The Oceans Surrounding Trieste, Italy
Today’s article focuses on the oceans surrounding Trieste, Italy. Trieste is a port city located in Northern Italy along the Adriatic Sea. It has a fairly large population of 198,668 individuals. It is located near the Italian-Slovenian & Italian-Croatian borders. The city links these 3 countries, as well as the rest of the Mediterranean, making it a center of trade. Modernly, it is considered the Mediterranean endpoint of the 21st-century Maritime Silk Road, an international development initiative developed by the Chinese Government.
Trieste is often colloquially referred to as the “City of Science”, given its heavy research presence. Across Europe, it has the highest number of researchers per capita, at an astounding 37.1 per thousand individuals.
In addition to its scientific prowess, it is also known for its contributions to the coffee industry, affectionately referred to by lovers of the drink as the “City of Coffee”. Annually, residents of Trieste consume twice the mean of the average Italian. The city is packed with historic cafes, coffee breweries, roasters, & important companies.
Apart from its statuesque architecture, vibrant culinary scene, & domineering research industry, Trieste is known for its natural beauty. With wonders such as the Miramare Nature Reserve, Rosandra Valley Reserve, & Carsiana Botanical Garden, the city is home to thousands of fascinating creatures, both terrestrial & marine.
Trieste’s coastlines boast brilliant biodiversity, from Fan Mussels (Atrina fragilis), to Peacock Blennies (Salaria pavo). Thousands of species large & small call the waters surrounding Trieste their home. As a result of these robust ecosystems, an eco-tourism economy has developed. Coastal walks, snorkelling, boat excursions, & scuba diving are all available at the UNESCO MaB Miramare Reserve.
In this article, we will discuss the salinity, tides, temperatures, & marine geography, the most prominent ecosystems, marine flora, & marine fauna of Trieste. With that being said, let us delve into the beautiful blue waters of Trieste, Italy!
The Salinity, Tides, Temperatures, Depth, & Marine Geography of Trieste
The salinity around Trieste fluctuates wildly depending on the season, weather, & local conditions. Salinity in the Gulf of Trieste may vary from 35 to 38 parts per thousand (practical salinity units). (Salinity is measured in 1000-gram increments of water, & for every 1000 grams of water, a certain amount of salt is present.)This measurement is called parts per thousand, or practical salinity units. Factors such as seasonal freshwater runoff from rivers, namely the Soča (Isonzo) River can play a role in influencing the salinity. Water leaving the region through processes such as evaporation can increase salinity, while water entering the region through freshwater inflow may decrease the salinity. As such, the salinity in the region varies significantly depending on seasonality & local conditions, with the average hovering around 37 parts per thousand (practical salinity units).
The tidal charts for Trieste may be found on a plethora of websites, including https://www.tide-forecast.com/, https://www.tideschart.com/, & https://www.thetidechart.com/. Tides are relatively low, with a maximum tidal range of approximately 130 centimeters (4.3 feet) during especially strong spring tides. Tides generally stay between 40 & 60 centimeters (1.3 to 1.9 feet). Trieste’s waters are generally calm, with gentle waves.
The temperature charts for Trieste may be found on similar websites, including https://www.seatemperature.org, https://seatemperature.info/, & https://seatemperature.info/. The average annual sea temperature is approximately 63.5° Fahrenheit (17.54 Celsius). According to this average, it is recommended that anyone who desires to engage in diving, or a similar aquatic recreation should use a 4 to 5-millimeter-thick wetsuit.
A few of the most popular beaches around Trieste include Beach Barcola, La Lanterna, Topolini Beach, Liburnia Beach, & Sisitiana.
In the Gulf of Trieste, water reaches a maximum of 121 feet, with an average of 61 feet.
The seafloor around Trieste is predominantly flat, & composed of Holocene-aged (8,800 to 10,000 years ago) marine sediment.
The Marine Ecosystems of Trieste
Ecosystem Type No. 1: Intertidal Zones
An intertidal zone is an area of coastline that is exposed to air at low tide, & is covered with water at high tide. It is a very important location for many small marine animals, such as gastropods, crustaceans, & bivalves. Many animals will take advantage of the nutrients & microorganisms that come in with the high tide. Tide pools are a kind of rock formation located in the intertidal zone, in which water becomes trapped to form a small pool at low tide as the tide recedes, creating a miniature sea of sorts. These pools generally have species from the phyla Echinodermata & Mollusca in them. Around Trieste, these zones are also inhabited by a species of endemic brown macroalgae known as Fucus virsoides. This brown macroalga provides important habitats to the local marine life.
Ecosystem Type No. 2: Soft Muddy Seabeds
Much of the seafloor in the Gulf of Trieste is composed of soft, flat, muddy seabeds. These seabeds are a hotspot for benthic, or bottom-dwelling marine life. They act as a space for benthic fish such as the common sole (Solea solea), & peacock blenny (Salaria pavo). In addition to benthic fish, they act as a hotspot for molluscs & echinoderms such as the common octopus (Octopus vulgaris), common cuttlefish (Sepia officinalis), noble pen shell (Pinna nobilis), purple sea urchin (Paracentrotus lindus), brittle stars, sea cucumbers, & sea stars.
Ecosystem Type No. 3: The Pelagic Zone
The open waters around Trieste are home to larger marine life such as the Blue Shark (Prionace glauca), bluefin tuna (Thunnus thynnus), squid, sea turtles, & dolphins. Blooms of the jellyfish species Rhizostoma pulmo can also be found from spring to autumn. As a result of the water column being so shallow, water can vary significantly in temperature depending on seasonal conditions.
The Marine Flora of Trieste
Trieste is home to an abundance of marine flora, including common eelgrass (Zostera marina), little neptune grass (Cymodocea nodosa), & the endemic brown macroalgae Fucus virsoides.
Common Eelgrass (Zostera marina):
Common eelgrass, also known as seawrack, is a true seagrass native to the North Pacific & Atlantic. It is characterized by bright green slender blades, usually 7.8 to 19.6 inches (20 to 50 centimeters) long. This species is frequently found along the coast, & is known for favouring muddy or sandy shorelines. It is known for forming dense aggregations known as meadows, which act as an important habitat for juvenile fish.
This species is also an important food source for seabirds.
Little Neptune Grass (Cymodocea nodosa):
Little Neptune grass is a species of true seagrass native to the Mediterranean Sea, & Atlantic Ocean. It is recognized for its long, thin, dark green blades.
Fucus virsoides:
Fucus virsoides is a species of brown macroalgae endemic to the Adriatic Sea. Although it once formed extensive underwater forests, it is now considered endangered. It is the only species of its genus known to inhabit the Mediterranean. Favouring rocky coastal waters, this species may be seen growing along the sea cliffs around Trieste. It is important to note that algae isn’t technically a plant, & is instead a heterokont/stramenopile, making it a protist.
The Marine Fauna of Trieste
From the shores to the pelagic, Trieste is positively teeming with marine animals. Creatures include the common sole (Solea solea), peacock blenny (Salaria pavo), common octopus (Octopus vulgaris), common cuttlefish (Sepia officinalis), noble pen shell (Pinna nobilis), purple sea urchin (Paracentrotus lindus), blue shark (Prionace glauca), bluefin tuna (Thunnus thynnus), squid, sea turtles, common bottlenose dolphin (Tursiops truncatus), barrel jellyfish (Rhizostoma pulmo), bull ray (Aetomylaeus bovinus), & assorted brittle stars, sea cucumbers, & sea stars.
Directories / Credits
Citation No. 1: “Trieste Gulf”, Written by Unknown, & Published at an Unknown Date. Published by the Friuli Venezia Giulia Tourism.
Citation No. 2: “The 33 best beaches in and around Trieste”, Written by the Wanderlog Staff, & Published on February 28th, 2025. Published by Wanderlog.
Citation No. 3: “Species and Habitat”, Written by Unknown, & Published at an Unknown Date. Published by AMP Miramare.
Citation No. 4: “Interactive Identification Key for Marine Organisms of the Gulf of Trieste”, Written by Nataša Dolenc Orbanić, Claudio Battelli, Janja Plazar, Petra Furlan, & Nastja Cotič, & Published at an Unknown Date. Published by the University of Trieste.
Citation No. 5: “Wetsuit thickness & temperature guide”, Written by Mark Evans, & Published on April 24th, 2023, at 3:05 PM. Published By Scuba Divers Magazine.
Citation No. 6: “Submerged and buried Pleistocene river channels in the Gulf of Trieste (Northern Adriatic Sea): Geomorphic, stratigraphic and tectonic inferences”, Written by Ana Trobec, Andrej Šmuc, Sašo Poglajen, & Marko Vrabec, & Published on June 1st, 2027. Published by Elsevier.
Citation No. 7: “Multi-platform study of the extreme bloom of the barrel jellyfish Rhizostoma pulmo (Cnidaria: Scyphozoa) in the northernmost gulf of the Mediterranean Sea (Gulf of Trieste) in April 2021”, Written by Nydia Catalina Reyes Suàrez, Valentina Tirelli, Laura Ursella, Matjaž Ličer, Massimo Cello, & Vanessa Cardin, & Published on May 31st, 2022. Published by EGUsphere.
Citation No. 8: “Thickness of marine Holocene sediment in the Gulf of Trieste (northern Adriatic Sea)”, Written by Ana Trobec, Martina Busetti, Fabrizio Zgur, Luca Baradello, Alberto Babich, Andrea Cova,
Emiliano Gordini, Roberto Romeo, Isabella Tomini, Sašo Poglajen, Paolo Diviacco, &
Marko Vrabec, & Published on June 14th, 2018. Published by Copernicus Publications.
Citation No. 9: “Trieste, sightings of bull rays: Unique Mediterranean case but threat to mussel farms”, Written by Chiara Zampiva, & Published on July 17th, 2026. Published by Euronews.
Citation No. 10: “Common Eelgrass”, Written by Unknown, & Published at an Unknown Date. Published by The Wildlife Trusts UK.
Citation No. 11: “Little Neptune Grass”, Written by Unknown, & Published at an Unknown Date. Published by PlantSnap.
Citation No. 12: “Fucus virsoides in the Adriatic Sea: a glacial relict in the era of climate changes”, Written by Emannuelle Descourvières, & Published on April 16th, 2026. Published by the University of Trieste.
Citation No. 13: “Ecophysiological responses of Fucus virsoides (Phaeophyceae, Fucales)
to past and present nutrient conditions in the northern Adriatic”, Written by Emmanuelle Descourvières, Martina Mulas, Sara Natale, Raquel Sánchez de Pedro, Alessandro Alboresi, Cosimo Solidoro, Vinko Bandelj, & Annalisa Falace, & Published October 7th, 2024. Published by the University of Trieste.
Citation No. 14: “9 Beaches in & Around Trieste”, Written by Kat Smith, & Published on April 16th, 2026. Published by Mamma Mia Indeed.
Strategic Partnerships
Reel Guppy Outdoors
SharkedSkooler
Marine Enthusiasts Podcast
Cash Daniels
Tides of Tomorrow
The Open Book, Topanga
Olivenbaum Music
Pitfire Artisan Pizza
Three J’s Kitchen
Presence News
Our Loyal Patrons
P. R. Ochoa
Comments