João P. G. Machado1,2 , Vinícius P. Oliveira1
1Multiuser Unit of Environmental Analysis, Institute of Biology, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.
2Laboratory of Macroalgae, Institute of Biology, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.
Algae are the staples of most marine environments. Paramount in influencing their distribution are light, space, nutrients, and herbivory. Thus, this work aimed to identify and quantify the current and past literature (1934-2022) on competitive interactions in seaweeds and to address the main questions on the patterns of competition and their consequences for community structure, as well as the comparisons made on the competitive capacity among different macroalgal taxa. To this avail, a quantitative literature search was done based on articles published from 1934 to 2022, using the following combination of Boolean operators and keywords: “Seaweed OR macroalgae OR macroalga, AND ecolog *, AND competiti *”. A total of 173 papers were thereafter compiled and selected. Our results contained 124 different genera of seaweeds in works on competition processes. 38% of the compiled taxa belonged to Ochrophyta; 31% Rhodophyta, and 18% Chlorophyta. The best-studied genera were Dictyota (6.8%), Sargassum (6.8%), Ulva (4.9%), Lobophora (4.2%), and Fucus (3.1%). Space was the most analysed resource (40.9%), seconded by studies related to herbivory (26.1%), and lastly by competition over nutrients (15.1%). The results, while attesting to the overarching complexity of competitive interactions, nevertheless allowed us to summarize the current knowledge regarding the patterns of competitive interactions on seaweeds, thus providing a useful synthesis for new perspectives on marine systems and research.