Marine reserves and optimal harvesting

Advocates of no‐take marine reserves emphasize their conservation benefits. Critics counter that reserves would decrease fisheries yield. Analysis of a spatially explicit harvesting model, however, shows that no‐take marine reserves are always part of an optimal harvest designed to maximize yield. The optimal harvest generates a spatial source–sink structure with source populations placed in reserves. The sizes and locations of the optimal reserves depend on a dimensionless length parameter. For small values of this parameter, the maximum yield is obtained by placing a large reserve in the centre of the habitat. For large values of this parameter, the optimal harvesting strategy is a spatial ‘chattering control’ with infinite sequences of reserves alternating with areas of intense fishing. Such a chattering strategy would be impossible to actually implement, but in these cases an approximate yet practicable policy, utilizing a small number of reserves, can be constructed.     

Mapping the Spatial Extent of Depositional Areas in Agricultural,Urban, and Residential California Streams: Implications for Pyrethroid Toxicity

Wetted stream-bed mapping at randomly selected sites in an agricultural stream (Del Puerto Creek), urban stream (Arcade Creek), and residential stream (Pleasant Grove Creek) in California was conducted to determine the spatial extent of depositional and non-depositional areas. This study evaluated the “representativeness” of standard sediment sampling approaches used in California by using hydrophobic pyrethroids as an example. Measured background concentrations of eight pyrethroids in sediment and potential sediment toxicity for each stream were discussed within the context of depositional areas. Four percent, 15%, and 12% of the randomly selected transects in Del Puerto Creek, Arcade Creek, and Pleasant Grove Creek, respectively, were depositional areas. For all three streams, depositional areas were more dominant in downstream segments. Pyrethroid concentrations in sediment were higher in depositional areas versus non-depositional areas in Del Puerto Creek and were also higher downstream. Pyrethroid concentrations in sediment were also higher in downstream areas of Arcade Creek but generally higher in upstream areas of Pleasant Grove Creek. The results from this study demonstrate the importance of determining “representativeness” of depositional areas for an entire stream if hydrophobic chemicals (pyrethroids) measured in sediment from depositional areas are suspected to be toxic.     

Toward a recovery time: forest herbs insight related to anthropogenic acidification

Atmospheric deposition is a global concern contributing to soil acidification and biodiversity changes in forest ecosystems. Although acidifying deposition has decreased in the last decades in Europe, few evidence of ecosystem recovery from acidification has been reported until now. The objective of this study was to reconstruct spatiotemporal changes in soil pH across the entire French forest territory over the last 100‐year period through herb species assemblages. Data were collected from floristic databases resulting in a total of 120 216 plots covering French forests and spanning from 1910 to 2010. To define acidity figures, pH values were inferred from herb assemblages for each plot of the prediction dataset based on a weighted averaging partial least squares (WA‐PLS) model (R² = 0.80, SD = 0.59 for the validation dataset). Spatiotemporal trends of mean pH changes were obtained by comparing plots with respect to the period (mean year of the period = 1933, 1966, 1984, 1997, 2007) and substrate (acidic and nonacidic forest areas). Bioindicated pH highlighted a decrease in soil pH in both acidic and nonacidic forest areas. The sharpest and most significant pH decrease occurred before 1984 in acidic areas, reaching 0.34 pH units. Subsequently, no significant changes were observed, with a tendency toward stabilization. By contrast, the pH decrease reached 0.19 pH units in nonacidic areas, only reaching significance between 1984 and 1997. Thereafter, we observed a slight and significant pH increase. Spatially, pH trends revealed a regionalized character of acidification regarding the substrate, which could not be related to the extent of deposition modeled by the European Monitoring and Evaluation Programme. Both temporal and spatial trends highlight the lagged responses of nonacidic areas compared with acidic areas. Hence, floristic reconstructed pH trends demonstrate a gradual cessation and recovery from acidification of French forests after a period of intense atmospheric pollution.     

Acoustic telemetry survey of the dusky grouper (Epinephelus marginatus) in the Marine Reserve of Cerbère-Banyuls: informations on the territoriality of this emblematic species

The Marine Reserve of Cerbère-Banyuls represents a refuge for dusky grouper populations (Epinephelus marginatus). Density survey and observation of the reproductive behavior of this species have been conducted there for the last 30 years. However, information on the behavior or habitat utilization for this species during winter time is limited. We conducted acoustic telemetry surveys from September 2005 to June 2006 in the Marine Reserve of Cerbère-Banyuls for a dusky grouper population. Six groupers were tagged and followed within the integral reserve and in the adjacent partial reserve. The results from the tracking of these individuals indicated that the largest dusky groupers are sedentary fishes with a high degree of site fidelity and a high sensitivity to variations of environmental conditions such as storms. This together with the life history characteristics of this species encourages the conservation and the protection of essential habitats of this species. Acoustic tracking coupled to the use of a fixed Kernel can be proposed to follow fish populations. To cite this article: J. Pastor et al., C. R. Biologies 332 (2009).     

The Northwest Passage Revisited

The Chinese annual fishing ban in the northwestern area of the South China Sea has been a cause for tension between Vietnam and China in recent years. This article advocates for the replacement of this unilateral fishing ban with a bilateral network of marine protected areas between China and Vietnam. Such a network, if properly implemented, could not only help to preserve the living resources of the South China Sea, but also contribute toward decreasing the tension between the two countries.     

Systematics of Cafius corallicola (Fairmaire) (Coleoptera: Staphylinidae) with a discussion of its phylogenetic relationships

A systematic review of the marine littoral Cafius corallicola (Fairmaire), widely distributed along the coasts from the Indian Ocean to the western Atlantic Ocean through the southern Pacific Ocean, is presented based on morphological and molecular characters (COI and 28S). Specimens of the two species [C. corallicola and C. caribeanus Bierig] are extremely similar to each other including the form of the aedeagus. The molecular analyses support the validity of C. corallicola with one synonymy based on morphological characters. Genetic divergence of COI using uncorrected p-distance among these two species ranged from 0.35% to 4.49%. Cafius caribeanus Bierig syn. nov. is synonymized under C. corallicola. Phylogenetic relationships of C. corallicola with similar congeners are resolved as (C. corallicola (C. rufescens (C. filum + C. sericeus))). Cafius corallicola is redescribed with illustrations of diagnostic characters.     

Protected area stewardship in the Anthropocene: integrating science,law, and ethics to evaluate proposals for ecological restoration in wilderness

Every year, the four federal agencies that manage designated wilderness in the United States receive proposals to implement small‐ and large‐scale ecological restorations within the National Wilderness Preservation System. The combination of climate change with other landscape stressors is driving ecological restoration to be one of the single most important, challenging, and potentially litigious wilderness stewardship issues. In addition, different stakeholders may have strongly divergent views about what the right decision should be, and decisions need to go beyond routine technical and scientific analyses to incorporate a broader range of legal and ethical considerations. We present a framework based on a comprehensive, structured set of scientific, legal, and ethical questions to guide the evaluation of proposals for ecological restoration and other types of ecological intervention in wilderness. This framework of questions is a voluntary tool designed to increase communication and transparency among scientists, managers, and interested publics regarding the trade‐offs and uncertainties of ecological restoration, and promote informed public deliberation in managing the public resource of wilderness.