“What species are there?”, “Where are they in the water column and why?”, “Who eats whom?” – These and other seemingly simple questions remain largely unanswered for the deep sea, the largest and least explored habitat for life on Earth. At the same time, climate change and increasing human exploitation are putting pressure on this unique system. In this situation, better scientific information to answer the “simple questions” and thus a better understanding of ecosystem functioning is of fundamental scientific interest, but also highly relevant to guide conservation efforts.
On 9 February, our cruise MSM126 “Jellyweb” Madeira left the port of Funchal, Madeira, Portugal, with 22 scientists from seven institutes in five nations and 24 permanent crew on board. Our mission: to improve the understanding of the biodiversity and food web structure of the deep-sea systems around Madeira down to depths of 3000 m. We are particularly interested in the role of gelatinous species such as jellyfish, hydromedusae, salps or chaetognaths (the “jelly web”), which can occur in high diversity and biomass, but are rarely caught intact in nets due to their fragile bodies and have therefore often been neglected in marine research.
A salp (Soestia zonaria), part of the gelatinous fauna in which we are particularly interested. Photo: Karen Osborn
Until the end of our cruise on 4 March in Las Palmas, Gran Canaria, we want to introduce you to our scientific questions, the equipment and approaches we use to address them, and share impressions of the deep sea and its amazing inhabitants.
Ultimately, we hope to convey some of the magic of the unique deep-sea world that we are privileged to witness every day on this cruise – a wonder worth sharing, worth our scientific attention and, above all, worth protecting.
All the best from aboard the research vessel MARIA S. MERIAN,
Jan (Chief Scientist MSM126, on behalf of all participants)
Cruise MSM126 “Jellyweb Madeira” now blogging from the Eastern Central Atlantic Ocean!
When I attended the OBIS Data Mobilization Workshop in the Azores (Thanks to the Air Center) this year, one observation immediately caught my attention: compared with countries such as the United States, Europe still appears surprisingly fragmented and underinvested in biodiversity data mobilization. The issue is not necessarily a lack of biodiversity research. European scientists produce enormous amounts of ecological data. The challenge is that publishing biodiversity observations into global infrastructures such as MBON/GBIF often remains an additional task rather than an integral part of funded research. In the United States, biodiversity data publication is frequently embedded in funding mechanisms and institutional mandates. Data management, curation, and dissemination seem to be recognized research activities. In much of Europe, including Denmark, researchers often mobilize data on top of their existing responsibilities, with limited dedicated funding for long-term stewardship.
I asked myself how is Denmark performing compared with its Nordic and neighboring countries?
Denmark is not lagging behind, but neither is it leading
The numbers reveal a mixed picture.
Germany clearly stands out as the regional leader, with both the highest number of datasets and the highest taxonomic coverage. Denmark has the lowest number of occurrence records and species represented among the four countries, despite having a very active biodiversity research community. What is striking is that Denmark does not fall dramatically behind in dataset numbers. Rather, the difference appears in scale and breadth. Danish datasets tend to contain fewer records and cover fewer taxa than those from Germany, Norway, and Sweden.
Different countries tell different biodiversity stories
The taxonomic breakdowns are equally revealing. Denmark should appreciate its fish and birds’ activists. Large portions of the records belong to Gadidae (cod family), Clupeidae (herring family), Laridae (gulls), and other marine vertebrates. This reflects Denmark’s historical strengths in fisheries monitoring, marine ecology, and seabird observations. However, many invertebrate groups, microorganisms, and less visible components of biodiversity remain comparatively underrepresented in global data sets despite active programs like national Program like MONIS.
Norway shows stronger contributions from invertebrate sides such as polychaetes, bivalves, copepods, and marine benthic fauna. The Norwegian data landscape appears heavily influenced by aquaculture sectores, long-term marine monitoring programs and offshore environmental surveys. There is greater representation of marine invertebrates, which are often critical indicators of ecosystem change.
What stood out in Sweden’s data profile is the relatively large contribution from copepods, diatoms, dinoflagellates, and macroalgae. These groups are often overlooked in biodiversity databases because they require specialized expertise and monitoring programs. Sweden’s contribution suggests sustained investment in aquatic ecosystem monitoring beyond commercially important species. Well done Sweden!
Germany’s profile appears the most diverse. While fish and vertebrates remain important, there are strong contributions from polychaete worms, molluscs, arthropods, plankton in general term and benthic organisms. Germany not only contributes more records but also appears to mobilize a wider variety of biodiversity data types. You made me proud Germany 
The real gap may be invisible biodiversity
One lesson from the workshop was that biodiversity databases often reflect what is easiest to observe, identify, and fund. Fish, birds, and mammals are well represented almost everywhere. The groups that drive ecosystem processes, such as jellyfish, zooplankton, benthic invertebrates, phytoplankton, and microbial communities, remain far less visible. This is particularly relevant for marine ecosystems. Some of the most important ecological changes currently occurring in our seas involve gelatinous zooplankton, plankton communities, and benthic assemblages, yet these groups remain underrepresented in many biodiversity repositories. For someone working with jellyfish and marine food webs, this raises an important question:
Are we documenting the biodiversity that is easiest to count, or the biodiversity that is most important for understanding ecosystem change?
This fall, Ocean Conservancy is celebrating its 41st annual International Coastal Cleanup® (ICC), once again bringing together volunteers to protect the beaches and waterways we all love. Ocean Conservancy recently hosted flagship events in Long Beach and Washington, D.C. that celebrated this global movement close to home.
Over the past four decades, nearly 20 million volunteers have rolled up their sleeves to remove more than 405 million pounds of trash from beaches and waterways around the world. And their impact extends far beyond what they collect. ICC volunteers have documented nearly 440 million individual items, creating the world’s largest marine debris database and providing invaluable information that helps Ocean Conservancy and others better understand—and tackle—ocean plastic pollution.
This year’s celebration continued that incredible legacy. At Alamitos Beach in Southern California, more than 150 volunteers gathered on September 19 and removed 1,109 pounds of trash, alongside members of Team USA Artistic Swimming and Olympic and Paralympic athletes. In Washington, D.C., 439 volunteers gathered on September 26 to remove 2,182 pounds of trash from Anacostia Park along the Anacostia River.
“I am so grateful to all of the volunteers who came out today for our ocean—and every volunteer who has made the last 41 years of impact possible,” said Ocean Conservancy’s Senior Director of Conservation Cleanups, Allison Schutes. “Every piece of plastic collected helps protect marine animals and habitats and contributes to research and advocacy.”
And the impact doesn’t stop when the cleanup ends. During International Coastal Cleanup events, volunteers do more than remove trash: They document what they find, helping build a clearer picture of the plastic pollution threatening our waterways and wildlife. Through the Clean Swell® app or paper data sheets, ICC volunteers contribute to Ocean Conservancy’s online, open-access database, the world’s largest repository of marine debris data. These records help scientists, conservation groups and governments understand pollution trends and identify solutions.
That data can also drive meaningful policy change. ICC data were recently used in a peer-reviewed study showing that plastic bag bans lead to reduced plastic bag pollution. The data have also helped advance policies ranging from California’s SB 54 to Florida’s balloon release ban and the federal Farewell to Foam Act. From a neighborhood cleanup to statewide action, every piece of documented trash helps build the evidence needed to tackle plastic pollution at its source.
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