ZMT has a long history of collecting field data throughout marine tropical habitats. However, despite the existence of a database, these data are not readily accessible to the broader scientific community. In addition, data from different institutions also about similar research locations are often hard to find and identify.

We developed a prototype of a scientific web portal to showcase data collected by ZMT and other institutions. The portal is connected to the ZMT database but capable to seamlessly integrate data from different sources into a simple web-based geoportal. The ZMT Research Data Portal is part of the broader DigiZ initiative to develop a digital ZMT.

It allows simultaneous display and comparison of disparate datasets on a single map. It aims to promote all data equally and provide the flexibility to connect to any storage system, effectively making long-tail datasets as visible as those in large, established repositories. Its low barrier of entry allows scientists and organisations to easily add data throughout the research process; enhancing transparency, openness and reproducibility. This flexibility and functionality makes Spatial Data Hub a novel platform for researchers to promote their work, develop new hypotheses and create new collaborations.

The portal prototype is available at: It is also embedded in the webpages of ZMT scientists.

The portal is presented in a paper in Nature Scientific Data

Its source code is available via open access on ZENODO:


Precipitation of calcium carbonate takes place in the metabolically controlled calcifying fluid beneath the polyp tissue. The model is adjusted to a state of activity as observed by direct microsensor measurements in the calcifying fluid. As aragonite precipitation removes carbonate ions in equal amount, this process also decreases total alkalinity and dissolved inorganic carbonate (DIC). Simulated CO2 perturbation experiments reveal decreasing calcification rates under elevated pCO2 despite strong metabolic control of the calcifying fluid.

Decreasing coral calcification at elevated seawater pCO2 is the result of increased CO2 diffusion into the calcification site. However, we found that CO2 diffusion alone is not sufficient to sustain observed calcification rates and that an additional mechanism must exist to supplement carbon into the calcifying fluid. The model correctly reproduces the observed changes in calcifying fluid pH and calcium ion concentrations and shows a sustained calcification only when bicarbonate transport in symport with protons is considered. In our model, coral calcification is not directly dependent on the abundance of carbonate ions in seawater.

Related literature:

S. Hohn & A. Merico (2015) Quantifying the relative importance of transcellular and paracellular ion transports to coral polyp calcification, Frontiers in Earth Science, 2(37), 1-11.

S. Hohn & A. Merico (2012) Modelling coral polyp calcification in relation to ocean acidification, Biogeosciences, 9, 4441-4454. 


Processes model coral polyp calcificationProcesses model coral polyp calcification


Temporal changes carbonate system variablesTemporal changes of carbonate system variables in the calcifying fluid.Red dots show data from microsensor studies, while continuous blue lines represent model results. Light periods from 0 to 420 seconds and from 840 to 1400 seconds. Dark period between 420 and 840 seconds.


calcification ratesElevated pCO2 in seawater increases CO2 diffusion into the calcifying fluid thus decreasing carbonate ion concentrations and aragonite saturation in that compartment. This cause a decrease in calcification rates.


Good research needs a good data basis. As digitalisation proceeds, the amount of scientific research data is rising at an inflationary rate. For interdisciplinary research, these data are of outstanding value because they enable comparative evaluations and meta-analyses on a large scale in space and time. The responsible and transparent management of research data makes scientific results reproducible and is therefore an essential part of good scientific practice. The ZMT is committed to making research data FAIR (findable, accessible, interoperable, reusable) and, whenever possible, openly accessible.

In 2015, the ZMT therefore adopted an Open Data Policy, which is currently being revised in view of the latest national and international developments in research data management. A concept for handling research data and metadata at the ZMT is currently being developed.

The graphic shows the percentage of coral reefs, mangroves and seagrasses are lost per year.

Our world is getting more and more complex and faces major ecological, social and economic challenges. Increasing urbanisation, unsparing use of natural resources and global climate change have dramatic effects on our seas and oceans.

These effects are particularly severe in regions with rapidly increasing economic development and high population growth, as in many countries of the tropics. Ecosystems situated near densely populated coasts of the tropical belt are particularly affected by the strong global, regional and local environmental changes.

Tropical coastal ecosystems such as mangroves, coral reefs or seagrass meadows are among the most productive and diverse habitats of our planet. They are an essential source of food and income for billions of people and central to economy and tourism in many tropical countries.

The Leibniz Centre for Tropical Marine Research (ZMT) in Bremen is the only scientific institute in Germany that investigates tropical and subtropical coastal ecosystems and their importance for nature and people. With its work, the ZMT provides a scientific basis for the protection and sustainable use of these tropical coastal ecosystems.

In addition to research, the focus lies on the development of competencies and consultation services – always in close cooperation with international and national partners.

Please see also About Us.