Fish grazing enhanced by nutrient enrichment may limit invasive seagrass expansion

Fee O.H. Smulders* (Co-auteur), S. Tatiana Becker, Justin E. Campbell, Elisabeth S. Bakker, Mickey J. Boässon, Mark M. Bouwmeester, J. Arie Vonk, Marjolijn J.A. Christianen

*Bijbehorende auteur voor dit werk

Onderzoeksoutput: Bijdrage aan wetenschappelijk tijdschrift/periodieke uitgaveArtikelWetenschappelijkpeer review

4 Citaten (Scopus)
93 Downloads (Pure)

Samenvatting

The success of invasive macrophytes can depend on local nutrient availability and consumer pressure, which may interact. We therefore experimentally investigated the interacting effects of nutrient (nitrogen and phosphorus) addition, the exclusion of large herbivorous fishes and mimicked grazing on the expansion rates of the invasive seagrass Halophila stipulacea. The experiments were established on Bonaire and Aruba, two islands in the southern Caribbean, which differ in fish community structure. We observed that multiple Caribbean fish species feed on H. stipulacea. At both study sites, nutrient enrichment decreased invasive leaf carbon:nitrogen ratios. However only on Bonaire, where herbivore fish abundance was 7 times higher and diversity was 4.5 times higher, did nutrient enrichment result in a significant reduction of H. stipulacea expansion into native Thalassia testudinum meadows. This effect was likely due to increased herbivory on nutrient enriched seagrass leaves, as we found that excluding large herbivorous fish (e.g. parrotfish) doubled invasive expansion rates in bare patches on Bonaire. On Aruba, H. stipulacea expansion rates were higher overall, which coincided with lower abundances and diversity of native fishes, and were limited by mimicked fish grazing. We suggest that top-down control by the native fish community may counteract eutrophication effects by increased grazing pressure on nutrient-rich invasive seagrass leaves. We conclude that diverse and abundant herbivore communities likely play an important role in limiting invasion success and their conservation and restoration may serve as a tool to slow down seagrass invasions.

Originele taal-2Engels
Artikelnummer103464
TijdschriftAquatic Botany
Volume176
DOI's
StatusGepubliceerd - jan. 2022

Vingerafdruk

Duik in de onderzoeksthema's van 'Fish grazing enhanced by nutrient enrichment may limit invasive seagrass expansion'. Samen vormen ze een unieke vingerafdruk.

Citeer dit