A little can be enough. Native fish from the Western Mediterranean Sea can act as a control agent for the invasive alga Caulerpa cylindracea

GRMAR Institute of Aquatic Ecology, University of Girona, Girona, Catalonia, Spain
Department of Fisheries and Wildlife, Oregon State University, Corvallis, Oregon, United States
Department of Ecology and Marine Resources - Instituto Mediterráneo de Estudios Avanzados (IMEDEA), Universitat de Les Illes Balears (UIB) - Consejo Superior de Investigaciones Científicas (CSIC), Esporles, Balearic Islands, Spain
Centro d´Estudis Avançats de Blanes, Consejo Superior de Investigaciones Científicas (CEAB-CSIC), Blanes, Catalonia, Spain
Seagrass Ecology Group - Centro Oceanográfico de Murcia, Instituto Español de Oceanografía (IEO), San Pedro del Pinatar, Murcia, Spain
DOI
10.7287/peerj.preprints.26772v1
Subject Areas
Ecology, Marine Biology
Keywords
Algae invasions, Caulerpa cylindracea, Biotic resistance, Fish herbivory, Mediterranean Sea
Copyright
© 2018 Santamaría et al.
Licence
This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, reproduction and adaptation in any medium and for any purpose provided that it is properly attributed. For attribution, the original author(s), title, publication source (PeerJ Preprints) and either DOI or URL of the article must be cited.
Cite this article
Santamaría J, Tomas F, Ballesteros E, Ruiz JM, Terrados J, Cebrian E. 2018. A little can be enough. Native fish from the Western Mediterranean Sea can act as a control agent for the invasive alga Caulerpa cylindracea. PeerJ Preprints 6:e26772v1

Abstract

In the Mediterranean Sea, different organisms can feed on invasive algae species, yet, how these species provide biotic resistance against algal invasions remains unclear. In this study, we analyzed fish stomach contents to determine which fish species feed on Caulerpa cylindracea and we performed an exclusion experiment to experimentally test how this grazing activity may limit invasive algae abundance and spread. Our results show that several fish species, many of them not considered strictly herbivores, feed on the invasive alga; however, the Ivlev´s Index suggests that its consumption was accidental except for Sarpa salpa. Additionally, the exclusion experiment demonstrated that fish species can limit C. cylindracea coverage at 10m but not at 30m deep; which is likely linked to the higher abundance and activity of these fish species at depths above 25m. These results are in agreement with the current distribution of C. cylindracea, which is much more abundant at depths from 25 to 50m. In this study we show that fish herbivory is a form of biotic resistance against C. cylindracea at shallow depths, not being able to completely remove it, but controlling its abundance.

Author Comment

This is an abstract which has been accepted for the WCMB (World Conference on Marine Biodiversity)