Threats of illegal,unregulated, and unreported fishing to biodiversity and food security in the Republic of the Congo

Illegal, unregulated, and unreported (IUU) fishing poses a major threat to effective management of marine resources, affecting biodiversity and communities dependent on these coastal resources. Spatiotemporal patterns of industrial fisheries in developing countries are often poorly understood, and global efforts to describe spatial patterns of fishing vessel activity are currently based on automatic identification system (AIS) data. However, AIS is often not a legal requirement on fishing vessels, likely resulting in underestimates of the scale and distribution of legal and illegal fishing activity, which could have significant ramifications for targeted enforcement efforts and the management of fisheries resources. To help address this knowledge gap, we analyzed 3 years of vessel monitoring system (VMS) data in partnership with the national fisheries department in the Republic of the Congo to describe the behavior of national and distant-water industrial fleets operating in these waters. We found that the spatial footprint of the industrial fisheries fleet encompassed over one-quarter of the Exclusive Economic Zone. On average, 73% of fishing activity took place on the continental shelf (waters shallower than 200 m). Our findings highlight that VMS is not acting as a deterrent or being effectively used as a proactive management tool. As much as 33% (13% on average) of fishing effort occurred in prohibited areas set aside to protect biodiversity, including artisanal fisheries resources, and the distant-water fleet responsible for as much as 84% of this illegal activity. Given the growth in industrial and distant-water fleets across the region, as well as low levels of management and enforcement, these findings highlight that there is an urgent need for the global community to help strengthen regional and national capacity to analyze national scale data sets if efforts to combat IUU fishing are to be effective.     

Variability in trophic dominance of crustaceans along a gradient of urban and industrial contamination

The trophic organization of the crustacean fauna belonging to a photophilic assemblage exposed to an urban and industrial contamination gradient in the Gulf of Fos (South of France) was studied over a period of 16 mo (May 1974 to August 1975). An increasing destabilization of the four major trophic groups from clean waters towards those most polluted was noted. Carnivores dominated at the relatively cleanwaterCystoseira stricta station; at the second, moderately pollutedC. stricta station, carnivores were replaced by suspension-feeders. Deposit-feeders dominated theCorallina cf.mediterranea stations affected by the warm-water effluent of a power plant. Other polluted stations, dominated byMytilus galloprovincialis andUlva cf.rigida, were dominated by grazers. The faunal destabilization was related to changes in the structural composition of the photophilic algal assemblage which were, in turn, related to the industrial contamination gradient along this coast.     

Teil II: Verfahren zur Monetarisierung von Ökosystemleistungen

As it is practically impossible in an industrial society to reduce impacts into ecosystems to a level that would preclude any damages, the need for damage valuation arises. One of the available valuation tools is the economic approach. Subsequent publications present this approach using the example of soils. In this second part, two methods are presented for monetarising ecosystem services, the contingent valuation method, the valuation on the basis of restoration and replacement costs. Common arguments against the monetarisation of ecosystems, like the omission of intrinsic values or the incomplete information of individuals, are then discussed. In conclusion, limits and possibilities of monetarising ecosystem services are described.     

Oxygen dynamics and transport in the Mediterranean sponge Aplysina aerophoba

The Mediterranean sponge Aplysina aerophoba kept in aquaria or cultivation tanks can stop pumping for several hours or even days. To investigate changes in the chemical microenvironments, we measured oxygen profiles over the surface and into the tissue of pumping and non-pumping A. aerophoba specimens with Clark-type oxygen microelectrodes (tip diameters 18–30 μm). Total oxygen consumption rates of whole sponges were measured in closed chambers. These rates were used to back-calculate the oxygen distribution in a finite-element model. Combining direct measurements with calculations of diffusive flux and modeling revealed that the tissue of non-pumping sponges turns anoxic within 15 min, with the exception of a 1 mm surface layer where oxygen intrudes due to molecular diffusion over the sponge surface. Molecular diffusion is the only transport mechanism for oxygen into non-pumping sponges, which allows total oxygen consumption rates of 6–12 μmol cm⁻³ sponge day⁻¹. Sponges of different sizes had similar diffusional uptake rates, which is explained by their similar surface/volume ratios. In pumping sponges, oxygen consumption rates were between 22 and 37 μmol cm⁻³ sponge day⁻¹, and the entire tissue was oxygenated. Combining different approaches of direct oxygen measurement in living sponges with a dynamic model, we can show that tissue anoxia is a direct function of the pumping behavior. The sponge-microbe system of A. aerophoba thus has the possibility to switch actively between aerobic and anaerobic metabolism by stopping the water flow for more than 15 min. These periods of anoxia will greatly influence physiological variety and activity of the sponge microbes. Detailed knowledge about the varying chemical microenvironments in sponges will help to develop protocols to cultivate sponge-associated microbial lineages and improve our understanding of the sponge-microbe-system.