Mapping marine habitats and species distributions is essential in conservation and resource management. The generation of such maps, however, is particularly challenging for the poorly sampled deep-sea species. In this study, we explored the spatial suitability of deep-water coral (Families Paragorgiidae and Primnoidae) habitat on both the Pacific and Atlantic Continental Margins of North America (PCM and ACM) using Biomapper, a modeling program which can determine habitat suitability using presence-only data. The PCM study area was divided into 2 regions to limit the geographic size of the modelled area: PCM:AK, which encompasses Alaska and PCM:BC-CA, which encompasses British Columbia, Washington, Oregon, and California. Suitable habitat was determined based on quantitative relationships between physical seascape factors and biological data. For the PCM study area, the most accurate model for Paragorgiidae in PCM:AK combined temperature, slope, current and chlorophyll (chl) a concentration (Spearman's ρ = 0.79), whereas in the PCM:BC-CA it combined depth and chl a concentration (ρ = 0.66). For Primnoidae, in the PCM:AK the most accurate combination included depth, slope, current and chl a concentration (ρ = 0.90), and in the PCM:BC-CA, it included depth, temperature, slope and current (ρ = 0.85). In the ACM study area, the most accurate model for Paragorgiidae combined temperature, slope and chl a concentration (ρ = 0.71), whereas the one for Primnoidae combined temperature, slope, current and chl a concentration (ρ = 0.74). In both study areas, corals were predicted to occur in areas of complex topography, mainly along the continental shelf break and on seamounts. Sensitivity analyses indicated that predicted mean values of seascape factors, in coral habitat as well as niche breadth, varied with number of coral locations, but to a much lesser extent with spatial resolution. To our knowledge, this is the first study to use Biomapper for the prediction of suitable habitat in marine species.KEY WORDS: Deep-water gorgonian corals · Paragorgiidae · Primnoidae · Habitat modeling · Biomapper · Continental margin · Environmental factors · Suitable habitat Resale or republication not permitted without written consent of the publisherMar Ecol Prog Ser 330: [113][114][115][116][117][118][119][120][121][122][123][124][125][126] 2007 rine canyons, gullies and on the edge of the continental shelf (MacIsaac et al. 2001). These sloping areas are normally associated with hard substrate, such as cobble and boulders, making them suitable for coral attachment (Freiwald et al. 1999). Because of the rarity of hard substrate in the deep sea, areas of high vertical relief often harbour abundant communities of benthic organisms, including deep-water corals (Herring 2002). Typically, these areas are also associated with strong current regimes (Genin et al. 1986, Herring 2002. As they are sessile filter feeders, deep-water corals rely on currents to provide nutrition as well as to remove sediments which may smother them. C...

No abstract

No abstract

The loss of blue carbon ecosystems results in significant levels of carbon emissions and decreased supply of other ecosystem services. West Africa contains approximately 14% of the world's mangrove area but despite 25% of coverage loss between 1980 and 2006, the region's mangroves have not been well studied. This study aims to provide a first step toward increasing the knowledge of the region's blue carbon stocks, with a focus on mangroves, and of their financial value based on their carbon storage benefit alone. The best available data suggest that the region contains 1.97 million hectares of mangroves storing 854 million metric tons of carbon in above-and below-ground biomass and the top meter of soil; 4.8 million hectares of seagrass storing 673 million metric tons of carbon; and 1.2 million hectares of salt marshes storing 303 million metric tons of carbon. Even without including values for other benefits of intact mangroves, the conservation of mangroves in the region appears viable. Specifically, the discounted value of 20-year emission reductions under a conservation scenario is estimated to be between $341.2-569.0 million at an 8% discount rate and carbon prices of $3 and $5 per metric ton respectively.

Experimental data suggest that exposure to the 50 and 60 Hz sinusoidal components of power-frequency magnetic fields (MFs) does not have an adverse impact on fetal development. However, the possible developmental toxicity of MF harmonics has not been investigated. This study was designed to determine whether exposure to 180 Hz MFs (third harmonic), alone or in combination with 60 Hz MFs, induces birth defects in Sprague-Dawley rats. Groups of sperm-positive dams (> or =20/group) were exposed for 18.5 h per day from gestation days 6 through 19 to (1) ambient MFs only (<0.0001 mT; sham controls); (2) 60 Hz MFs at 0.2 mT; (3) 180 Hz MFs at 0.2 mT; or (4) 60 Hz + 180 Hz MFs (10% third harmonic; total field strength = 0.2 mT). Litter size, litter weight, percentage live births, sex ratio, and number of resorption sites were determined for each dam, and gross external, visceral, cephalic and skeletal examinations were performed on all fetuses. MF exposure had no significant effects on litter size, litter weight, or fetal development. With the exception of common rib variants, the incidence of fetal anomalies was comparable in all groups. A small increase in the incidence of rib variants was seen in the group exposed to 60 Hz + 180 Hz MFs; however, the incidence of rib variants in this group was similar to that in historical controls from our laboratory. These data extend the existing database on developmental toxicity of MFs by demonstrating that exposure to 180 Hz MFs, either alone or superimposed on an underlying 60 Hz signal, does not induce biologically significant developmental toxicity. These data do not support the hypothesis that exposure to power-frequency MFs is an important risk factor for fetal development.