文档介绍：JOURNAL OF PLANKTON RESEARCH j VOLUME 30 j NUMBER 10 j PAGES 1189–1202 j 2008
Downward flux anic matter and
pigments in Lake Kinneret (Israel):
relationships between phytoplankton and
the material collected in sediment traps
Y. Z. YACOBI* AND I. OSTROVSKY
ISRAEL OCEANOGRAPHIC AND LIMNOLOGICAL RESEARCH LTD., YIGAL ALLON KINNERET LIMNOLOGICAL LABORATORY, PO BOX 447, MIGDAL 14950, ISRAEL
*CORRESPONDING AUTHOR: ******@.il
Received April 9, 2008; accepted in principle June 12, 2008; accepted for publication June 26, 2008; published online June 28, 2008
Corresponding editor: William Li
Sedimentation rates anic materials and algal pigments were measured by near-bottom traps
in Lake Kinneret (Israel) throughout 2006. position in the epilimnion and in the
traps pared by trap-to-water indices (TWIs) based on the proportion of a given pigment
to the concentration of b-carotene. The appearance of particular pigment in traps was associated
with its ability to pose and be transferred to the trap. The relative lability of pigments
increased in the following order: b-carotene. lutein+zeaxanthin. Chlorophyll b. Chlorophyll
a. echinenone. fucoxanthin. Chlorophyll c. peridinin. A seasonal variability, pertaining to
the thermal stratification in the lake was observed in the TWI; it showed highest values during
holomixis, and lowest after an establishment of anoxic conditions in the hypolimnion.
Bacteriochlorophyll e was one of the dominant pigments in traps from mid-July to mid-September,
when the green sulfur bacterium Chlorobium phaeobacteroides formed dense populations in the
metalimnion. Using chlorophyllous pigments as a proxy for biomass, we evaluated the possible
contribution of Ch. phaeobacteroides to the total sedimentation flux of all an-
isms on an annual basis. The proportion of freshly fixed carbon in the downward flux changed
seasonally, depending on position of the phytoplankton and thermal stratification, and was
on average 22% of primary productivity at