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| Titel |
Thin terrestrial sediment deposits on intertidal sandflats: effects on pore-water solutes and juvenile bivalve burial behaviour |
| VerfasserIn |
A. Hohaia, K. Vopel, C. A. Pilditch |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1726-4170
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| Digitales Dokument |
URL |
| Erschienen |
In: Biogeosciences ; 11, no. 8 ; Nr. 11, no. 8 (2014-04-22), S.2225-2235 |
| Datensatznummer |
250117371
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| Publikation (Nr.) |
 copernicus.org/bg-11-2225-2014.pdf |
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| Zusammenfassung |
| Nearshore zones experience increased sedimentation due to
coastal development and enhanced loads of fine terrestrial sediment
(hereafter, TS) in river waters. Deposition of TS can alter seabed
biogeochemical processes but the effects on benthic ecosystem functioning
are unknown. The results of a past experiment with defaunated, intertidal
sediment suggest that a decrease in the oxygenation of this sediment by a
thin (mm) TS deposit causes substrate rejection (refusal to bury) by
post-settlement juvenile recruits of the tellinid bivalve Macomona liliana. We further
examined this behaviour, asking if such deposits negatively affect burial
when applied to intertidal sediment that is oxygenated by bioturbation (C)
or depleted of dead and living organic matter (D). We observed recruits on
the surface of four treatments: C, D, and the same sediments to which we
added a 1.7–1.9 mm layer of TS (CTS, DTS). The TS deposit decreased the
oxygenation and the pH of the underlying intertidal sediment (CTS)
confirming previous results, but significantly increased but not decreased
the probability of burial, irrespectively of treatment. Juveniles more
likely buried into C than into D. The mechanism that caused previously
observed substrate rejection by post-settlement juvenile M. liliana remains unclear
but our results suggest that contact of the recruits with the TS deposit
does not cause substrate rejection. We now hypothesise that conditioning of
sediment by bioturbation can mediate negative effects of TS deposits on the
recruits' burial behaviour. |
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