Exposure to elevatedpCO₂alters post‐treatment diel movement patterns of largemouth bass over short time scales

Abstract

Summary Studies with marine fishes indicate that exposure to elevated partial pressures of CO2 (pCO2) related to climate change have negative consequences for fish behaviour. Freshwater fishes may experience similar increases in pCO2 due to a number of different mechanisms, but there is a paucity of information on how freshwater fishes may respond to exposure to elevated pCO2. To define the effects of elevated pCO2 on a free‐swimming freshwater fish, 19 adult largemouth bass (Micropterus salmoides) were tagged with acoustic transmitters, held in water with pCO2 levels of either ˜10 000 μatm or ambient pCO2 (<100 μatm) for 5 days and released into a naturalised, earthen‐bottom pond outfitted with an acoustic telemetry array. Findings indicate that largemouth bass not exposed to elevated levels of pCO2 decreased movement over 35% during the daylight periods; however, fish exposed to elevated levels of pCO2 did not exhibit this pattern. This difference in diel movement patterns between fish exposed to elevated pCO2 and fish not exposed was not detectable after 11 days. Changes in home range size and daily distance travelled were not observed. However, based on an assessment of position estimates after the completion of the telemetry monitoring portion of the study, space use differed for fish exposed to elevated pCO2. Exposure to elevated pCO2 therefore can have consequences for some movement behaviours of freshwater fish and this may influence a variety of ecological processes including energetics, foraging and predator–prey dynamics. CO2‐induced alterations to behaviour should recover upon a return to ambient water.

Elevated carbon dioxide has limited acute effects on Lepomis macrochirus behaviour

“…Increased activity and potentially being bolder can result in fishes having greater risk of being consumed by predators and may shift their habitat‐use (Coleman & Wilson, ). While the current study is one of the first to examine CO 2 ‐induced behavioural changes for an obligate freshwater fish species (Hasler et al ., in press), previous work on marine, temperate and anadromous species have also suggested that exposure to fishes to elevated p CO 2 , even for short durations, can alter behaviour. For example, Munday et al .…”

“…Previous work has shown that behavioural changes induced by exposure to elevated p CO 2 can be reversed following removal of the CO 2 stimulus, but this potential for recovery has not been well studied. For example, predator avoidance behaviours were re‐established in larval P. wardi after returning to ambient sea water for 2 days (Munday et al ., ), and anxiety behaviours in juvenile splitnose rockfish Sebastes diploproa (Gilbert 1890) affected by CO 2 exposure returned to normal after 12 days in ambient conditions (Hamilton et al ., ), and movement patterns between CO 2 ‐exposed and non‐exposed adult largemouth bass Micropterus salmoides (Lacépède 1802) were no longer different after 11 days (Hasler et al ., in press) probably because previously disrupted cellular ion gradients re‐established. In L. macrochirus , it is possible that additional recovery time at ambient conditions ( i.e .…”

Intergenerational effects of CO2‐induced stream acidification in the Trinidadian guppy (Poecilia reticulata)

“…pH for the acidified treatment was maintained by an Aqua Medic ® CO 2 computer coupled with a solenoid valve and multi‐pH probe (Hasler, Midway, et al, ; Kates, Dennis, Noatch, & Suski, ; Midway et al, ). This was set to a threshold of 6.52, above which the solenoid valve would open and CO 2 gas would bubble through the treatment tank until a pH of 6.50 was achieved.…”

“…This was contrasted to the control treatment pH of 8.2 that laboratory stock populations had become adapted to over several generations since their initial collection in -2009(Nilsson, Lundbäck, Postavnicheva-Harri, & Persson, 2011. pH for the acidified treatment was maintained by an Aqua Medic ® CO 2 computer coupled with a solenoid valve and multi-pH probe (Hasler, Midway, et al, 2016;Kates, Dennis, Noatch, & Suski, 2012;Midway et al, 2017). This was set to a threshold of 6.52, above which the solenoid valve would open and CO 2 gas would bubble through the treatment tank until a pH of 6.50 was achieved.…”

Evaluation of lacustrine groundwater discharge, hydrologic partitioning, and nutrient budgets in a proglacial lake in the Qinghai–Tibet Plateau: using &lt;sup&gt;222&lt;/sup&gt;Rn and stable isotopes

“…Surface water samples were filtered with 0.45 µm filters (Advantec, Co.) in situ and taken into 5, 15, 15, and 50 ml Nalgene centrifugation tubes for stable isotope, major anion, cation, and nutrient analysis. Porewater samples were taken from the lakeshore aquifers with a push point sampler (M.H.E, Co.) connected to a peristaltic pump (Solinst, Co.) (Luo et al, 2014(Luo et al, , 2016; 100 ml raw surface water or porewater was titrated with a 0.1 µM H 2 SO 4 cartridge (Hach, Co.) in situ to measure total alkalinity (Hasler et al, 2016;White et al, 2016;Warner et al, 2013). Porewater was filtered with 0.45 µm syringe filters in situ and taken into 5, 15, 15, and 50 ml Nalgene centrifugation tubes for stable isotope, major anion, cation, and nutrient analysis; 250 ml porewater was taken for 222 Rn measurement with RAD7 H 2 O (Durridge, Co.).…”