Sea Control - Sea Control 462 - Ecosystems of the Mediterranean Sea with Daniel Abed-Navandi

Episode Date: September 14, 2023

Links1. Ecosystems of the Mediterranean Sea: A Photographic Dive, by Daniel Abed-Navandi and Georg Glaeser, Springer, 2023.

Hello and welcome to the G-Control podcast. I'm Nathan Miller. Dr. Daniel Abed-Navandi, the Deputy Director and Curator of Vienna's Aqua Terra Zoo, joins me to discuss the health of the Mediterranean Sea and his book, Ecosystems of the Mediterranean Sea, a photographic dive. I would like to pause here to highlight our local chapters. Whether you are in South Korea, Egypt, Singapore, France, New York, India, or the Caribbean, chances are there's a SimSec local chapter near you. You can find a full listing of local chapters and contact information on our website at simsec.org. So if you are interested, please reach out. Finally, I want to take the opportunity to recommend our partners in the SimSec podcast network, The Bilge Pumps.

You can find Alex, Jamie, Drack, and a pile of Iron Brew bottles wherever you download your podcasts. And with that, Kimber's Men. You're listening to Sea Control, posted by the Center for International Maritime Security. Hello, and welcome to the Sea Control Podcast. I'm Nathan Miller. My guest today is Dr. Daniel Abed-Navandi, and we're discussing his book that he co-authored with Georg Glaser entitled Ecosystems of the Mediterranean, a Photographic Dive.

Daniel, welcome aboard. Could you start by telling the listeners a little bit about yourself, please? hello nathan i'm happy to tell you everything you would like to know about our new book my name is daniel abed navandi i am based in vienna austria which is a landlocked country of course and i am despite of this fact an educated marine scientist my main see i'm working since many years more than 30 years i guess is the mediterranean sea but i did also research in the caribbean bermuda and also covered quite a range of habitats during field trips i undertook with the university of vienna and which brought me to australia pacific colder pacific of the

Americas, and yeah, but mainly it's the Adriatic Sea and the Mediterranean Sea where I do my marine things. As a reminder to the listeners, all opinions here are our own and not reflective of any institution with which we might be otherwise associated. So Daniel, can you tell us a little bit about the origins of your book? It's a little unique in that it's breadth and all the photos, and you also structured it in a really interesting way. Can you tell the listeners about how that structure came about? Yeah, the book is structured according to ecosystem types. There are many ecosystem types on land and as well underwater, of course, and I think it's the natural order to see organisms in their habitat

rather than seeing them in a way they are presented in museums, for instance. They are presented in taxonomic order from, let's say, all the vertebrates are together, then all the insects and all the echinoderms and all the sponges, all the corals. But this is, as said, it's an artificial order. It's an order needed when you try to study them taxonomically to see who is related with whom. But the way they present themselves naturally is in their habitat, in their environment. And since many years, I see there are no books helping marine interested people to learn about the environment they're entering. you take out a crab look at a crab and then you don't know where you took it from then you'd start

looking in books all the crabs but you will find crabs from seagrass meadows you'll find crabs from deeper muddy bottoms you will find crabs from rocky euliteral intertidal and this is not helpful and therefore we started we had the idea to to do this habitat guide which is I think for me the most logical way to look at animals where did they evolve and this is where they all the forces which made these organisms came into place it's their habitat and not the cupboard in a museum one of the most striking things about the book are all the photos and is just it's a rich uh as you said habitat guide how did that come into being how did you and garrick think about this book and and how did you put it together garrick is a passionate photographer he's interested in

geometry and in biology and he is taking pictures of every living organisms he can find and he he is then of course interested in how do these organisms function which geometrical forms can he see in them how do these forms evolve so he has a general wide interest in everything living takes a lot of photos and also of birds and and land insects which are not so interesting to me but at one point i visited or i get acquainted with with georg and he said daniel we have to sort my pictures can you help me and i said yes of course i am all those marine organisms you took pictures of i can put in the right order but in my opinion the right order is an ecosystem them order and not all the crabs and all the sponges together and he said yes let's do it and

maybe we can do a book together and this is how this project was born actually i was asked to sort his pictures and tell him what's on them and within several years this book came into life this habitat guide you mentioned that you're sorting his photos do you know how long it took him to collect all of those photos the technique of underwater photography is evolving and if you look at the book the best photos in the book are the most recent ones and the not so good photos they are probably 10 or 15 years old and if you have a picture older than 15 years it's not that good that you can show it anymore because the resolution of the pictures is changing the capacity of all those underwater gears is is getting better and better

so the thing i'm curious do you have any ecosystems or species in particular that you're looking at as a scientist i know that obviously there are keystone species but are there any that are particularly illuminating as far as how the mediterranean is doing health-wise the book covers eight habitats and you can separate them roughly into hard bottom and soft bottom habitats and of course the open water the hard bottom habitats are either bright lit so there's a lot of sunlight hitting

them or shadowy hard bottom which gives a totally different habitat or even habitats which are completely dark like marine caves of course and a fourth solid rocky bottom is the intertidal which is a very special habitat because it's not always covered by water the other habitat group are the soft bottom ones and there you have sandy bottoms you have seagrass meadows and you have deep muddy bottoms which are probably the largest habitat in the mediterranean area wise and the last habitat was is obviously the the open water of course which is in terms of volume the largest habitat those eight habitats we cover and if you ask me which is my my most favorite one of those eight

I would name the muddy bottoms, the deep muddy bottoms, which sounds odd because if you didn't look at the book, you may think that muddy bottom is rather boring. but of course not because those muddy bottoms they have benthic islands sitting on them which are actually hard bottom substrates hard bottom habitats which grow slowly on top of the mud and form so-called benthic islands and they're full of life full of colorful life this life lives from plankton but not from light there is not not a lot of light reaching those deep bottoms they may be 20 to 30 meters deep so they rely mainly on plankton which the currents bring and those deep muddy bottom with benthic islands on them they are in danger because they're heavily fished if you go for scallops you take a beam trawl and remove

a few scallops but most of those benthic islands which are 20 50 or 100 years old are toppled tumble down some benches and then you actually lose very old habitats and nobody goes there because they're deep and divers usually don't bother with deep muddy bottoms but in terms of ecosystem function they are very very important because they cover such a large area if they're lost we lose a fishery grounds of course and the main reason why they are fished are the scallops of course scallops are expensive and you take one percent of the content of the net and the rest is discarded it may live on of course after reaching the seafloor but the structure is is broken it's like removing a whole forest

because you're looking for a few mushrooms and then the forest of course if it's broken down it may grow again but it's not easy to compare a recently broken down forest to a 500 year old one and the same thing is happening with all these deep muddy bottoms especially in the Mediterranean, especially in the Adriatic Sea I've seen a calculation saying that every square meter of the northern Adriatic Sea is turned upside down every other year by beam trawls going after scallops or other high-priced bottom-dwelling wild animals. So this would be my most favorite habitat in the Mediterranean, the deep muddy bottoms.

you at the end of the book you all have a section on human interaction with the ocean and you start that that section with a photo of a naval mine uh i thought that was particularly poignant but do you see any challenges in particular with the mediterranean and the environment and human interaction or is it more similar to the rest of the world's oceans no no i think the mediterranean is a very particular sea because yeah it's actually where all started where our culture started if you think about the antique cultures greek cultures romans or even earlier ones and they were all linked to the sea. There were seagoing ships, of course,

and trade and also wars happening. So it's a heavily colonized ocean and therefore it's not a big surprise that you see a lot of human impacts in the Mediterranean, even more in the Adriatic Sea if you think about Venice and all the other powers

which worked there in the last 500 or 1,000 years. And this naval mine, probably its origin is from the First World War, I heard, which surprises me a little bit. And it's somewhere close to those northern Adriatic islands in Croatia. And to my knowledge, it was removed a few weeks after Georg made this picture during a dive. But this is a good example.

Luckily, this mine never exploded, but that's a good example about traces which we leave on the seafloor, of course. You mentioned that this book functions as an invitation to divers and to snorkelers to kind of explore their surroundings. can you say a little more about how how you want this book to be used and who the audience is for this book yeah thank you for asking the book is thought as a a guide for interested naturalists but they don't um it's does not address a scientific audience although it has a we try to cover a very high level we use scientific names when there is no other equally clear trivial name and we if there are scientific names used then we explain them but brown algae for instance are called brown algae and not pheophytes and red algae are called that way and not

stratophytes which makes it much easier to read and does not exclude readers and we of course feature the most abundant and most visible organisms of course so there are no bacteria featured or microscopic organisms because usually when you're in the habitat you do not see them So there are those macro organisms like different fish, different plants, which you encounter abundantly when you visit, for instance, the bright sunlit rocky littoral. and one of those 500 algae species of course needs to be the most abundant and this of course is then featured and not those very rare ones which fill books but don't actually help you we have more than 400 pictures in the book probably about this this amount of species also are covered and and the pictures are taken from from a very how to say a empathic standpoint

point so this is Garak's this is what he can very good he does very well he looks at this at the organisms and then he finds their side which makes the most appealing to to the viewers so they are not displayed like on a plate to to show all the features equally but they they get then they create emotions in you the fish looks at you or the fish is turning so you even feel the movement these organisms are undertaking. The book is up to date I would say this year there are certain features where you can recognize that this is a

timely book for instance the colonization path of the lionfish which is an invasive species originating from the Red Sea and during the last decades these fishes colonized the eastern Mediterranean starting from Egypt and now the last year it reached already the Adriatic Sea and this tells you that it's up to date. The last data point we took was from the central Adriatic Sea and we will

probably all find lionfish in the next decades until next to Gibraltar probably. Is there anything else that you would like to share with our readers about the book that I've missed or neglected to ask you? One thing which I forgot, but it's in the book, of course, is the decline of the white shark population. This is also related to time, of course. The Mediterranean was a global hotspot of white shark populations.

but since many hundred years their numbers are going down and we probably in this decade are facing their complete extinction there is a rough estimate of the white shark numbers in the book there may be around 10 adult species living right now and within the next years they may also end up in fishing gear And this is also one thing where you see that the time is progressing.

We're getting new species, of course, but those old species which are naturally here, mostly megafauna, of course, they are getting scarcer and scarcer due to our interactions. Well, I'm sorry, but that is all the time that we have for today. I would like to thank my guest, Daniel Abed-Devandi. Daniel, where can we find you online and what are you working on next? Online, you can find me on the Haus des Meeres, Vienna homepage, of course. And currently, I'm working on establishing a mangrove forest, an artificial mangrove forest to show the visitors of our public aquarium where I'm working, how this habitat is looking like. Of course, it's a tropical one. This is my next task.

Well, thank you again for joining us and to the listeners. Thank you for tuning in. We will see you next time. ¶¶