Dynamics of benthic copepods and other meiofauna in the benthic boundary layer of the deep NW Mediterranean Sea

Ld Guidi-Guilvard,D Thistle,A Khripounoff,S Gasparini

doi:10.3354/meps08408

Abstract

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 396:181-195 (2009) - DOI: https://doi.org/10.3354/meps08408 Dynamics of benthic copepods and other meiofauna in the benthic boundary layer of the deep NW Mediterranean Sea L. D. Guidi-Guilvard1,2,*, D. Thistle3, A. Khripounoff4, S. Gasparini1,2 1CNRS, and 2Université Pierre et Marie Curie, Laboratoire d’Océanographie de Villefranche, 06234 Villefranche/Mer, France 3Department of Oceanography, Florida State University, Tallahassee, Florida 32306-4320, USA 4IFREMER centre de Brest, Laboratoire Environnement Profond, 29280 Plouzané, France *Email: laurence.guidi@obs-vlfr.fr ABSTRACT: A continuous high-resolution time-series survey of the hyperbenthic community and local environmental conditions was conducted in the benthic boundary layer (BBL) of the DYFAMED-BENTHOS station (43°24.61’N, 7°51.67’E at 2347 m depth in the NW Mediterranean) between January 1996 and April 1998 using bottom-moored sediment traps and a current meter. Sediment traps were set 4 m above the bottom. Hyperbenthos was collected as ‘swimmers’, i.e. those organisms that are alive when they enter the traps but are not part of the particle flux. Identification of these organisms showed that ~90% were meiobenthic. Copepods dominated and comprised on average 75% of total swimmers. They were followed by nauplii (12%), annelids (7.8%), nematodes and bivalves (1.8% each), ostracods, isopods, and amphipods (1.2% altogether). Of the 3930 copepods examined, 4% were calanoids, 15% were harpacticoids and 81% were cyclopoids. Among the non-calanoid copepods, 25 species or groups of species were distinguished. Two benthic copepod species outnumbered all others: the cyclopinid genus Barathricola represented 90% of the cyclopoids, and the tisbid genus Tisbe represented 57% of the harpacticoids. Temporal variations, both intra- and interannual, in swimmer fluxes were high (26 to 361 ind. m–2 d–1), but not all groups/taxa/species were equally affected. Statistical analyses showed that these variations were the result of variability in both physical (near-bottom current) and trophic (particle flux) environmental factors. Organisms had both immediate and delayed responses, which involved passive (i.e. erosion, suspension) and active (i.e. emergence) reactions, as well as population growth. Most of the dispersal mechanisms previously reported for shallow-water benthic organisms were encountered, denoting the remarkable similarities in the general processes between coastal and deep-sea environments. KEY WORDS: Deep sea · Swimmers · Hyperbenthos · Benthic storms · Resuspension · Emergence · Population growth · Biodiversity Full text in pdf format PreviousNextCite this article as: Guidi-Guilvard LD, Thistle D, Khripounoff A, Gasparini S (2009) Dynamics of benthic copepods and other meiofauna in the benthic boundary layer of the deep NW Mediterranean Sea. Mar Ecol Prog Ser 396:181-195. https://doi.org/10.3354/meps08408Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 396. Online publication date: December 09, 2009 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2009 Inter-Research.

Highlights

In the past several decades, there has been a considerable increase in knowledge about the functioning of open oceans, from surface waters to the deep-sea floor
Time-series observations with sediment traps, which collect material as it settles through the water column, have demonstrated that seasonal and episodic variations in surface productivity result in highly variable amounts of organic matter arriving at the seafloor (e.g. Karl et al 2003), which is subject to variable hydrodynamic conditions (e.g. Lampitt et al 2001)
The present study was part of a long benthic time-series, the DYFAMED-BENTHOS survey (Guidi-Guilvard 2002), that was established in 1991 at the DYFAMED permanent station in the NW Mediterranean (Fig. 1) to investigate bentho–pelagic coupling. This 2300 m-deep station is relatively close to land (~52 km off Nice, France), but presents many of the characteristics of the open ocean with strong seasonal signals in surface productivity and essentially vertical particle fluxes. It was the site of the French Joint Global Ocean Flux Study (JGOFS) activities (Marty 2002, Karl et al 2003) and is an ongoing permanent observatory of atmospheric and water column biogeochemical fluxes and processes

Summary

Introduction

In the past several decades, there has been a considerable increase in knowledge about the functioning of open oceans, from surface waters to the deep-sea floor. Time-series observations with sediment traps, which collect material as it settles through the water column, have demonstrated that seasonal and episodic variations in surface productivity result in highly variable amounts of organic matter arriving at the seafloor (e.g. Karl et al 2003), which is subject to variable hydrodynamic conditions (e.g. Lampitt et al 2001). The rapid delivery of fresh organic material to the deep-sea floor has important implications for life cycles of the benthos. In the food-limited deep sea, the abundance and biomass of benthic organisms depend on the. There is still little evidence that metazoan meiofaunal abundances increase following sedimentation events (Kalogeropoulou et al 2009)

Methods

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Discussion

Conclusion