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Ocean carbon sequestration: The climate solution hiding in seaweed forests · How To Protect The Ocean

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  Seaweed forests may be one of the planet's largest natural climate allies, yet
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  most are invisible to climate policy, unprotected by conservation laws and
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  missing from carbon accounting entirely.
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  While mangroves and seagrasses get the spotlight, kelp forest and other seaweed
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  habitat are quietly doing the work without recognition, protection, or funding.
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  So how can one of the most productive ecosystems on earth be almost
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  completely ignored in climate solutions?
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  We're gonna be talking about that on today's episode of the How
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  to Protect the Ocean Podcast.
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  Let's start the show.
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  Hey everybody.
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  Welcome back to another exciting episode of the How to Protect the Ocean Podcast.
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  I'm your host, Andrew Lewin, Marine biologist and science communicator
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  here to tell you what's happening with the Ocean, how you can speak up for
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  the Ocean, and what you can do to live for a better Ocean by taking action.
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  And you're probably wondering right off the bat, Andrew,
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  what's going on with your voice.
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  If you listen to this podcast for any number of times,
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  this is not my normal voice.
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  If you're new here, this isn't my normal voice.
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  I was at a hockey tournament.
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  I coach hockey for my youngest and she's in new 18.
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  We had a great tournament.
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  We got to the semis, and I lost my voice.
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  It just happens.
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  This is what happens.
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  I tried to do a recording beforehand, ran outta time, but
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  now I am doing this recording because this is an important topic.
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  We're talking about seaweed, not seagrasses, which
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  I've talked about before.
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  I've talked about seaweed before in terms of kelp, but we're gonna talk about a
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  number of different things of seaweed, and I just want you to think, although I
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  may not mention every species of seaweed or really a lot of species of seaweed.
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  I'm gonna be telling you just about seaweed in general and
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  how important it is in climate solutions in blue carbon capture.
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  Now, a lot of the times you're going to hear about carbon capture in Canada,
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  you're gonna be here all around the world.
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  A lot of oil and gas execs and supporters like to use the fact
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  that they use carbon capture.
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  Well, carbon capture can be done well except if you're putting
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  out so much greenhouse gases.
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  Carbon capture does not and has not been able to keep up with the demand.
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  But we do have natural sources of carbon capture.
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  Trees and forests are one, but they do not have the ability to take in
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  as much carbon as you would think.
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  When you have seagrasses, mangroves, kelp forest is a seaweed and other
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  seaweed, you would be able to capture four to 10 times more carbon
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  than any other tree on the planet.
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  So.
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  Why do we not focus on that?
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  Why are we not focusing on rebuilding or protecting seagrasses, mangroves
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  and then the seaweeds like kelp so that we can better protect our
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  planet against climate change?
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  That is the question that we're gonna be talking about today,
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  especially focusing in on seaweed.
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  Kelp and other seaweed.
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  The first thing we should do is define what blue carbon is.
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  Blue carbon refers to the carbon captured and stored by
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  coastal and Marine ecosystems.
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  So traditionally it includes, like I said, mangrove, salt marshes
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  even, and seagrass meadows.
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  These systems trap carbon in sediments for centuries to millennia, which is great.
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  They are recognized in climate frameworks such as National Carbon Inventories.
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  but there's a major carbon capturing ecosystem that is missing from
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  that list, and that is seaweed.
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  Seaweeds, including kelp forest and macroalgae grow incredibly fast, and a
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  lot of times people don't like seaweed.
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  We have to have a lot of problem with seaweed when we put our feet into the
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  Ocean, if we're away on a trip to a tropical paradise, we see seaweed.
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  We're like, ah, I don't like seaweed on my feet.
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  It feels gross.
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  But it's a naturally occurring thing.
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  It's something that should be in the ocean.
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  Now sometimes, it's a lot and sometimes it's not so much, but it's always
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  there and people don't like it.
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  Oftentimes in resorts and in anywhere where there's tropical
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  areas where there's a high tourist attraction or a high tourist usage,
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  you'll see dredging of the seaweed.
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  And dredging of the beach because people don't wanna see seaweed,
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  so they'll clean up the seaweed.
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  But it's a natural occurring It's required to be there in the ecosystems
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  because part of the ecosystem, and it does a really good job at capturing carbon.
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  The only thing is, is like even though they capture massive amounts of carbon
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  dioxide through photosynthesis, much of their carbon isn't staying in that
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  same area like seagrasses or mangroves.
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  When seagrasses or mangroves take in carbon through photosynthesis,
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  they actually put it into the sediments right below where they are.
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  With algae, algae can break off and it can float across oceans through
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  circulation patterns and so forth.
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  And so the fact that they don't stay there is very difficult to
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  measure how much carbon is actually being captured in that one area.
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  That carbon can sink as it floats away.
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  A carbon can sink into the deep sea and it can be stored for hundreds of years
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  in the deep sea, which is fantastic to have as it's naturally occurring.
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  Seaweed does not store the carbon place like mangroves, but it exports
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  carbon across the ocean, which challenges how we measure and value it.
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  Why do seaweed meadows matter beyond carbon?
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  We'll seaweed habitats like kelp forests, they support fish
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  invertebrates and juvenile fish and all different types of life stages.
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  They act as a coastal buffer against waves and erosion.
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  They improve local water quality.
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  Many of the coastal fisheries depend on kelp associated species
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  as another seaweed species.
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  So this is something that is huge.
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  If kelp forests disappear, entire food webs unravel, not just carbon pathways.
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  Entire food webs unravel.
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  So the central problem that the recent scientists have uncovered is that most
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  seaweed ecosystems lack formal protection.
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  Marine protected areas often don't consider kelp specifically.
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  Seaweed is excluded from many blue carbon policies because it
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  does not store carbon locally.
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  So it's very difficult to measure the local carbon storage effect because
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  seaweed is transported across oceans.
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  So climate finance mechanisms rarely apply to macroalgae because even though we
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  know the science of seaweed, it matters, but the policy hasn't caught up to what
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  seaweed could do for the climate system.
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  So climate is only now uncovering the way that carbon is stored in seaweed and how
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  much of it is actually stored in seaweed.
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  And that's through improved tracking of carbon export pathways.
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  So the fact is we start to be able to see how carbon is stored within seaweed
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  and how it's traveled across the way.
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  Now it's a number of different ways that we can see what's happening.
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  Like we better model deep sea carbon sequestration.
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  We better model ocean currents.
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  We recognize that ignoring seaweed underestimates ocean carbon uptake,
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  and of course, growing calls to expand the definition of blue carbon
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  helps include different pathways such as seaweed in this carbon.
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  Now, some of the ways that we can track carbon is very interesting.
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  So we have better ocean centers and autonomous platforms.
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  So autonomous gliders, floats and underwater vehicles now
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  carry biogeochemical sensors.
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  So we can see where carbon is stored and we can also track
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  where that carbon is coming from.
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  So it's not just, this is Marine carbon.
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  It's coming from, this is a carbon that was coming from
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  specific species of seaweed.
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  That's how good we've got it.
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  So these instruments that we have, like these autonomous gliders, the
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  floats, the underwater vehicles, these instruments continually measure
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  dissolved carbon, oxygen, nutrients.
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  They operate for months, even years, in some cases across
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  coastal and offshore water.
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  So these are huge, huge things.
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  So seaweed carbon does not just stay where it grows.
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  These platforms let researchers detect carbon rich water masses moving offshore.
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  Something that ships alone could not track this reliably.
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  So you have to have something like this, some sort of improved systems
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  like we do, like I just mentioned.
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  Now of course we can use stable isotopes to better help distinguish seaweed
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  derived from phytoplankton carbon.
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  Biomarker compounds unique to macroalgae can now be traced
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  in sediments and deep waters.
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  So scientists can now say with far more confidence that this carbon came from kelp
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  and not that just this carbon is Marine.
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  Huge, huge aspect of that.
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  Now of course we can also use particle tracking and ocean balls.
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  This is something that I was going to be doing for my PhD. If
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  I was gonna go through with it.
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  We were gonna be tracking particles within a network of Marine protected areas to
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  see how these biological systems are connected within the marine protected area
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  network to make sure that all the biology, all the larval stages will actually go
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  to another part of the Marine protected area to ensure that is protected.
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  So these high resolution circulation models simulate how seaweed fragments
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  drift and sink particle tracking models follow carbon pathways
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  from coastlines to the deep sea.
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  And models are validated with real world sensor data that I just discussed before.
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  We can also track kelp forests and kelp through remote sensing.
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  So any kind of seaweed extend or productivity satellites can map kelp
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  canopy extent and seasonal growth.
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  So we can see the growth or even a retraction of that habitat from a
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  number of different disturbances.
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  And then of course, long term data sets show how much
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  biomass is produced each year.
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  So you can't just estimate carbon export without knowing how much
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  seaweed exists in the first place.
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  So these satellite imagery are able to close this major accounting gap.
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  And of course now linking the export to long-term storage sediment cores
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  that these big long tubes that go into the sediment, right into the
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  sediment, they can get a number of different layers depending on the
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  size of the core reveals that macro algal carbon is buried at depth.
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  And then genetic and chemical markers linked, buried carbon
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  back to coastal seaweed.
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  If you have the same markers, you can track it back to, like from the depth
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  in like say the middle ocean to a coastal area that's nearby or even further.
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  And it's really cool to be able to have that.
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  So the fact is, without these systems, we didn't know how much carbon the
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  seaweed was actually bearing into the deep sea or around the ocean.
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  And now that we have this, we know that we're underestimating the carbon
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  capture and we know that there's more, and we're getting closer and closer to
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  fully understanding how much the seaweed is not only capturing carbon, but also,
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  that is dispersing it across the ocean.
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  So here is what really needs to change when we talk about seaweed.
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  We need to expand blue carbon definitions to include macroalgae, which is seaweed.
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  Protect seaweed habitats through targeted marine protections, like
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  marine protected areas of kelp habitats.
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  And fund research into carbon export and sequestration.
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  This is something that's really important 'cause we don't
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  have a lot of knowledge in it.
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  And include seaweed ecosystems in climate and biodiversity planning.
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  I can't stress enough how much biodiversity is in like a kelp forest.
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  It is something that is huge, is a part of the ocean needs to be introduced and
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  it needs to be shown how important it is.
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  To be honest,
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  doing this research was actually surprising that kelp hasn't been included
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  in more of these policies or seaweed hasn't been included in more of these
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  policies, I guess because of the way it gets dispersed across the ocean.
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  But I'm glad we're seeing more progress to get it better.
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  But as climate solutions become more urgent, overlooking powerful,
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  natural allies like seaweed is a risk we can't just afford.
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  The ocean is already doing the work, but only if we let it.
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  So we have to understand how the seaweed works, how it is able to be dispersed,
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  and what it could do for climate change for us in terms of carbon sequestration.
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  If we want real climate solutions, we have to start paying attention
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  to the ecosystems we have
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  that we've been ignoring for a long time.
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  This is something that we've done for a while.
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  We need to fund more research in this, to understand this.
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  The solutions might already be there.
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  We just might not know that they're there, and we may not
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  know how we can play a role.
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  So that's it for today
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  talking about seaweed and climate solutions and blue carbon.
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  It's something that is very important to fighting climate
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  change, reducing climate change.
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  So I encourage you to follow, subscribe to this podcast.
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  Make sure you support the podcast not only for seaweed, but for
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  seagrasses that we're trying to do.
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  Go over to speak up for blue.com/sea grass.
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  We need to talk more about how these systems are so important for blue carbon
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  and for doing something for climate change or to reduce climate change.
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  And so going to speak up for blue.com/seagrass Supporting the
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  Seagrass podcast as crowdfunded.
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  I'm an independent podcaster.
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  I wanna bring more information to you.
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  I need your help, so go to speak up for blue.com/seagrass and hopefully my
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  voice gets better when I start recording this podcast after it gets funded.
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  I'm sure it will be.
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  This is temporary.
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  Might be for one other episode, but we'll be good in the long run.
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  But I wanna thank you so much for joining me on today's episode of the
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  How to Protect the Ocean Podcast.
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  I'm your host, angel Lewin.
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  Have a great day.
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  We'll talk to you next time and happy conservation.