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Matthew Costa @mangrovematt.bsky.social · 6h

Check out the incredible density of fiddler crabs in the #saltmarsh at North Inlet-Winyah Bay National Estuarine Reserve, where colleagues and I were measuring nitrogen cycling in June 2024.

Matthew Costa @mangrovematt.bsky.social · 1d

Fallen asleep on the job? Dropped a contact lens? No, in fact estimating aboveground biomass in the #saltmarsh by measuring every shoot in a 25 cm x 25 cm plot means hours with your face in the grass (while perched precariously on a boardwalk plank or milk crate platform) @pie-lter.bsky.social.

Matthew Costa @mangrovematt.bsky.social · 5d

These are our experimental plots in summer 2024, in SC and MA respectively. Some have been given ammonium, some nitrate, and others are controls. Can you see the plants' response to treatment?

Matthew Costa @mangrovematt.bsky.social · 5d

Since 2023, we (@bowenlab.bsky.social, @randallhughes.bsky.social) have been testing how nitrogen inputs affect #saltmarsh plants, microbes, and carbon and nitrogen cycling, @pie-lter.bsky.social in Massachusetts and at North Inlet Winyah Bay NERR in South Carolina.

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Reposted by Matthew Costa

COMPASS @compassscicomm.bsky.social · 13d

During National Estuaries Week, we're reflecting on our blue carbon work & the role of coastal ecosystems in storing carbon.

Check out our blog with Dr. Matthew Costa @mangrovematt.bsky.social: buff.ly/8qHDj5A

#NationalEstuariesWeek #CommunicationSkills #SciComm #SciPol #StrategicMessaging

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Matthew Costa @mangrovematt.bsky.social · Aug 28

When our measurements in the #saltmarsh @pie-lter.bsky.social involve hanging out on the boardwalk over high tide, we get to see a whole other side of the environment, from the marsh organs being overtopped by the tide to egrets (and the midges...) waiting at the edge of the water to feed.

Matthew Costa @mangrovematt.bsky.social · Aug 18

Then every 45 minutes we pump back up ("pull") a sample of porewater into an airtight tube to be analyzed back at the lab to find out how much of that 15N-nitrate, as well as the nitrate already present, has been converted into N2 gas. Lots of work (with intervals of waiting) in a beautiful place!

Matthew Costa @mangrovematt.bsky.social · Aug 18

and the water and added nitrate is mixed using this fun magnet trick, all without mixing the porewater with the atmosphere, which would affect its dissolved gas content. Then that mixture is then pumped ("pushed") back underground to incubate over the course of high tide.

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Matthew Costa @mangrovematt.bsky.social · Aug 18

We insert one of these metal tubes below the marsh surface and use them to pump porewater (the water down among the roots and sediment beneath the marsh surface) up into one of these graduated cylinders. 15N-isotopically-labelled nitrate is added to the porewater in the cylinder,

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Matthew Costa @mangrovematt.bsky.social · Aug 18

How do we measure #denitrification in our #saltmarsh ammonium and nitrate treatment plots at @pie-lter.bsky.social? Anne Giblin and Jane Tucker from @mblscience.bsky.social bring the lab into the field for this in situ "push-pull" denitrification measurement.

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Matthew Costa @mangrovematt.bsky.social · Aug 16

In April 2024, 1 year after planting these Spartina alterniflora in the #saltmarsh organs at North Inlet, they were going strong! We simulated different marsh elevations in three rows of pipes, and randomly assigned each plant a #nitrogen treatment. Stephanie and Karen survey the plants' progress.

Matthew Costa @mangrovematt.bsky.social · Aug 11

gothamist.com/news/phd-stu...

PhD student paddles 315 miles down Hudson River to show it’s cleaner than many think

John Henkelman spent a month testing the river’s health.

gothamist.com

Matthew Costa @mangrovematt.bsky.social · Aug 5

Word of the Day: estuary www.nytimes.com/2025/08/05/l...

Word of the Day: estuary

www.nytimes.com

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Matthew Costa @mangrovematt.bsky.social · Jul 10

www.nytimes.com/2025/07/10/o...

Opinion | Why Hiring Professors With Conservative Views Could Backfire on Conservatives

www.nytimes.com

Matthew Costa @mangrovematt.bsky.social · Jun 17

news.northeastern.edu/2025/06/05/s...
#saltmarsh @bowenlab.bsky.social

What are runnels, the man-made channels that help restore salt marshes?

Northeastern research finds that the narrow channels help salt marshes remove nitrogen before it can pollute waterways.

news.northeastern.edu

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Matthew Costa @mangrovematt.bsky.social · Jun 3

Putting Science Engagement into Practice with Dr. Matthew Costa | COMPASS www.compassscicomm.org/putting-scie...

Putting Science Engagement into Practice with Dr. Matthew Costa | COMPASS

Dr. Matthew Costa’s path to conservation and coastal science began as a curious kid drawn to explore coastal ecosystems in his hometown. That early fascination deepened in college, where hands-on […]

www.compassscicomm.org

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Matthew Costa @mangrovematt.bsky.social · May 25

At our #saltmarsh field plots @pie-lter.bsky.social and North-Inlet-Winyah Bay, we are measuring Spartina alterniflora biomass and CO2 uptake/release using clear plastic chambers attached to a CO2 analyzer (and a precariously perched laptop!). Thanks Stephanie, Camille, and Pooja (September 2023)!

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Matthew Costa @mangrovematt.bsky.social · May 23

We tend to put #saltmarshes and the #rockyintertidal into very different ecosystem boxes, but here's an example of salt marsh plants (Spartina alterniflora) growing in a patch of shallow peat among sand and gravel on the rocky shore in Essex County, MA (August 2023).

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Matthew Costa @mangrovematt.bsky.social · May 17

This particular spot in the #rockyintertidal environment in Essex County, MA, upon closer inspection, was crawling with springtails! Seashore springtails (Anurida maritima) are known to aggregate by use of a pheromone that helps them find each other. August 2023.

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Matthew Costa @mangrovematt.bsky.social · May 16

By August 2023 the #Spartina alterniflora plants we had planted in our marsh organs @pie-lter.bsky.social had grown to a healthy size! The different elevations of the marsh organ simulate the effects of varying sea level scenarios. Also, check out all those mud snails (Ilyanassa obsoleta?)!

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Matthew Costa @mangrovematt.bsky.social · Apr 29

April in the salt marsh at @pie-lter.bsky.social means that the Spartina alterniflora is sending up new shoots! See the little green new leaves among the brown of the previous year's dead biomass. This #saltmarsh plant's rhizomes overwinter underground but send up new leaves each spring. Apr 2023

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Reposted by Matthew Costa

Chris Janousek @janousekwild.bsky.social · Apr 27

Oregon Public Broadcasting briefly covered our recent #bluecarbon research on the Pacific coast

www.opb.org/article/2025...

Forested swamps on the Northwest coast are some of the biggest carbon storehouses around, new research finds

A new study suggests that restoring tidal swamps along the Pacific Northwest coastline could provide the most bang for your carbon storage buck.

www.opb.org

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Matthew Costa @mangrovematt.bsky.social · Apr 28

xkcd.com/3081/ #Resist

PhD Timeline

xkcd.com

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Matthew Costa @mangrovematt.bsky.social · Apr 26

www.opb.org/article/2025...

Did you know about the large carbon-burial capacity of the Sitka spruce swamps of the Pacific Northwest? Their carbon stocks, along with those of other coastal #bluecarbon ecosystems, are reported in our recent paper: agupubs.onlinelibrary.wiley.com/doi/10.1029/... .

Forested swamps on the Northwest coast are some of the biggest carbon storehouses around, new research finds

A new study suggests that restoring tidal swamps along the Pacific Northwest coastline could provide the most bang for your carbon storage buck.

www.opb.org

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Matthew Costa @mangrovematt.bsky.social · Apr 25

Thanks for taking an interest, and your paper looks interesting and relevant! All the genotypes we used are tall form S. alterniflora.

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