in the Susquehanna River revealed that ov~position of C'hrirrtierto~p~syc-he speciosn and Hydropsyche phalerata began 26-44 min (mean, 33 min) after sunset and lasted for 19-30 mln (mean. 24 min). Females oriented into the current on acrylic plates and ociposited in 30-60 s. Cheumntopsyc.hr (probably C'. .\prcsio.\c:) and H . phulernta egg masses contained a mean of 265 ( 134-504) and 367 ( 1 16-679) eggs, respectively; maws were largest and most densely packed with eggs in mid-June. Cheumatop.svc.he egg masses (84% of the 15 000 hydropsychid masses collected in 198 1) were found from 21 May to 30 September; up to 980 egg masses . m ' day ' occurred In mid-July. H~drc~p.s!c.he phcilercitn egg masses ( 15% of the total) were found from 22 May to 14 September; up to 170 . m ' day ' occurred in early June. Both species oviposited almost daily when river temperature exceeded 15°C. During a 30-day period when rlver temperature and depth were stable, there was a highly significant ( P < 0.01) positive correlation between the number of Cheumatop.syc.he egg masses and evening air temperature. Positive correlation between the number of egg masses and river current ( 10-47 cm/s) at eight sites was highly significant ( P < 0.01) for H . phalerntu but not for Cheumntopsvc-he ( P , 0.05) Hydropsychid egg masses were widely distributed over an acrylic hemisphere in a slow (15 cm/s) current but were concentrated on the top, downstream portion in a strong (58 cm/s) current. DEUTSCH, W. G. 1984. Oviposition of Hydropsychidae (Trichoptera) in a large river. Can. J. Zool. 62: 1988-1994. Des plongkes dans la riviere Susquehanna ont rkvele que, chez Chrumatop.s!~c*he sprc-iosc: et Hydrop.syc.he phuleruta, les activitks de ponte dkbutent 26-44 min (en moyenne 33 min) avant Ie cclucher du soleil et durent 19-30 min (en moyenne 24 min). Pour pondre sur des plaques d'acrylique, les femelles s'orientent avec le courant et completent la ponte en 30-60 s. Les masses d'oeufs de Cheumatopsyche (vraisemblablement C . spec-iosa) contiennent en moyenne 265 oeufs (134-504) et celles d'H. phulerutu. en moyenne 367 oeufs ( l 16-679) et c'est au niil~eu dc juiri que les masses contiennent les densitks absolues et relatives d'oeufs les plus Clevkes. Des masses d'oeufs de Chr:rm~itopsychc (84% des 15 000 masses rkcoltkes en 198 I ) ont kt6 rkcoltkes du 2 1 mai au 30 septembre; jusqu'a 980 masses. m -l o u r ' ont etd pondues a la mi-juillet. Les masses d'oeufs d'H. phcilerum ont ktk trouvkes du 22 mai au 14 septembre et un taux de ponte de 170 masses. m '. jour ' a Ctk observC au dkbut de juin. Les deux espkces semblent pondre presque tous les jours, des que la temperature de I'eau de la riviere dCpasse 15°C. Durant une pkriode de 30 jours pendant laquelle la tempkrature et le niveau de la riviere se sont maintenus constants, il a ktk possible d'ktablir une corrklation positive tres significative ( P < 0.01 entrc Ie nombre de pontes de Cheumatopsyc-he et la temperature de I'air en soirCe. De plus, il existe une correlation positive entrc la vitesse du...
ABSTRACT. Volunteer water monitoring programs are one of the most popular forms of citizen science, but many face governmental funding cuts and other threats to their continuation. Alabama Water Watch (AWW) is such a program that for more than 20 years has had positive influences on ecosystems and society through environmental education, waterbody protection and restoration, and promotion of improved water policy. A temporal analysis of 15 program indicators revealed 4 phases of AWW that followed general patterns of organizational development. These included periods of rapid growth, cresting, moderate decline, and stabilization at a lower level of activity. Five factors influenced these trends: saturation of potential groups, loss of monitors from aging, disillusionment and monitor fatigue, societal change, and loss of government funding. These factors were evaluated and responses to each are described. Keys to long-term viability of AWW include consistent attention to monitors, data credibility, a user-friendly online database, volunteer trainers, a nongovernmental association, and an institutional transition resulting in funding and staff continuity.
Twelve 0.1-ha rectangular ponds (mesocosms) were constructed during 1986 and 1987 to test ecosystem-level responses to a pyrethroid insecticide containing esfenvalerate. Treatment consisted of 10 weekly drift and 5 biweekly runoff simulations of formulated esfenvalerate between July 9 and September 17, 1988. Control ponds received only untreated runoff, while low, medium, and high treatments received total loadings of 0.23, 4.1, and 23.3 g active ingredient (a.i.)/ pond. The top vertebrate predator in the mesocosms was bluegill (Lepomis macrochirus). Once adult bluegill spawned and young fish were present, microcrustaceans declined in number. Following esfenvalerate applications, nauplii in medium-and high-rate ponds underwent further significant reductions, indicating a response to esfenvalerate not observed in control and low-rate ponds. Relative to other treatments, high-rate ponds were found to have significantly increased metabolism and reduced macroinvertebrates following application. Bluegill exhibited no significant differences in population structure among treatments, although 2-cm-size bluegill were missing from high-rate ponds at harvest. Patterns of response emerged in this whole ecosystem test of esfenvalerate. Variation measured among communities was high as is typical of natural ecosystems; however, we suggest that this experiment provided an acceptable way of detecting impacts at both the community and the ecosystem level.
Twelve 0.1‐ha rectangular ponds (mesocosms) were constructed during 1986 and 1987 to test ecosystem‐level responses to a pyrethroid insecticide containing esfenvalerate. Treatment consisted of 10 weekly drift and 5 biweekly runoff simulations of formulated esfenvalerate between July 9 and September 17, 1988. Control ponds received only untreated runoff, while low, medium, and high treatments received total loadings of 0.23, 4.1, and 23.3 g active ingredient (a.i.)/ pond. The top vertebrate predator in the mesocosms was bluegill (Lepomis macrochirus). Once adult blue‐gill spawned and young fish were present, microcrustaceans declined in number. Following esfenvalerate applications, nauplii in medium‐ and high‐rate ponds underwent further significant reductions, indicating a response to esfenvalerate not observed in control and low‐rate ponds. Relative to other treatments, high‐rate ponds were found to have significantly increased metabolism and reduced macroinvertebrates following application. Bluegill exhibited no significant differences in population structure among treatments, although 2‐cm‐size bluegill were missing from high‐rate ponds at harvest. Patterns of response emerged in this whole ecosystem test of esfenvalerate. Variation measured among communities was high as is typical of natural ecosystems; however, we suggest that this experiment provided an acceptable way of detecting impacts at both the community and the ecosystem level.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.