ORCID
- Andy Foggo: 0000-0002-0280-0824
Abstract
Extreme fluctuations in abiotic conditions can induce a biological stress response (e.g. bleaching) detrimental to an organism's health. In some instances, organisms can recover if conditions are alleviated, such as through co-occurrence with other species that confer protection. Biodiverse, multitrophic communities are increasingly recognised as important promoters of species persistence and resilience under environmental change. On intertidal shores, the role of grazers as top-down determinants of algal community structure is well recognised. Similarly, the harvesting of grazers for human consumption is increasingly prevalent with potential to greatly alter the community dynamics. Here, we assess how differences in harvesting pressure of grazers under three management regimes (no-take; managed access; open-access) alters the trophic interactions between grazers, and algal communities. Grazer density and body size frequencies were different among regimes leading to changes in the photosynthetic performance and recovery of crustose coralline algae (CCA) post-bleaching, as well as their presence altering the strength of interactions between species. The exclusion of grazers from patches using cages led to different emergent communities and reduced negative correlations between taxa. The absence of larger grazers (>9 cm) at the managed access site led to macroalgal overgrowth of bleached CCA negatively affecting its recovery, whereas no-take or open-access led to a moderated algal growth and a shift from competitive to facilitative interactions between algal species. Given that CCA play an important role in the population growth and development of other species, the choice of management measure should be carefully considered before implementation, depending on objectives.
DOI
10.1016/j.marenvres.2019.03.003
Publication Date
2019-01-01
Publication Title
Marine Environmental Research
Volume
146
ISSN
0141-1136
Embargo Period
2020-04-18
Keywords
Conservation, Ecosystem management, Environmental change, Herbivory, MPA
Creative Commons License
This work is licensed under a Creative Commons Attribution-NonCommercial-No Derivative Works 4.0 International License.
First Page
57
Last Page
65
Recommended Citation
Knights, A., Chaverra, A., Wieters, E., & Foggo, A. (2019) 'Removal of intertidal grazers by human harvesting leads to alteration of species interactions, community structure and resilience to climate change', Marine Environmental Research, 146, pp. 57-65. Available at: https://doi.org/10.1016/j.marenvres.2019.03.003
