Ecosystem function of subarctic Zostera marina meadows: influence of shoot density on fish predators and predation rates

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 630:41-54 (2019) - DOI: https://doi.org/10.3354/meps13115 Ecosystem function of subarctic Zostera marina meadows: influence of shoot density on fish predators and predation rates Katrin Reiss1,*, Nina N. Fieten2, Pamela L. Reynolds3, Britas Klemens Eriksson2 1Faculty for Biosciences and Aquaculture, Nord University, 8049 Bodø, Norway 2Groningen Institute for Evolutionary Life Sciences, Marine Ecology, University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands 3DataLab: Data Science and Informatics, University of California Davis, Davis, California 95616, USA *Corresponding author: katrin.sieben@gmail.com ABSTRACT: Recent studies have shown a decline in predation intensity in seagrasses with higher latitude, but knowledge about arctic and subarctic regions is scarce. Moreover, changes in trophic structure are likely to vary with latitude, and to impact predation. Thus inclusion of high-latitude sites and the quantifyication of predation at multiple trophic levels are critical for our understanding of predator-prey dynamics in seagrasses at a global scale. In this in situ study, we investigated predator communities and predation rates in 2 subarctic seagrass meadows in Northern Norway. We measured the effect of seagrass density on abundances of small-bodied fish and predation rates on small (amphipods/mesograzers) and medium-sized crustaceans (shrimps/mesopredators) using a standardized live tethering technique. Results varied strongly between both study sites. Juvenile fish occurred in higher diversity and density in high seagrass density in one meadow, while sticklebacks dominated the other meadow, irrespective of habitat complexity. Predation rates varied strongly between prey type; on average, 41% of shrimps and 16% of amphipods were consumed, while a standardized non-live prey was consumed at a rate of only 3%. In one meadow, predation on shrimp was strongly reduced (from 60% outside the meadow to 3% in high-density patches), indicating the importance of habitat complexity in reducing predation rates at this site. The results demonstrate that predation rates differ between trophic levels, and that habitat effects on predation depend on local meadow characteristics. We found that subarctic seagrass provides habitat for a diverse fish community, and specifically one meadow hosted more juveniles of commercial species compared to bare habitats. KEY WORDS: Eelgrass · Fish composition · Nursery role · Ecosystem functioning · Tethering · Habitat complexity Full text in pdf format PreviousNextCite this article as: Reiss K, Fieten NN, Reynolds PL, Eriksson BK (2019) Ecosystem function of subarctic Zostera marina meadows: influence of shoot density on fish predators and predation rates. Mar Ecol Prog Ser 630:41-54. https://doi.org/10.3354/meps13115 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 630. Online publication date: November 07, 2019 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2019 Inter-Research.