Title

Temperature-Based Competitive Interactions Between Brook Trout and Creek Chubs; Implications of Climate Change

Start Date

26-10-2018 8:00 PM

End Date

26-10-2018 9:59 PM

Description

Water temperature can strongly influence competitive interspecific behaviors of many fish species because of species-level differences in thermal tolerance. Global warming may negatively impact competitive advantages among cold freshwater fish due to induced thermal stress that can influence feeding and social behavior, growth rates, and species phenology. Small coldwater streams in the Appalachian Mountains are facing stream temperature increases from global climate change and deforestation. The common cyprinid species, Creek Chub (Semotilus atromaculatus) is found in both warm and cold water streams and is sympatric and syntopic with Brook Trout (Salvelinus fontinalis) in Pennsylvania headwaters. Because of broader thermal tolerances among Creek Chub, increased stream temperatures may enlarge Creek Chub ranges while contracting that of Brook Trout. To date, the effects of temperature on these species competitive interactions is largely unknown. Previous research shows that Brook Trout should respond negatively to increases in stream temperature because they have a much lower thermal maximum and a much higher demand for increased oxygen concentrations than Creek Chubs, which have been found to be able to adjust rapidly to changing landscapes and stream conditions. We predict that when Brook Trout and Creek Chubs are kept together in high water temperatures, Creek Chubs will show aggressive behaviors and take preferential feeding habitat from thermally stressed Brook Trout. We measured feeding and aggressive behaviors among three combinations of conspecific and heterospecific dyads of Creek Chub and Brook Trout within laboratory raceways at three different temperatures (16°C, 18°C, and 20°C). We used a within-between subjects experimental design with three between-species treatments (Creek Chub pairs, Brook Trout pairs, chub/trout pair) and three within-temperature treatments among each dyad. Behaviors measured included feeding latency, feeding rate, aggressive bumps, and displacement during feeding. We also documented submissive and defensive behaviors including freezing, dropping, and avoidance among each pair.

Keywords

Appalachian Mountains, creek chub, brook trout, stream tempoerature, fish behavior

Type

Poster

Session

Poster session

Language

eng

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Oct 26th, 8:00 PM Oct 26th, 9:59 PM

Temperature-Based Competitive Interactions Between Brook Trout and Creek Chubs; Implications of Climate Change

Elaine Langone Center, Terrace Room

Water temperature can strongly influence competitive interspecific behaviors of many fish species because of species-level differences in thermal tolerance. Global warming may negatively impact competitive advantages among cold freshwater fish due to induced thermal stress that can influence feeding and social behavior, growth rates, and species phenology. Small coldwater streams in the Appalachian Mountains are facing stream temperature increases from global climate change and deforestation. The common cyprinid species, Creek Chub (Semotilus atromaculatus) is found in both warm and cold water streams and is sympatric and syntopic with Brook Trout (Salvelinus fontinalis) in Pennsylvania headwaters. Because of broader thermal tolerances among Creek Chub, increased stream temperatures may enlarge Creek Chub ranges while contracting that of Brook Trout. To date, the effects of temperature on these species competitive interactions is largely unknown. Previous research shows that Brook Trout should respond negatively to increases in stream temperature because they have a much lower thermal maximum and a much higher demand for increased oxygen concentrations than Creek Chubs, which have been found to be able to adjust rapidly to changing landscapes and stream conditions. We predict that when Brook Trout and Creek Chubs are kept together in high water temperatures, Creek Chubs will show aggressive behaviors and take preferential feeding habitat from thermally stressed Brook Trout. We measured feeding and aggressive behaviors among three combinations of conspecific and heterospecific dyads of Creek Chub and Brook Trout within laboratory raceways at three different temperatures (16°C, 18°C, and 20°C). We used a within-between subjects experimental design with three between-species treatments (Creek Chub pairs, Brook Trout pairs, chub/trout pair) and three within-temperature treatments among each dyad. Behaviors measured included feeding latency, feeding rate, aggressive bumps, and displacement during feeding. We also documented submissive and defensive behaviors including freezing, dropping, and avoidance among each pair.