‚Infauna‘ includes all animals living in the sea bottom (sediment). Our division is mainly interested in marine habitats which also include brackish coastal waters or river outlets.
We focus on the macrozoobenthos, small invertebrates hold back by a mesh larger than 0.5 mm in diameter. Typical representative are for example various worm-like creature like bristle worms (polychaetes) or ribbon worms (nemertines), molluscs (e.g. gastropods or bivalves), crustaceans (e.g. amphipods or crabs), and echinoderms (e.g. sea stars or sea urchins).
The standard devices for the collection of infauna are various grabs. They are used for the extraction of defined amounts of bottom sediment. Organisms are usually separated from the sediment by sieving and retained for further studies.
The research of the division Infauna is strongly related to research activities of Senckenberg scientist as well as other national and international research institutes and researchers. We support planning, management, practical work and sample sorting for research expeditions conducted in all parts of the world and studying different marine habitats.
Most important expeditions of the last years supported by our division were e.g. IceAGE 1-2, IceAGE-RR, DISCOl, JPIO, MANGAN, DIVA 1-3, ANDEEP, ANDEEP_SYSTCO, KuramBio I and II.
Our research activities at the DZMB in Hamburg focus on marine invertebrates as for example ‘polychaetes’, or marine bristle worms. The taxonomy and morphology of Spionidae and Pholoidae is the main subject. Apart from light, confocal and scanning electron microcopy histological methods are undertaken. Current studies investigate the spionid fauna from the North Atlantic Ocean, from Atlantic seamounts, and from the Australian shelf. We also study deep-sea species and their global distribution.
In the scope of the IceAGE project species ecology and species distribution are the main focus. By means of species distribution modeling the relationship between the occurrence of a species and the different environmental parameter of their habitat is analyzed. Eventually a species distribution model is formulated and visualized by a prediction map.
The identification of species can be regarded a fundamental precondition for conducting research in life sciences. In the marine environment the Polychaeta often dominate among macrozoobenthic taxa in soft sediments. But there are also larval stages and few taxa that can be found in the Plankton.
Our work focuses on Spionidae. They usually live in tubes in soft sediments or attached to hard surfaces. The polydorids also bore in calcarous substrates (e.g. mollusc shells or corals). Spionids are widespread and occur from intertidal depths to the deepsea.
Dealing with spionid taxonomy not only the description of new species
but also the discovery of new morphological characters is a particular challenge. Here the inclusion of histological studies is promising.
Benthic Ecology (Analysis of species-habitat relationships, benthic community analyses)
The distribution of species is influenced by environmental (abiotic and biotic) factors. Modern statistical techniques make it possible to analyse species-habitat relationships and, given a sufficient data availability, to develop habitat models. Such models provide a quantitative description of the species-habitat relationship.
Focus of the IceAGE project is on the development of species distribution models for benthic invertebrates occurring in Icelandic waters. As a result, species distribution maps are presented (examples for the polychaete Prionospio cirrifera shown here). In subarctic environments (as e.g. Iceland) the importance of climate-related predictors in the models is of particular interest. Potential changes of species distribution against the background of future climate scenarios can be discussed.
Apart from focussing on single species the analysis of species assemblages (e.g. benthic communities) by means of multivariate statistical methods can be undertaken. One aspect is to analyse community structure against the background of various environmental conditions. In conclusion, a change in community structure can be described in detail and the background of change revealed.
Our oceans and seas have always been used by humans and the exploitation of marine resources will further increase in the future.
Besides from rather traditional uses such as transport (shipping), installation of subsea cables, fishing activities, marine aggregate extraction, and military activities new developments as offshore wind farms or subsea pipelines are established. Even the exploitation of the deepsea environment (collection of manganes nodules; for manganese nodules see lower picture on the right) is intensified.
There are quite a number of possible impacts associated with such uses. The responsibility of marine ecologists is to identify potential risks for the marine ecosystem and to make results from scientific studies concerning such issues public. They provide the basis for the application of adequate measures by federal and state governments as well as environmental agencies to protect our oceans.
