Pelagic trophic network in the Scotia Sea (2006-2009)

• Main Authors: Lopez-Lopez, Lucia, Genner, Martin, Tarling, Geraint, Saunders, Ryan, O'Gorman, Eoin
• Format: Dataset
• Language: English
• Published: UK Polar Data Centre, Natural Environment Research Council, UK Research & Innovation 2020
• Subjects: "EARTH SCIENCE","BIOSPHERE","ECOLOGICAL DYNAMICS","ECOSYSTEM FUNCTIONS","FOOD-WEB DYNAMICS"; "EARTH SCIENCE","OCEANS","MARINE ENVIRONMENT MONITORING"; Scotia Sea; Southern Ocean; pelagic ecosystem; trophic interactions; trophic network
• Online Access: https://dx.doi.org/10.5285/9f615353-c621-4216-865e-7d38a9b21e2c; https://data.bas.ac.uk/full-record.php?id=GB/NERC/BAS/PDC/01407

Among all possible interaction types, trophic interactions are easily observable and essential in terms of energy transfer, and thus binary networks have arisen as the most straightforward method to describe complex ecological communities. These food-web models also inform on the ecosystem dynamics and function, and the patterns arising from food web topology can be indicators for ecosystem stability. We present a comprehensive pelagic network for the Scotia Sea underpinned by surveys and dietary studies conducted in the Scotia Sea in the last century. Selection of the trophic links followed a protocol based on taxonomy and geographic location, and was further refined based on the consumer and resource depth ranges and their body size ratios. The resulting network consists on 228 nodes and 10880 links which represent the main trophic paths in the Scotia Sea ecosystem and can serve as a basis for ecosystem modelling in the Scotia Sea or comparison with other ecosystems. Funding was provided by NERC Highlight Topic grant NE/N005937/1 and NERC Fellowship NE/L011840/1. : The metaweb is primarily based on data gathered during the Discovery surveys (2006-2009) and complemented through a literature research to identify consumer-resource interactions in the Scotia Sea and Southern Ocean. Subsequently, we instigated a step-wise procedure based on taxonomy and geographic distribution for allocating interactions to each node in the network. The resources identified in stomach contents were often described to a lower taxonomic resolution than the taxa in our list of nodes. In such instances, we included links to all the taxa in our list of nodes that fell within that taxonomic group (e.g. if a predator was shown to feed on the copepod genus Clausocalanus, we would include feeding links between that predator and all Clausocalanus species in our metaweb). Note that we only followed this procedure up to the class level, i.e. we did not include links to all taxa in the case of phyla such as Crustacea or Mollusca. To avoid overestimating the number of links, we applied two filters to our list of links. (1) Only consumer-resource pairs whose vertical distribution is known to overlap were kept as links. (2) Feeding links were removed if the consumer-resource body mass ratio was unrealistically large or small. : R software v.3.5.3 : We tested the integrity of the network through a series of simulations in which between 1 and 25 nodes were randomly deleted (999 permutations without replacement).