Ultrahigh temperature and strain hybrid integrated sensor system based on Raman and femtosecond FBG inscription in a multimode gold-coated fiber.

In this paper, a novel approach for hybrid systems combining Raman distributed sensors with fiber Bragg grating (FBG) sensors to carry out distributed and quasi-distributed temperature/strain measurements was proposed and experimentally demonstrated. Three FBGs were inscribed by the point-by-point technique in a simple setup for type I femtosecond inscription in a pure silica core multimode gold-coated fiber. Employing a single fiber, temperatures up to 600 °C and strains up to 4144 µÉ› approximately were measured simultaneously and without interferences between both distributed and point measurements. Moreover, a new calibration technique was implemented to calibrate the distributed temperature system using the FBG measurements as reference.

Assessment of seabed litter at Concepción Seamount (Canary island) using a remotely operated towed vehicle.

The seafloor is recognised as a major sink for marine litter. However, studies conducted in this compartment addressing marine litter densities and its interactions with fauna are scarce, mainly due to sampling constraints. In this paper, we assess marine litter density, composition and interactions with marine communities and evaluate its relationship with fishing activities at the "Banco de la Concepción" seamount (Canary Islands, Spain). We took advantage of underwater video records taken with a Remotely Operated Towed Vehicle in the framework of the LIFE IP INTEMARES project. A total of 56 video transects were analysed covering about 9 km with 19 h of video recording. Transects were categorised as high, low, and null fishing effort based on the Vessel Monitoring System (VMS) positional data registered between 2009 and 2017. Litter items were recorded in 70% of the transects with a mean density of 2122 (±2464) items km-2. There were significant differences in litter densities over the three levels of fishing pressure, with a density decrease from stations of high to stations of null fishing pressure. Regarding categories, plastic was by far the most abundant category found (83.1%), mainly consisting of fishing lines, both monofilaments and entangled longlines. The study of the interactions of marine litter with fauna showed that less than 20% of the items presented an interaction with benthic organisms either by causing or not a visible impact. The sponge Asconema setubalense accounted for more than half (57.4%) of all interactions, but only 5% of all A. setubalense specimens showed physical damage.

Invasion of Sargassum muticum in intertidal rockpools: patterns along the Atlantic Iberian Peninsula.

Spatial patterns of non-indigenous species show scale-dependent properties. Sargassum muticum is an invasive macroalga widely distributed along the Atlantic Iberian Peninsula. Despite being quite abundant from Norway to South Portugal, there is little information about its patterns of distribution, particularly at a large spatial scale (i.e. thousands of kilometres). Here, we examined the spatial variation in the invasion success of S. muticum from rockpools at multiple spatial scales using a hierarchical design. In addition, we analysed how the richness of native assemblages was related to its invasion success and how this relationship changed over different scales. Most of the variation in the invasion success was found at the smallest scales of pool and plot. Furthermore, the invasibility of native macroalgal assemblages was related to the native species richness, but causes that determined invasion success could not be separated from the effects provoked by the invader. Results suggest that small-scale (centimetres to metres) processes contribute considerably to the heterogeneity of S. muticum invasion success.