Atlantic Sturgeon Spatial and Temporal Distribution in Minas Passage, Nova Scotia, Canada, a Region of Future Tidal Energy Extraction.

In the Bay of Fundy, Atlantic sturgeon from endangered and threatened populations in the USA and Canada migrate through Minas Passage to enter and leave Minas Basin. A total of 132 sub-adult and adult Atlantic sturgeon were tagged in Minas Basin during the summers of 2010-2014 using pressure measuring, uniquely coded, acoustic transmitters with a four or eight year life span. The aim of this study was to examine spatial and seasonal distribution of sturgeon in Minas Passage during 2010-2014 and test the hypothesis that, when present, Atlantic sturgeon were evenly distributed from north to south across Minas Passage. This information is important as tidal energy extraction using in-stream, hydrokinetic turbines is planned for only the northern portion of Minas Passage. Electronic tracking data from a total of 740 sturgeon days over four years demonstrated that Atlantic sturgeon used the southern portion of Minas Passage significantly more than the northern portion. Sturgeon moved through Minas Passage at depths mostly between 15 and 45 m (n = 10,116; mean = 31.47 m; SD = 14.88). Sturgeon mean swimming depth was not significantly related to bottom depth and in deeper regions they swam pelagically. Sturgeon predominately migrated inward through Minas Passage during spring, and outward during late summer-autumn. Sturgeon were not observed in Minas Passage during winter 2012-2013 when monitoring receivers were present. This information will enable the estimation of encounters of Atlantic sturgeon with in-stream hydrokinetic turbines

Results of OTN range test experiment calculated by Sanderson et al. (in preparation).

<p>Probability of detection of Atlantic sturgeon tagged with V16 acoustic tags (158 db, 75 sec average transmission interval) passing the OTN Minas Passage Line. Individual receivers are represented by blue lines with left hand side representing the south (first blue peak = receiver MPS012) and right side (last blue peak = receiver MPS001). Solid black line represents the probability of a tagged sturgeon being detected by at least one of the receivers. Probability of being detected by at least one receiver is nearly identical for the north and south sections of the line, with a small reduction in probability of detection in the middle.</p

Sturgeon day distribution for acoustically tagged Atlantic sturgeon recorded on the Ocean Tracking Network Minas Passage Line, Minas Passage, Nova Scotia, Canada, totals for years 2010–2014.

<p>Sturgeon day distribution for acoustically tagged Atlantic sturgeon recorded on the Ocean Tracking Network Minas Passage Line, Minas Passage, Nova Scotia, Canada, totals for years 2010–2014.</p

Summary of yearly detections of acoustically tagged Atlantic sturgeon that occurred in Minas Passage during 2010–2014 (n = 132).

<p>Summary of yearly detections of acoustically tagged Atlantic sturgeon that occurred in Minas Passage during 2010–2014 (n = 132).</p

Depth box plots (Line = median, box = 25 and 75% quartiles, whiskers = SD and dots = outliers) distribution for acoustically tagged Atlantic sturgeon recorded on the Ocean Tracking Network, Minas Passage Line, Minas Passage, Nova Scotia, Canada, totals for years 2010–2014.

<p>Depth box plots (Line = median, box = 25 and 75% quartiles, whiskers = SD and dots = outliers) distribution for acoustically tagged Atlantic sturgeon recorded on the Ocean Tracking Network, Minas Passage Line, Minas Passage, Nova Scotia, Canada, totals for years 2010–2014.</p

Summary of coded acoustic tag models used during Atlantic sturgeon tagging project in Minas Basin during the summers of 2010, 2011, 2012 and 2014 (n = 132).

<p>All models supplied by Vemco Inc., Halifax, NS, Canada.</p

The Minas Basin is the north-eastern portion of the inner Bay of Fundy (A); Minas Passage, links Minas Basin to the rest of the Bay of Fundy (B).

<p>The Minas Basin is the north-eastern portion of the inner Bay of Fundy (A); Minas Passage, links Minas Basin to the rest of the Bay of Fundy (B).</p