
TY  - JOUR
A1  - Rincón, Pedro A. 
A1  - Lobón-Cerviá, Javier 
T1  - Temporal patterns in macroinvertebrate drift in a northern Spanish stream
JF  - Marine and Freshwater Research
JO  - Mar. Freshwater Res.
Y1  - 1997
VL  - 48
IS  - 5
SP  - 455
EP  - 464
KW  - drift composition, diel cycles, seasonal variation, multivariate techniques
UR  - https://doi.org/10.1071/MF97037 
N2  - Drift in the River Negro (Asturias, Spain) was dominated by terrestrial invertebrates, chironomid larvae, simuliid larvae, water mites and the mayfly Baetis rhodani. Trichopterans and Leuctra spp. (plecopterans) occasionally exhibited increased abundances related to events in their life cycle (hatching, emergence). Total numbers of drifting macroinvertebrates increased after sunset, and on some dates a second, pre-dawn peak appeared. Baetis spp., plecopterans, adult aquatic Coleoptera and simuliid larvae drifted mostly at night. Terrestrial invertebrates and water mites were more abundant during the day, whereas trichopterans, chironomid larvae and naidid oligochaetes showed no consistent diel pattern. Drift composition changed seasonally and daily. Seasonal changes appeared to be determined mainly by seasonal shifts in the assemblage of benthic macroinvertebrates. The combined use of UPGMA cluster analysis and detrended correspondence analysis showed that seasonal variation was the major factor influencing overall drift composition, but that diel changes were only slightly less important. The degree of diel variation also changed seasonally. In January and March, day and night samples from a given date were quite similar. In contrast, in May and October, diel variation was greater and the dissimilarity between day and night samples was comparable to that between samples from different dates. Resumen. Los invertebrados terrestres, larvas de quiron&oacute;midos y sim&uacute;lidos, &aacute;caros acu&aacute;ticos y la ef&#233;mera Baetis rhodani dominaron la deriva en el R&#237;o Negro (Asturias, Espa&ntilde;a). Tric&oacute;pteros y plec&oacute;pteros (Leuctra spp.) aumentaron puntualmente su abundancia en relaci&oacute;n, aparentemente, con eventos en sus ciclos de vida (eclosi&oacute;n, emergencia). El total de macroinvertebrados en la deriva creci&oacute; tras el ocaso y, en ocasiones, antes del amancer. Baetis spp., los plec&oacute;pteros, cole&oacute;pteros acu&aacute;ticos adultos y sim&uacute;lidos derivaron principalmente durante la noche. Los invertebrados terrestres y &aacute;caros acu&aacute;ticos lo hicieron durante el d&#237;a, mientras que tric&oacute;pteros, quiron&oacute;midos y na&#237;didos no mostraron un patr&oacute;n consistente. La composici&oacute;n de la deriva cambi&oacute; estacional y diariamente. Los cambios estacionales parecieron relacionarse con la variaci&oacute;n de la comunidad de macroinvertebrados bent&oacute;nicos. El uso del an&aacute;lisis de agrupamiento UPGMA y del detrended correspondence analysis identific&oacute; la estacionalidad como el principal determinante de la composici&oacute;n de la deriva, pero los cambios diarios fueron s&oacute;lo ligeramente menos importantes. La magnitud de &#233;stos tambi&#233;n vari&oacute; estacionalmente. En enero y marzo las muestras de d&#237;a y noche de una misma fecha fueron muy parecidas. En cambio, en mayo y octubre la diferencia fue marcada y comparable a la existente entre muestras de fechas distintas. 
ER  -

