Density-dependent growth of bivalves dominating the intertidal zone of Banc d'Arguin, Mauritania: importance of feeding mode, habitat and season

Type Article
Date 2019-02
Language English
Author(s) Van Der Geest Matthijs1, 2, 3, Van Der Lely Jorge A. C.1, 2, Van Gils Jan A.1, 2, Piersma Theunis1, 2, 4, Lok Tamar1, 2
Affiliation(s) 1 : NIOZ Royal Netherlands Inst Sea Res, Dept Coastal Syst, POB 59, NL-1790 AB Den Burg, Texel, Netherlands.
2 : Univ Utrecht, POB 59, NL-1790 AB Den Burg, Texel, Netherlands.
3 : Univ Montpellier, MARBEC Ctr Marine Biodivers Exploitat & Conservat, UMR 9190, IRD IFREMER CNRS UM, F-34095 Montpellier 5, France.
4 : Univ Groningen, Conservat Ecol Grp, Groningen Inst Evolutionary Life Sci GELIFES, POB 11103, NL-9700 CC Groningen, Netherlands.
Source Marine Ecology Progress Series (0171-8630) (Inter-research), 2019-02 , Vol. 610 , P. 51-63
DOI 10.3354/meps12851
WOS© Times Cited 6
Keyword(s) Carrying capacity, Chemosymbiosis, Density dependence, Environmental heterogeneity, Feeding guild, Seagrass, Soft-sediment habitat
Abstract

Accurate predictions of population dynamics require an understanding of the ways by which environmental conditions and species-specific traits affect the magnitude of density dependence. Here, we evaluated the potential impact of season and habitat (characterized by sediment grain size and seagrass biomass) on the magnitude of density dependence in shell growth of 3 infaunal bivalve species dominating the tropical intertidal benthic communities of Banc d'Arguin, Mauritania. Two of our focal species were filter feeders (Senilia senilis and Pelecyora isocardia) and one was a facultative mixotroph (Loripes orbiculatus), mainly relying on organic carbon provided by sulphide-oxidizing endosymbiotic gill-bacteria (i.e. chemosymbiotic). Distinguishing 2 seasons, winter and summer, we manipulated local bivalve densities across habitats (from bare sandy sediments to seagrass-covered mud). In situ growth of individually tagged and relocated clams was measured and compared with those of tagged clams that were allocated to adjacent sites where local bivalve densities were doubled. Growth was negatively density-dependent in both winter and summer in P. isocardia and L. orbiculatus, the 2 species that mainly inhabit seagrass sediments, but not in S. senilis, usually found in bare sediments. As reproduction and survival rates are generally size-dependent in bivalves, our results suggest that in our tropical study system, the bivalve community of seagrass-covered sediments is more strongly regulated than that of adjacent bare sediments, regardless of species-specific feeding mode or season. We suggest that ecosystem engineering by seagrasses enhances environmental stability, which allows bivalve populations within tropical seagrass beds to stay close to carrying capacity.

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Supplementary material 2 395 KB Open access
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How to cite 

Van Der Geest Matthijs, Van Der Lely Jorge A. C., Van Gils Jan A., Piersma Theunis, Lok Tamar (2019). Density-dependent growth of bivalves dominating the intertidal zone of Banc d'Arguin, Mauritania: importance of feeding mode, habitat and season. Marine Ecology Progress Series, 610, 51-63. Publisher's official version : https://doi.org/10.3354/meps12851 , Open Access version : https://archimer.ifremer.fr/doc/00492/60319/