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octopuses

Octopuses May Be Adapting to The Rising Acidity of Our Oceans, Study Suggests

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We know that all the excess CO2 we’re pumping into the air – alongside a host of other damaging effects – is driving up the acidity of the oceans as it sinks and dissolves into the water, but it seems as though the hardy octopus can find ways to adapt to its rapidly changing environment.

 

Previous research into the impact of ocean acidification on cephalopods such as octopuses, cuttlefish, and squid has shown some indication increased carbon dioxide in the water could negatively impact this type of marine life.

However, in a new study, a group of Octopus rubescens – a species of octopus common to the west coast of North America – were observed adjusting their routine metabolic rate (RMR) over a series of weeks in response to lowering pH levels in the surrounding water.

“Challenges to an organism’s physiology are often reflected in changes in energy use and therefore can be observed as changes in aerobic metabolic rate,” write the researchers in their paper.

A total of 10 octopuses were studied under controlled lab conditions, with RMR measured immediately after exposure to acidic water, after one week, and after five weeks. Critical oxygen pressure – a measure of whether not not animals are getting enough oxygen – was monitored at the same time.

To begin with, high levels of metabolic change were detected in the creatures – a sort of shock reaction that actually conflicts with earlier research into cephalopods, which had recorded a reduction in metabolic change in similar scenarios.

 

However, RMR had returned to normal after one week, and remained the same five weeks later, suggesting some adaptation had occurred. The increased acidity did have an impact on the ability of the octopuses to function at low oxygen levels, however.

“This response in RMR suggests that O. rubescens is able to acclimate to elevated CO2 over time,” write the researchers. “The observed increase in RMR may be the result of multiple acute responses to hypercapnia [increased CO2 in the blood], possibly including both behavioural and physiological strategies.”

Those strategies could include preparing to move to find a new stretch of water to inhabit, for example, the researchers suggest (something that wasn’t possible here). The short RMR boost might also reflect the octopuses making quick adjustments to their biological processes to suit the new acid level.

The study is the first to look at both short-term (one week) and longer-term (five week) changes in metabolism rates in cephalopods in response to ocean acidification. We know these creatures are tough, and it seems they even have coping strategies that might allow them to adapt to humans destroying the natural environment all around them.

None of this means that we should be okay with the current climate crisis though, or not be trying to make major changes to reverse it. When we don’t take proper care of the planet, it’s not just ourselves that we’re potentially dooming to extinction.

Also, these tests were done in controlled laboratory conditions that don’t take into account many other interlinking factors in the animals’ natural environment. For instance, even if the octopus themselves are able to adjust, what about their food supply?

“While this species may be able to acclimate to near-term ocean acidification, compounding environmental effects of acidification and hypoxia may present a physiological challenge for this species,” write the researchers.

The research has been published in Physiological and Biochemical Zoology.

 



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Scientists Have Warned That We Absolutely Must Not Farm Octopuses

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There’s no denying that keeping livestock has deeply benefited humanity over the millennia. But, while sheep and cows may have adapted well to farm life, there’s one animal humans like to eat that would fare poorly in farms.

 

Octopuses, scientists have argued in a May 2019 essay, should never be farmed – not just because of their intelligence, but because of the environmental impacts such farms would create.

It’s already started. Global demand for octopus as a food is on the rise, which last year saw prices soaring amid poor supply

The yield of octopuses fished in the wild is variable, which in turn contributes to an unreliable supply – hence attempts to farm octopuses have already commenced. In multiple countries around the world, efforts are underway to produce an octopus farm, including trials of genetic modifications to accelerate cephalopod aquaculture.

This, of course, would produce some known environmental impacts, a team of environmental scientists, philosophers and psychiatrists writes in a recent edition of Issues in Science and Technology.

Such impacts include nitrogen and phosphorus pollution from animal waste, interbreeding and the spread of disease, and loss of habitat, to name a few.

But the biggest environmental concern is the octopus diet. Like most farmed aquatic creatures, they’re carnivores, and need fish protein and oil in their diet. And octopus larvae only eat live food – that has to come from somewhere.

 

“Feeding most farmed aquatic animals puts additional pressure on wild fish and invertebrates for fishmeal,” the researchers wrote.

“Around one-third of the global fish catch is turned into feed for other animals, roughly half of which goes to aquaculture. Many fishmeal fisheries are subject to overfishing and are declining.”

Octopuses need a lot of food – at least three times the weight of the animal over its lifetime – and making sure their needs are met in factory farms would create more, not less pressure on these already declining fisheries. This would likely decrease global food security for humans.

But, even if this problem could be solved, keeping octopuses in factory farms would be cruel.

If you’ve ever been to a marine aquarium, you likely know this. Octopuses are well known for their intelligence and problem-solving skills. Toys are often kept in the octopus tanks to keep the cephalopods from getting bored.

They can open jars, recognise individual humans, remember puzzles they’ve been given before, even escape an aquarium when they’ve had enough (so, you know, that’s a consideration too – imagine an entire farm of octopuses making a jailbreak).

 

They’ve also shown worrying behaviours in captivity, including cannibalism, and eating the tips of their own tentacles (which could be the result of an infectious disease). In an environment with no stimulation, these animals grow frustrated and bored.

“Beyond their basic biological health and safety, octopuses are likely to want high levels of cognitive stimulation, as well as opportunities to explore, manipulate, and control their environment,” the scientists wrote. “Intensive farm systems are inevitably hostile to these attributes.”

At the moment, there are some pretty big challenges to overcome even getting an octopus farm off the ground, such as keeping the young animals alive through to adulthood. But technological advances could see that change.

Research is surging ahead around the world. Octopus farming experimentation in Mexico has reported breakthroughs in the last decade, and a Japanese seafood company has reported successfully hatching eggs in 2017. They have predicted they’d have farmed octopus on the market next year.

With so many problems already evident, the scientists are hoping this can be nipped in the bud.

“It is our hope that if such an option does become practical, society will recognise the serious welfare and environmental problems associated with such projects and octopus farming will be discouraged or prevented,” they wrote.

“Better still would be for governments, private companies, and academic institutions to stop investing in octopus farming now and to instead focus their efforts on achieving a truly sustainable and compassionate future for food production.”

The essay was published in Issues in Science and Technology 35.

A version of this article was first published in May 2019.

 



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Watch The Mesmerising Colour Shifts of a Sleeping Octopus

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You ever watch your pets sleeping? When they twitch their paws and whiskers, and yip and mewl? Well, cats and dogs experience REM sleep, which means they’re probably dreaming. And, while evidence of REM sleep has so far not been seen in octopuses, they do have a kind of sleep twitch of their own.

 

Sleeping octopuses flicker. While they rest, some neuronal firing in their optic lobe causes their chromatophores, or pigment-containing cells, to become active.

As a result, the octopuses shift between colours and patterns while they snooze, as though they’re reacting to something that only they can sense.

This effect is seen beautifully in a newly released video, filmed for the documentary Octopus: Making Contact on Nature on PBS. It’s narrated by marine biologist David Scheel of Alaska Pacific University, who explains the colour changes of a sleeping octopus named Heidi.

These colour and pattern shifts seem consistent with real-world behaviours – Scheel links them to possible real-life encounters.

We don’t really know for sure why we dream, but scientists believe it has something to do with the way the brain processes and stores memories. If that’s the case, it would make sense that many animals dream – even cephalopods, whose intelligence is rather different from how the mammalian brain works.

Although REM sleep hasn’t been recorded in octopuses, another cephalopod has evinced something similar. A 2012 study found that cuttlefish Sepia officinalis “display a quiescent state with rapid eye movements, changes in body colouration and twitching of the arms, that is possibly analogous to REM sleep.”

Heidi isn’t the only octopus filmed changing colours while sleeping. In October 2017, Rebecca Otey, who had been interning at The Butterfly Pavilion invertebrate zoo, filmed a sleeping Caribbean two-spot octopus (Octopus hummelincki) and posted the video to YouTube last year.

We do know that octopuses use their amazing colour-changing ability for camouflage. You’d think involuntary colour spasms would ruin that camouflage, but you can rest as easily as the octopuses on that score. They build themselves hidden dens, where they retire for naps.

If any neuroscientists out there want to look into octopus dreaming, we’d love to know what they find.

 



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Scientists Are Warning That We Absolutely Must Not Farm Octopuses

in Science News by


There’s no denying that keeping livestock has deeply benefited humanity over the millennia. But, while sheep and cows may have adapted well to farm life, there’s one animal humans like to eat that would fare poorly in farms.

 

Octopuses, scientists have argued in a new essay, should never be farmed – not just because of their intelligence, but because of the environmental impacts such farms would create.

It’s already started. Global demand for octopus as a food is on the rise, which last year saw prices soaring amid poor supply. Prices are expected to remain high for at least the rest of 2019.

The yield of octopuses fished in the wild is variable, which in turn contributes to an unreliable supply – hence attempts to farm octopuses have already commenced. In multiple countries around the world, efforts are underway to produce an octopus farm, including trials of genetic modifications to accelerate cephalopod aquaculture.

This, of course, would produce some known environmental impacts, a team of environmental scientists, philosophers and psychiatrists writes in a recent edition of Issues in Science and Technology.

Such impacts include nitrogen and phosphorus pollution from animal waste, interbreeding and the spread of disease, and loss of habitat, to name a few.

But the biggest environmental concern is the octopus diet. Like most farmed aquatic creatures, they’re carnivores, and need fish protein and oil in their diet. And octopus larvae only eat live food – that has to come from somewhere.

 

“Feeding most farmed aquatic animals puts additional pressure on wild fish and invertebrates for fishmeal,” the researchers wrote.

“Around one-third of the global fish catch is turned into feed for other animals, roughly half of which goes to aquaculture. Many fishmeal fisheries are subject to overfishing and are declining.”

Octopuses need a lot of food – at least three times the weight of the animal over its lifetime – and making sure their needs are met in factory farms would create more, not less pressure on these already declining fisheries. This would likely decrease global food security for humans.

But, even if this problem could be solved, keeping octopuses in factory farms would be cruel.

If you’ve ever been to a marine aquarium, you likely know this. Octopuses are well known for their intelligence and problem-solving skills. Toys are often kept in the octopus tanks to keep the cephalopods from getting bored.

They can open jars, recognise individual humans, remember puzzles they’ve been given before, even escape an aquarium when they’ve had enough (so, you know, that’s a consideration too – imagine an entire farm of octopuses making a jailbreak).

 

They’ve also shown worrying behaviours in captivity, including cannibalism, and eating the tips of their own tentacles (which could be the result of an infectious disease). In an environment with no stimulation, these animals grow frustrated and bored.

“Beyond their basic biological health and safety, octopuses are likely to want high levels of cognitive stimulation, as well as opportunities to explore, manipulate, and control their environment,” the scientists wrote. “Intensive farm systems are inevitably hostile to these attributes.”

At the moment, there are some pretty big challenges to overcome even getting an octopus farm off the ground, such as keeping the young animals alive through to adulthood. But technological advances could see that change.

Research is surging ahead around the world. Octopus farming experimentation in Mexico has reported breakthroughs in the last decade, and a Japanese seafood company has reported successfully hatching eggs in 2017. They have predicted they’d have farmed octopus on the market next year.

With so many problems already evident, the scientists are hoping this can be nipped in the bud.

“It is our hope that if such an option does become practical, society will recognise the serious welfare and environmental problems associated with such projects and octopus farming will be discouraged or prevented,” they wrote.

“Better still would be for governments, private companies, and academic institutions to stop investing in octopus farming now and to instead focus their efforts on achieving a truly sustainable and compassionate future for food production.”

The essay has been published in Issues in Science and Technology 35.

 



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