The neglected status of the vermetid reefs in the Mediterranean Sea: A systematic map

Studied since late 1800, vermetid reefs are marine bioconstructions of well-acknowledged importance in the Mediterranean Sea. Despite their persistence being jeopardized in the whole basin, recent studies have referred to this bioconstruction as a neglected habitat. In this study, we assessed the neglected status of the Mediterranean vermetid reefs in the scientific literature producing a systematic map through a multi-method bibliometric protocol. Scopus and Web of Science databases were jointly used for data collection. Vermetid reefs publication rate (i.e., number of publications per year) was investigated compared to the other Mediterranean bio-constructions using ANOVA analysis and Zero-Inflated Poisson regression. Later, VOSviewer software was used to perform a bibliometric network analysis and for mapping visualization. The analysis aimed at investigating gaps, patterns, and trends of the vermetid reefs together with the other main Mediterranean bioconstructions (i.e., Astroides calycularis, Cladocora caespitosa and coralligenous formations, and sabellariid and Lithophyllum reefs). The ANOVA analysis of the number of publications from 1966 to 2020 found statistically significant differences between coralligenous and vermetid reefs publication rates in the 2006-2010, 2011-2015, and 2016-2020 timeframes and pointed out a clear before/after-2010 pattern in coralligenous publication rate, which was also confirmed by the Zero-Inflated Poisson regression model. The bibliometric network analysis of the bio-constructions literature revealed the same temporal pattern, with the vermetid reefs poorly investigated and weakly connected to newer research lines and conservation topics. Instead, coralligenous showed strong con-nections with biodiversity conservation and was indicated as a recent research hotspot. Overall, the results of this study confirm previous references of the vermetid reefs as a neglected habitat and, among others, show an increasing research interest in the coralligenous topic.