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The role of eopepod fecal pellets in the deposition of diatoms in Lake Tanganyika 1
Author(s) -
Haberyan Kurt A.
Publication year - 1985
Publication title -
limnology and oceanography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.7
H-Index - 197
eISSN - 1939-5590
pISSN - 0024-3590
DOI - 10.4319/lo.1985.30.5.1010
Subject(s) - diatom , pellets , fragilaria , sediment , sedimentation , grazing , deposition (geology) , environmental science , abundance (ecology) , algae , paleolimnology , biology , ecology , oceanography , geology , phytoplankton , paleontology , nutrient
Fecal pellets from a 16,000‐year sediment core from southern Lake Tanganyika account for over 40% of all diatom deposition and about 30% of total bulk sedimentation. Comparison of diatoms inside pellets with those in the surrounding sediment indicates that small, blunt species like Fragilaria brevistriata and Gomphonema clevei are preferentially ingested by grazing copepods. Long, fragile species like Nitzschia spiculum are strongly avoided. Filamentous Melosira spp. seem to be an important food of copepods. This grazing selectivity, coupled with the enhanced sinking rates and preservation of fecal pellets, could distort the fossil diatom record. Relative diatom abundances in pelletized, nonpelletized, and pooled stratigraphies indicate that pellets actually cause shifts of <4% of total diatom abundance in Lake Tanganyika. Even with selective grazing, F. brevistriata and G. clevei are rare in sediments (<2% of all diatoms).