Movement Patterns of Adult Anadromous Rainbow Smelt in Great Bay Estuary, New Hampshire, USA.

Pearson, Chloe*¹, Linas W. Kenter², Aliya E. Caldwell¹, Emily A. Burke¹, Alyson L. Eberhardt², David L. Berlinsky¹, Nathan B. Furey¹, ¹University of New Hampshire, Durham, NH, ²New Hampshire Sea Grant, Durham, NH

Anadromous rainbow smelt in the northeastern USA have experienced range contraction over the past few decades, and are now restricted to waters north of Massachusetts. In their current range, populations appear to be in decline, including in New Hampshire; in Great Bay, New Hampshire, conservation efforts such as habitat restoration and stocking efforts have been suggested to improve populations. To optimize these conservation efforts, gaps in current knowledge regarding rainbow smelt habitat use need to be filled, including precise locations, timing, and duration of use. In March 2021, we used acoustic telemetry to monitor seasonal movements of adult rainbow smelt in Great Bay, New Hampshire, USA. We tagged 44 smelt (mean FL = 164 mm) with Innovasea V5 tags at upriver spawning sites in three tributaries of Great Bay. An array of 22 180 kHz VR2W receivers were deployed throughout Great Bay to detect movements of tagged fish from March-October 2021. Preliminary analyses suggest that rainbow smelt can use multiple rivers during the spawning season (March-April). Additionally, approximately three quarters (34 of 44) reached the seaward-most receivers and were presumed to have survived emigration. Among these survivors, individuals resided in the system for an average of 38.9 +/- 1.2 days prior to emigration, with most remaining in the estuary for a few weeks after spawning. Thus, these data will provide context for ongoing otolith microchemistry research, and it appears that adult rainbow smelt rely on a variety of riverine and estuarine habitats, utilizing the estuary as important habitat post-spawning.