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.

A groundbreaking research paper by Merman Conservation Expeditions Ltd has revealed the first confirmed sighting of the invasive coral species Oculina patagonica in the Pagasetic Gulf near Volos, Greece. This discovery, published in the International Journal of Fisheries and Aquatic Studies, underscores both the ecological significance of this semi-enclosed gulf and the potential threat posed by this resilient species.

Citation of the published article: Taklis Christos. First record of Oculina patagonica de Angelis D'Ossat, 1908 in the Pagasetic Gulf, Greece. Int J Fish Aquat Stud 2024;12(6):24-27. DOI: https://doi.org/10.22271/fish.2024.v12.i6a.2990

Pagasetic Gulf: A Jewel of Marine Biodiversity
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The Pagasetic Gulf is a marine treasure in the Thessaly region of Greece. This semi-enclosed body of water, connected to the Aegean Sea through a narrow strait, hosts a vibrant array of marine life, thanks to its mix of natural sandy, rocky, and muddy substrates. These varied habitats support everything from fish and crustaceans to delicate coral ecosystems, making it a critical hotspot for biodiversity in Greek waters.

However, this ecological haven is now facing a new challenge. The discovery of Oculina patagonica—a coral species known for its invasive tendencies—has raised concerns about its impact on the delicate balance of this thriving ecosystem.

A Significant Discovery by Merman Conservation Expeditions Ltd

This research, spearheaded by Christos Taklis, Director of Merman Conservation Expeditions Ltd, highlights how rising sea temperatures and human activities such as shipping and coastal development are facilitating the spread of invasive species. The study documented the coral at Faraggi Beach during a 2021 biodiversity survey, where three colonies were found thriving in shallow waters.

“This finding is not just about a new species record,” the study emphasizes. “It’s about understanding how non-native species can alter marine ecosystems in areas like the Pagasetic Gulf, which are already facing stress from climate change and human interference.”