Major reductions in seafloor marine life from climate change by 2100

Major reductions in seafloor marine life from climate change by 2100
Large animals (megafauna), such as this hydroid Corymorpha glacialis, are projected to suffer major declines under the latest climate change predictions. Credit: National Oceanography Centre

A new study quantifies for the first time future losses in deep-sea marine life, using advanced climate models. Results show that even the most remote deep-sea ecosystems are not safe from the impacts of climate change.

An international team of scientists predict seafloor dwelling will decline by up to 38 per cent in the North Atlantic and over five per cent globally over the next century. These changes will be driven by a reduction in the plants and animals that live at the surface of the oceans that feed deep-sea communities. As a result, ecosystem services such as fishing will be threatened.

In the study, led by the National Oceanography Centre, the team used the latest suite of to predict changes in throughout the world oceans. They then applied a relationship between food supply and biomass calculated from a huge global database of marine life.

The results of the study are published this week in the scientific journal Global Change Biology.

These changes in seafloor communities are expected despite living on average four kilometres under the surface of the ocean. This is because their food source, the remains of surface ocean marine life that sink to the seafloor, will dwindle because of a decline in nutrient availability. Nutrient supplies will suffer because of climate impacts such as a slowing of the , as well as increased separation between water masses – known as 'stratification' – as a result of warmer and rainier weather.

Lead author Dr Daniel Jones says: "There has been some speculation about on the seafloor, but we wanted to try and make numerical projections for these changes and estimate specifically where they would occur.

"We were expecting some negative changes around the world, but the extent of changes, particularly in the North Atlantic, were staggering. Globally we are talking about losses of marine life weighing more than every person on the planet put together."

The projected changes in marine life are not consistent across the world, but most areas will experience negative change. Over 80 per cent of all identified key habitats – such as cold-water coral reefs, seamounts and canyons – will suffer losses in total biomass. The analysis also predicts that animals will get smaller. Smaller animals tend to use energy less efficiently, thereby impacting seabed fisheries and exacerbating the effects of the overall declines in available food.

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More information: Jones, D.O.B., Yool, A., Wei, C-L., Henson, S.A., Ruhl, H.A., Watson, R.A., Gehlen, M. (2013) Global reductions in seafloor biomass in response to climate change, Global Change Biology, DOI: 10.1111/gcb.12480
Journal information: Global Change Biology

Citation: Major reductions in seafloor marine life from climate change by 2100 (2013, December 31) retrieved 17 September 2019 from
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Dec 31, 2013
"using advanced climate models"

Four words that have changed the face of science - for the worse, and forever.

Follow the money.

Dec 31, 2013
"Climate models" again...

The climate models showing a reduction in biomass with a warming climate, and Old Mother Earth doing exactly the opposite, must mean Old Mother Earth is wrong!

Dec 31, 2013
All the same BS...

Dec 31, 2013
Ironically, China has been easing it's "one child per couple" policy, for no rational reason within their prior policy.

As population grows, whatever damage we are doing will increase.

Suppose we assume the Earth can keep up with "X" number of billion humans, assuming the humans were recycling, reusing as much as possible and conserving properly.

In the real world, we are doing none of those things, therefore the real Earth can't support as many people, whatever the real number is, but for sake of argument we ignore that fact.

Now as our population passes "X", whatever that number is, detrimental effects do not grow linearly with population, they grow cumulatively, which is to say, the excess from one year carries forward to the next year, contributing twice as much excess that year...Once you have an excess, even if population stops growing and remains the same, the excess pollutants continue growing linearly. If population resumes growing, the pollutants resume quadratically.

Dec 31, 2013
But that math isn't hard to do. The real issue is the assumption of how much is too much, how much is beyond the Earth's ability to deal with.

For example, I am wondering how much deep ocean life the authors think was present in past eons, such as the Cretacious and Triassic periods, where CO2 was much higher.

Personally, I think over-fishing is probably a bigger threat to aquatic ecosystems than CO2 ever will be, since at 7 billion population we have already greatly reduced the number of large predatory fish, either by killing them directly, or by out competing them for the food supply. If our population were to increase by a few billion more, we could easily fish these species to extinction far sooner than any alleged AGW conditions would threaten them.

if 7 billion of us have reduced large fish population by 90%, then each billion represents more than 10% reduction.

An 8th billion of people would then represent extinction, given the same policy and behavior.

Dec 31, 2013
Major reductions in seafloor marine life from climate change by 2100

That's funny, were already seeing major reductions in seafloor marine life right now.


among other things...


If CO2 caused climate change is Russian roulette with a revolver, nuclear power is Russian roulette with a semi-auto.

Jan 01, 2014
We have just discovered these "life" forms. We don't even know enough about them to form hypotheses. Zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz

Jan 01, 2014
face it people. there are too many people on the planet. don't worry though, the united nations has a plan...

Jan 01, 2014
There are certainly too many useless parasites on the planet that produce nothing. Most of them spend lots of time on their computers talking about too many people on the planet. So I have a question for those's your garden and livestock? If you're not part of the solution, you're the problem and if you really cared, you'd kill yourself right now so that those of us who actually contribute wont have to deal with you.

Jan 01, 2014

You are partly correct in a certain sense, but you spoiled your own post with you evil comments at the end.

it is true that a lot of people living in cities and suburbs wouldn't be able to survive a week without rural families, farmers, and fishermen who actually provide the food we eat.

There are millions of city-dwellers who have never grown and harvested their own produce, and have never raised and butchered a livestock animal of any kind. They live on paper work jobs and service jobs, most of which are obsolete and could be done by a computer if owners and executives thought about it the right way.

So yes, from that perspective, lots of people, including many of those executives, are in the role of a parasite socially, fiscally, and ecologically.

Who makes the things that actually provide our living?

Farmers, fishers, construction, light industrial workers, that's who; Not pen and paper pushers.

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