‘I’ve been listening to seagrass meadows’

Isabel Key spent time snorkelling to monitor seagrass meadows on the Isle of Skye, among other locations on the west coast of Scotland (Isabel Key, CC BY-ND)
Isabel Key spent time snorkelling to monitor seagrass meadows on the Isle of Skye, among other locations on the west coast of Scotland (Isabel Key, CC BY-ND)

ISABEL KEY of the University of Edinburgh listens in to seagrass to understand how its underwater soundscapes reflect biodiversity

The rugged west coast of Scotland looks glorious in the sunshine. The turquoise sea is calm but, even in July, it’s a chilly 12°C. Armed with my recording kit, snorkelling equipment and my thick wetsuit, I’ve been listening to the marine creatures living in three different Scottish seagrass meadows.

Also read: HMS OCToPUS arms divers to sow seagrass fast

For my marine ecology PhD, I’m investigating the biodiversity of Scottish seagrass meadows which, right now in midsummer, are in full bloom. Unlike seaweed, this marine plant has got flowers, seeds, pollen and underground roots.

Seagrass meadows are buzzing with activity. Sea snails scrape rocks as they eat algae, young fish feed on tiny zooplankton, crabs fight to defend their territories, plus birds, seals and otters hunt for food.

Also read: English seagrass success promises worldwide boost

There’s a cacophony of sounds from all of this busy-ness and I’m researching how seagrass soundscapes – that’s the collections of sounds that can be heard in an environment – differ depending on the wildlife living there.

Hearing a wider variety of sounds might mean there are more animals in the seagrass and potentially indicate a healthier, more biodiverse seagrass meadow.

Seagrass meadows have declined drastically due to sediment and nutrient run-off from agriculture, coastal development, destructive fishing practices and disease. The UK has lost more than 40% of its seagrass cover, possibly up to 90% compared to pre-industrial levels.

Globally, 29% of seagrass has disappeared since the 18th century, and the rate of decline has accelerated, with about 7% lost every year since the 1990s.

Green blades of seagrass, thin black starfish
A brittlestar is just one of the species inhabiting seagrass meadows (Isabel Key, CC BY-ND)

Seagrass is an important breeding ground for fish, it improves water quality and acts as a carbon store. So its decline affects the marine creatures living within the habitat, animals further up the food-chain and ocean health more broadly.

Recording soundscapes in seagrass is useful because it allows researchers like me to detect creatures that we can’t necessarily see, either because they’re camouflaged or hiding, or perhaps nocturnal.

It also causes minimal disturbance compared to some other monitoring methods, and it could become cheap and efficient. In the future, you may be able to simply put down a recorder, pick it up, run some algorithms and get some information about the animals present.


Listen to Isabel Key explaining the sounds she’s collected in an interview on The Conversation Weekly podcast.


At each meadow I visit, I set up palm-sized underwater microphones on stands and leave them on the seabed for a week.

On a daily basis, I snorkel down to put a video camera next to the microphone so I can match up the sound with the video. This helps me work out which sound is made by which animal.

Green seagrass meadow, underwater camera kit on seabed
Key set up her underwater microphone next to a baited camera to compare audio recordings with video clips and aim to match sounds with creatures present in that habitat (Isabel Key, CC BY-ND)

Back in the office, I have been analysing my audio recordings using “acoustic indices”, which are measures of the complexity of the soundscape. That includes animal sounds but also waves, boat noise and chinking mooring chains.

Next, I assess phonic richness by listening to one-minute-long clips. Looking at the spectrogram – a visual depiction of these sounds – I can count how many different types of animal sounds are present. That’s time-consuming but gives a great insight.

So far, I have identified 14 different types of sound that I suspect belong to fish and crabs living in the seagrass, plus dolphin whistles and clicks that I can hear from further away as they swim past.

I can look at the exact frequencies (or pitch) that sounds are hitting and the patterns they make, then more accurately assign that sound to an animal or human activity.

Purple graph with orange lines to indicate sound waves
This annotated spectrogram is a visual representation of an audio clip that includes sounds from dolphins, fish and crabs (Isabel Key, CC BY-ND)

I’ve found some evidence for a characteristic seagrass soundscape with certain sounds occurring more commonly in seagrass than in sandy habitat. Fish make low-pitched grunting, burping or purring noises. Crabs make higher-pitched metallic sort of scraping sounds.

I often hear a popping noise which becomes more prominent during the day. As the seagrass photosynthesises, especially during the middle of the day when the sun is warm and bright, the plant produces bubbles of oxygen that collect on the surface of the seagrass blades and pop as they move into the water.

Underwater shot of blades of seagrass, tiny clear round bubbles of gas, small yellow tentacles of anenome.
The photosynthesis bubbles are visible on the surface of this seagrass blade (as well as a snakelocks anenome) (Isabel Key, CC BY-ND)

It’s hard to decipher which animal is making which sound, especially because our oceans are such noisy places. Acoustic pollution can be a serious problem for marine animals that rely on sound for their survival, either to find a mate, navigate, communicate with each other or hunt for food.

Interestingly, however, seagrass could act as a buffer to some underwater noise pollution. As a 3D structure, seagrass acts as a physical barrier to wave energy – that’s one reason why it plays a crucial role in protecting coastal areas from erosion.

It can also absorb sound waves and even protect fish from dolphins that use echolocation to navigate towards their prey. The clicks of dolphins don’t penetrate seagrass very well, so fish can be safer in this seagrass sound shelter than in the open sea.

green seagrass blades on seabed, small orange fish swimming across, blue water
Juvenile pollack and two-spotted gobies are commonly found living among seagrass (Isabel Key, CC BY-ND)

In two meadows, I found more fish and crab sounds in the seagrass than in the sandy sites that I was comparing them against, just as expected. But at one location, I heard more sounds over the sand than in the seagrass despite there being less wildlife there. So biodiversity levels are not necessarily directly reflected by the soundscape.

This may be partly due to differences in how sound travels in different habitats. Sound is transmitted more easily over sand than through seagrass. This phenomenon could lead to misleading results where it’s harder to hear fish in denser seagrass, because of the seagrass itself absorbing the sound, even if it is home to more fish.

Researchers need to be cautious about interpreting soundscape data, and take into account how the habitat structure affects how sounds are heard. Acoustic monitoring could therefore be more useful for studying changes in animal life over time at one site rather than comparing between different areas.

Meadow monitoring

The hope is that this type of work can be used to train machine-learning algorithms and eventually build an easy-to-use tool for monitoring biodiversity in seagrass and other marine habitats.

That requires a comprehensive library of sounds. This already exists for dolphins and other marine mammals but it’s not yet well-established for sounds of fish, crabs and other invertebrates such as shrimp.

Capturing all the different sounds each species can make usually starts with recordings taken in an aquarium. Then, automated detection can attempt to match that up with sounds that researchers like me record in the field.

This should enable scientists to identify early indicators of meadow decline or measure the success of seagrass restoration projects.

Isabel Key (CC BY-ND)
Isabel Key at work (CC BY-ND)

Perhaps one day, marine scientists around the world will set up sound recorders that can transmit audio clips from coastal seas to a central online database where soundscapes could be automatically analysed to assess ocean health.

This could give us near-real time data on animal populations and movements, helping to inform marine protection measures and sustainable fishing practices. That’s an exciting prospect.

ISABEL KEY is a PhD candidate in marine ecology at the UNIVERSITY OF EDINBURGH.

This article is republished from The Conversation under a Creative Commons licence. Read the original article.

Also on Divernet: 5 WAYS TO IMPROVE MARINE CONSERVATION AROUND BRITAIN, GREAT SEAGRASS SURVEY SURPRISES ORGANISERS, SEAGRASS THRIVES NEAR INHABITED MALDIVES ISLANDS – HERE’S WHY, SEAGRASS PROJECT GETS GOING IN CORNWALL

@timpell49
#AskMark Mark great video love your content I recently had my cylinder hydro tested it was filled with air how long can you keep the air in the cylinder before you use it .Also dive shop can drain the air and fill with nitrox?
#scuba #scubadiving #scubadiver

Become a fan: https://www.scubadivermag.com/join

GEAR PURCHASES: https://www.scubadivermag.com/affiliate/dive-gear 

-----------------------------------------------------------------------------------
OUR WEBSITES

Website: https://www.scubadivermag.com ➡️ Scuba Diving, Underwater Photography, Hints & Advice, Scuba Gear Reviews
Website: https://www.divernet.com ➡️ Scuba News, Underwater Photography, Hints & Advice, Travel Reports
Website: https://www.godivingshow.com ➡️ The Only Dive Show in the United Kingdom
Website: https://www.rorkmedia.com ➡️ For advertising within our brands
-----------------------------------------------------------------------------------
FOLLOW US ON SOCIAL MEDIA

FACEBOOK: https://www.facebook.com/scubadivermag
TWITTER: https://twitter.com/scubadivermag
INSTAGRAM: https://www.instagram.com/scubadivermagazine

We partner with https://www.scuba.com and https://www.mikesdivestore.com for all your gear essentials. Consider using the affiliate link above to support the channel.

The information in this video is not intended nor implied to be a substitute for professional SCUBA Training or recommendations for every manufacturer. All content, including text, graphics, images, and information, contained in this video is for general information purposes only and does not replace training from a qualified Dive Instructor or specific requirements from equipment manufacturers.

@timpell49
#AskMark Mark great video love your content I recently had my cylinder hydro tested it was filled with air how long can you keep the air in the cylinder before you use it .Also dive shop can drain the air and fill with nitrox?
#scuba #scubadiving #scubadiver

Become a fan: https://www.scubadivermag.com/join

GEAR PURCHASES: https://www.scubadivermag.com/affiliate/dive-gear

-----------------------------------------------------------------------------------
OUR WEBSITES

Website: https://www.scubadivermag.com ➡️ Scuba Diving, Underwater Photography, Hints & Advice, Scuba Gear Reviews
Website: https://www.divernet.com ➡️ Scuba News, Underwater Photography, Hints & Advice, Travel Reports
Website: https://www.godivingshow.com ➡️ The Only Dive Show in the United Kingdom
Website: https://www.rorkmedia.com ➡️ For advertising within our brands
-----------------------------------------------------------------------------------
FOLLOW US ON SOCIAL MEDIA

FACEBOOK: https://www.facebook.com/scubadivermag
TWITTER: https://twitter.com/scubadivermag
INSTAGRAM: https://www.instagram.com/scubadivermagazine

We partner with https://www.scuba.com and https://www.mikesdivestore.com for all your gear essentials. Consider using the affiliate link above to support the channel.

The information in this video is not intended nor implied to be a substitute for professional SCUBA Training or recommendations for every manufacturer. All content, including text, graphics, images, and information, contained in this video is for general information purposes only and does not replace training from a qualified Dive Instructor or specific requirements from equipment manufacturers.

YouTube Video UEw2X2VCMS1KYWdWbXFQSGV1YW84WVRHb2pFNkl3WlRSZS41ODI2RjhGOTVBODI2NDE5

How Long Can You Keep Air in a Cylinder? #AskMark #scubadiving

Full List of Dive Shows with Links:
https://divernet.com/scuba-diving/your-worldwide-dive-show-guide-for-2025/

JANUARY 18-26: Boot Düsseldorf (International Boat Show)
FEBRUARY 1-2: Duikvaker 
FEBRUARY 21-23: European Dive Show (EUDI)
FEBRUARY 21-23: Diving Resort Travel (DRT) Show, Malaysia
MARCH 1-2: GO Diving Show (The UK Dive Show)
MARCH 15-16: ADEX Ocean Festival / OZTek Australia
MARCH 28-30: Mediterranean Diving Show 
APRIL 4-6: Asia Dive Expo (ADEX) 
MAY 22-25: Thailand Dive Expo (TDEX)
MAY 31 – JUNE 1: Scuba Show
JUNE 13-15: Malaysia International Dive Expo (MIDE)
SEPTEMBER 6-7: GO Diving ANZ Show
OCTOBER 17-19: Diving Talks 
NOVEMBER 11-14: DEMA Show 

#scuba #scubadiving #scubadiver

Become a fan: https://www.scubadivermag.com/join

GEAR PURCHASES: https://www.scubadivermag.com/affiliate/dive-gear 

-----------------------------------------------------------------------------------
OUR WEBSITES

Website: https://www.scubadivermag.com ➡️ Scuba Diving, Underwater Photography, Hints & Advice, Scuba Gear Reviews
Website: https://www.divernet.com ➡️ Scuba News, Underwater Photography, Hints & Advice, Travel Reports
Website: https://www.godivingshow.com ➡️ The Only Dive Show in the United Kingdom
Website: https://www.rorkmedia.com ➡️ For advertising within our brands
-----------------------------------------------------------------------------------
FOLLOW US ON SOCIAL MEDIA

FACEBOOK: https://www.facebook.com/scubadivermag
TWITTER: https://twitter.com/scubadivermag
INSTAGRAM: https://www.instagram.com/scubadivermagazine

We partner with https://www.scuba.com and https://www.mikesdivestore.com for all your gear essentials. Consider using the affiliate link above to support the channel.

The information in this video is not intended nor implied to be a substitute for professional SCUBA Training or recommendations for every manufacturer. All content, including text, graphics, images, and information, contained in this video is for general information purposes only and does not replace training from a qualified Dive Instructor or specific requirements from equipment manufacturers.
00:00 Introduction
01:35 Scuba.com Ad
02:35 Duikvaker
03:15 EUDI
04:23 DRT
05:04 GO Diving Show UK
06:24 ADEX OZTek
07:06 Mediterranean
07:34 ADEX
08:21 TDEX
08:51 Scuba Show
09:36 MIDE
10:06 GO Diving ANZ
11:09 Diving Talks
11:58 DEMA

Full List of Dive Shows with Links:
https://divernet.com/scuba-diving/your-worldwide-dive-show-guide-for-2025/

JANUARY 18-26: Boot Düsseldorf (International Boat Show)
FEBRUARY 1-2: Duikvaker
FEBRUARY 21-23: European Dive Show (EUDI)
FEBRUARY 21-23: Diving Resort Travel (DRT) Show, Malaysia
MARCH 1-2: GO Diving Show (The UK Dive Show)
MARCH 15-16: ADEX Ocean Festival / OZTek Australia
MARCH 28-30: Mediterranean Diving Show
APRIL 4-6: Asia Dive Expo (ADEX)
MAY 22-25: Thailand Dive Expo (TDEX)
MAY 31 – JUNE 1: Scuba Show
JUNE 13-15: Malaysia International Dive Expo (MIDE)
SEPTEMBER 6-7: GO Diving ANZ Show
OCTOBER 17-19: Diving Talks
NOVEMBER 11-14: DEMA Show

#scuba #scubadiving #scubadiver

Become a fan: https://www.scubadivermag.com/join

GEAR PURCHASES: https://www.scubadivermag.com/affiliate/dive-gear

-----------------------------------------------------------------------------------
OUR WEBSITES

Website: https://www.scubadivermag.com ➡️ Scuba Diving, Underwater Photography, Hints & Advice, Scuba Gear Reviews
Website: https://www.divernet.com ➡️ Scuba News, Underwater Photography, Hints & Advice, Travel Reports
Website: https://www.godivingshow.com ➡️ The Only Dive Show in the United Kingdom
Website: https://www.rorkmedia.com ➡️ For advertising within our brands
-----------------------------------------------------------------------------------
FOLLOW US ON SOCIAL MEDIA

FACEBOOK: https://www.facebook.com/scubadivermag
TWITTER: https://twitter.com/scubadivermag
INSTAGRAM: https://www.instagram.com/scubadivermagazine

We partner with https://www.scuba.com and https://www.mikesdivestore.com for all your gear essentials. Consider using the affiliate link above to support the channel.

The information in this video is not intended nor implied to be a substitute for professional SCUBA Training or recommendations for every manufacturer. All content, including text, graphics, images, and information, contained in this video is for general information purposes only and does not replace training from a qualified Dive Instructor or specific requirements from equipment manufacturers.
00:00 Introduction
01:35 Scuba.com Ad
02:35 Duikvaker
03:15 EUDI
04:23 DRT
05:04 GO Diving Show UK
06:24 ADEX OZTek
07:06 Mediterranean
07:34 ADEX
08:21 TDEX
08:51 Scuba Show
09:36 MIDE
10:06 GO Diving ANZ
11:09 Diving Talks
11:58 DEMA

YouTube Video UEw2X2VCMS1KYWdWbXFQSGV1YW84WVRHb2pFNkl3WlRSZS43OTNDNTk0OUNGMDA1MUNG

Upcoming Dive Shows in 2025 #scubadiving #diveshow

US diver Barrington Scott has set a verified Guinness World Record for the fastest time to scuba dive across all seven continents.Cartagena City Council says it is preparing to tighten access to the Cueva del Agua (Water Cave) system in southern Spain, following the death of a 37-year-old female diver there on 18 January. And an underwater habitat builder has just extended the record for longest time spent submerged. 

https://divernet.com/scuba-news/scuba-dash-across-7-continents-brings-world-record/
https://divernet.com/scuba-news/health-safety/spanish-cave-divers-death-prompts-calls-for-controls/ 
https://www.kentucky.com/news/nation-world/national/article299289964.html
https://divernet.com/scuba-news/pod-builder-completes-120-days-under-sea/

#scuba #scubadiving #scubadiver

Become a fan: https://www.scubadivermag.com/join

GEAR PURCHASES: https://www.scubadivermag.com/affiliate/dive-gear 

-----------------------------------------------------------------------------------
OUR WEBSITES

Website: https://www.scubadivermag.com ➡️ Scuba Diving, Underwater Photography, Hints & Advice, Scuba Gear Reviews
Website: https://www.divernet.com ➡️ Scuba News, Underwater Photography, Hints & Advice, Travel Reports
Website: https://www.godivingshow.com ➡️ The Only Dive Show in the United Kingdom
Website: https://www.rorkmedia.com ➡️ For advertising within our brands
-----------------------------------------------------------------------------------
FOLLOW US ON SOCIAL MEDIA

FACEBOOK: https://www.facebook.com/scubadivermag
TWITTER: https://twitter.com/scubadivermag
INSTAGRAM: https://www.instagram.com/scubadivermagazine

We partner with https://www.scuba.com and https://www.mikesdivestore.com for all your gear essentials. Consider using the affiliate link above to support the channel.

The information in this video is not intended nor implied to be a substitute for professional SCUBA Training or recommendations for every manufacturer. All content, including text, graphics, images, and information, contained in this video is for general information purposes only and does not replace training from a qualified Dive Instructor or specific requirements from equipment manufacturers.

US diver Barrington Scott has set a verified Guinness World Record for the fastest time to scuba dive across all seven continents.Cartagena City Council says it is preparing to tighten access to the Cueva del Agua (Water Cave) system in southern Spain, following the death of a 37-year-old female diver there on 18 January. And an underwater habitat builder has just extended the record for longest time spent submerged.

https://divernet.com/scuba-news/scuba-dash-across-7-continents-brings-world-record/
https://divernet.com/scuba-news/health-safety/spanish-cave-divers-death-prompts-calls-for-controls/
https://www.kentucky.com/news/nation-world/national/article299289964.html
https://divernet.com/scuba-news/pod-builder-completes-120-days-under-sea/

#scuba #scubadiving #scubadiver

Become a fan: https://www.scubadivermag.com/join

GEAR PURCHASES: https://www.scubadivermag.com/affiliate/dive-gear

-----------------------------------------------------------------------------------
OUR WEBSITES

Website: https://www.scubadivermag.com ➡️ Scuba Diving, Underwater Photography, Hints & Advice, Scuba Gear Reviews
Website: https://www.divernet.com ➡️ Scuba News, Underwater Photography, Hints & Advice, Travel Reports
Website: https://www.godivingshow.com ➡️ The Only Dive Show in the United Kingdom
Website: https://www.rorkmedia.com ➡️ For advertising within our brands
-----------------------------------------------------------------------------------
FOLLOW US ON SOCIAL MEDIA

FACEBOOK: https://www.facebook.com/scubadivermag
TWITTER: https://twitter.com/scubadivermag
INSTAGRAM: https://www.instagram.com/scubadivermagazine

We partner with https://www.scuba.com and https://www.mikesdivestore.com for all your gear essentials. Consider using the affiliate link above to support the channel.

The information in this video is not intended nor implied to be a substitute for professional SCUBA Training or recommendations for every manufacturer. All content, including text, graphics, images, and information, contained in this video is for general information purposes only and does not replace training from a qualified Dive Instructor or specific requirements from equipment manufacturers.

YouTube Video UEw2X2VCMS1KYWdWbXFQSGV1YW84WVRHb2pFNkl3WlRSZS4yNkZBOTQyMkYxQkQyMzc2

Spanish Cave Closed After Fatality #scuba #podcast #news

LET’S KEEP IN TOUCH!

Get a weekly roundup of all Divernet news and articles Scuba Mask
We don’t spam! Read our privacy policy for more info.
Subscribe
Notify of
guest

0 Comments
Most Voted
Newest Oldest
Inline Feedbacks
View all comments
Recent Comments
Recent News