Shallow Water Baitfish Assemblages in New Hampshire Coastal and Estuarine Waters.

Comeau, Samuel*, Aliya Caldwell, Nathan B. Furey, University of New Hampshire, Durham, NH

Shallow water estuarine habitats can be nurseries for juvenile fish, providing food and shelter from predation. Great Bay, New Hampshire, USA, provides nursery habitat to various species of commercial, recreational, and ecological importance. Despite being a large system, the sampling of juvenile fishes in Great Bay is currently restricted to open-water and soft-bottom habitats, which may exclude species that associate with rocky and structured habitats. To describe fish assemblages in these habitats, we deployed minnow traps throughout the estuary during the summer of 2022. Traps were deployed for ~24 hours, and the number of fish captured, number of unique species captured, and the total length of each fish were recorded. Numerous species were captured at sizes consistent with juvenile life stages, including cunner (Tautogolabrus adspersus), Atlantic tomcod (Microgadus tomcod), and winter flounder (Pseudopleuronectes americanus). Fourspine stickleback (Apeltes quadracus), Atlantic tomcod, and sculpin (Myoxocephalus spp.), were the most abundant species captured. In addition, several species that associate with rocky bottoms were captured more frequently compared to state-led surveys, including sculpin, cunner, and rock gunnel (Pholis gunnellus). The higher frequency of species that utilize rocky substrates captured relative to state-led monitoring suggests that current monitoring efforts may underrepresent these species. Thus, a suite of gear types are likely most effective in determining how juvenile fishes use large estuaries such as Great Bay.