Selected for FY21 PLCI Umbrella funding:

1) Artificially propagated (AP) and "wild" (W) lamprey have recently been compared using respiration rates, burrowing, and sustained swimming ability (Moser et al. 2020). We propose to expand this work by comparing the swimming ability of tagged lamprey and describing the performance of AP and W lamprey over time in captivity. W larvae may demonstrate different behaviors than “domesticated” AP larvae, and understanding when behavioral changes occur is an important consideration in decisions about when AP fish are appropriate surrogates for W fish. Study goals include: 1) compare the swimming ability of AP and W juvenile lamprey implanted with the lamprey-eel acoustic tag (JLAT), matching the procedures of Moser et al. (2020), and 2) investigate the effects of captive holding duration by evaluating night activity levels, burrowing ability, and photokinetic response to tail illumination of AP and W larvae over a 6-9-month period.

2) A flexible spill program in the federal Columbia River power system increased the total dissolved gas (TDG) water quality standards (110% to 125%) to balance spill for fish and power generation. Juvenile salmon are monitored for signs of gas bubble trauma (GBT) using criteria developed, in part, through USGS laboratory studies (Mesa et al., 2000), which are generally applied to all bony fishes. GBT signs are analogous to “the bends” in human divers and are expressed as the formation of bubbles in the skin, fins, or eyes. Where and when bubbles appear, their prevalence and severity, and how long they persist are species and life-stage specific. Existing protocols are unlikely to be effective in lamprey due to different body forms, physiology, and life history. Additionally, the critical linkage of what signs and levels of GBT result in increased risk of mortality is lacking for lamprey. The objective of this work is to develop a quantitative, rapid, non-lethal assessment protocol for GBT signs in larval lamprey, linking the signs to the risk of mortality for a given exposure. The work will follow similar procedures as the Mesa et al. (2000) studies, monitoring and evaluating the prevalence and severity of bubbles.