PERSPECTIVE published: 05 March 2021 doi: 10.3389/fmars.2021.591292 Edited by: Christos Dimitrios Arvanitidis, Hellenic Centre for Marine Research, Greece Reviewed by: Thanos Dailianis, Hellenic Centre for Marine Research, Greece Julie Bremner, Centre for Environment, Fisheries and Aquaculture Science (CEFAS), United Kingdom *Correspondence: Paolo Rossi paolo.rossi@unimore.it Specialty section: This article was submitted to Marine Ecosystem Ecology, a section of the journal Frontiers in Marine Science Received: 04 August 2020 Accepted: 10 February 2021 Published: 05 March 2021 Citation: Rossi P, Ponti M, Righi S, Castagnetti C, Simonini R, Mancini F, Agrafiotis P, Bassani L, Bruno F, Cerrano C, Cignoni P, Corsini M, Drap P, Dubbini M, Garrabou J, Gori A, Gracias N, Ledoux J-B, Linares C, Mantas TP, Menna F, Nocerino E, Palma M, Pavoni G, Ridolfi A, Rossi S, Skarlatos D, Treibitz T, Turicchia E, Yuval M and Capra A (2021) Needs and Gaps in Optical Underwater Technologies and Methods for the Investigation of Marine Animal Forest 3D-Structural Complexity. Front. Mar. Sci. 8:591292. doi: 10.3389/fmars.2021.591292 Needs and Gaps in Optical Underwater Technologies and Methods for the Investigation of Marine Animal Forest 3D-Structural Complexity Paolo Rossi 1,2 * , Massimo Ponti 2,3,4 , Sara Righi 2,5 , Cristina Castagnetti 1,2 , Roberto Simonini 2,5 , Francesco Mancini 1,2 , Panagiotis Agrafiotis 6 , Leonardo Bassani 7 , Fabio Bruno 2,8 , Carlo Cerrano 2,9,10 , Paolo Cignoni 11 , Massimiliano Corsini 11 , Pierre Drap 12 , Marco Dubbini 7 , Joaquim Garrabou 11,12 , Andrea Gori 13 , Nuno Gracias 14 , Jean-Baptiste Ledoux 15,16 , Cristina Linares 13 , Torcuato Pulido Mantas 9 , Fabio Menna 17 , Erica Nocerino 12 , Marco Palma 18,19 , Gaia Pavoni 11 , Alessandro Ridolfi 2,20,21 , Sergio Rossi 2,22,23 , Dimitrios Skarlatos 24 , Tali Treibitz 25 , Eva Turicchia 2,4,26 , Matan Yuval 25 and Alessandro Capra 1,2 1 Department of Engineering “Enzo Ferrari”, University of Modena and Reggio Emilia, Modena, Italy, 2 Consorzio Nazionale Interuniversitario per le Scienze del Mare (CoNISMa), Rome, Italy, 3 Biological, Geological and Environmental Sciences Department, University of Bologna, Bologna, Italy, 4 Centro Interdipartimentale di Ricerca Industriale Fonti Rinnovabili, Ambiente, Mare ed Energia, University of Bologna, Ravenna, Italy, 5 Life Sciences Department, University of Modena and Reggio Emilia, Modena, Italy, 6 Department of Topography, School of Rural and Surveying Engineering, National Technical University of Athens, Athens, Greece, 7 Department of History, Cultures and Civilizations, University of Bologna, Bologna, Italy, 8 Department of Mechanical, Energy and Management Engineering, University of Calabria, Rende, Italy, 9 Department of Life and Environmental Sciences, Polytechnic University of Marche, Ancona, Italy, 10 Stazione Zoologica Anton Dohrn, Naples, Italy, 11 Istituto di Scienza e Tecnologie dell’Informazione – Consiglio Nazionale delle Ricerche (ISTI-CNR), Pisa, Italy, 12 LIS UMR 7020, Aix-Marseille Université, Centre national de la recherche scientifique – École nationale Supérieure d’Architecture de Montpellier (CNRS-ENSAM), Université De Toulon, Domaine Universitaire de Saint-Jérôme, Marseille, France, 13 Department of Evolutionary Biology, Ecology and Environmental Sciences, Institut de Recerca de la Biodiversitat (IRBio), University of Barcelona, Barcelona, Spain, 14 Computer Vision and Robotics Institute, University of Girona, Girona, Spain, 15 Institute of Marine Sciences Consejo Superior de Investigaciones Científicas (CSIC), Barcelona, Spain, 16 Centro Interdisciplinar de Investigação Marinha e Ambiental (CIIMAR), Porto, Portugal, 17 3DOM – 3D Optical Metrology Unit, Fondazione Bruno Kessler (FBK) – Bruno Kessler Foundation, Trento, Italy, 18 Underwater Bio-Cartography (UBICA) srl, Genova, Italy, 19 Habitats Edge Ltd., Norwich, United Kingdom, 20 Department of Industrial Engineering, University of Florence, Florence, Italy, 21 Interuniversity Center of Integrated Systems for the Marine Environment (ISME), Genova, Italy, 22 Department of Biological and Environmental Sciences and Technologies, University of Salento, Lecce, Italy, 23 Labomar, Universidade Federal do Ceará, Fortaleza, Brazil, 24 Civil Engineering and Geomatics Department, Cyprus University of Technology, Limassol, Cyprus, 25 School of Marine Sciences, University of Haifa, Haifa, Israel, 26 Department of Cultural Heritage, University of Bologna, Ravenna, Italy Marine animal forests are benthic communities dominated by sessile suspension feeders (such as sponges, corals, and bivalves) able to generate three-dimensional (3D) frameworks with high structural complexity. The biodiversity and functioning of marine animal forests are strictly related to their 3D complexity. The present paper aims at providing new perspectives in underwater optical surveys. Starting from the current gaps in data collection and analysis that critically limit the study and conservation of marine animal forests, we discuss the main technological and methodological needs Frontiers in Marine Science | www.frontiersin.org 1 March 2021 | Volume 8 | Article 591292