Pluri-annual study of the reproduction of two Mediterranean Oscarella species (Porifera, Homoscleromorpha): cycle, sex-ratio, reproductive effort and phenology

This study presents the phenology of two common Mediterranean sponges belonging to the genus Oscarella (Porifera, Homoscleromorpha). Oscarella tuberculata and Oscarella lobularis are two sibling species, dwellers of shallow benthic communities which tend to have distinct ecological behavior, respectively, euryecious and rather stenoecious. The comparative study of their reproductive cycle showed that both Oscarella species have a seasonal reproductive cycle with a successive phase duration differing from one species to another. In both species, there is a continuous oogenesis, with new oocytes appearing in spring, whereas the spermatogenesis generally starts later with the early warming of the sea. The embryonic development and the larval release are restricted to the warmest months of the year. We also observed a shift in the period of gametogenesis and larval emission depending on species and differences in their sensitivity to changes in thermal regime. It appears that an increase in seawater temperature can affect sex determination, with mainly a shift toward males in both species. Their reproductive efforts are variable in time, and can be in some cases influenced by the temperature regime. This is especially the case of O. lobularis which seems to be the most thermosensitive, its phenology responding significantly to changes in thermal regime, whereas O. tuberculata seems to be less sensitive and/or reactive. By detecting phenological changes among sponges, this study demonstrated the relevance of such monitoring to assess the possible biological response to climate change.     

Development of a new standardised method for sustainable monitoring of the vulnerable pink sea fan Eunicella verrucosa

The aim of this survey was to test a standardised method to follow the demographic evolution of a dense aggregative ‘forest’ population of the temperate gorgonian Eunicella verrucosa (Octocorallia, Gorgoniidae) using in situ photographic recordings. Distribution, density, growth and demographic evolution of the colonies was compared along two parallel transects. Computer treatment allowed the estimation of the total branch fan surface area, and the individual growth of tagged colonies was determined by measuring the increase in this surface area, using consecutive photographs taken at two-year intervals. To integrate the potential bias of branch overlapping, we proposed a correction factor between the in situ photographic surface area and the surface area of the gorgonian calculated from ex situ photographic surface area with all branches deployed. The surface-frequency distribution of colonies was converted to estimated-age-frequency distribution using an estimated growth curve based on the net growth rate. The technique used revealed significant differences in population structure and the dynamics of gorgonian colonies, as the two transects appeared to be influenced by different environmental conditions. The recruitment also seemed to vary according to year and transect, resulting in different densities. Our work showed clear results in characterising the variations of gorgonian demographic evolution at a small spatial scale; thus, it is assumed that this method could be a sustainable tool for coastal environmental managers.     

Sustainable poverty alleviation through a forestry project in Tamilnadu State of India

The World Development Report 2000–2001 recommends action on three complementary and synergistic fronts for poverty alleviation – promoting opportunity, facilitating empowerment and enhancing security. This paper analyses the Tamilnadu Forestry Project, funded by US$100 million from the Japan Bank for International Cooperation, for community forestry. The project was launched in 1997–1998 in this southern state of India and has evolved into a comprehensive poverty alleviation programme for the forest abutting villages where the proportion of poor people is largest. It endeavours to explain how the project provides the above three elements at the local level for sustainable poverty alleviation. Regeneration of forests, improvement of basic infrastructure through integration of line departments and promotion of alternate livelihoods provide ample economic opportunities. Establishment of Village Forest Councils, and delegation of sufficient powers to these Councils, has empowered the poorest of the poor. Tree assets, promotion of alternate income generation activities and water harvesting structures have provided security by reducing vulnerability to natural vagaries, particularly drought. In this project, the restoration of biodiversity and people development go hand in hand in a synergistic way that makes the project worth replicating elsewhere in the country and other parts of the world, with suitable modifications.     

Effects of environmental parameters on the oxygen consumption of four marine invertebrates: a comparative factorial study

The oxygen consumption curves of two decapod crustaceans (Palaemon serratus, Penaeus monodon) and two prosobranch molluscs (Trunculariopsis trunculus, Nassarius mutabilis) have been detected in the entire pO₂ interval from 0 to 160 mmHg, under different conditions of temperature and salinity. From the experimental curves, physiological parameters such as the initial oxygen consumption velocity, the Q ₁₀ values and the oxygen independence indices have been measured. The latter parameters have been obtained using normalised plots which allow their better evaluation. The effects of temperature, salinity and oxygen partial pressure on the oxygen-consumption features have been studied using a factorial experimental plan which allows measurement of the effects of each experimental variable as well as the effects of synergistic interactions between different variables. Received: 27 March 2000 / Accepted: 13 November 2000     

Critical review of Integrated Water Resources Management: Moving beyond polarised discourse

Integrated Water Resource Management (IWRM) emerged as a popular concept in the water sector in the 20th century. From a highly techno-centric approach in the past, it has taken a new turn embracing Habermasian communicative rationality as a place-based nexus for multiple actors to consensually and communicatively integrate decisions in a hydrological unit. The 'how to integrate' approach had remarkable appeal worldwide in promoting authentic participation of all stakeholders. However, critics argue that the domain of water resource management is a political process of contestation and negotiation; the emphasis is on complexities, contextuality, power dynamics and the importance of analysing real world situations. They demonstrate 'how integration cannot be achieved' given the power dynamics in social interactions. These apparently contradictory discourses draw on different theoretical paradigms and polarise the discourse on IWRM, without offering constructive alternatives. To this end, this paper offers an option to complement this polarised discourse by examining 'how integration actually does take place' in a strategic context thereby facilitating consensual decisions to integrate water management for a sustainable future.     

Severity analysis of Indian coal mine accidents – A retrospective study for 100 years

A retrospective study on severity analysis of Indian coal mines accidents for 100 years was done considering fatal and serious accidents and the resulting causalities. The impact of recommendations based on safety conferences and committees over the years was studied. An event evaluation algorithm (EEA) was developed for this purpose. The hazard rate functions and cumulative risk functions for major hazards in Indian coal mines were developed. The study evaluated the status of safety level as well as the scope of improvement for Indian coal mines safety.     

Macrophage activity and histopathology of the lymphohematopoietic organs in male Wistar rats orally exposed to single or mixed pesticides

The noxious effects of low or effective dose exposure to single or mixed pesticides on macrophage activity and the lymphohematopoietic organs were investigated. Male Wistar rats were orally exposed to dichlorvos, dicofol, endosulfan, dieldrin and permethrin, either as single or combined mixtures during a 28-day study containing eight groups: one group received a semipurified diet (non-treated); two groups received a semipurified diet containing low dose mixture (dieldrin 0.025 mg/kg, endosulfan, 0.6 mg/kg, dicofol 0.22 mg/kg, dichlorvos 0.23 mg/kg, permethrin 5 mg/kg) or an effective dose mixture (dichlorvos 2.3 mg/kg, dicofol 2.5 mg/kg, endosulfan 2.9 mg/kg, dieldrin 0.05 mg/kg and permethrin 25.0 mg/kg), respectively; the other five groups received a semipurified diet containing each single pesticide in effective doses. At sacrifice, the thymus, spleen, mesenteric lymph nodes, Payer's patches and bone marrow were removed for histological analysis. Peritoneal macrophages were obtained to determine the phagocytosis and spreading indexes and tumoral necrosis factor alpha (TNF-α), nitric oxide (NO) and H₂O₂ production. Exposure to pesticide mixtures did not alter the percentage of macrophage phagocytosis and spreading, TNF-α production or the NO and H₂O₂ release when compared to the non-treated group. Neither was there any apparent evidence that a pesticide mixture at low or effective doses altered the histological structure of the lymphohematopoietic organs. The findings indicate that short-term treatment with pesticide mixtures did not induce an apparent immunotoxic effect in male Wistar rats.