2011
Kupferberg, Sarah J.; Lind, Amy J.; Thill, Vanessa; Yarnell, Sarah M.
Water velocity tolerance in tadpoles of the foothill yellow-legged frog (Rana boylii): swimming performance, growth, and survival Journal Article
In: Copeia, vol. 2011, no. 1, pp. 141-152, 2011, ISSN: 0045-8511.
Abstract | Links | BibTeX | Tags: Rana boylii, tadpoles, water velocity
@article{Kupferberg2011,
title = {Water velocity tolerance in tadpoles of the foothill yellow-legged frog (Rana boylii): swimming performance, growth, and survival},
author = {Sarah J. Kupferberg and Amy J. Lind and Vanessa Thill and Sarah M. Yarnell},
url = {https://angelo.berkeley.edu/wp-content/uploads/sites/59/Kupferberg_2011_Copeia.pdf},
doi = {10.1643/CH-10-035},
issn = {0045-8511},
year = {2011},
date = {2011-03-01},
journal = {Copeia},
volume = {2011},
number = {1},
pages = {141-152},
abstract = {We explored the effects of large magnitude flow fluctuations in rivers with dams, commonly referred to as pulsed flows, on tadpoles of the lotic-breeding Foothill Yellow-legged Frog, Rana boylii. We quantified the velocity conditions in habitats occupied by tadpoles and then conducted experiments to assess the tolerance to values at the upper limit of, and outside, the natural range. In laboratory flumes and field enclosures we mimicked the velocities observed during pulsed flows. In all experimental venues, the behavioral response of tadpoles was to seek refuge in the channel substrate when velocity increased. In a large laboratory flume, tadpoles moved freely at low water velocities (0–2 cm•s−1) and then sheltered among rocks when velocity increased. In a smaller scale laboratory flume, the median critical velocity was 20.1 cm•s−1. Critical velocity varied inversely with tadpole size, developmental stage, and proportion of time spent swimming. Velocities as low as 10 cm•s−1 caused tadpoles approaching metamorphosis to be displaced. In field mesocosm experiments, tadpoles exposed to repeated sub-critical velocity stress (5–10 cm•s−1) grew significantly less and experienced greater predation than tadpoles reared at ambient velocities. Responses to velocity manipulations were consistent among tadpoles from geographically distinct populations representing the three identified clades within R. boylii. The velocities associated with negative effects in these trials are less than typical velocity increases in near shore habitats when recreational flows for white water boating or peaking releases for hydroelectric power generation occur.},
keywords = {Rana boylii, tadpoles, water velocity},
pubstate = {published},
tppubtype = {article}
}
We explored the effects of large magnitude flow fluctuations in rivers with dams, commonly referred to as pulsed flows, on tadpoles of the lotic-breeding Foothill Yellow-legged Frog, Rana boylii. We quantified the velocity conditions in habitats occupied by tadpoles and then conducted experiments to assess the tolerance to values at the upper limit of, and outside, the natural range. In laboratory flumes and field enclosures we mimicked the velocities observed during pulsed flows. In all experimental venues, the behavioral response of tadpoles was to seek refuge in the channel substrate when velocity increased. In a large laboratory flume, tadpoles moved freely at low water velocities (0–2 cm•s−1) and then sheltered among rocks when velocity increased. In a smaller scale laboratory flume, the median critical velocity was 20.1 cm•s−1. Critical velocity varied inversely with tadpole size, developmental stage, and proportion of time spent swimming. Velocities as low as 10 cm•s−1 caused tadpoles approaching metamorphosis to be displaced. In field mesocosm experiments, tadpoles exposed to repeated sub-critical velocity stress (5–10 cm•s−1) grew significantly less and experienced greater predation than tadpoles reared at ambient velocities. Responses to velocity manipulations were consistent among tadpoles from geographically distinct populations representing the three identified clades within R. boylii. The velocities associated with negative effects in these trials are less than typical velocity increases in near shore habitats when recreational flows for white water boating or peaking releases for hydroelectric power generation occur.
1999
Finlay, Jacques C.; Power, Mary E.; Cabana, Gilbert
Effects of water velocity on algal carbon isotope ratios: Implications for river food web studies Journal Article
In: Limnology and Oceanography, vol. 44, pp. 1198-1203, 1999.
Abstract | Links | BibTeX | Tags: carbon isotopes, food webs, water velocity
@article{Finlay1999,
title = {Effects of water velocity on algal carbon isotope ratios: Implications for river food web studies},
author = {Jacques C. Finlay and Mary E. Power and Gilbert Cabana},
url = {https://angelo.berkeley.edu/wp-content/uploads/sites/59/Finlay_LimnolOceanogr1999.pdf},
doi = {10.4319/lo.1999.44.5.1198},
year = {1999},
date = {1999-07-13},
journal = {Limnology and Oceanography},
volume = {44},
pages = {1198-1203},
abstract = {We used variation in algal d13C between river habitats to study the spatial scale of energy flow through river food webs. We found a strong negative relationship between herbivore d13C (which reflects algal d13C) and water velocity in three productive Northern California rivers but not in unproductive streams. The contrast among habitats suggests that water velocity affects algal d13C most strongly when CO2 availability is low relative to photosynthetic rates. Our results help explain the wide variation in published river biota d13C and show that past studies using carbon isotope analyses may have significantly underestimated the importance of algal-derived carbon to river food webs. While flow related variation in d13C complicates this common application of carbon isotope analysis, we show that it provides a natural tracer of the flux of algal production derived from different habitats within rivers to higher trophic levels. Measurements of consumer d13C showed that most invertebrate and vertebrate consumers relied on local production, except for filter feeding insects and steelhead trout, which relied on production derived from multiple sources. Stable carbon isotopes may thus be used to spatially delineate the habitats that support river food webs, providing previously unavailable information for understanding and managing river ecosystems.},
keywords = {carbon isotopes, food webs, water velocity},
pubstate = {published},
tppubtype = {article}
}
We used variation in algal d13C between river habitats to study the spatial scale of energy flow through river food webs. We found a strong negative relationship between herbivore d13C (which reflects algal d13C) and water velocity in three productive Northern California rivers but not in unproductive streams. The contrast among habitats suggests that water velocity affects algal d13C most strongly when CO2 availability is low relative to photosynthetic rates. Our results help explain the wide variation in published river biota d13C and show that past studies using carbon isotope analyses may have significantly underestimated the importance of algal-derived carbon to river food webs. While flow related variation in d13C complicates this common application of carbon isotope analysis, we show that it provides a natural tracer of the flux of algal production derived from different habitats within rivers to higher trophic levels. Measurements of consumer d13C showed that most invertebrate and vertebrate consumers relied on local production, except for filter feeding insects and steelhead trout, which relied on production derived from multiple sources. Stable carbon isotopes may thus be used to spatially delineate the habitats that support river food webs, providing previously unavailable information for understanding and managing river ecosystems.
1995
Bergey, E. A.; Boettiger, C. A.; Resh, V. H.
Effects of water velocity on the architecture and epiphytes of Cladophora glomerata (Chlorophyta) Journal Article
In: Journal of Phycology, vol. 31, no. 2, pp. 264-271, 1995.
Abstract | Links | BibTeX | Tags: Cladophora glomerata, epiphytes, water velocity
@article{Bergey1995b,
title = {Effects of water velocity on the architecture and epiphytes of Cladophora glomerata (Chlorophyta)},
author = {E. A. Bergey and C. A. Boettiger and V. H. Resh},
url = {https://angelo.berkeley.edu/wp-content/uploads/sites/59/Bergey_1995_JourPhyc.pdf},
doi = {10.1111/j.0022-3646.1995.00264.x},
year = {1995},
date = {1995-04-00},
journal = {Journal of Phycology},
volume = {31},
number = {2},
pages = {264-271},
abstract = {The architecture of the filamentous green alga Cladophora glomerata (L.) Kütz. and the composition of this alga's epiphytes [primarily the diatoms Epithemia turgida (Ehrenb.) Kütz., Epithemia sorex Kütz., and Cocconeis pediculus Ehrenb.] were examined in different velocity regimes. After transferring algal-bearing cobbles among velocities, the effects of changes in velocity were also examined. Cladophora branching pattern did not initially differ among slow, medium, and fast velocities, indicating that stable water velocities did not affect branching pattern. Two weeks after cobble transfer, Cladophora in fast velocity had fragmented more (i.e. had fewer filaments and fewer branch points per length of filament and had a higher percentage of unbranched filaments) than Cladophora in slow velocity. Fragmentation was greatest in tufts moved from slow velocity, suggesting velocity-associated differences in susceptibility to breakage. Epiphytic assemblage composition differed among slow, medium, and fast velocities and between locations on the filament (base and apex). Cocconeis pediculus dominated where exposure to high velocity was greater (filament apices in medium and fast velocities), whereas the Epithemia spp. dominated where lower velocities occurred (filament bases in all velocities and apices in slow velocity). Two weeks after the cobble transfer, the translocated diatom assemblages had changed and the original pattern of diatom distribution was restored.},
keywords = {Cladophora glomerata, epiphytes, water velocity},
pubstate = {published},
tppubtype = {article}
}
The architecture of the filamentous green alga Cladophora glomerata (L.) Kütz. and the composition of this alga’s epiphytes [primarily the diatoms Epithemia turgida (Ehrenb.) Kütz., Epithemia sorex Kütz., and Cocconeis pediculus Ehrenb.] were examined in different velocity regimes. After transferring algal-bearing cobbles among velocities, the effects of changes in velocity were also examined. Cladophora branching pattern did not initially differ among slow, medium, and fast velocities, indicating that stable water velocities did not affect branching pattern. Two weeks after cobble transfer, Cladophora in fast velocity had fragmented more (i.e. had fewer filaments and fewer branch points per length of filament and had a higher percentage of unbranched filaments) than Cladophora in slow velocity. Fragmentation was greatest in tufts moved from slow velocity, suggesting velocity-associated differences in susceptibility to breakage. Epiphytic assemblage composition differed among slow, medium, and fast velocities and between locations on the filament (base and apex). Cocconeis pediculus dominated where exposure to high velocity was greater (filament apices in medium and fast velocities), whereas the Epithemia spp. dominated where lower velocities occurred (filament bases in all velocities and apices in slow velocity). Two weeks after the cobble transfer, the translocated diatom assemblages had changed and the original pattern of diatom distribution was restored.