts detected by electrofishing (n.efish), hydroacoustic sonar (n.hssw), and PIT tagging (n.PIT), along with average fish length in inches. The table includes 30 species such as Atlantic salmon, longnose sucker, rainbow trout, and white sucker, totaling 3,683 fish. A note at the bottom indicates that an asterisk denotes a sample size of one.

Table 1. The number of fishes (n) sampled in spring of 2025 in the lower Boardman/Ottaway River (i.e., Below Union Street Dam), the number sampled during eight electrofishing surveys (n.efish) on 09, 15, 23, 28 April, 07, 13, 21, 27 May, 03, 10,17, 25 June, and 29 July 2025, the number of fish sampled at the Horizontal Submerged Screen Weir Trap (n.HSSW), the number of passive integrated transponder tags implanted (n.PIT) in the fishes, and the average length and weight of individuals measured and during all sampling events.

Data table summarizing fish species captured, including count, average length, and population estimates. The table lists 8 species such as brook trout, brown trout, and sculpin mixed species. Columns include species name, sample size (n), average total length in inches with standard error, adjusted Lincoln-Peterson population estimate with 95% confidence interval, acreage, fish per acre, and pounds per acre. A note below the table indicates that an asterisk denotes a sample size of one.

Table 2. The number of fishes captured (n), mean length and weight, adjusted Lincoln-Peterson population abundance estimate and density for brook, brown trout, and a pooled abundance estimate for slimy and modeled sculpin at the Forks long-term monitoring site 15 July 2025.

Table displaying data for seven fish species, including brown trout, rainbow trout, rock bass, sea lamprey, smallmouth bass, white sucker, and yellow perch. Columns list the number of individuals sampled (n) and their average lengths in inches. Some species have small sample sizes, with sea lamprey showing no recorded average length. A footnote indicates that asterisks denote a sample size of one.

Table 3. Average length and number of fish (n) sampled during electrofishing in the lower Boardman/Ottaway River on 29 July 2025.

Outreach:

  • FishPass Tours — Offered throughout June and July to the public at large, project adjacent neighbors, and mission-related partners including 20Fathoms, the National Cherry Festival, Hagerty, staff from Representative Tim Walberg, Inland Seas Education Association and multiple groups from Hagerty. 7 tours were hosted, attended by more than 150 people.
  • 4 June — Hosted a FishPass tour for the Michigan Downtown Association (60+ppl)
  • 8-13 June — The International Conference on Fish Telemetry was held in Traverse City. The conference brought together hundreds of research professionals and industry experts to discuss advancements in technology, novel methods, and research results used to advance our understanding of fish behavior and ecology. As part of the conference, the public and conference attendees gathered for a screening of "All too Clear,"" a fantastic documentary film full of spectacular underwater footage and tells the story of how invasive mussels have impacted the Great Lakes ecosystem (https://inspiredplanet.ca/alltooclear/).
  • 16 June — FishPass presentation to the TC Optimists Club (20+ppl)
  • Ongoing June — October; FishPass staff is playing an advisory role in the Blue Tech Challenge, locally sponsored by Northwestern Michigan College(NMC).
  • 14 & 21 July — FishPass staff participated in "History of the Anishinaabe" taught by JoAnne Cook at NMC — knowledge to be incorporated in future FishPass stories/presentations.
  • 15 July — TC New Tech Expo — Michigan's Blue Tech Innovation Hub
  • July + Ongoing — Collaboration with TC Arts Commission re: public art plan for FishPass site
  • 24 July — IPR Guest Host during fund drive + FishPass update with reporter Ellie Katz
  • 29-30 July — PBS Great Lakes Now — part 2 of 3 documentary on river restoration

Upcoming:

  • 8 August — Senior Staff Visit from the Office of Senator Gary Peters (31 ppl)
  • 18 August — ReShore: Innovation at the Intersection of Water, Mobility and Outdoor Tech
  • 28 August — UnPlugged with 20Fathoms: Northern MI’s Blue Tech Innovation Hub Round Table
  • 12 September — Freshwater Research and Innovation Center Ground Breaking
  • 17 September — GLOS Leadership Visit + Tour
  • 25 September — Tribal Council FishPass Tour
  • 25 September — Presentation during Leadership Grand Traverse Natural Resources Day
  • 29 September — October 1 — Oceans25 and BlueTech Challenge Finale

In the News:

Previous Updates