Description: After the closure of the Central American Seaway around 3.6 Ma, the benthic carbonate ecosystems developed differently in the Caribbean and on the Pacific side of the Isthmus of Panama. In this thesis, fossil and recent carbonate systems were studied and a comparison was made between fossil and present-day carbonate ecosystems from the same paleolatitude. This opens up the possibility to document the evolution of these sedimentation systems through time.

Description: This is the first volume of the entirely rewritten, revised and updated version of the original FAO Catalogue of Cephalopods of the World (1984). The present Volume is a multiauthored compilation that reviews six families: Nautilidae, Sepiidae, Sepiolidae, Sepiadariidae, Idiosepiidae and Spirulidae, with 23 genera and the 201 species known to the date of the completion of the volume. It provides accounts for all families and genera, as well as illustrated keys to all taxa. Information under each species account includes: valid modern systematic name and original citation of the species (or subspecies); main synonyms; English, French and Spanish FAO names for the species; illustrations of dorsal and ventral aspect of the whole animal (as necessary) and other distinguishing illustrations; field characteristics; diagnostic features; geographic and vertical distribution, including GIS map; size; habitat; biology; interest to fishery; local names when available; a remarks section (as necess ary) and literature. The volume is fully indexed and also includes sections on terminology and measurements, an extensive glossary, an introduction with an updated review of the existing biological knowledge on cephalopods (including fisheries information and catch data for recent years) and a dedicated bibliography.

Description: BASEWECS is a contribution to the German Climate Research Program DEKLIM. The project started in May 2001 and lasted until December 2004. BASEWECS aimed at the investigation of the influence of the Baltic Sea and its annual ice coverage on the water and energy budget of the BALTEX area

Description: Lake Tahoe is an ultra-oligotrophic subalpine lake that is renowned for its clarity. The region experiences little cloud cover and is one of the most UV transparent lakes in the world. As such, it is an ideal environment to study the role of UV radiation in aquatic ecosystems. Long-term trends in Secchi depths showed that water transparency to visible light has decreased in recent decades, but limited data are available on the UV transparency of the lake. Here we examine how ultraviolet radiation varies relative to longer-wavelength photosynthetically active radiation (PAR, 400-700 nm, visible wavelengths) horizontally along inshore-offshore transects in the lake and vertically within the water column as well as temporally throughout 2007. UV transparency was more variable than PAR transparency horizontally across the lake and throughout the year. Seasonal patterns of Secchi transparency differed from both UV and PAR, indicating that different substances may be responsible for controlling transparency to UV, PAR, and Secchi. In surface waters, UVA (380 nm) often attenuated more slowly than PAR, a pattern visible in only exceptionally transparent waters with very low dissolved organic carbon. On many sampling dates, UV transparency decreased progressively with depth suggesting surface photobleaching, reductions in particulate matter, increasing chlorophyll a, or some combination of these increased during summer months. Combining these patterns of UV transparency with data on visible light provides a more comprehensive understanding of ecosystem structure, function, and effects of environmental change in highly transparent alpine and subalpine lakes such as Tahoe.

Description: The aim of this thesis was to examine metazoan parasite communities and viral infections of European eel, Anguilla anguilla, from fresh water, brackish and marine localities in northern Germany. The here collected data shall help to evaluate the suitability of the studied localities for potential restocking purposes regarding the presence of pathogens. In Chapter I a comparative examination of the metazoan parasite communities of the European eel was conducted including measures of parasite diversity characteristics. Special focus was given on the prevalence and intensity of infection with the invasive swim bladder nematode Anguillicoloides crassus and the gill monogenean Pseudodactylogyrus spp. In all, 29 parasite species/taxa were found in 170 eels from six different sample sites. Parasite communities of European eels clearly exhibit the habitat preferences of their hosts, salinity-dependent specificities, and a clustering into fresh-water, brackish, and marine groups. The highly pathogenic parasite species Anguillicoloides crassus and Pseudodactylogyrus spp. were found at all sampling sites in fresh water and brackish water, with high prevalence. Therefore, the common practice of catching glass eels in river estuaries for restocking solely in inland waters as management measure for stock recovery should be critically considered. To set a baseline for future trend analyses and biodiversity considerations an updated and comprehensive literature review on prevalence and distribution of parasites of the European eel in European waters was conducted (Chapter II). The resulting checklist provides evidence for 161 parasite species/taxa from 30 countries. Special consideration was given to the distribution of the swimbladder nematode Anguillicoloides crassus. A map and table of first reported records as well as a survey map indicating all published localities of A. crassus documented in the checklist are provided. In Chapter III the prevalence of virus infections in European eels from natural habitats with differing salinity regimes were evaluated. Out of the 140 examined eels, HVA was detected in two of the five investigated water bodies with an overall infection prevalence of 2%. Virus infection was only detected by direct PCR testing, whereas none of the three HVA PCR-positive eels showed any clinical sign of disease. However latent infections of HVA were found in the investigated water bodies and as proven for the first time, also in a marine habitat (Helgoland) of northern Germany. The only reliable method for the verification of viral genome in latent herpesvirus infections is by PCR examination. For the verification of even low virus copy numbers in asymptomatic carriers, a more sensitive detection method was developed (Chapter IV). This method was tested on eel samples from two freshwater localities in northern Germany, Lake Pönitz (n=16) and River Elbe (n=30). But even with this high sensitive nested-PCR, HVA positive eels were only detected in 2 eels from Lake Pönitz (Chapter IV). Hence, the rate of HVA infection seemed to be quite low among northern German eel stocks. But the source of infection is present in at least three of the seven studied localities (Chapter III & IV) and under favourable conditions for virus replication like high water temperature or stress a reactivation and further dispersal of HVA might be induced.