Moreira-Saporiti Agustín

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Last Name
Moreira-Saporiti
First Name
Agustín
ORCID
0000-0002-4798-3775

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  • Article
    Bottom-up and top-down control of seagrass overgrazing by the sea urchin Tripneustes gratilla
    (Wiley, 2023-01-19) Moreira-Saporiti, Agustín ; Hoeijmakers, Dieuwke ; Reuter, Hauke ; Msuya, Flower E. ; Gese, Katrin ; Teichberg, Mirta
    The lack of top-down control on Tripneustes gratilla, a sea urchin commonly known to graze on seagrass, and the bottom-up control of its feeding preference, led to the overgrazing of seagrass meadows of the species Thalassodendron ciliatum in Changuu Island (Zanzibar Archipelago). The impact of overgrazing on seagrasses was assessed by mapping the presence of grazed versus non-grazed seagrass patches in the study site, while the top-down control on T. gratilla was assessed by measuring the abundance of its fish predators. The feeding preference and distribution of T. gratilla were characterized by calculating the electivity indexes for each seagrass species and measuring sea urchin density, respectively. Approximately half of the patches of T. ciliatum were overgrazed, while predatory fishes of T. gratilla were absent from the site. The Vanderploeg and Scavia's Relativized Electivity Index indicated that T. gratilla had a feeding preference for T. ciliatum, which was also supported by higher urchin densities within T. ciliatum dominated patches. Bottom-up control of grazing activity was observed by quantifying and analyzing morphological, nutritional, and the chemical defense traits of the seagrass in relation to feeding preference and urchin density. Feeding was positively correlated to the seagrass tissue C:P ratio (? = 0.9), whereas urchin density showed no correlations. The bottom-up control of the feeding preference and agglomeration of T. gratilla in T. ciliatum meadows, together with the lack of evidence of substantial top-down control and the long recovery time of T. ciliatum led to the overgrazing of this species at this site. Overgrazing, therefore, was shown to be the result of multiple factors ranging from the traits of the seagrass and feeding preference of T. gratilla, to the abundance of predators in this area.
  • Article
    A trait-based framework for seagrass ecology: trends and prospects
    (Frontiers Media, 2023-03-20) Moreira-Saporiti, Agustín ; Teichberg, Mirta ; Garnier, Eric ; Cornelissen, J. Hans C. ; Alcoverro, Teresa ; Björk, Mats ; Boström, Christoffer ; Dattolo, Emanuela ; Eklöf, Johan S. ; Hasler-Sheetal, Harald ; Marbà, Nuria ; Marín-Guirao, Lázaro ; Meysick, Lukas ; Olivé, Irene ; Reusch, Thorsten B. H. ; Ruocco, Miriam ; Silva, João ; Sousa, Ana I. ; Procaccini, Gabriele ; Santos, Rui
    In the last three decades, quantitative approaches that rely on organism traits instead of taxonomy have advanced different fields of ecological research through establishing the mechanistic links between environmental drivers, functional traits, and ecosystem functions. A research subfield where trait-based approaches have been frequently used but poorly synthesized is the ecology of seagrasses; marine angiosperms that colonized the ocean 100M YA and today make up productive yet threatened coastal ecosystems globally. Here, we compiled a comprehensive trait-based response-effect framework (TBF) which builds on previous concepts and ideas, including the use of traits for the study of community assembly processes, from dispersal and response to abiotic and biotic factors, to ecosystem function and service provision. We then apply this framework to the global seagrass literature, using a systematic review to identify the strengths, gaps, and opportunities of the field. Seagrass trait research has mostly focused on the effect of environmental drivers on traits, i.e., "environmental filtering" (72%), whereas links between traits and functions are less common (26.9%). Despite the richness of trait-based data available, concepts related to TBFs are rare in the seagrass literature (15% of studies), including the relative importance of neutral and niche assembly processes, or the influence of trait dominance or complementarity in ecosystem function provision. These knowledge gaps indicate ample potential for further research, highlighting the need to understand the links between the unique traits of seagrasses and the ecosystem services they provide.