Our team at Merman Conservation Expeditions Ltd. recorded a striking jellyfish bloom yesterday afternoon in the Pagasetic Gulf. In the waters just off Milina, more than 30 mauve stingers (Pelagia noctiluca) were observed gathering approximately 20 meters from the beach, while swimmers were still enjoying the sea.

This local observation appears to be part of a wider bloom event that is now expanding beyond the Pagasetic Gulf toward northern Evia and parts of the Sporades. The density and behavior of the jellyfish suggest that this bloom may continue to spread in the coming days.

The mauve stinger is a well-known species in the Mediterranean, recognizable for its translucent body with pink or purple markings and its bioluminescent glow. Although small, it can deliver a painful sting and occasionally forms dense swarms that impact both swimmers and fisheries.

We will continue to monitor the bloom and provide updates as its extent becomes clearer. Events like this remind us how dynamic and unpredictable marine ecosystems can be, especially during the warmer months.
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Stay informed and stay mindful when entering the sea.

Yesterday’s dive survey along the coasts of Agrielia and Neraki in South Pelion focused on documenting nudibranch diversity, as part of an ongoing seasonal monitoring project. While the waters were teeming with life across multiple taxa, the nudibranch yield was notably lower than in previous years for this time of season.

This post summarizes the species observed, categorized by type with scientific names italicized and common names in parentheses.

🐌 Nudibranchs & Sacoglossans

Despite targeted efforts, the number of nudibranch taxa was relatively low. This may be due to seasonal variability, temperature shifts, or local ecological pressures or factors we’ll continue monitoring closely in the coming weeks.

• Elysia timida
• Calmella cavolini
• Cratena peregrina (Wandering Cratena) 
• Flabellina affinis (Mediterranean Violet Aeolid) 
• Facelina rubrovittata  
• Nemesignis banyulensis (Lady Godiva) 

Compared to past surveys at the same sites during mid-June, both species richness and individual counts were reduced—warranting further ecological investigation.

🐟 Fish
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• Tripterygion tripteronotum (Red-black Triplefin) 
• Thalassoma pavo (Ornate Wrasse)  
• Diplodus sargus (Sargo) 
• Sarpa salpa (Salema Porgy) 
• Oedalechilus labeo (Boxlip Mullet) 
• Diplodus vulgaris (Common Two-banded Seabream)
• Microlipophrys canevae (Caneva's Blenny) 
• Parablennius gattorugine (Tompot Blenny) 
• Epinephelus marginatus (Dusky Grouper) 

🪸 Corals & Anemones

• Cladocora caespitosa (Cushion Coral) 
• Balanophyllia europaea (Pig-tooth Coral) 
• Caryophyllia inornata (Carnation Coral) 
• Aiptasia mutabilis (Trumpet Anemone) 
• Parazoanthus axinellae (Yellow Cluster Anemone) 

🐚 Mollusks (Excl. Nudibranchs)
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• Patella caerulea (Mediterranean Limpet) 
• Phorcus turbinatus (Turbinate Monodont) 
• Spondylus gaederopus (European Thorny Oyster) 
• Arca noae (Noah's Ark Shell) 

🧽 Sponges & Tunicates
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• Tethya aurantium (Golf Ball Sponge) 
• Phorbas tenacior (Bluish Encrusting Sponge) 
• Clathrina clathrus 
• Microcosmus polymorphus 
• Diplosoma spongiforme 

🌪️ Polychaeta
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• Protula tubularia (Red-spotted Horseshoe Worm) 

🌿Hydroids

• Eudendrium racemosum 

🥒 Holothuria

• Holothuria sanctori (Variable Sea Cucumber)

🌿 Algae & Marine Flora
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• Genus Laurencia 
• Flabellia petiolata (Fan Weed) 
• Class Phaeophyceae (Brown Algae) 

Yesterday's marine biodiversity survey at Ammitsa Beach in South Pelion offered a vivid snapshot of the Mediterranean’s underwater richness. Under calm June skies and crystalline waters, our fieldwork revealed a surprisingly high diversity of species, ranging from nudibranchs to seagrasses, sponges, corals, and bony fishes.

This survey was conducted between 12:25 and 13:10 EEST and included over 36 unique taxa, highlighting Ammitsa as a thriving marine microhabitat worth continued observation and conservation attention.

Below is a list of species observed:

🐠 Fish

• Chromis chromis (Mediterranean Damselfish)
• Tripterygion melanurus (Small Triplefin Blenny)
• Sarpa salpa (Salema Porgy)
• Thalassoma pavo (Ornate Wrasse)
• Trachinotus ovatus (Pompano)
• Oblada melanurus (Saddled Seabream)
• Serranus scriba (Painted Comber)
• Diplodus puntazzo (Sharpsnout Seabream)
• Symphodus tinca (East Atlantic Peacock Wrasse)
• Diplodus vulgaris (Common Two-banded Seabream)
• Diplodus sargus (Sargo)
• Mullets (can't identify the species)
• Sparidae (can't identify the species)

🐌 Mollusks

• Conus ventricosus (Mediterranean Cone Snail)
• ​Phorcus turbinatus (Turbinate Monodont)

🐛 Nudibranchs and Sea Slugs

• Flabellina affinis (Mediterranean Violet Aeolid)
• Nemesignis banyulensis (Lady Godiva)
• Cratena peregrina (Wandering Cratena)

🪱Worms

• Galeolaria hystrix (Scarlet Tubeworm)

🪸Corals

• Cladocora caespitosa (Cushion Coral)
• Caryophyllia inornata (Carnation Coral)
• Balanophyllia europaea (Pig-tooth Coral)

🌿Algae and Marine Plants

• Posidonia oceanica (Neptune Grass)
• Acetabularia acetabulum (Mermaid's Wine Glass)
• Flabellia petiolata (Fan Weed)
• Dictyota dichotoma (Forked Ribbons)
• Padina pavonica complex

🧽Sponges

• Crambe crambe (Oyster Sponge)
• Sarcotragus spinosulus (Black Leather Sponge)
• Chondrosia reniformis (Kidney Sponge)
• Chondrilla nucula (Potato Sponge)
• Ircinia variabilis (Variable Loggerhead Sponge)

⭐Echinoderms

• Arbacia lixula (Black Sea Urchin)

🪼Hydroids

• Eudendrium racemosum

🦪 Oysters

• Ostrea edulis (European Flat Oyster)

🟨 Fungi

• Amyloporia xantha (Yellow Porecrust)

Today’s marine survey revealed a vibrant and encouraging array of marine life, highlighting signs of ecological resilience following the 2023 floods.

Below is a list of species observed:

🐠 Fish

• ​Lithognathus mormyrus (Striped Seabream)
• Serranus cabrilla (Comber)
• Serranus scriba (Painted Comber)
• Coris julis (Mediterranean Rainbow Wrasse)
• Thalassoma pavo (Ornate Wrasse)
• Chromis chromis (Mediterranean Damselfish)
• Diplodus sargus (Sargo)
• Diplodus annularis (Annular Seabream)
• Diplodus vulgaris (Common Two-banded Seabream)
• Sarpa salpa (Salema Porgy)
• Genus Atherina (likely Sand Smelt, species undetermined)
  
  

🪼 Invertebrates​

• Cratena peregrina (Wandering Cratena)
• Thuridilla hopei
• Chondrosia reniformis (Kidney Sponge)
• Family Serpulidae (Serpulid Tubeworms)
• Leucothea multicornis (Comb Jelly)
  

​🪸 Algae, Seagrasses & Cnidarians​

• Cladocora caespitosa (Cushion Coral)
• Asparagopsis taxiformis (Red Sea Plume) 
• Wrangelia penicillata (Pink Bush Alga)
• Acetabularia acetabulum (Mermaid’s Wine Glass)
• Posidonia oceanica (Neptune Grass)

This encouraging biodiversity snapshot underscores the importance of ongoing post-flood monitoring and habitat protection.

We're excited to announce a new step forward for Zoologica Nexus Lab, the research branch of Merman Conservation Expeditions Ltd:

We now carry field pH and water hardness test strips as part of our standard survey equipment.

This allows us to measure key water quality parameters directly in the field—on rivers, streams, wetlands, and ponds—while documenting local biodiversity.

• pH tells us if the water is acidic or alkaline, which directly affects the survival of amphibians, fish, and aquatic invertebrates.
  
  
• Water hardness (levels of calcium and magnesium) influences reproductive success, shell development, and species presence in freshwater systems.
  
  

These simple tools give us quick environmental context during surveys, making our research more complete and ecologically meaningful.

This marks the beginning of equipping our lab with dedicated field gear to support long-term wildlife monitoring and conservation work in South Pelion, Greece and beyond.

Yesterday’s birdwatching survey at Karla Lake, a biodiverse wetland in central Greece, offered a vibrant glimpse into the rich avian life of the area. From elegant waders to striking passerines, the wetland and surrounding fields buzzed with feathered activity.

Below is a list of all bird species observed on April 17, 2025, during the survey—each species a beautiful reminder of why Karla remains a critical habitat for both migratory and resident birds.

Species recorded:
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1. Eurasian Jackdaw (Coloeus monedula)
2. Grey Heron (Ardea cinerea)
3. Eurasian Magpie (Pica pica)
4. Pygmy Cormorant (Microcarbo pygmaeus)
5. Black-headed Gull (Chroicocephalus ridibundus)
6. Mediterranean Gull (Ichthyaetus melanocephalus)
   
7. Black-winged Stilt (Himantopus himantopus)
8. Glossy Ibis (Plegadis falcinellus)
9. Little Egret (Egretta garzetta)
10. Great Crested Grebe (Podiceps cristatus)
11. Purple Heron (Ardea purpurea)
12. Dalmatian Pelican (Pelecanus crispus)
13. Corn Bunting (Emberiza calandra)
14. Northern Shoveler (Spatula clypeata)
15. Common Shelduck (Tadorna tadorna)
16. Eurasian Coot (Fulica atra)
17. Great Cormorant (Phalacrocorax carbo)
18. Common Hoopoe (Upupa epops)
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📝 Notes from the Field
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• Dalmatian Pelicans soared over the lake, a spectacular sight with their massive wingspans.
• Several Glossy Ibises foraged in shallow water, their iridescent plumage gleaming in the afternoon sun.
• The wetlands hosted a diverse mix of herons and egrets, showcasing the area's value for wading birds.
• Great Crested Grebes were seen displaying courtship behaviors.

🌿 Why It Matters

Karla continues to demonstrate its importance as a year-round bird habitat. Regular observations like these help monitor species populations, detect early signs of ecological change, and contribute to conservation efforts across Greece and beyond.

We’re excited to announce that the Wildlife Observations Of Pelion (WOOP) project is now officially part of Merman Conservation Expeditions Ltd. 🎉

Since its launch in February 2020, WOOP has been a grassroots effort to document and protect the biodiversity of Pelion through citizen science. From native wildlife to alien species, the project has brought together locals, tourists, researchers, and nature lovers to better understand and conserve the incredible natural heritage of the region.

By moving WOOP under the company "Merman Conservation Expeditions Ltd", we aim to expand its impact, improve public access to research and data, and continue building strong conservation awareness across communities. 🌍✨

🏔️ Mt. Pelion holds a special place in our hearts, which is why we have established our research base there. Numerous studies and surveys have been conducted in this region, and they will continue, reflecting its significance to our work.

➡️ Wildlife observations continue to be recorded through our iNaturalist project:
🔗 https://www.inaturalist.org/projects/wildlife-observations-of-pelion-project-woop

➡️ Research and conservation materials are available on the website:
🔗 https://www.mermanconservation.co.uk/project-woop.html

Whether you’re a scientist, a hiker, a student, or simply curious about the wildlife in Pelion, you’re welcome to join us. Every observation matters. Every effort counts.

Let’s keep exploring, learning, and protecting together. 💚​

In July 2024, during a field visit to the remote and stunning Cave of Thetis at Radakia Beach in South Pelion, We spotted something new—something small, winged, and easy to miss. It was Rhinolophus euryale, the Mediterranean Horseshoe Bat. This was the first time this elusive species had ever been recorded in the cave.

But this wasn’t just a “tick the box” kind of observation. It was part of something much bigger.

Citation of the published article: Taklis Christos. Updated bat (chiroptera) records from the cave of thetis, south pelion, greece. Acta Entomol Zool 2025;6(1):189-191. DOI: 10.33545/27080013.2025.v6.i1c.205​

Why this research matters?

This latest discovery adds a new species to the known bat community of the Cave of Thetis, which had previously only included Miniopterus schreibersii (Schreibers’ Long-fingered Bat), first documented there in 2019. In 2021, Christos Taklis observed juveniles of that species inside the cave, confirming that the site is more than just a temporary roost—it's a breeding ground.

This means the Cave of Thetis isn’t just a cool place to explore—it’s an important home to species that are considered Vulnerable on the IUCN Red List.

And what makes this even more significant is that the 2024 survey was conducted as part of the Wildlife Recovery Survey: After the September 2023 Floods in Pelion. We were looking to see what had survived, what habitats were damaged, and how resilient the wildlife of the region really is.

The presence of both species—especially a new one—after such a major environmental disruption is a hopeful sign.

What do the results tell us?

• Long-Term Roosting: Miniopterus schreibersii has used the cave consistently for over five years, even raising young there. That’s long-term commitment in bat years.
  
  
• New Presence of Rhinolophus euryale: The discovery suggests that the cave may support more biodiversity than previously thought—or that species are shifting their roosts in response to environmental pressures.
  
  
• Resilience Post-Disaster: Even after catastrophic flooding in 2023, bats are returning to their roosts (or they never left). That tells us something about the ecological value and stability of this site.
  
  

Why we should care?

Bats might not get the spotlight that dolphins or bears do, but they are absolutely crucial to ecosystems. They eat insects (many of which are pests), pollinate plants, and disperse seeds. A single roosting site like the cave of Thetis can be the lifeline for entire local populations.

When we lose caves like this—or when they're disturbed by noise, tourism, or development—we risk losing more than just a handful of bats. We chip away at a fragile, interconnected ecosystem.

That’s why this research matters. That’s why we need to keep exploring, documenting, and protecting places like the Cave of Thetis.

Curious to see the cave or learn more about the species?
📸 Check out photos and observations on iNaturalist.
🦇 Follow updates from my conservation work at Merman Conservation Expeditions.