Ecological Archives E092-172-D1

David W. Thieltges, Karsten Reise, Kim N. Mouritsen, John P. McLaughlin, and Robert Poulin. 2011. Food web including metazoan parasites for a tidal basin in Germany and Denmark. Ecology 92:2005.

METADATA CONTENTS

1. Data Set Descriptors
   1. Data Set Title
   2. Data Set Identification Code
   3. Data Updates
   4. Authors
   5. Abstract
   6. Key Words
2. Research Origin Descriptors
   1. Overall Project Description
   2. Research Motivation
   3. General Methodology
   4. Data Limitations and Potential Enhancements
3. Data Set Status and Accessibility
   1. Latest Data Update
   2. Latest Metadata Update
   3. Copyright or Proprietary Restrictions
4. Data Set Structural Descriptors
   1. Data Files
   2. Metadata Tables
5. Acknowledgements
6. Literature Cited

METADATA

CLASS I. DATA SET DESCRIPTORS

A. Data set title: Food web including parasitic metazoans, for a tidal basin in Germany/Denmark.

B. Data set identification code: ThielEtAl2010-syltweb.

C. Data updates: The data set may be periodically updated. For a record of previous versions and identification codes see Table 1.

D. Authors

Individual: Dr. David W. Thieltges
Role: Owner, Corresponding Author
Organization: Royal Netherlands Institute for Sea Research (NIOZ)
Position: Marine Ecologist
Address: P.O. Box 59
NL-1790 AB Den Burg
The Netherlands
Phone: (+31) (0)222-369508
Fax: (+31) (0)222-319674
Email: [email protected]
URL: http://www.nioz.nl/nioz_nl/887ad31245d87cf58e26deaaef96444d.php

Individual: Dr. Karsten Reise
Role: Owner
Organization: Alfred Wegener Institute for Polar and Marine Research
Position: Professor
Address: Wadden Sea Station Sylt
Hafenstrasse 43,
25992 List, Germany
Phone: +49(4651)956-4304
Email: [email protected]
URL: http://www.awi.de/People/show?kreise

Individual: Dr. Kim N. Mouritsen
Role: Owner
Organization: Aarhus University
Position: Associate Professor
Address: Aarhus University
Department of Biological Sciences
8200 Aarhus N, Denmark
Phone: +45 8942 4386
Fax: +45 8942 4387
Email: [email protected]
URL: http://person.au.dk/en/kim.mouritsen@biology

Individual: John P. McLaughlin
Role: Content Provider
Organization: University of California, Santa Barbara
Position: Graduate Student
Address: Department of Ecology, Evolution and Marine Biology
University of California
Santa Barbara, CA 93106-9610
USA
Phone: (805) 893-3998
Fax: (805) 893-4724
Email: [email protected]
URL: http://www.lifesci.ucsb.edu/eemb/labs/kuris/

Individual: Dr. Robert Poulin
Role: Owner
Organization: University of Otago
Position: Professor
Address: Department of Zoology
University of Otago
P.O. Box 56
Dunedin, New Zealand
Phone: +643 479-7983
Fax: +643 479-7584
Email: [email protected]
URL: http://www.otago.ac.nz/parasitegroup/home.html

E. Abstract: This data set presents a food web for the Sylt tidal basin, an intertidal ecosystem in Germany and Denmark. The intertidal part of this bight consists of extensive tidal flats with the main habitats being lugworm sandflats, seagrass meadows, and mixed mussel and oyster beds. This food web has three noteworthy attributes: (1) high resolution of free-living organisms, (2) inclusion of metazoan parasites and other infectious agents, and (3) inclusion of ontogenetic stages of parasites with complex life cycles. The food web contains 230 nodes, 161 species/assemblages, and 3338 links. Of the 161 species/assemblages, 6 are basal, 120 are free-living, and 35 are infectious. Data on the free-living assemblages and parisitism were gathered during original field sampling and supplemented with information from additional published sources and local expert knowledge. Taxonomic resolution is high, although a few functional or taxonomic groups (e.g., phytoplankton, macroalgae) are lumped into single nodes. Each ontogenetic stage of parasites with complex life cycles is treated separately and coded accordingly. For each node, we have included additional information such as taxonomy, life history, residency, and vagility. Further, for each link, we define a specific interaction type. We present the data and metadata in the system-neutral format standardized by R.F. Hechinger and colleagues, and thus we recognize variables that are not represented in our data set but may be added by further study.

F. Key words: benthos; complex life-cycles; consumer-resource; food webs; infectious agents; intertidal, parasites; Sylt Basin; trematodes; trophic interactions.

CLASS II. RESEARCH ORIGIN DESCRIPTORS

A. Overall project description: Not applicable, as this is a stand-alone project.

B. Research motivation: Recent studies examining the ecological role of parasites (Lafferty et al. 2008) have found that parasites can dramatically influence properties such as food web structure (Lafferty et al. 2006a, Lafferty et al. 2006b) and ecosystem energetics (Kuris et al. 2008). Here, we provide full data on the intertidal food web of Sylt tidal basin, in Germany/Denmark. This data set was compiled as part of a postdoctoral research project to investigate the role of parasites in food webs. The food web of free-living species is based on long-term research data from the area spanning over several decades and expands on an earlier web from the same basin, solely concerned with energy flow (Baird et al. 2004). Knowledge of parasites in this area dates back several decades (Thieltges et al. 2008) and was complemented by recent extensive studies during 2001–2006

C.1 System definition

C.1.i Description: The Sylt tidal basin, also called Sylt-R�m� Bight, is located in the northern Wadden Sea (North Sea, Germany/Denmark) and is enclosed by the islands of Sylt and R�m�, two causeways to the islands and by the mainland. The total tidal basin covers 407 km2 and has a tidal range of approximately 1.8 m. The intertidal area accounts for 33% of the total basin area and is composed of 72% sand, 25% mixed, and 3% mudflats. The main habitats are lugworm sandflats (66%), seagrass meadows (12%), and mixed mussel and oyster beds (3%). Over 2000 species (not including bacteria) from the basin have been described to date. Mean water temperature is 9 �C, (half year mean: 5 �C in winter and 15 �C in summer) and salinity remains close to the mean of 30 psu. For more information on the basin see G�tje and Reise (1998). The following is a map of the Sylt tidal basin:

Map Sylt: The Sylt tidal basin (also called Sylt-Rømø-Bight) in the northern Wadden Sea, enclosed by the islands of Sylt (Germany) and Rømø (Denmark), the mainland and causeways to the two islands. Shaded areas indicate the intertidal zone.

Geographic description:	Sylt tidal basin
Bounding coordinates:	East: 54.83
	West: 55.12
	North: 8.33
	South: 8.67
Temporal coverage:	Beginning date: 2001
	Ending date: 2006

C.2. Nodes

C.2.i. Orientation: Nodes for the food web are listed in the Nodes data files. Two metadata tables describe the Nodes data files. Table 2A defines node data column headers. Table 2B defines node data column variables. Below, we provide additional background information on the nodes.

C.2.ii. Node inclusion: Node inclusion in the food web was determined as follows for free-living species and for parasites. From the more than 2000 known free-living species, only the most important ones in terms of abundance and biomass were included. We based the inclusion on long-term observations and sampling campaigns using original data, literature sources and local expert knowledge, thus expanding on an existing web from the basin that was solely concerned with the flow of energy (Baird et al. 2004). The inclusion of metazoan parasites in various host species in this system was based on original data, literature sources and local expert knowledge. Trophic interactions for free-living species as well as parasites were obtained from original data, literature sources and local expert knowledge.

C.2.iii. Node resolution: In general, taxonomic resolution is high, though some functional or taxonomic groups (e.g., phytoplankton, benthic diatoms, macroalgae) are aggregated into single nodes. The �Node Resolution� column in the node data files indicates the degree of resolution for each node, while the �Node Type� column is descriptive of the kind of resolution attributed to each node. Finally, as indicated by their discrete number codes and working names all nodes are mutually exclusive.

In addition to providing a unique working name for each node, and indicating the general organismal �Group� to which each node belongs, the data sets also include a series of columns for the taxonomic hierarchy (i.e., Kingdom through Specific epithet). This is primarily to aid users in understanding node identity and to facilitate taxonomic diversity analyses, vs. the adoption of any particular taxonomic scheme.

C.2.iv. Additional node classifications: To facilitate analyses and interpretation, we have additionally classified nodes by several different schemes. The node metadata tables list and define all such categories and variables (Tables 2A, 2B). For example, we indicate each node�s �Feeding type� (feeding, non-feeding, autotrophic), �Lifestyle� (e.g., free-living, infectious, commensal), �Consumer Strategy� (e.g., predator, macroparasite, pathogen, detritivore), and �Native� or non-native status. Additionally, the columns �Mobility� and �Residency� indicate for each node the general degree of vagility characterizing individuals on daily and seasonal time scales.

C.2.v. Node biomass estimation: We do not estimate the biomass of each node.

C.2.vi. Node body size estimation: We do not estimate the body size of each node.

C.3. Links

C.3.i. Link orientation: Consumer-resource links for the food web are listed in the links data files. Two metadata tables describe the links data files. Table 3A defines all column headers. Table 3B defines all column variables, except for the Link Types, which are indicated in Table 3C. Below, we provide additional background information.

C.3.ii. Link determination: Trophic interactions for free-living species as well as parasites were obtained during original field sampling and supplemented with literature sources and local expert knowledge.

C.3.iii. Link type: We provide information on the nature of the individual consumer–resource interactions based on the consumer–resource node classifications and other information. The following �Link types� are recognized: Predation, Micropredation, Parasitic Castration, Pathogen Infection, Macroparasitism, Trophically Transmitted Parasitism, Concomitant Predation on Symbionts, Trophic Transmission, Predation on Free-living Non-feeding Parasite Stages, Detritivory, and Parasite Intraguild Trophic Interaction. Given the importance of link types, we have pulled this information from the metadata link variable table and placed it in Table 3C, which provides definitions of all link types. Understanding link types is essential prior to conducting analyses of the network. For instance, links defined as Predation involve predators as consumers, whereas links defined as Parasitic Castration involve parasitic castrators as consumers. Also, several of the link types that are not typically included in food webs do not represent resource dependencies (i.e., Concomitant Predation on Symbionts, Trophic Transmission). For this reason, such links should be excluded from some analyses. However, Concomitant Predation on Symbionts represents mortality sources for symbionts, and Trophic Transmission is important to understand parasite transmission.

D. Data limitations and potential enhancements

D.1. General note: As with all ecological networks there is uncertainty in link assignment and in the inclusion or omission of some nodes in this food web and we welcome any input from colleagues facilitating augmentation or improvement of the web. Along these lines, we will periodically update the dataset (please check for the latest update before using the data set).

D.2. Nodes: The primary shortcoming of the data set is the absence and under-representation of certain groups and the severe aggregation of many nodes. Table 4 details the missing and under-represented groups as well as the extent of aggregation of various assemblages. Ectoparasites of birds and fishes are largely absent from the dataset. Parasites and micropredators of seagrass and algae are also poorly incorporated into the data set. Additionally, including microfauna such as protists (both symbiotic and free-living), bacteria and viruses to an extent that accurately reflects their importance to the system will likely require an effort which exceeds that required to assemble the current web.

While most nodes have been resolved to species (or life cycle stages of species) some nodes represent aggregated species assemblages. Meiofaunal groups are both severely aggregated and under-represented, this includes the smallest free-living metazoans (e.g., gnathostomulids, kinorhynchs and nematodes). Epipelic flora is another aggregated but speciose assemblage, though it is mostly composed of benthic diatoms lacking feeding links and likely sharing consumer links.

D.3. Links: By supplementing direct observation of links with expert opinion and literature sources we believe we have provided a relatively comprehensive view of the trophic interactions in the system. If future study is able to decompose aggregated assemblages into their component species the respective trophic interactions will have to be modified with equal care. Additionally, future study might wish to explicitly identify non-substitutable resources for various consumers.

D.4. Potential enhancements: Beyond addressing the inclusion and resolution of the nodes outlined above, future studies can make valuable contributions to the dataset by quantifying the abundance, body size and biomass of the nodes present in this system. This is would be a valuable next step and would aid in determining how infectious agents compare with free-living organisms.

CLASS III. DATA SET STATUS AND ACCESSIBILITY

A. Latest data update: The data set may be periodically updated. For a record of previous versions and identification codes see Table 1.

B. Latest metadata update: There have been no alterations to the metadata subsequent to first publication.

C. Copyright or proprietary restrictions: These data sets are freely available for non-commercial scientific use, given the appropriate scholarly citation.

CLASS IV. DATA STRUCTURAL DESCRIPTORS

A. Data files: Below are the files containing the raw data for the Sylt Basin food web. The data are in two comma-separated value files. The first file contains descriptive information of the species in the system. The second file contains information describing the trophic interactions between these species. Complete descriptions of the data (both column headers and variables) are in the Metadata Tables section below. To download the entire data set click here, or download individual files click on the relevant heading below.

Sylt_Data_Nodes.csv - The node information for the Sylt tidal basin food web. File is 4511 records, not including header row, and is formatted as comma separated values. No compression scheme was used. Blank cells indicate that information has yet to be collected.

Sylt_Data_Links.csv � The trophic link information for the Sylt tidal basin food web. File is 26720 records, not including header row, and is formatted as comma separated values. No compression scheme was used. Blank cells indicate that the information has yet to be collected.

All_Sylt_Data_Files.zip � A zip file containing both the above data files.

B. Metadata tables: Below are the metadata tables which describe the column header and variable information contained in the above data files. These are the same set of tables linked to in the methods section. There are six metadata tables organized into 2 groups: Tables 2A–B refer to the Node data sheets, while Tables 3A–C refer to the Links data sheets. The A tables describe the information contained within each column; the B tables define the variables found in each column. Specific variable definitions can also be accessed by clicking on the header for any particular column in the A tables. Table 4 details the missing and underrepresented groups and severely aggregated nodes. Table 3C includes the definitions of link-type variables extracted from Table 3B.

Table 2A - Column header descriptions for Nodes data files: Column headers are taken directly from the Sylt_Data_Nodes.csv data file and are followed directly by their descriptions. To obtain a list of the variables in a column, as well as their definition, click on the column header.

Table 2B - Column variable descriptions for Nodes data files: Definitions of variables are organized by column headers from Table 2A.

Table 3A - Column header descriptions for Links data files: Column headers are taken directly from the Sylt_Data_Links.csv data files and are followed directly by their descriptions. To obtain a list of the variables and their definitions present in any column click on the column header.

Table 3B - Column variable descriptions for Links data files: Definitions of variables are organized by column headers from Table 3A. Link-type variables are defined in Table 3C.

Table 3C - Link-type definitions for Links data files: Definitions of Link-type variables are organized for this column header from Table 3A.

Table 4 - Missing and under-represented groups and severely aggregated nodes.

All_Sylt_Metadata_Tables.zip � A zipped file containing Tables 2A, 2B, and 3A, 3B, 3C, and 4.

ACKNOWLEDGMENTS

We are grateful to the many people who have provided field and laboratory assistance during the assembly of the data set, in particular Henrike Andresen, Christian Buschbaum, Silke Fottner, Klaus G�nther, Judith Hermann, Birgit Hussel, Dominik Kneer, Ulrike K�nig, Manuela Krakau, Georg Nehls, Britta Noll, D�rte Poszig, Penny Stoddard, and Sabine Wolf. This work was in part funded by a grant to D.W. Thieltges by the German Research Foundation (DFG). The data compilation was conducted as part of the Parasites and Food Webs Working Group supported by the National Center for Ecological Analysis and Synthesis (NCEAS), a center funded by NSF (grant #DEB-0553768), the University of California, Santa Barbara, and the State of California.

LITERATURE CITED

Baird, D., H. Asmus and R Asmus. 2004. Energy flow of a boreal intertidal ecosystem, the Sylt-R�m� Bight. Marine Ecology Progress Series 279:45–61.

G�tje, C. and K. Reise. 1998. �kosystem Wattenmeer: Austausch-, Transport- und Stoffumwandlungsprozesse. Springer, Berlin, Germany.

Hechinger, R. F., K. D. Lafferty, J. P. McLaughlin, J. C. Shaw, K. Whitney, T. C. Huspeni, M. E. Torchin, J. Lorda, P. Sandhu, B. Fredensborg, and A. M. Kuris. 2011. Food webs including parasites, biomass, body sizes, and life-stages, for three California/Baja California estuaries. Ecology 92(3):791.

Kuris, A. M., R. F. Hechinger, J. C. Shaw, K. L. Whitney, L. Aguirre-Macedo, C. A. Boch, A. P. Dobson, E. J. Dunham, B. L. Fredensborg, T. C. Huspeni, J. Lorda, L. Mababa, F. T. Mancini, A. B. Mora, M. Pickering, N. L. Talhouk, M. E. Torchin, and K. D. Lafferty. 2008. Ecosystem energetic implications of parasite and free-living biomass in three estuaries. Nature 454:515–518.

Lafferty, K. D., S. Allesina, M. Arim, C. J. Briggs, G. De Leo, A. P. Dobson, J. A. Dunne, P. T. J. Johnson, A. M. Kuris, D. J. Marcogliese, N. D. Martinez, J. Memmott, P. A. Marquet, J. P. McLaughlin, E. A. Mordecai, M. Pascual, R. Poulin, and D. W. Thieltges. 2008. Parasites in food webs: the ultimate missing links. Ecology Letters 11:533–546.

Lafferty, K. D., A. P. Dobson, and A. M. Kuris. 2006a. Parasites dominate food web links. Proceedings of the National Academy of Sciences of the United States of America 103:11211–11216.

Lafferty, K. D., R. F. Hechinger, J. C. Shaw, K. L. Whitney, and A. M. Kuris. 2006b. Food webs and parasites in a salt marsh ecosystem. Pages 119–134 in S. K. Collinge and C. Ray, editors. Disease ecology: community structure and pathogen dynamics. Oxford University Press, Oxford, UK.

Michener, W. K., J. W. Brunt, J. J. Helly, T. B. Kirchner, and S. G. Stafford. 1997. Nongeospatial metadata for the ecological sciences. Ecological Applications 7:330–342.

Thieltges, D.W., B. Hussel, J. Hermann, K. T. Jensen, M. Krakau, H. Taraschewski and K. Reise. 2008. Parasites in the northern Wadden Sea: a conservative ecosystem component over four decades. Helgoland Marine Research 62:37–47.