Untersuchungen des Zanderbestandes in den deutschen Küstengewässern der Ostsee von 1992 bis 2002

Pike-perch is an important resource for the coastal fishery in the brackish waters of the eastern part of the coast. For the conservation of the stocks regulation measures (minimum landing size, closed season and minimum mesh size) have been introduced since many years. Basic biological material of the last decade sampled from the commercial fishery and for recruitment by a standard trawl survey. For the “Eastern stock” this paper presents the results concerning age distribution, year-class strengths, growth, proportion spawners, natural mortality and yield-per-recruit analyses

Zanderfischerei an der deutschen Ostseeküste - Jungzander 1992 - extrem in Vorkommen, Verbreitung und Wachstum

Die Zanderanlandungen an der deutschen Ostseeküste lagen in den letzten 10 Jahren auf einem verhältnismäßig hohen Niveau (Durchschnitt 471 t; 1992,477 t). Im jahreszeitlichen Verlauf gibt es eine Frühjahr (April)- und Herbst (Oktober)-Saison. Hauptfangplätze waren 1992 Außenstrand (bis zu 3 sm) und Ostsee, Kleines Haff und Darßer Bodden. Im Oderbankgebiet wurde im Herbst 1992 die überdurchschnittlich gut eingeschätzte 0-Gruppe untersucht, die ab 1994 und teilweise ab 1995 in den befischbaren Bestand eintritt. Die Entwicklung des Bestandes wird weiterhin wissenschaftlich überwacht

How Behavior, Physiology, and Ontogeny of Klamath Redband Trout Shape the Functionality of Habitats in a Landscape of Temperature Extremes

Climate change is a global phenomenon, but natural selection occurs within landscapes. A central tenet of landscape ecology is that mobile species depend on complementary habitats, which are insufficient in isolation, but combine to support animals through the full annual cycle. For coldwater fishes, it is widely assumed that maximum temperatures are limiting, and that summer data alone can predict refugia and population persistence. In a naturally warm basin emulating the future of cooler systems, we demonstrate how such assumptions can overlook portions of the riverscape that are critical for supporting fisheries. In this dissertation, we investigated the complex relationship between redband trout and temperature in the Upper Klamath Basin, from a landscape ecology perspective introduced in Chapter 1. Chapter 2 used parallel data sets from radio telemetry, diet sampling, and fish condition monitoring to explore seasonal movement among complementary thermal habitats. During summer, populations of redband rainbow trout (Oncorhynchus mykiss newberrii) were only found in cool tributaries or springs and distinctly avoided Upper Klamath Lake, which exhibited stressful temperatures >25°C. However, during spring and fall most trout migrated to the lake to forage, achieving high rations and growth that compensated for a net loss of energy in cool summer habitats. In winter, most trout returned to tributaries to spawn, completing a biannual migration totaling 60-300 km. Thus, while perennially cool tributaries supported thermal refuge and spawning, foraging opportunities in the seasonally hot lake ultimately fueled these behaviors. In Chapter 3, we compared coldwater fish from neighboring habitats in a naturally warm, recently fragmented basin to understand how different responses to warming may arise from landscape constraints. Trout in warm, hydrologically connected Upper Klamath Lake fled summer temperatures and sought refuge in cool tributaries, while trout in an equally warm but fragmented reach of the Klamath River endured summer conditions. Respirometry experiments revealed that trout in the river were more physiologically tolerant of high temperatures than trout in the lake across four metrics, including routine metabolism, aerobic scope, recovery from exertion, and loss of equilibrium. Two independent metrics of energetic condition indicated that the behavioral strategy of trout in the lake came at a substantial energetic cost, while the physiological strategy of trout in the river was able to mitigate most energetic consequences of high temperatures. No clear genetic basis for enhanced tolerance was found in trout from the river, which may suggest tolerance was derived from plasticity but cannot rule out genetic adaptation. Chapter 4 examines the mismatch between the extent and resolution of available data for temperature versus for fish habitat use. We surveyed cool springs identified by infrared technology to quantify their functionality as thermal refuges for juvenile and adult salmonids in the warm Sprague River sub-basin. Juvenile trout inhabited approximately half of potential refuges and were most prevalent in ponds and their outflow channels. Larger size classes were present in just 10% of refuges and were more prevalent in plumes. All trout selected cool, oxygenated habitats, but refuges occupied by larger trout were colder and deeper. Regression models for juvenile trout suggested that complex refuges, especially those associated with beaver dams, were more likely to be occupied; further, those containing complementary habitat types also contained more trout. Basin-scale analyses revealed that Sprague River springs provided minimal thermal refuge for the meta-population of large migratory trout in summer. However, these springs were a premier location for winter spawning in the Upper Klamath Basin and offered a moderate degree of warm refuge when temperatures were near freezing. Together, results of the three studies show that applications such as climate change adaptation and water quality standards could benefit from considering temperature as a resource, the use of which is constrained by time, space, and life history. Chapter 5 discusses these applications and concludes that managing for how fish respond to temperature, rather than how temperature controls fish, should be a goal for maintaining resilient ecosystems in a changing climate. Allocation of funds for habitat conservation, as well as policy design for water temperature standards, should consider other aspects of temperature regimes besides summer conditions that can influence how fish survive in warm landscapes

The WEI6K, a 6-kW 7-m Small Wind Turbine: Final Technical Report

This project was selected by the U.S. Department of Energy under a DOE solicitation “Low Wind Speed Technology for Small Turbine Development.” The objective of this project has been to design a new small wind turbine with improved cost, reliability and performance in grid-connected residential and small business applications, in order to achieve the overall DOE goal of cost effectiveness in Class 3 wind resources that can now be achieved in Class 5 resources. The scope of work for this project has been to complete the preliminary design of an improved small wind turbine, including preliminary loads and strength analyses; analysis and design of all major components; systems integration and structural dynamic analysis; estimation of life-cycle cost of energy; and design documentation and review. The project did not entail hardware fabrication or testing. The WEI6K Turbine resulting from this project is an upwind horizontal-axis wind turbine rated at 6 kW. It features a 3-blade 7-m diameter rotor. The generator is a direct-drive permanent magnet synchronous machine generating 3-phase power at 240 VAC. The turbine is maintained oriented in to the wind via active yaw control using electromechanical servos. Power is regulated with active blade pitch control. The turbine is presently designed to be placed on a 100-foot (30m) tower. The turbine is predicted to generate electricity at a levelized cost of energy (COE) between 7.3 and 8.9 ¢/kWh at an IEC Class II site, with an average wind speed of 8.5 m/s at hub height, depending upon whether the customer uses a guyed truss tower (the lower figure) or a monopole tower. For the NREL Reference Site, with a mean wind speed of 5.35 m/s at 10 m height, the turbine would generate at a levelized cost of energy of between 9.7 and 11.9 ¢/kWh. The lowest of these numbers is presently competitive with retail electricity rates in most of the country. The 8.9 ¢/kWh is still competitive with retail rates in many regions of the country with high electricity costs. The study further concludes that several design changes could shave 10-14% from the cost of energy determined in the preliminary design. These changes include a new tower design that offers tilt-up capability without guy wires and takes better advantage of the lowered loads produced by pitch control; design a family of airfoils more appropriate for pitch regulation on a turbine of this size; tune the pitch controller properly to minimize shedding of power during turbulent operation in the transition from Region 2 to 3; value engineer the pitch system to shave costs, including consideration of a collective pitch system; and refine the design of the hub and main frame castings to minimize weight and cost. We are generally encouraged by the results. These preliminary numbers show that we can produce a turbine that is competitive with retail electric rates at relatively windy IEC Class II sites. With further improvements in the design, we believe the turbine could be competitive at sites with lesser wind resource

The juvenile three-spined stickleback : model organism for the study of estrogenic and androgenic endocrine disruption in laboratory and field

Industrial and domestic sewage effluents have been found to cause reproductive disorders in wild fish, often as a result of the interference of compounds in the effluents with the endocrine system. This thesis describes laboratory-based exposure experiments and a field survey that were conducted with juveniles of the three-spined stickleback, Gasterosteus aculeatus. This small teleost is a common fish in Swedish coastal waters and was chosen as an alternative to non-native test species commonly used in endocrine disruption studies, which allows the comparison of field data with results from laboratory experiments. The aim of this thesis was to elucidate 1) if genetic sex determination and differentiation can be disturbed by natural and synthetic steroid hormones and 2) whether this provides an endpoint for the detection of endocrine disruption, 3) to evaluate the applicability of specific estrogen- and androgen-inducible marker proteins in juvenile three-spined sticklebacks, 4) to investigate whether estrogenic and/or androgenic endocrine disrupting activity can be detected in effluents from Swedish pulp mills and domestic sewage treatment plants and 5) whether such activity can be detected in coastal waters receiving these effluents. Laboratory exposure experiments found juvenile three-spined sticklebacks to be sensitive to water-borne estrogenic and androgenic steroid substances. Intersex – the co-occurrence of ovarian and testicular tissue in gonads – was induced by 17β-estradiol (E2), 17α-ethinylestradiol (EE2), 17α-methyltestosterone (MT) and 5α-dihydrotestosterone (DHT). The first two weeks after hatching was the phase of highest sensitivity. MT was ambivalent by simultaneously eliciting masculinizing and feminizing effects. When applying a DNA-based method for genetic sex identification, it was found that application of MT only during the first two weeks after hatching caused total and apparently irreversible development of testis in genetic females. E2 caused gonad type reversal from male to female. E2 and EE2 induced vitellogenin - the estrogen-responsive yolk precursor protein, while DHT and MT induced spiggin – the androgen-responsive glue protein of the stickleback. None of the effluents from two pulp mills and two domestic sewage treatment plants had any estrogenic or androgenic activity. Juvenile three-spined sticklebacks were collected during four subsequent summers at the Swedish Baltic Sea coast in recipients of effluents from pulp mills and a domestic sewage treatment plant as well as remote reference sites. No sings of endocrine disruption were observed at any site, when studying gonad development or marker proteins, except for a deviation of sex ratios at a reference site. The three-spined stickleback – with focus on the juvenile stage – was found to be a sensitive species suitable for the study of estrogenic and androgenic endocrine disruption

Subaquatisch-gravitativ umlagerte Sedimente des Devons und Karbons um Bad Lauterberg (SW-Harz)

3 mapsSIGLETIB Hannover: RA 356(31)+a+b / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

Subaquatisch-gravitativ umgelagerte Sedimente des Devons und Karbons um Bad Lauterberg (SW-Harz)

Aus dem SW-Harz werden Ton-/SiItsteine mit Einlagerungen aus verschiedenartigen und -alten Gesteinen beschrieben. Die Sedimentkörper werden aufgrund eindeutig submarin-gravitativer Umlagerungsgefüge als Olisthostrome eingestuft. Andere Strukturen innerhalb der Olisthostrome können auch diagenetisch oder tektonisch bedingt sein. Es werden drei verschiedene Olisthostromkomplexe ausgegliedert, die voneinander durch unterschiedliche Klastenführung abgegrenzt werden. Neben Olisthostromen stehen im Untersuchungsgebiet auch slumps und Steinschlagsedimente an.In the S-W-Harz Mountains pelites with inclusions from rocks of different origin and age are described. Due to definitiveley submarine gravitational structures of deposition these sediments are classified as olistostromes. Other textures in the olistostromes could be the result of diagenesis or tectonics. Three olistostrome complexes are separated which contain different clasts. Moreover slumps and rockfall sediments are found in the area investigation.DFG/HE/394/14-1 , 14-