Journal
MARINE ECOLOGY PROGRESS SERIES
Volume 340, Issue -, Pages 63-71Publisher
INTER-RESEARCH
DOI: 10.3354/meps340063
Keywords
tethering experiment; temporal variation; Posidonia oceanica; seagrass defoliation; Sarpa salpa; Paracentrotus lividus; bite marks
Categories
Ask authors/readers for more resources
The rates of seagrass defoliation exerted by the herbivorous fish Sarpa salpa and by the sea urchin Paracentrotus lividus were evaluated through both direct (tethering experiment) and indirect (bite marks) methods. Sampling was conducted once per season in 10 shallow meadows of Posidonia oceanica (L.) Delile from the continental NW Mediterranean coast covering a spatial scale of > 300 km. Results indicated that a large proportion (ca. 57 %) of the annual leaf production is lost to herbivory, et with considerable spatial variation. Patterns of seagrass defoliation showed high temporal variability, with a peak in summer with values that exceeded about 2.5 times those of leaf production and a minimum during the winter period. On average, defoliation exerted by S. salpa accounted for 40% of leaf production (ca. 70% of total annual losses to herbivory), while P. lividus was also responsible for a substantial 17 % removal of leaf production. High discrepancies encountered when comparing direct and indirect measurements suggest that the latter are inappropriate to achieve accurate estimates of herbivory pressure. This study evidences that P. oceanica leaf losses to herbivores are not marginal, but a widespread process that occurs at much higher rates than previously estimated through indirect methods (ca. 2 %), resetting the paradigm of the negligible importance of herbivory in temperate systems.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available