In hot water? Study says warming may reduce sea life by 17%

In hot water? Study says warming may reduce sea life by 17%
In this Sept. 10, 2018, file photo a lobster takes a defensive posture as it moves to hide below aquatic plants off the coast of Biddeford, Maine. A study published Tuesday, June 11, 2019 finds a warmer world may lose a billion tons of fish and other marine life by the end of the century. The international study used computer models to project that for every degree Celsius the world warms, the total weight of life in the oceans drop by 5%. (AP Photo/Robert F. Bukaty, File)

The world's oceans will likely lose about one-sixth of their fish and other marine life by the end of the century if climate change continues on its current path, a new study says.

Every degree Celsius (1.8 degrees Fahrenheit) that the world's oceans warm, the total mass of sea animals is projected to drop by 5%, according to a comprehensive computer-based study by an international team of marine biologists. And that does not include effects of fishing.

If the world's greenhouse gas emissions stay at the present rate, that means a 17% loss of biomass—the total weight of all the marine animal life—by the year 2100, according to Tuesday's study in the Proceedings of the National Academy of Sciences. But if the world reduces carbon pollution, losses can be limited to only about 5%, the study said.

"We will see a large decrease in the biomass of the oceans," if the world doesn't slow climate change, said study co-author William Cheung, a marine ecologist at the University of British Columbia. "There are already changes that have been observed."

While warmer water is the biggest factor, climate change also produces oceans that are more acidic and have less oxygen, which also harms sea life, Cheung said.

Much of the world relies on the oceans for food or livelihood, scientists say.

In hot water? Study says warming may reduce sea life by 17%
In this March 28, 2018 file photo, a North Atlantic right whale feeds on the surface of Cape Cod bay off the coast of Plymouth, Mass. A study published Tuesday, June 11, 2019 finds a warmer world may lose a billion tons of fish and other marine life by the end of the century. The international study used computer models to project that for every degree Celsius the world warms, the total weight of life in the oceans drop by 5%. (AP Photo/Michael Dwyer, File)

"The potential ramifications of these predicted losses are huge, not just for ocean biodiversity, but because people around the world rely on ocean resources," said University of Victoria biology professor Julia Baum, who wasn't part of the study but says it makes sense. "Climate change has the potential to cause serious new conflicts over ocean resource use and global food security, particularly as human population continues to grow this century."

The biggest animals in the oceans are going to be hit hardest, said study co-author Derek Tittensor, a marine ecologist at the United Nations World Conservation Monitoring Center in England.

"The good news here is that the main building blocks of marine life, plankton and bacteria may decline less heavily, the bad news is that those marine animals that we use directly, and care about most deeply, are predicted to suffer the most as climate change is working its way up the food chain," co-author Boris Worm, a marine biologist at Dalhousie University in Canada, said in an email.

Tropical areas, already warm, will also see the biggest losses, Cheung said.

Scientists had already thought that climate change will likely reduce future ocean life, but past computer simulations looked at only part of the picture or used only one model. This study uses six different state-of-the-art computer models that give the best big picture look yet, Cheung said.

It is hard to separate past climate change impacts from those of fishing, but past studies have shown places where observed fish loss can be attributed to human-caused climate change, Chung added.

In hot water? Study says warming may reduce sea life by 17%
In this Wednesday, July 8, 2015 file photo, herring are unloaded from a fishing boat in Rockland, Maine. A study published Tuesday, June 11, 2019 finds a warmer world may lose a billion tons of fish and other marine life by the end of the century. The international study used computer models to project that for every degree Celsius the world warms, the total weight of life in the oceans drop by 5%. (AP Photo/Robert F. Bukaty, File)

Tittensor pointed to lobsters off Maine and North Atlantic right whales as examples of creatures already being hurt by global warming hitting the ocean.

University of Georgia marine biologist Samantha Joye, who wasn't part of the research, praised the study as meticulous and said it is also "an urgent call for action."

"Healthy oceans are required for planetary stability," Joye said in an email. "Aggressive global action to slow climate change is a moral imperative."


Explore further

Effective fisheries management can reduce extinction risk of marine fish stocks

More information: Global ensemble projections reveal trophic amplification of ocean biomass declines with climate change, Proceedings of the National Academy of Sciences (2019). DOI: 10.1073/pnas.1900194116 , https://www.pnas.org/content/early/2019/06/10/1900194116.short

© 2019 The Associated Press. All rights reserved.

Citation: In hot water? Study says warming may reduce sea life by 17% (2019, June 11) retrieved 21 October 2019 from https://phys.org/news/2019-06-hot-sea-life.html
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.
1202 shares

Feedback to editors

User comments

Jun 11, 2019
Study says warming may reduce sea life by 17%


is that what happened during the Holocene Climate Optimum? If not, why not? The poor critters were coming out of the last glacial maximum for algore's sake, and global temperatures had sky-rocketed.

Jun 11, 2019
That spells the death knell for the climate science denial idea that CO2 is always "a nutrient". The land plant biomass production is roughly unaffected (by CO2 variation alone), but the ocean animals biomass production decreases roughly linearly (by total warming effect).

Jun 11, 2019
It was 15 degrees C warmer on Earth though most it's history, with plenty of life everywhere including the sea.

This basic fact never mentioned, should be the death knell for climate alarmist fools.

None of the warming has anything to do with CO2. It's a long Sun cycle, 100 million on, 20 million off, repeat.

if climate change continues on its current path


It's current natural path, which is very slow warming.
Banks still give out 30 year mortgages in Miami. So it's slow alright. Alarmist fool article.


Jun 11, 2019
It's current natural path, which is very slow warming


https://cdn.theat...B-CD.jpg

https://en.wikipe...ison.png
None of the warming has anything to do with CO2.
So look hard at the last couple of hundred years of either one of those graphs - and tell us what the driver of the up tick in temperatures is. Please (-:

Jun 11, 2019
This is unpredictable.

Jun 11, 2019
It's beyond amusing to see just what morons the AGW Cult take their Chicken Littles for.
The gold standard for SST from the Argo buoys has showed the oceans cooling, so what is the Cult to do. Well, they cook the data and then blatantly conceal the original from the scientific community.

Jun 11, 2019
Argo buoys show the ocean is warming.

https://undark.or...scandal/
The fact that the new NOAA record is effectively identical with records constructed only from higher quality instruments (buoys, satellite radiometers, and Argo floats) strongly suggests that NOAA got it right and that we have been underestimating ocean warming in recent years.

Jun 11, 2019
Why don't the climate change naysayers say what their real reasoning is --- "Too bad for your grandkids and the fishes, but I just want to keep driving my gas guzzler and pretend things will be as they always were"

Jun 11, 2019
Liar... Liar... Pants on fire...

It was 15 degrees C warmer on Earth though most it's history, with plenty of life everywhere including the sea.
- Old C Code

Land plants didn't evolve until around 450 million years ago.
The first land animals didn't show up until 370 million years ago.

The Earth is 10 times older than those ages.

So why did you feel a need to lie about it, Old C Code?

Jun 11, 2019
Liar.. Liar... Pants on fire...

The gold standard for SST from the Argo buoys has showed the oceans cooling, so what is the Cult to do.
- Antigoracle

http://www.argo.u...tml#temp

You are mentally ill, boy.
Seek medical attention.


Jun 11, 2019
So look hard at the last couple of hundred years of either one of those graphs


Totally crap data. You are full of chit. You can't even see the current century in the first.

If thing s were truly dire, banks wouldn't be giving out 30 year mortgages in Miami.

Jun 11, 2019
Land plants didn't evolve until around 450 million years ago.
The first land animals didn't show up until 370 million years ago.


Yo meathead, The Cretaceous, Triassic, Jurassic and more.
all less than 370 million years ago you arrogant buffoon.

When you look at Earth's temperature history graph, it's basically a square wave with a 85% duty cycle. Warm at 25 C for 100 million years or so (proper order of magnitude) to 10 C for 20 million years or so (proper order of magnitude, could be more or less).

Jun 12, 2019
Old C -
Totally crap data
Of course said without providing any data of your own. I am sure you could make up better data Old C - why not give it a shot. Remember to make sure that it reflects your assertion
It's current natural path, which is very slow warming

Jun 12, 2019
There are too many variables to predict what will happen to sea creatures. All we know is that CO2 levels are going up. It is strongly correlated with a warmer earth in the past and life flourished under these conditions. We also know that photovoltaics, biomass,batteries, and wind are the here and growing fast. Fossil fuels will be on a big down trend within 10 years.

Jun 12, 2019
All we know is that CO2 levels are going up. It is strongly correlated with a warmer earth in the past and life flourished under these conditions
Well that is good to know grandpa - we can all stop worrying now - because you have declared that everything is copacetic. Are you a scientist by the way? Do you study these issues? Can you tell us why the insects are dying?

https://news.mong...america/

Jun 12, 2019
Love it when antigoracle and all his sockpuppies come out to play, trying harder than life itself to prove their utter cluelesness about climate change and it works, Everytime :), and today the comment of his grandpa sock "All WE know is..."
That WE being himself and all his single minded puppets above, they which is antigoracle himself alone only know what he can thumbsuck up and put down in writing. Not having a stone cooking clue as to what Science And reality is.

Jun 12, 2019
Of course said without providing any data of your own.


Look at a graph of Earth's temperature history, fool.

You guys are such lame debaters. The insects vanishing from warming? lol

Jun 12, 2019
Look at a graph of Earth's temperature history, fool
No you look at the graph. You said
It's current natural path, which is very slow warming
So I presented two graphs - that contradict your assertion. So who is the bad debater. When you make an assertion - you support your assertion with evidence. When someone questions your assertion (made without evidence) - and actually presents evidence to support their challenge - you can provide your counter evidence - or you can hide behind stupid little quips - and not provide any evidence. So you show us how the earth's natural path is one of slow warming. Fool.

Do you want to challenge my assertion that scientists are really really concerned about the crash of insect populations around the world. You are the one saying - high C02 levels - equals thriving life. Where is your evidence - fool?????

Jun 12, 2019
I think Antigoracle's granny sockpuppet glasses misted up because of global warming, of course he can still not figure out that the climate it changing. it's like putting his finger in the fire, while it burns he'll scream of the pain, but won't be able to figure out it's the flame thats burning him. It must be some thumbed sucked phenomena right ? lol...

Jun 12, 2019
Here's an example of the Earth history square wave temperature profile I've seen several places on the web... thing is, University graphs don't seem to show up at the top on google.
I don't know what medium.com is... the blue curve on the graph.

https://medium.co...69a68046

Just search for various temperature profiles on the web, like "Jurassic Temperature" which shows a 7 C increase in warming, at the top of google... that alone proves my point. Though 15 C was common further back.

Jun 12, 2019
Old C
Here's an example of ...
But you said
It's current natural path, which is very slow warming
So I challenge you on that assertion - and I provide evidence to support my challenge. Now you supply a graph that shows the exact opposite. The point being - that you are a denier - you make wild assertions - and when asked for actual support for your assertions - you spout a bunch of bullshit. Hope you understand that people who are interested in science - which requires evidence and support - get snarky with you.

Jun 13, 2019
A one sided slap everyday, i guess if you isolate yourself from reality like antigoracle, the phantoms become real :)

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more