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Parasites in kelp-forest food webs increase food-chain length, complexity, and specialization, but reduce connectance

January 10, 2022

We explored whether parasites are important in kelp forests by examining their effects on a high-quality, high-resolution kelp-forest food web. After controlling for generic effects of network size, parasites affected kelp-forest food web structure in some ways consistent with other systems. Parasites increased the trophic span of the web, increasing top predator vulnerability and the longest chain length. Unique links associated with parasites, such as concomitant predation (consumption of parasites along with their hosts by predators) increased the frequency of network motifs involving mutual consumption and decreased niche contiguity of free-living species. However, parasites also affected kelp-forest food web structure in ways not seen in other systems. Kelp-forest parasites are richer and more specialized than other systems. As a result, parasites reduced diet generality and decreased connectance in the kelp forest. Although mutual consumption motifs increased in frequency, this motif type was still a small fraction of all possible motifs, so their increase in frequency was not enough to compensate for the decrease in connectance caused by adding many specialist parasite species.

Citation Information

Publication Year 2022
Title Parasites in kelp-forest food webs increase food-chain length, complexity, and specialization, but reduce connectance
DOI 10.1002/ecm.1506
Authors Dana N. Morton, Kevin D. Lafferty
Publication Type Article
Publication Subtype Journal Article
Series Title Ecological Monographs
Series Number
Index ID 70230139
Record Source USGS Publications Warehouse
USGS Organization Western Ecological Research Center