MEPS 445:97-107 (2012)  -  DOI: https://doi.org/10.3354/meps09367

Dual processes for cross-boundary subsidies: incorporation of nutrients from reef-derived kelp into a seagrass ecosystem

Glenn A. Hyndes1,*, Paul S. Lavery1, Christopher Doropoulos2

1Centre for Marine Ecosystems Research, School of Natural Sciences, Edith Cowan University, 270 Joondalup Drive, Joondalup, Western Australia 6027, Australia
2School of Biological Sciences and ARC Centre of Excellence for Coral Reef Studies, The University of Queensland, Brisbane, Queensland 4072, Australia

ABSTRACT: Movement of organic material across ecosystem boundaries can be critical for subsidizing production in recipient systems, particularly in systems with low in situ productivity or resource availability. Yet, what happens in highly productive and resource-rich ecosystems? Kelp, which is dislodged in high quantities in temperate regions, can accumulate in seagrass ecosystems where productivity and resource availability are high. Using an experimental approach of adding isotopically-labelled (15N) kelp in laboratory and field experiments, we tested whether allochthonous kelp could be incorporated into seagrass ecosystems via (1) the uptake of leached nutrients by macrophytes and (2) the assimilation of nutrients by consumers. Seagrass and epiphytes assimilated kelp-15N under laboratory and field conditions, with epiphytes showing a greater rate of uptake than the seagrass leaves. Unlabelled kelp leached 1225 and 736 µg N (100 g kelp)−1 d−1 of dissolved organic nitrogen from freshly detached and 2 wk old kelp, respectively. Mesograzers (gastropods) assimilated kelp-15N under laboratory and field conditions, despite the presence of alternative food sources. We conclude that reef-derived kelp can act as an important vector of nutrient and energy transfer to both primary producers and consumers in marine landscapes, regardless of their levels of productivity and resource availability.


KEY WORDS: Food webs · Trophic subsidies · Posidonia · Ecklonia · Detritus · Spatial ecology


Full text in pdf format 
Cite this article as: Hyndes GA, Lavery PS, Doropoulos C (2012) Dual processes for cross-boundary subsidies: incorporation of nutrients from reef-derived kelp into a seagrass ecosystem. Mar Ecol Prog Ser 445:97-107. https://doi.org/10.3354/meps09367

Export citation
Mail this link - Contents Mailing Lists - RSS
- -