Cephalopods and litter at sea: interactions and potential impacts

, Freitas Tainah, Leite Tatiana, Proietti Maira.

Litter in the ocean, which is mostly composed by plastics, has numerous negative effects on several organisms; however, the extent of such impacts is not well known for all groups. Few studies have explored the interaction of invertebrates with litter, but negative impacts have already been recorded for corals, polychaetes, crustaceans and cephalopods. Considering the ecological and economic importance of cephalopods, it is necessary to better understand the impacts of litter on this group. In this work, we review the types of documented interactions between cephalopods and litter, in order to evaluate impacts and knowledge gaps. We performed a scientometric analysis of data collected from scientific literature and citizen science, and found 21 scientific articles and 243 underwater photos, in which we recorded 23 species of benthic octopuses and 7 cuttlefish interacting with litter worldwide. Microplastic ingestion has been observed for the squid Dosidicus gigas, and the transfer of synthetic microfibers from the pelagic octopus Argonauta nouryi to its predators has been investigated. The largest number of records involved use of litter as dens, and transparent plastic and glass items were the materials most used (respectively 21.5% and 28.4%). Asia presented the largest number of records, especially Indonesia, and the octopus Amphioctopus marginatus was the most common species observed. With citizen science images we also observed the deposition of squid eggs on fishing gear, but the main recorded interaction was litter use as dens - which could represent a potential positive impact. However, it is necessary to clarify the ecological implications of this choice and its long-term consequences to organisms. Regarding ingestion, further studies are needed to elucidate its occurrence and impacts on cephalopods and their predators, including humans. Citizen science provided important information, highlighting its value and the need for more scientific investigations on the subject.

View online