EXPEDITIONS
Please click below to learn more about the respective expedition.
Heligoland
Heligoland – Germany’s only kelp forest
Description
Kelp forests are unique ecosystems which grow along about one fourth to one third
of global Arctic and temperate coastlines. They are named after their main ecosystem engineer: kelp. The term is used for several genera of large brown algae
belonging to the order Laminariales: Macrocystis, Nereocystis, Laminaria, Lessonia,
and Ecklonia. They offer a manifold of ecosystem services, including coast protection
by wave dampening, oxygen production, CO 2 storage, shelter from predation for all
kinds of wildlife, and fish nursery.
Unlike seagrass, kelp does not have roots to anchor itself in loose sediment. Instead,
it has holdfasts that it uses to strongly attach to hard surfaces like rocks. Heligoland
is Germany’s only rocky shore and as a consequence the only place in Germany where a kelp forest is found. Here, the dominant species is Laminaria hyperborea. A
natural paradise above and below the surface, the island has been studied by naturalists for centuries. It was here where Noctiluca scintilans was found to be the
reason for the milky seas effect by Christian Gottfried Ehrenberg, the term plankton was coined by Johannes Peter Müller, and Ernst Haeckel decided he wanted to become a zoologist. In other words: Heligoland screams marine biology like few other places in Germany.
Kelp, like other macroalgae, is overgrown by microbial biofilms. In the past, the Jogler lab isolated many novel members of the bacterial phylum Planctomycetota from Pacific kelp forests off the coast of California, as well as waters around Heligoland. It goes without saying that the kelp forest around the island is worth further investigations. The natural wonder comes with a caveat, though: situated in the middle of the very erratic North Sea, the weather conditions can change without
warning and heavy storms can make it inaccessible even in summer, or may keep
everyone on the island longer than planned. Even on site, the weather often messes
with sampling strategies: the rocky shore might be submerged also during low tide,
because wind pushes water landwards. Boat-based operations like scientific diving
easily become too dangerous and have to be aborted due to high waves or extremely
strong currents.
And if everything seems perfect, the wildlife messes with you. Heligoland is home to
about 2.000 grey seals (Halichoerus grypus). They are not only cute but also
Germany’s biggest predator. Especially the younger bulls are very curious and have
to be met with caution while working underwater. They not only sneak up from behind and drag divers backwards by biting into their fins, they also steal equipment to play with it. What sounds adorable now is actually both a bit frightening and definitely annoying when you are on a mission underwater and have no time for playing with a majestic creature two times your size, six times your weight, and with a mouth full of sharp teeth that easily cut through your dry suit or air supply hoses… Nevertheless, the Jogler lab has already undertaken several field campaigns on Heligoland and will continue to do so in the future.
Methods
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Scientific Diving
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Mesocosm experiments
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Amplicon sequencing
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Cultivation
Lab members associated to the project
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Prof. Christian Jogler
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Dr. Vivien Hotter
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PhD Student Tom Haufschild
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PhD Student Madeleine Kündgen
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PhD Student Carmen Wurzbacher
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René Maskos
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Helene Grubmüller
Collaborations
Related publications
Funding
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VW Stiftung
Panarea
Panarea - Hot, hotter, Volcano!
Description
In 2013, Prof. Christian Jogler was part of an expedition to Panarea. Panarea is a tiny
beautiful Aeolian island in the North of Sicily which has become a chick epicentre of high-class Euro Summer. Unlike Christian, few of its visitors know what lies beneath the surface of the crystal-clear turquoise waters surrounding it: an active volcanic field emitting boiling hot water, sulfuric acid, carbon dioxide, and heavy metals day and night. Sites comparable to the ones around Panarea occur in the deep sea in thousands of meters of depth, which makes scientific investigations very expensive and technically demanding. Nevertheless, the deep sea sites have been at the centre of scientific attention and are very well characterized, also microbiologically. They are even considered as places where life on Earth originated from. Around Panarea, the depths are not as extreme, and geologists and volcanologists study the Aeolian volcanic fields since decades. They even regularly discover new active formations and craters. Luckily, not all known spots around Panarea require technical diving skills but are in shallower depths and hence accessible for scientific divers. Christian knew that and first investigations following his expedition confirmed what he had anticipated: the microbial life around the Panarea volcanic sites is very intriguing!
Fast forward to 2026, when it was finally time for another expedition to Panarea’s underwater volcano. So Carmen Wurzbacher, Dr. Vivien Hotter and student helpers prepared everything needed for thorough sampling and, accompanied by dive mission leader Dr. Florian Huber from Submaris, set out to look for new microbial mysteries to be solved. Equipped with about 180 kg of luggage dispersed over 9 bags, the two started their trip to Panarea, which is best described as a modern odyssey with a gamble: from Jena to Frankfurt by car, from Frankfurt to Naples by plane. Two hours to collect all luggage and get everything from the airport it to the ferry port by cab. Will all bags arrive in Naples? Will two hours be enough to collect all the luggage and reach the ferry? 5 hours ferry from Naples to Panarea. Arrive in Panarea, unpack and prepare everything for the diving and sampling which will start the following morning.
The following twelve days were filled with hard physical work loading and unloading the diving boat in an ongoing heatwave, but also with lots of awe and wonder, as sampling the different underwater volcanic sites was an otherworldly experience. The lack of laboratory space was compensated by the accommodation’s desk and bathroom, where samples were immediately processed after the dives, sometimes until late at night. The room’s minibar was essential for storage of samples until departure. After long, hard days in the name of microbiology, Vivi and Floh could admire the nearby Stromboli most nights. The volcano is very active and emits a bright red cloud of lava about every 20 minutes. With that much exciting work, the time on the island passed in no time and Vivi and Floh returned to Jena with their bags even heavier than before, now full of precious samples that need further analysis in the lab.
Ever thought sampling campaigns were a holiday? Come join our expeditions once and tell me if you still think so afterwards…
Methods
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Scientific Diving
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Amplicon Sequencing
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Cultivation
Lab members associated to the project
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Dr. Vivien Hotter
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PhD Student Carmen Wurzbacher
Collaborations
Funding
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VW Stiftung
Related Articles
Related publications
Mexico
Mexico - Sampling the Mayan Underworld
Description
The Yucatan peninsula in the South East of Mexico is a biodiversity hot spot made of
limestone that is as holey as Swiss cheese. It harbours the longest flooded cave systems on Earth, with some exceeding several hundred kilometres in length. In many places, the thin roof of these cave systems collapsed over time and created the world-famous, iconic cenotes. Nowadays, these cenotes attract millions of tourists annually that swim in their crystal clear waters.
In ancient Mayan culture, however, the cenotes were the only access to drinking water on the peninsula and thus closely connected with life and death. The Mayans used them for rituals such as human sacrifices and saw them as gateways to the underworld, which they called xibalba – place of fear.
Naturally, the Mayan underworld calls for microbiological exploration! Who knows which elusive, fascinating microbes this pristine place harbours? In order to safely explore and hunt for bacteria in flooded caves, a special cave diving certification is required, so prior to descending into the actual underworld, the lab’s diving postdoc Vivi had to undergo further training. Her instructor was no less a figure than renowned cave diver and explorer Robbie Schmittner.
Like all pristine places on Earth, the ecosystem on Yucatan peninsula is threatened by human activities. Water pollution is a big environmental issue, with big holiday resorts and pig farms, amongst others, disposing of untreated waste water directly into the underground freshwater reservoir. Finding and fighting major pollutants to ensure a safe source of drinking water for future generations is one of Robbie’s self-declared life goals. The team of the Jogler lab is supporting his quest with their microbiological expertise, a nice win-win side effect for everyone involved.
Once the initial training was over, Vivi could start sampling cenotes and caves hidden deep in the jungle, always supported by Robbie as well as Dr. Florian Huber in his function as dive mission leader. Next to small amounts of water and sediment samples for cultivation back in Jena, hundreds of litres of water had to be collected and filtered right away for metagenomic analysis. The filtration unit was kindly provided by Prof. Kirsten Küsel’s lab for Aquatic Geomicrobiology.
After three weeks of intensive cave diving training, carrying heavy gear and cannisters full of water through the dense jungle, roadside tacos, and endless hours spent filtering water, the team returned to Jena, where first promising microbes are currently isolated and described.
The first insights from metagenomics as well as cultivation and isolation already show that the hard work paid off…
Methods
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Scientific Cave Diving
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Metagenomic Sequencing
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Cultivation
Lab members associated to the project
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Dr. Vivien Hotter
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PhD Student Madeleine Kündgen
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PhD Student Carmen Wurzbacher
Collaborations
Funding
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VW Stiftung
Malta
Malta - June 2025
Description
Rising from the heart of the Mediterranean Sea, the limestone archipelago of Malta has been shaped by wind, water and thousands of years of human footsteps. Located just south of Sicily and north of Libya, the islands have long been a meeting point between continents. Phoenician traders, Roman sailors, Arab scholars and the Knights of St John have all left their mark here, turning Malta into a living crossroads where stories, ideas and cultures have converged for millennia.
Yet beyond the ancient temples, fortresses and sun-drenched harbors lies another world hidden in the cliffs, soil and salt-sprayed rocks along the coast. Due to its geographical isolation, Malta has nurtured unique ecosystems and endemic species that cannot be found anywhere else. Its varied landscapes range from rugged shorelines carved by the sea and quiet bays to dry garigue plateaus and fertile valleys. The interplay of geology, climate, and a long human history has shaped a mosaic of microhabitats where life has adapted in ingenious ways.
For microbiologists, such environments are more than beautiful — they are an invitation. Microbes thrive in places shaped by extremes, transitions and isolation, and Malta offers all three. Its rocky surfaces, mineral-rich soils and coastal niches quietly harbor diverse microbial communities, many of which remain largely unexplored.
Keeping this in mind, we set out to sample Malta’s coasts, collecting traces of the microbial communities living there in order to broaden our understanding of planctomycetal diversity and to uncover the microbial richness embedded in these distinctive environments.
Methods
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Cultivation
Lab members associated to the project
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Dr. Vivien Hotter
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PhD Student Madeleine Kündgen
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PhD Student Carmen Wurzbacher
Corsica
Corsica - Campaign Movie
Corsica - June 2025
Description
In June 2025, we packed our sampling equipment for a scientific diving expedition to the mediterranean seagrass meadows in the South of Corsica. Led by an experienced dive mission leader, we collected samples to isolate and cultivate novel bacteria from the seagrass microbiome and surrounding sediment.
On site, in our apartment kitchen turned laboratory, we carefully documented the samples and prepared them for transport back to Jena.
Currently, we are processing our samples in Jena and hope that they will yield novel bacteria and novel, useful natural products in the near future.
Don´t miss to check out our little campaign movie!
Update 2026
Once doesn’t count, which is why in June 2026, we packed our sampling equipment
for a second time and conducted another scientific diving expedition to the
mediterranean seagrass meadows in the South of Corsica.
First results from 2025 are interesting yet very different from what Christian observed when he first came to Corsica in 2015. A comparison of findings dating over 10 years back with new data obtained from two consecutive years will help us to understand if the differences are the new pattern or only an outlier accidentally observed in 2025.
We also stepped up our cultivation game to obtain even more novel bacterial isolates
from the important ecosystem, so stay tuned for upcoming publications connected to
these two expeditions!
Methods
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Scientific Diving
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Amplicon Sequencing
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Cultivation
Lab members associated to the project
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Prof. Christian Jogler
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Dr. Vivien Hotter
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PhD Student Carmen Wurzbacher
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PhD Student Tom Haufschild
Collaborations
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Lea Buse (2025, Scientific Diver)
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Dr. Carsten Spisla (2026, Scientific Diver)
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Station de Recherches Sous-marines et Océanographiques STARESO
Related publications
Funding
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VW Stiftung
Greenland
Ikka Fjord - June 2025
Description
Over thousand years ago, famous Viking Erik the Red set sail to explore what lies west of Iceland. He succeeded in finding land and set foot on what we nowadays call Greenland. Other Vikings followed and settled along the fjords around today’s town of Narsarsuaq. However, Greenland was not theirs alone, as it already was home to Inuit for millennia. Mostly living side by side peacefully, conflicts between Vikings and Inuit occurred nevertheless. And so it happened that one cold, dark winter’s day a Viking family was driven out of their home by angry Inuit. Fleeing over a frozen Fjord, the ice broke under the hunted’s feet and they found their death in the icy waters underneath. Where they touched the seabed, they froze to white, branched pillars that still can be admired today in Ikka Fjord.
Since the 1960s, we know that these pillars are not the remnants of dead Vikings but consist of the extremely rare mineral ikaite. Found in few other places on the planet, Ikka Fjord is the only place where the mineral builds mighty columns as high as 20 m. Like every other unique natural phenomenon in the world, the ikaite columns are threatened by climate change and if that weren’t enough, an Australian company plans to mine the site for rare minerals. In the early 2000s, geologists, hydrologists and biologists teamed up with local Inuit to thoroughly investigate the fjord and lay a scientific foundation for its long-term protection.
20 years down the road, the columns of Ikka fjord are still standing and untouched, thanks to the efforts of the group of scientists and the local community. Investigations have included the fjord’s hydrology and the column’s formation as well as the animals and algae living on and around them. However, little is known about the microorganisms occurring on the columns or along the fjord’s shores. To shed light on this understudied aspect of Ikka fjord’s biology, the Jogler lab sent Dr. Vivien Hotter to join the scientists and support their research as a scientific diver. Together with Dr. Florian Huber, she deployed light loggers on selected columns and sampled for the lab’s research both underwater and above. Back in Jena, the Jogler lab is working towards discovering intriguing novel bacteria from this unique Arctic habitat.
Here’s a link to a newspaper article about the research that has been going on in and around Ikka fjord: https://jarvik.dk/wp-content/uploads/2025/09/SERM_20250829-28-30.pdf
Methods
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Scientific Diving
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Metagenomics
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Cultivation
Lab members associated to the project
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Dr. Vivien Hotter
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PhD Student Carmen Wurzbacher
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PhD Student Madeleine Kündgen
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Nicole Wohlfarth
Collaborations
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Dr. Erik Trampe (Biologist, ikkaton Climate Solutions)
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Dr. Gabrielle Stockmann (Geologist, Jarvik Geoconsulting AB)
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Dr. Paul Seaman (Hydrologist)
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Dr. Florian Huber (Dive Mission Leader, Submaris)
Palau
Palau - January 2025
Description
Palau – a tropical paradise in the South Pacific. Palm trees, sandy beaches, a bit of diving in pristine coral reefs for sample collection and the rest just a lot of relaxation. At least that’s what everyone has in mind when picturing our PostDoc and sampling enthusiast Dr. Vivien Hotter on that sampling campaign. But oh, they could not have gotten things any more wrong! So let’s start from the beginning. From the very beginning, in fact.
According to an old legend, Palau’s biggest island, Babeldaob, as well as the many tiny Rock Islands in its South are the remains of the gluttonous giant Uab, who was murdered for terrorizing his home village. In 2019, Japanese researchers paid tribute to this old legend by naming a bacterium they discovered in the waters around Palau after it. Like Uab the giant, Uab the bacterium has an insatiable appetite. Unlike any other known bacterium, it stills this appetite by engulfing other bacteria. Bacteria engulfing other bacteria was always believed to be energetically impossible. Thus, “Candidatus Uab amorphum” proved to be a microbiological sensation which turned the beliefs of microbiologists all over the world upside down. As if that wasn’t enough, it turned out to be a planctomycete. Naturally, “Ca. Uab amorphum” soon moved into the Jogler lab for further investigation.
Fast forward to October 2024, when Vivi picks up her phone to learn from a friend and fellow scientific diver about an upcoming expedition to Palau. Realizing that this poses a unique opportunity to draw further secrets from Palau’s waters, it is decided that Vivi will join the expedition. Palm trees, sandy beaches, a bit of diving in pristine coral reefs for sample collection and a lot of relaxation in mind, Vivi applies for the sampling permit. Fast forward again, to end of January 2025, when Vivi still has not successfully obtained the sampling permit despite several phone calls with Palau officials but nevertheless leaves Jena for Palau via train at 4.30 in the morning. 24 h flight with a 6 h stop over lie ahead of her, not to mention the train ride with two train changes in between to Frankfurt airport with 60 kg of luggage full of diving, sampling and photography equipment in tow. So much for the relaxation…
Once in Palau and united with the team of scientific divers, determined and stubborn yet charming Vivi finally obtains the sampling permit from the officials. Now the diving in pristine coral reefs for sample collection can begin! Or so she thinks, as Mother Nature has other plans and soon sends a tropic storm instead. Not only does it hinder all diving, it also turns the usually crystal clear waters with 30-40 m of visibility into a murky soup. While this circumstance doesn’t keep the diving team from doing their work, it heavily impacts the accessibility of certain dive sites, thereby shortening the list of intended sampling sites.
Luckily, all members of the diving team are blessed with an extra portion of thirst for adventure. They learn about hidden, remote water bodies deep in the jungle, scattered all over the islands. Swapping their scuba gear for hiking boots and snorkelling equipment, they set out to explore, ignoring the massive spiders along their way and with just the right amount of respect for the salt water crocodiles said to live in the remote water bodies. Navigating through dense rain forest, crawling under fallen trees and climbing steep walls of sharp, rough lime stone, what they find blows their mind: no water body resembles the other. Some harbour pristine coral reefs, others are muddy, shallow, and full of trash, yet others contain remnants from WWII or ancient settlers from times before Europeans even knew about Palau’s existence. It goes without saying that all of the visited sites were thoroughly documented and sampled.
By the end of February, Vivi returns to Jena, her luggage now even heavier from all the samples she collected. Did she spend her time sunbathing under palm trees on sandy beaches? Not a single day. Did she spend her free time relaxing? No. There were no free days. Even on the rainy days, she collected samples snorkelling in the harbour, documented the samples, prepared for the upcoming days or worked through her piling mails. Does Vivi describe the sampling campaign as exhausting and challenging, both physically and mentally? Yes. Would she do it again? Any time! Bur for now, she is looking forward to the scientific discoveries the diving team’s efforts will enable.
Methods
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Scientific Diving
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Cultivation
Lab members associated to the project
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Dr. Vivien Hotter
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PhD Student Carmen Wurzbacher
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PhD Madeleine Kündgen
Collaborations
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Dr. Florian Huber (Dive Mission Leader)
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Uli Kunz (Scientific Diver)
