DOCSLIB.ORG

Processing of 13C-Labelled Phytoplankton in a Fine-Grained Sandy-Shelf Sediment (North Sea): Relative Importance of Different Macrofauna Species

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Processing of 13C-Labelled Phytoplankton in a Fine-Grained Sandy-Shelf Sediment (North Sea): Relative Importance of Different Macrofauna Species MARINE ECOLOGY PROGRESS SERIES Vol. 297: 61–70, 2005 Published August 1 Mar Ecol Prog Ser Processing of 13C-labelled phytoplankton in a fine-grained sandy-shelf sediment (North Sea): relative importance of different macrofauna species Anja Kamp1, 2,*, Ursula Witte1, 3 1Max Planck Institute for Marine Microbiology, Celsiusstr. 1, 28359 Bremen, Germany 2Present address: Institute for Microbiology, University of Hannover, Schneiderberg 50, 30167 Hannover, Germany 3Present address: Oceanlab, University of Aberdeen, Newburgh, Aberdeen AB41 6AA, UK ABSTRACT: On-board and in situ experiments with 13C-labelled diatoms were carried out to inves- tigate the processing of algal carbon by the macrofauna community of a fine sandy-shelf site in the southern German Bight (North Sea). The time series (12, 30, 32 and 132 h incubations) was supple- mented by additional laboratory experiments on the role of the dominant macrofauna organism, the bivalve Fabulina fabula (Bivalvia: Tellinidae), for particulate organic matter subduction to deeper sediment layers. The specific uptake of algal 13C by macrofauna organisms was visible after 12 h and constantly increased during the incubation periods. F. fabula, a facultative (surface) deposit- and suspension-feeder, Lanice conchilega (Polychaeta: Terebellidae), a suspension-feeder and the (sur- face) deposit-feeder Echinocardium cordatum (Echinodermata: Spatangidae) were responsible for the majority of macrofaunal carbon processing. Predatory macrofauna organisms like Nephtys spp. (Polychaeta: Nephtyidae) also quickly became labelled. The rapid subduction of fresh organic matter by F. fabula down to ca. 4 to 7 cm sediment depth could be demonstrated, and it is suggested that entrainment by macrofauna in this fine-grained sand is much more efficient than advective transport. KEY WORDS: Carbon processing · Macrofauna · Sandy sediments · 13C labelling · Stable isotopes · North Sea · German Bight Resale or republication not permitted without written consent of the publisher INTRODUCTION eable sediments (Huettel & Rusch 2000), and to enhance the remineralisation and nutrient release in Shelf areas such as the North Sea cover approxi- comparison to non-permeable sediments (Ehrenhauss mately 7.5% of the total ocean area (Wollast 2003) and et al. 2004b). 70% of the shelf is covered by sandy deposits (Emery In addition, the activities of macrofauna can signifi- 1968). This comparably small area has a very high bio- cantly affect the transport of solutes and particulates logical productivity, which amounts to 30% of the total across the sediment–water interface (Graf & Rosen- oceanic primary production (Jørgensen 1996). Despite berg 1997). For example, bioirrigation by tube-build- this, sandy-shelf sediments contain a low amount of ing worms is responsible for rapid water pumping; organic matter (Shum & Sundby 1996) and low bacter- bioturbation is well known to enhance the particle ial standing stocks (Llobet-Brossa et al. 1998). The low transport within the sediment (Forster & Graf 1995, organic carbon content may be a result of high turn- Ziebis et al. 1996). The macrofauna community of the over rates, rather than low activity; the high perme- North Sea shelf consists mainly of bivalves, poly- ability of most sands is thought to allow advective per- chaetes, crustaceans and echinoderms (Salzwedel et colation of the upper sediment layers. Advection, al. 1985). The infaunal suspension and (surface) deposit- however, has been shown to result in an effective feeders in particular, such as the bivalve Fabulina fab- exchange of pore water (Huettel et al. 2003), to rapidly ula and the polychaete Lanice conchilega, both com- transport particulate organic matter (POM) into perm- mon at our study site, may have immediate access to a *Email: [email protected] © Inter-Research 2005 · www.int-res.com 62 Mar Ecol Prog Ser 297: 61–70, 2005 fresh organic carbon source and may be responsible the composition, abundance and biomass of the macro- for fast transport of this POM into deeper sediment fauna community as well as the processing of added, layers by bioirrigation, bioturbation or defecation. This labelled diatom carbon by the different macrofauna matter is thus available for other benthic organisms, taxa. We report on the potential of Fabulina fabula, the living in deeper sediment layers. Carnivorous macro- dominant macrofauna organism, for POM subduction, fauna organisms are expected to have a delayed and discuss the relative importance of bioturbation and access to a fresh carbon source but can nevertheless advective transport. contribute to sediment mixing by bioturbation due to hunting activities. In recent years, pulse-chase experiments with iso- MATERIALS AND METHODS topically labelled substrates have been established as a useful tool for following and quantifying the process- Area of investigation. The study site was situated in ing and remineralisation of fresh organic carbon in a the southern German Bight (North Sea), seaward variety of marine sedimentary habitats (e.g. Levin et al. of the East Frisian island Spiekeroog (53° 51’ N, 1997, Middelburg 2000, Aberle & Witte 2003, Witte et 007° 44’ E) (Fig. 1). The water depth in this area was al. 2003a). However, information on the benthic pro- 19 m with a tidal range about 2 m. Salinity was 31 to 32 cessing of fresh POM in sandy-shelf environments is and the mean water temperature was 9°C in April and still scarce. We therefore carried out a series of on- 13°C in June. The sediment type is fine sand with a board and in situ pulse-chase experiments in North grain size of 163 ± 20 µm and a permeability of 3.0 ± Sea sandy sediments and followed the entrainment, 1.7 × 10–12 m2 (Janssen et al. 2005). processing and degradation of algal carbon by the The experiments and sampling took place during benthic community. Within the project, not only the Expeditions HE 145 in April 2001 (on-board and labo- macrofauna but also bacterial carbon processing was ratory experiments) and HE 148 in June 2001 (in situ studied (Bühring et al. 2004) as well as the entrainment experiments) of the RV ‘Heincke’. and degradation of diatoms into the sediment (Ehren- Cultivation of labelled phytoplankton. Ditylum bright- hauss et al. 2004a,b). wellii (Bacillariophyceae: Biddulphiales) was cultured This contribution focuses on the importance of with F/2 medium (Guillard & Ryther 1962) in sterile macrofauna for carbon transport processes in a fine- artificial seawater (Grasshoff et al. 1999) with a salinity grained, sandy North Sea sediment. We investigated of 33. The diatoms were labelled with 13C by replacing 13 25% of the NaHCO3 in the formula by NaH CO3 (99%; Cambridge Isotope Laboratories). The algae were incubated for 10 d at 25°C under a light:dark cycle of 16:8 h and a light intensity of 34.9 µmol pho- tons m–2 s–1. The algal carbon produced consisted of 15 at.% 13C (on-board experiments) and 9 at.% 13C (in situ experiments). For the laboratory experiments we used Chlorella sp. (Chlorophyceae: Chlorococcales). The algal carbon of Chlorella sp. consisted of >60 at.% 13C. Sampling and determination of macrofauna for nat- ural abundance and biomass. For the determination of the natural abundance and biomass of macrofauna, sediment samples were collected with a van Veen grab (surface area 0.1 m2). Each haul (9 during the cruise in April and 10 in June) was separately sieved (1.0 mm- mesh aperture), and the sieve contents were preserved in 4% formaldehyde buffered with sodium tetraborate until taxonomic identification under a stereomicro- scope. The wet weight (g WW m–2) for each taxonomic group was determined in the laboratory in Bremen. Sampling of macrofauna for natural isotope signa- tures. The macrofauna samples for the measurements of the natural isotope signatures (δ13C) were also taken Fig. 1. Area of investigation in the southern German Bight with a van Veen grab, but after sorting the individuals (North Sea) were immediately frozen at –20°C, as fixation with Kamp & Witte: Macrofaunal carbon processing 63 of 60°C. Before determination of the δ13C signatures, the dry weights (DW) of each individual was deter- mined (g DW ind.–1). Often the organisms had to be homogenised, and a subsample (approximately 0.5 to 1.5 mg) was transferred into tin cups for measurement. Organisms were pooled when their individual dry weight was <0.5 mg. Laboratory experiments. The experimental chambers used for the laboratory experiments were similar to those used for the in situ and on-board experiments. Sediment and Fabulina fabula organisms were sampled with a van Veen grab. The sediment was sieved to remove macro- fauna organisms and stored at 4°C. F. fabula were kept in an aquarium at in situ temperature (9°C). Prior to the experiments, the chambers were filled with the sediment (18 cm). The surface water from the area of investigation was sampled with a water sam- pler. Fabulina fabula were put into the sediment cores in abundances of 0 and 14 individuals per core (2 repli- Fig. 2. Experimental chambers within their frame cates each) and allowed to settle in the sediment for 1 wk. The experiments were initiated by injecting the formaldehyde would change the natural isotope signa- chambers with labelled Chlorella sp. (equivalent to tures (Kaehler & Pakhomov 2001). Measurements of 1gC m–2), and ran for 132 h. After incubation, the sed- δ13C were made with an isotope ratio mass spectro- iment of the chambers was sliced at 0.5 cm intervals for meter (IRMS) (see subsection ‘Measurements’). the first 1 cm and at 1 cm intervals to a depth of 10 cm, On-board and in situ experiments. The experiments followed by a 10 to 12.5 cm and then a 12.5 to 18 cm were conducted in cylindrical acrylic chambers (31 cm layer. F. fabula were picked out, and a carefully homo- high, 19 cm diameter) with a horizontally rotating disk.
Load more

Recommended publications
  • National Monitoring Program for Biodiversity and Non-Indigenous Species in Egypt
    UNITED NATIONS ENVIRONMENT PROGRAM MEDITERRANEAN ACTION PLAN REGIONAL ACTIVITY CENTRE FOR SPECIALLY PROTECTED AREAS National monitoring program for biodiversity and non-indigenous species in Egypt PROF. MOUSTAFA M. FOUDA April 2017 1 Study required and financed by: Regional Activity Centre for Specially Protected Areas Boulevard du Leader Yasser Arafat BP 337 1080 Tunis Cedex – Tunisie Responsible of the study: Mehdi Aissi, EcApMEDII Programme officer In charge of the study: Prof. Moustafa M. Fouda Mr. Mohamed Said Abdelwarith Mr. Mahmoud Fawzy Kamel Ministry of Environment, Egyptian Environmental Affairs Agency (EEAA) With the participation of: Name, qualification and original institution of all the participants in the study (field mission or participation of national institutions) 2 TABLE OF CONTENTS page Acknowledgements 4 Preamble 5 Chapter 1: Introduction 9 Chapter 2: Institutional and regulatory aspects 40 Chapter 3: Scientific Aspects 49 Chapter 4: Development of monitoring program 59 Chapter 5: Existing Monitoring Program in Egypt 91 1. Monitoring program for habitat mapping 103 2. Marine MAMMALS monitoring program 109 3. Marine Turtles Monitoring Program 115 4. Monitoring Program for Seabirds 118 5. Non-Indigenous Species Monitoring Program 123 Chapter 6: Implementation / Operational Plan 131 Selected References 133 Annexes 143 3 AKNOWLEGEMENTS We would like to thank RAC/ SPA and EU for providing financial and technical assistances to prepare this monitoring programme. The preparation of this programme was the result of several contacts and interviews with many stakeholders from Government, research institutions, NGOs and fishermen. The author would like to express thanks to all for their support. In addition; we would like to acknowledge all participants who attended the workshop and represented the following institutions: 1.
    [Show full text]
  • Appendix to Taxonomic Revision of Leopold and Rudolf Blaschkas' Glass Models of Invertebrates 1888 Catalogue, with Correction
    http://www.natsca.org Journal of Natural Science Collections Title: Appendix to Taxonomic revision of Leopold and Rudolf Blaschkas’ Glass Models of Invertebrates 1888 Catalogue, with correction of authorities Author(s): Callaghan, E., Egger, B., Doyle, H., & E. G. Reynaud Source: Callaghan, E., Egger, B., Doyle, H., & E. G. Reynaud. (2020). Appendix to Taxonomic revision of Leopold and Rudolf Blaschkas’ Glass Models of Invertebrates 1888 Catalogue, with correction of authorities. Journal of Natural Science Collections, Volume 7, . URL: http://www.natsca.org/article/2587 NatSCA supports open access publication as part of its mission is to promote and support natural science collections. NatSCA uses the Creative Commons Attribution License (CCAL) http://creativecommons.org/licenses/by/2.5/ for all works we publish. Under CCAL authors retain ownership of the copyright for their article, but authors allow anyone to download, reuse, reprint, modify, distribute, and/or copy articles in NatSCA publications, so long as the original authors and source are cited. TABLE 3 – Callaghan et al. WARD AUTHORITY TAXONOMY ORIGINAL SPECIES NAME REVISED SPECIES NAME REVISED AUTHORITY N° (Ward Catalogue 1888) Coelenterata Anthozoa Alcyonaria 1 Alcyonium digitatum Linnaeus, 1758 2 Alcyonium palmatum Pallas, 1766 3 Alcyonium stellatum Milne-Edwards [?] Sarcophyton stellatum Kükenthal, 1910 4 Anthelia glauca Savigny Lamarck, 1816 5 Corallium rubrum Lamarck Linnaeus, 1758 6 Gorgonia verrucosa Pallas, 1766 [?] Eunicella verrucosa 7 Kophobelemon (Umbellularia) stelliferum
    [Show full text]
  • High Level Environmental Screening Study for Offshore Wind Farm Developments – Marine Habitats and Species Project
    High Level Environmental Screening Study for Offshore Wind Farm Developments – Marine Habitats and Species Project AEA Technology, Environment Contract: W/35/00632/00/00 For: The Department of Trade and Industry New & Renewable Energy Programme Report issued 30 August 2002 (Version with minor corrections 16 September 2002) Keith Hiscock, Harvey Tyler-Walters and Hugh Jones Reference: Hiscock, K., Tyler-Walters, H. & Jones, H. 2002. High Level Environmental Screening Study for Offshore Wind Farm Developments – Marine Habitats and Species Project. Report from the Marine Biological Association to The Department of Trade and Industry New & Renewable Energy Programme. (AEA Technology, Environment Contract: W/35/00632/00/00.) Correspondence: Dr. K. Hiscock, The Laboratory, Citadel Hill, Plymouth, PL1 2PB. [email protected] High level environmental screening study for offshore wind farm developments – marine habitats and species ii High level environmental screening study for offshore wind farm developments – marine habitats and species Title: High Level Environmental Screening Study for Offshore Wind Farm Developments – Marine Habitats and Species Project. Contract Report: W/35/00632/00/00. Client: Department of Trade and Industry (New & Renewable Energy Programme) Contract management: AEA Technology, Environment. Date of contract issue: 22/07/2002 Level of report issue: Final Confidentiality: Distribution at discretion of DTI before Consultation report published then no restriction. Distribution: Two copies and electronic file to DTI (Mr S. Payne, Offshore Renewables Planning). One copy to MBA library. Prepared by: Dr. K. Hiscock, Dr. H. Tyler-Walters & Hugh Jones Authorization: Project Director: Dr. Keith Hiscock Date: Signature: MBA Director: Prof. S. Hawkins Date: Signature: This report can be referred to as follows: Hiscock, K., Tyler-Walters, H.
    [Show full text]
  • Ring Test Bulletin – RTB#52
    www.nmbaqcs.org Ring Test Bulletin – RTB#52 Tim Worsfold David Hall Søren Pears (Images) APEM Ltd. March 2017 E-mail: [email protected] RING TEST DETAILS Ring Test #52 Type/Contents – Targeted - Bivalvia Circulated – 12/11/16 Results deadline – 16/12/16 Number of Subscribing Laboratories – 24 Number of Participating Laboratories – 21 Number of Results Received – 21* *multiple data entries per laboratory permitted Summary of differences Total differences for 21 Specimen Genus Species Size returns Genus Species RT5201 Thyasira flexuosa 2-3mm 0 1 RT5202 Abra alba 10mm 0 1 RT5203 Cochlodesma praetenue 3-5mm 5 5 RT5204 Thyasira equalis 2-4mm 3 9 RT5205 Abra nitida 4-6mm 0 1 RT5206 Fabulina fabula 3-5mm 1 1 RT5207 Cerastoderma edule 1mm 6 13 RT5208 Tellimya ferruginosa 3-4mm 0 0 RT5209 Nucula nucleus 8-9mm 0 3 RT5210 Nucula nitidosa 2-3mm 1 3 RT5211 Asbjornsenia pygmaea 2-3mm 1 1 RT5212 Abra prismatica 3-5mm 1 1 RT5213 Chamelea striatula 3-4mm 7 9 RT5214 Montacuta substriata 1-2mm 5 5 RT5215 Spisula subtruncata 1mm 4 6 RT5216 Adontorhina similis 1-2mm 4 4 RT5217 Goodallia triangularis 1-2mm 0 0 RT5218 Scrobicularia plana 1mm 20 20 RT5219 Cerastoderma edule 2-3mm 9 13 RT5220 Arctica islandica 1mm 4 4 RT5221 Kurtiella bidentata 2-3mm 2 2 RT5222 Venerupis corrugata 2-3mm 9 9 RT5223 Barnea parva 10-20mm 0 0 RT5224 Abra alba 4-5mm 1 2 RT5225 Nucula nucleus 2mm 0 11 Total differences 83 124 Average 4.0 5.9 differences /lab. NMBAQC RT#52 bulletin Differences 10 15 20 25 0 5 Arranged in order of increasing number of differences (by specific followed by generic errors).
    [Show full text]
  • Attachments Table of Contents
    ATTACHMENTS TABLE OF CONTENTS FORESHORE LICENCE APPLICATION Fenit Harbour, Tralee, Co. Kerry ATTACHMENT CONTENTS Attachment A Figure 1 proximity to sensitive shellfish areas Attachment B B.1 Sediment Chemistry Results Attachment B.1(I) Dumping at Sea Material Analysis Reporting Form Attachment B.1(II) Copies of the laboratory reports Attachment B.1(III) Comparison to Irish Action Level B.2 Characteristics /Composition of the Substance or Material for Disposal Attachment B.2 Sediment Characterisation Report (AQUAFACT, 2018) Attachment C Assessment of Alternatives Attachment D D.1 Purpose Of The Operation D.2 Loading Areas D.3 Details Of The Loading Operations Attachment E E.1 DUMPING SITE SELECTION E.2 GENERAL INFORMATION E.3 DETAILS OF THE DUMPING OPERATION Attachment E.1(I) Attachment E.2(I) Marine Benthic Study Fenit Harbour Dredging and Disposal Operations (Aquafact 2018) Attachment F F.1 Assessment of Impact on the Environment Appendix 1 Assessment of Risk to Marine Mammals from Proposed Dredging and Dumping at Sea Activity, Fenit Harbour, Co. Kerry. Appendix 2 Underwater Archaeological Impact Assessment Report Fenit Harbour and Tralee Bay, Co. Kerry. Appendix 3: Nature Impact Statement Attachment G G.1 Monitoring Programme Attachment-A FIGURE 1 SHELLFISH WATERS FORESHORE LICENCE APPLICATION Fenit Harbour, Tralee, Co. Kerry Legend Foreshore Licence Area Shellfish Area 5091m Proposed Dump Site 4 89m Fenit Harbour Map Reproduced From Ordnance Survey Ireland By Permission Of The Government. Licence Number EN 0015719. 0 1.5 3 km Ü Project Title: Fenit Harbour Client: Kerry County Council Drawing Title: Foreshore Licence and Shellfish Areas Drawn: JK Checked: CF Date: 15-10-2019 Scale (A4): 1:85,000 Attachment-B MATERIAL ANALYSIS DUMPING AT SEA PERMIT APPLICATION Fenit Harbour, Tralee, Co.
    [Show full text]
  • Impact of Windfarm OWEZ on the Local Macrobenthos Communiy
    Impact of windfarm OWEZ on the local macrobenthos community report OWEZ_R_261_T1_20090305 R. Daan, M. Mulder, M.J.N. Bergman Koninklijk Nederlands Instituut voor Zeeonderzoek (NIOZ) This project is carried out on behalf of NoordzeeWind, through a sub contract with Wageningen-Imares Contents Summary and conclusions 3 Introduction 5 Methods 6 Results boxcore 11 Results Triple-D dredge 13 Discussion 16 References 19 Tables 21 Figures 33 Appendix 1 44 Appendix 2 69 Appendix 3 72 Photo’s by Hendricus Kooi 2 Summary and conclusions In this report the results are presented of a study on possible short‐term effects of the construction of Offshore Windfarm Egmond aan Zee (OWEZ) on the composition of the local benthic fauna living in or on top of the sediment. The study is based on a benthic survey carried out in spring 2007, a few months after completion of the wind farm. During this survey the benthic fauna was sampled within the wind farm itself and in 6 reference areas lying north and south of it. Sampling took place mainly with a boxcorer, but there was also a limited programme with a Triple‐D dredge. The occurrence of possible effects was analyzed by comparing characteristics of the macrobenthos within the wind farm with those in the reference areas. A quantitative comparison of these characteristics with those observed during a baseline survey carried out 4 years before was hampered by a difference in sampling design and methodological differences. The conclusions of this study can be summarized as follows: 1. Based on the Bray‐Curtis index for percentage similarity there appeared to be great to very great similarity in the fauna composition of OWEZ and the majority of the reference areas.
    [Show full text]
  • Supplementary Tales
    Metabarcoding reveals different zooplankton communities in northern and southern areas of the North Sea Jan Niklas Macher, Berry B. van der Hoorn, Katja T. C. A. Peijnenburg, Lodewijk van Walraven, Willem Renema Supplementary tables 1-5 Table S1: Sampling stations and recorded abiotic variables recorded during the NICO 10 expedition from the Dutch Coast to the Shetland Islands Sampling site name Coordinates (°N, °E) Mean remperature (°C) Mean salinity (PSU) Depth (m) S74 59.416510, 0.499900 8.2 35.1 134 S37 58.1855556, 0.5016667 8.7 35.1 89 S93 57.36046, 0.57784 7.8 34.8 84 S22 56.5866667, 0.6905556 8.3 34.9 220 S109 56.06489, 1.59652 8.7 35 79 S130 55.62157, 2.38651 7.8 34.8 73 S156 54.88581, 3.69192 8.3 34.6 41 S176 54.41489, 4.04154 9.6 34.6 43 S203 53.76851, 4.76715 11.8 34.5 34 Table S2: Species list and read number per sampling site Class Order Family Genus Species S22 S37 S74 S93 S109 S130 S156 S176 S203 Copepoda Calanoida Acartiidae Acartia Acartia clausi 0 0 0 72 0 170 15 630 3995 Copepoda Calanoida Acartiidae Acartia Acartia tonsa 0 0 0 0 0 0 0 0 23 Hydrozoa Trachymedusae Rhopalonematidae Aglantha Aglantha digitale 0 0 0 0 1870 117 420 629 0 Actinopterygii Trachiniformes Ammodytidae Ammodytes Ammodytes marinus 0 0 0 0 0 263 0 35 0 Copepoda Harpacticoida Miraciidae Amphiascopsis Amphiascopsis cinctus 344 0 0 992 2477 2500 9574 8947 0 Ophiuroidea Amphilepidida Amphiuridae Amphiura Amphiura filiformis 0 0 0 0 219 0 0 1470 63233 Copepoda Calanoida Pontellidae Anomalocera Anomalocera patersoni 0 0 586 0 0 0 0 0 0 Bivalvia Venerida
    [Show full text]
  • Seasonal Variation in the Occurrence of Planktic Bivalve Larvae in the Schleswig-Holstein Wadden Sea
    HELGOLdkNDER MEERESUNTERSUCHUNGEN Helgolander Meeresunters. 51, 23-39 {1997} Seasonal variation in the occurrence of planktic bivalve larvae in the Schleswig-Holstein Wadden Sea Andrea Pulfrich* Institut ffir Meereskunde; Dfisternbrooker Weg 20, 24105 Kiel, Germany ABSTRACT: In the late 1980s, recruitment failures of the mussel Mytilus edulis led to economic pro- blems in the mussel fishing and cultivation industries of northwestern Europe. As part of a collabo- rative study to gain a better understanding of the mechanisms affecting recruitment processes of mussels, plankton samples were collected regularly over a four-year period (t990-I993) from three stations in the Schleswig-Holstein Wadden Sea. The bivalve component of the plankton was domi- nated by the Solenidae, which was almost exclusively represented by Ensis americanus [= directus). NI. eduhs was the second most abundant species. Abundances of mussel larvae peaked 2 to 4 weeks after spawning maxima in the adult populations. Although variations in timing and amplitude of the tota~ [arvaL densities occurred, annua[ abuadances o[M. edulis larvae remained stable during the study period, and regional abundance differences were insignificant. A close relaUonsh~p was found between peaks in larval abundance and phytoplankton blooms. Differences in larval concentrations in the ebb and the flow currents were insignificant. Planktic mussel larvae measured between 200 }am and 300 ~tm, and successive cohorts were recognizable in the majority of samples. Most lar- vae were found to originate from local stocks, although imports from outside the area do occur. INTRODUCTION Successive years of failing spatfall and recruitment of the edible mussel Mytilus edu- lis L. (Bivalvia) on the northwestern European coast during the late 1980s caused sub- stantial production Losses in the mussel fishing and cultivation industries.
    [Show full text]
  • The Impact of Hydraulic Blade Dredging on a Benthic Megafaunal Community in the Clyde Sea Area, Scotland
    Journal of Sea Research 50 (2003) 45–56 www.elsevier.com/locate/seares The impact of hydraulic blade dredging on a benthic megafaunal community in the Clyde Sea area, Scotland C. Hauton*, R.J.A. Atkinson, P.G. Moore University Marine Biological Station Millport (UMBSM), Isle of Cumbrae, Scotland, KA28 0EG, UK Received 4 December 2002; accepted 13 February 2003 Abstract A study was made of the impacts on a benthic megafaunal community of a hydraulic blade dredge fishing for razor clams Ensis spp. within the Clyde Sea area. Damage caused to the target species and the discard collected by the dredge as well as the fauna dislodged by the dredge but left exposed at the surface of the seabed was quantified. The dredge contents and the dislodged fauna were dominated by the burrowing heart urchin Echinocardium cordatum, approximately 60–70% of which survived the fishing process intact. The next most dominant species, the target razor clam species Ensis siliqua and E. arcuatus as well as the common otter shell Lutraria lutraria, did not survive the fishing process as well as E. cordatum, with between 20 and 100% of individuals suffering severe damage in any one dredge haul. Additional experiments were conducted to quantify the reburial capacity of dredged fauna that was returned to the seabed as discard. Approximately 85% of razor clams retained the ability to rapidly rebury into both undredged and dredged sand, as did the majority of those heart urchins Echinocardium cordatum which did not suffer aerial exposure. Individual E. cordatum which were brought to surface in the dredge collecting cage were unable to successfully rebury within three hours of being returned to the seabed.
    [Show full text]
  • (Spatangoida) Abatus Agassizii
    fmicb-11-00308 February 27, 2020 Time: 15:33 # 1 ORIGINAL RESEARCH published: 28 February 2020 doi: 10.3389/fmicb.2020.00308 Characterization of the Gut Microbiota of the Antarctic Heart Urchin (Spatangoida) Abatus agassizii Guillaume Schwob1,2*, Léa Cabrol1,3, Elie Poulin1 and Julieta Orlando2* 1 Laboratorio de Ecología Molecular, Instituto de Ecología y Biodiversidad, Facultad de Ciencias, Universidad de Chile, Santiago, Chile, 2 Laboratorio de Ecología Microbiana, Departamento de Ciencias Ecológicas, Facultad de Ciencias, Universidad de Chile, Santiago, Chile, 3 Aix Marseille University, Univ Toulon, CNRS, IRD, Mediterranean Institute of Oceanography (MIO) UM 110, Marseille, France Abatus agassizii is an irregular sea urchin species that inhabits shallow waters of South Georgia and South Shetlands Islands. As a deposit-feeder, A. agassizii nutrition relies on the ingestion of the surrounding sediment in which it lives barely burrowed. Despite the low complexity of its feeding habit, it harbors a long and twice-looped digestive tract suggesting that it may host a complex bacterial community. Here, we characterized the gut microbiota of specimens from two A. agassizii populations at the south of the King George Island in the West Antarctic Peninsula. Using a metabarcoding approach targeting the 16S rRNA gene, we characterized the Abatus microbiota composition Edited by: David William Waite, and putative functional capacity, evaluating its differentiation among the gut content Ministry for Primary Industries, and the gut tissue in comparison with the external sediment. Additionally, we aimed New Zealand to define a core gut microbiota between A. agassizii populations to identify potential Reviewed by: Cecilia Brothers, keystone bacterial taxa.
    [Show full text]
  • Role of Reef-Building, Ecosystem Engineering Polychaetes in Shallow Water Ecosystems
    diversity Review Role of Reef-Building, Ecosystem Engineering Polychaetes in Shallow Water Ecosystems Martín Bruschetti 1,2 1 Instituto de Investigaciones Marinas y Costeras (IIMyC)-CONICET, Mar del Plata 7600, Argentina; [email protected] 2 Laboratorio de Ecología, Universidad Nacional de Mar del Plata, FCEyN, Laboratorio de Ecología 7600, Argentina Received: 15 June 2019; Accepted: 15 September 2019; Published: 17 September 2019 Abstract: Although the effect of ecosystem engineers in structuring communities is common in several systems, it is seldom as evident as in shallow marine soft-bottoms. These systems lack abiotic three-dimensional structures but host biogenic structures that play critical roles in controlling abiotic conditions and resources. Here I review how reef-building polychaetes (RBP) engineer their environment and affect habitat quality, thus regulating community structure, ecosystem functioning, and the provision of ecosystem services in shallow waters. The analysis focuses on different engineering mechanisms, such as hard substrate production, effects on hydrodynamics, and sediment transport, and impacts mediated by filter feeding and biodeposition. Finally, I deal with landscape-level topographic alteration by RBP. In conclusion, RBP have positive impacts on diversity and abundance of many species mediated by the structure of the reef. Additionally, by feeding on phytoplankton and decreasing water turbidity, RBP can control primary production, increase light penetration, and might alleviate the effects of eutrophication
    [Show full text]
  • Effects of a Commercial Mussel Mytilus Edulis Lay on a Sublittoral, Soft Sediment Benthic Community
    MARINE ECOLOGY PROGRESS SERIES Vol. 282: 185–191, 2004 Published November 16 Mar Ecol Prog Ser Effects of a commercial mussel Mytilus edulis lay on a sublittoral, soft sediment benthic community Julie Smith*, Susan E. Shackley School of Biological Sciences, University of Wales Swansea, Singleton Park, Swansea SA2 8PP, UK ABSTRACT: A commercial mussel Mytilus edulis lay was established in 1998 in western inner Swansea Bay (Wales, UK) in a shallow, sublittoral, high tidal energy environment, on a substrate which previously supported a diverse inshore, sand/muddy sand benthic community. Within a year of commencement of this fishery, a significant change in the species composition of the benthic com- munity occurred, with a decrease in the number of species and in the total number of individuals. The abundance of carnivorous and deposit feeding benthic species increased, whilst the mussels out- competed other benthic filter feeding organisms, preventing the settlement of these organisms by ingestion of the larvae, and removed other benthic organisms by physical smothering. KEY WORDS: Mussel lay · Benthos · Community effects · Coastal waters Resale or republication not permitted without written consent of the publisher INTRODUCTION Swansea Bay is a high-energy embayment, located on the northern coastline of the Bristol Channel, with Mussels Mytilus edulis L. are of growing commercial maximum depths of 20 m relative to chart datum (CD) importance, with increased numbers of applications for and an extensive, low gradient intertidal zone (Fig. 1). permission to site commercial mussel lays around the The tidal current takes the form of a rectilinear, revers- UK coast in shallow, sheltered, inshore environments.
    [Show full text]