When seashells are sold as souvenirs at the seaside, various types of sea life are forced to adapt and use other abundant materials along the ocean floor for shelter, even human waste.
A new analysis has found octopuses use trash, like plastic and glass bottles, as camouflage, shelter and even a place to lay their eggs, the report reports. Independentis Vishwam Sankaran. The study, published last month in the Marine Pollution Bulletinanalyzed images from social media, marine institutions and diving interest groups that show octopuses interacting with human waste, reports Linda Geddes for the Guardian.
For decades, researchers and divers have observed curious octopuses investigating litter, often using the objects as tools or taking up residence in containers like jars or glass bottles. However, the study illustrates how widespread the behavior is. Marine biologists gathered 261 underwater images and videos of octopuses using marine litter from posts shared on social media websites and collected by research institutes. A total of 24 different species of octopus have been found sheltering in broken glass bottles, soda cans and even old batteries. According to Guardiansome buried themselves under a mixture of seashells and bottle caps.
“It’s becoming so common that they use these objects for protection instead of their natural shelters, like seashells, which are becoming scarce in the ocean,” said study author Maira Proietti, an oceanographer at the Federal University of Rio Grande. tells CBC.
Scientists have even observed a coconut octopus (Amphioctopus marginatus) “stilt walking”, which occurs when the animal hides its upper body inside a container, but sticks its arms out from under the object to crawl on the ground and look for food. Usually this species “walks on stilts” using shells or coconuts. The coconut octopus was the most frequently observed species interacting with litter, reports Carly Cassella for Scientific alert.
In total, the research team found that 40% of interactions happened with glass objects, while 25% involved plastic objects, the Independent reports. Scientists suspect this could be because glass more closely mimics the texture and feel of seashells.
Analyzing the data, the biologists also found that octopus interactions with litter increased the most between 2018 and 2021. However, the increase could be attributed to the increased accessibility of underwater photography, but could also indicate that ocean pollution is getting worse, Scientific alert reports. Images obtained from remotely operated vehicles have revealed for the first time that deep-sea octopuses in the Mediterranean also use sunken waste.
Surprisingly, the team found the recently described pygmy octopus (Paroctopus cthulu) has only been observed using marine litter, such as beer cans, as shelter. Scientists have yet to observe the tiny sea creature using natural objects, such as seashells, which could indicate a scarcity in their environment, for Scientific alert.
While the results are eye-opening, Stefan Linquist, a biological philosopher at the University of Guelph, told CBC the study lacked a control subject. Comparing octopuses to other sea creatures that may use trash in the same way would allow the research team to observe how common the behavior is across different species.
“Ideally, you’d want a comparable species that also digs burrows for shelter. Then we could at least ask the question of whether octopuses are more or less dependent on litter, based on the images. In the state things stand, we don’t have any comparative information,” Linquist said. tells CBC via email.
Study author Proietti told CBC that collecting the outsourced images was a complicated process, so a control subject was not studied but could serve as an entry point for a study of monitoring.
Despite their ability to adapt to the increasing presence of trash in their habitat, the use of batteries or plastic objects could expose cephalopods to heavy metals or harmful chemicals, according to the Independent.
“This information is fundamental to help prevent and mitigate the impacts of litter on octopuses and identify knowledge gaps that require attention,” the study authors write in the paper.