Chambered nautiluses might be the last members of an ancient lineage that stretches back 500 million years, but all of that time on earth hasn't done much for their coordination.
What looks to be trash lying on the sea floor in the video is actually a netted can, positioned as part of ongoing research from the Save the Nautilus Foundation (SNF). The clumsy cohort of marine molluscs is simply trying to get a share of the delectable rotting meat within.
"Nautiluses roam around the bottom of the ocean seeking the smell of rotting meat," explains project director Dr Gregory Barord. "So we set our traps with chicken, drop them between 300 and 400 metres deep, and hope for the best."
Unlike the tentacles of their octopus cousins, the appendages of a nautilus are suckerless. Instead, grooves and ridges on the tentacles are used to grip prey and deliver it to a crushing, parrot-like beak.
By monitoring baited traps throughout the South Pacific, the SNF team hopes to get a better idea of just how many nautiluses exist in the wild, and to find out more about how local fisheries and the global wildlife trade are affecting these enigmatic creatures.
This trio's tiniest member is of particular significance. "This is one of the smallest nautiluses caught on video," the team explains. "We don't know exactly where or when nautiluses lay eggs, or where the hatchlings go right after hatching, or how many hatchlings survive to adulthood."
We also understand very little about the global strongholds and migration patterns of nautilus populations – and those information gaps need to be filled if we want to protect these animals more effectively.
Between 2006 and 2010, over 500,000 nautilus shells were imported into the US alone, and scientists fear the growing demand for nautilus jewellery has led to a tipping point for the ancient animals. While nautilus fishing has been banned in some places, the industry remains highly unregulated.
As jewellery, the opalescent material from the shell’s inner surface is marketed as a cheap alternative to pearl. Shell pieces can fetch hundreds of dollars on eBay, but fishermen in the South Pacific have reported collecting just $1 per shell.
"When it once took only one trap to catch one nautilus, it now takes 10-15 traps to catch just one nautilus," says Barord. And there's another problem: the most highly prized nautilus shells are those with the greatest number of segments – and those belong to fully grown, sexually mature individuals. Just as we've seen with some sharks, when the biggest specimens are targeted, the effects on a population can be extreme.
A nautilus begins life with about four slotted chambers in its shell. The animal itself occupies only the outermost chamber, and as it grows, it must expand its mobile home. More and more calcium carbonate is laid until the spiralled structure has reached some 30 chambers.
It takes a long 12 to 15 years for a nautilus to reach sexual maturity, and they produce just one to ten eggs per brood. This is typical of many deep-sea species since reproduction requires an immense amount of energy – and that can be tricky to store up in an environment where food is scarce. We know nautiluses are vulnerable to fishing pressure, but until marine biologists have a clearer picture of how the animals are coping, the species can't be considered for IUCN, CITES or Endangered Species Act listing.
The SNF team's next step will be to expand the survey region to waters beyond the Philippines and Australia, and collaborate with more local fishermen – a partnership vital to the project's success.
"Our research is not only helping to protect nautiluses. It is also providing data on many other species," adds Barord. "Conserving nautiluses not only protects the overall diversity of the deep sea, but it also promotes good stewardship of the resource by fishermen. The extinction of nautiluses negatively impacts the ecosystem and the fishermen. By working together, we can ensure that everyone and everything survives."
To learn more about the project and ways you can get involved, head on over to the Experiment page.
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Top header image: Wikimedia Commons
Oceans
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