In an octopus's garden in the shade: Underwater image analysis of litter use by benthic octopuses

• Published in: Marine pollution bulletin Vol. 175; p. 113339
• Main Authors: Freitas, Tainah B.N., Leite, Tatiana S., de Ramos, Bruna, di Cosmo, Anna, Proietti, Maíra C.
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.02.2022; Elsevier BV
• Subjects: Animals; Asia; Benthos; Cephalopoda; Citizen Science; Environmental Monitoring - methods; gardens; glass; Image analysis; Image processing; Impacts; Litter; Marine debris; Marine molluscs; Marine pollution; Octopodiformes; Octopuses; Plastics; Records; Seafood; Shelter selection; Shelters; species; Underwater; Waste Products - analysis; Asia; Cephalopoda; Impacts; Shelter selection; Citizen science; Octopuses; Marine debris
• ISSN: 0025-326X; 1879-3363; 1879-3363
• DOI: 10.1016/j.marpolbul.2022.113339

Benthic octopuses have been widely documented in artificial shelters for decades, and this use is apparently increasing. Despite any possible positive effects, the use of litter as shelter could have negative implications. In this work, we aimed to elucidate the interactions of octopuses with marine litter, identifying types of interactions and affected species and regions. To achieve this, we obtained 261 underwater images from ‘citizen science’ records, and identified 8 genera and 24 species of benthic octopuses interacting with litter. Glass objects were present in 41.6% of interactions, and plastic in 24.7%. Asia presented the highest number of images, and most records were from 2018 to 2021. Citizen science provided important evidence on octopus/marine litter interactions, highlighting its value and the need for more investigations on the subject. This information is fundamental to help prevent and mitigate the impacts of litter on octopuses, and identify knowledge gaps that require attention. •Worldwide underwater images showed benthic octopuses interacting with litter.•Sheltering in glass items was the most common interaction.•Amphioctopus marginatus was the main species observed in images.•Underwater ROV surveys showed deep-sea species interacting with marine litter.•Images from divers emerge as a valuable tool to better understand this interaction.