Introduction & Objectives

This telemetry monitoring study was initiated in May 2021 to collect year-round occurrence data for Atlantic and shortnose sturgeon in the lower Kennebec River (including Bath Iron Works) and also to collect data during recurrent Naval activities. This study will also implement monitoring stations offshore of Popham Beach to capture coastal movements of sturgeon and other species, including white sharks. This area encompasses a curtain between Fox-Seguin Islands and the JackKnife Ledge Dredge Disposal area. Additionally, an additional 55 total Atlantic and shortnose sturgeon will be tagged in the Kennebec River to increase the population of tagged fish.

Project objectives are: 1) monitor sturgeon activity in the proximity of Bath Iron Works; 2) Document coastal movements of fish offshore from Popham Beach: ESA sturgeon species, striped bass, white sharks, and other highly migratory species; 3) Monitoring year-round presence and migration of Atlantic sturgeon in the lower Kennebec River; 4) Monitoring year-round presence and migration of shortnose sturgeon in the lower Kennebec River; and 5) add additional acoustically tagged species to the Kennebec River system. Collaborators on this project include State of Maine Department of Marine Resources, University of Maine, U.S. Geological Survey, Portsmouth Navy Yard, University of Maryland (data analytics).

Technical Approach

The technical approach is to deploy year-round telemetry monitoring stations in the Lower Kennebec River including Bath Iron Works area to capture timing and movement through these areas, and also offshore stations to assess movements of ESA-listed sturgeon between river systems.  Locations and habitat of deployments are chosen carefully to maximize detection of sturgeon and also to minimize potential loss of equipment.  Data analysis will include summaries of number of unique sturgeon detected at each station for each month, and number of days per month sturgeon detected.  Also, finer scale telemetry data for the array will be reviewed for metrics such as likelihood of detection for different areas across seasons, and comparative rates of movement. 

With many previously deployed sturgeon tags expiring, the approach is also to surgically tag minimum 55 new Atlantic and shortnose sturgeon.  Biometrics are collected during tagging including inter-orbital and mouth width, a PIT tag inserted, and a fin clip collected for DNA analysis.

Progress & Results

In May 2021, 8 telemetry stations were deployed in the river to supplement MEDMR existing 3, and an additional six were deployed offshore. In the first year, Atlantic sturgeon, shortnose sturgeon, striped bass, and American shad were detected on river stations.  No Atlantic or shortnose sturgeon were detected in December or January.  Additionally, white sharks and Atlantic bluefin tuna were detected offshore, with several unknown tag IDs still pending.

Detection downloaded in May 2022 showed the highest number of Atlantic sturgeon detects in May and June, with up to 21 unique Atlantic sturgeon detected in June at a station just north of Bath Iron Works.  Twenty-five unique white sharks tagged by MA Division of Marine Fisheries were also detected, with up to 9 unique individual white sharks on a single offshore station.

Current configuration of the array consists of 12 stations in the river in coordination with MEDMR, and 5 offshore.

Additionally, 63 total sturgeon were tagged in 2022, consisting of 40 Atlantic and 23 shortnose.