Skin and skeletal system lesions of european pond turtles (Emys orbicularis) from natural habitats

Water pollution is known to play an important role in the pathogenesis of plastron, carapace and skin diseases of turtles. In this study, a total of 150 European pond turtles (Emys orbicularis) of different age and both sexes, originating from natural habitats in Serbia, were examined for morphological changes of the skin, plastron, carapace and skeletal system. The turtles were taken out from their natural habitats in Lake Ludas, Lake Palic and Lake Tresetiste. After artificial hibernation, they were subjected to detailed examination, sampled and treated, and finally returned into their natural habitat. Biopsies from the skin and shell were subjected to histopathological examination and microbiological analysis. X-ray scanning was also performed to detect changes in the skeletal system. Macroscopic changes of the skin, most frequently degenerative, inflammatory or neoplastic diseases, were diagnosed in 49.33% of the turtles examined. Dermatitis of different origin and form was the most prominent histopathological finding (28.00%). In the plastron, inflammatory and degenerative processes were frequently found. Osteopathy and mechanical injuries were the dominant findings. Macroscopic changes of the plastron, carapace and skeletal system were diagnosed in 67.33% of the turtles examined. Using X-ray scanning, generalised osteopathy, anomalies and malformations of different aetiology were also diagnosed on the tail and legs. Microbiological examinations showed the presence of a variety of bacterial and fungal agents, either primary pathogens or potential polluters, which invaded the skin and shell, or were present in cloacal swab samples. Bacterial infection was diagnosed in 76.66% of the turtles, first of all in those with skin and shell necrosis. Mycoses were diagnosed in 33.33% of the animals

Basin-Scale Control on the Phytoplankton Biomass in Lake Victoria, Africa

The relative bio-optical variability within Lake Victoria was analyzed through the spatio-temporal decomposition of a 1997–2004 dataset of remotely-sensed reflectance ratios in the visible spectral range. Results show a regular seasonal pattern with a phase shift (around 2 months) between the south and north parts of the lake. Interannual trends suggested a teleconnection between the lake dynamics and El-Niño phenomena. Both seasonal and interannual patterns were associated to conditions of light limitation for phytoplankton growth and basin-scale hydrodynamics on phytoplankton access to light. Phytoplankton blooms developed during the periods of lake surface warming and water column stability. The temporal shift apparent in the bio-optical seasonal cycles was related to the differential cooling of the lake surface by southeastern monsoon winds. North-south differences in the exposure to trade winds are supported by the orography of the Eastern Great Rift Valley. The result is that surface layer warming begins in the northern part of the lake while the formation of cool and dense water continues in the southern part. The resulting buoyancy field is sufficient to induce a lake-wide convective circulation and the tilting of the isotherms along the north-south axis. Once surface warming spreads over the whole lake, the phytoplankton bloom dynamics are subjected to the internal seiche derived from the relaxation of thermocline tilting. In 1997–98, El-Niño phenomenon weakened the monsoon wind flow which led to an increase in water column stability and a higher phytoplankton optical signal throughout the lake. This suggests that phytoplankton response to expected climate scenarios will be opposite to that proposed for nutrient-limited great lakes. The present analysis of remotely-sensed bio-optical properties in combination with environmental data provides a novel basin-scale framework for research and management strategies in Lake Victoria

The Northern mozambique channel

The Northern Mozambique Channel is a treasure of unique oceanography, rich coral reefs, migrating tuna, and whales, bounded by the Comoros, France, Madagascar, Mozambique, Seychelles, and Tanzania. Its living resources are relatively intact and of great importance for food and livelihood security and the developing economies of its surrounding countries. It holds newly discovered natural gas fields of global importance that could fuel unprecedented development pressure, and its 10 million coastal population could grow an order of magnitude by the turn of the century. With these immense pressures against the backdrop of rapid climate change, effective governance across different sectors and among countries will be essential to maintain the region’s natural capital and deliver on the promise of sustainable development and “blue economy” subscribed by the surrounding countries. This chapter outlines some of the novel ocean management and governance approaches that may provide the best chance to deliver on a prosperous future.</p

Seasonal Variability of Carbon Dioxide in the Rivers and Lagoons of Ivory Coast (West Africa)

peer reviewedWe report partial pressure of CO2 (pCO2) and ancillary data in three rivers (Bia, Tanoé, and Comoé) and five lagoons (Tendo, Aby, Ebrié, Potou, and Grand-Lahou) in Ivory Coast (West Africa), during four cruises covering the main climatic seasons. The three rivers were oversaturated in CO2 with respect to atmospheric equilibrium, and the seasonal variability of pCO2 was due to dilution during the flooding period. Surface waters of the Potou, Ebrié, and Grand-Lahou lagoons were oversaturated in CO2 during all seasons. These lagoons behaved similarly to the oligohaline regions of macrotidal estuaries that are CO2 sources to the atmosphere due to net ecosystem heterotrophy and inputs of riverine CO2 rich waters. The Aby and Tendo lagoons were undersaturated in CO2 with respect to the atmosphere because of their permanent haline stratification (unlike the other lagoons) that seemed to lead to higher phytoplankton production and export of organic carbon below the pycnocline