First in situ observations of soft bottom megafauna from the Cascais Canyon head

We report the first in situ observations of soft bottom megafauna from the Cascais Canyon head. Observations were collected opportunistically during three technical dives with the ROV Luso between 460-805 m at two locations distanced 1,230 m. The habitats were clas-sified as upper bathyal fine mud. The soft bottom fauna was dominated by burrows of Nephrops norvegicus reaching up to 2.9 burrows/m2, a common habitat along the Portu-guese continental margin. To our knowledge, densities are the highest ever reported for depths below 300 m. The ichthyofauna at the upper Cascais Canyon is a mixture of lower shelf and upper bathyal species, including Phycis blennoides, Scyliorhynus canicula, Coe-lorhynchus labiatus/occa and Chimaera monstrosa. Bait release attracted Myxine glutinosa. Surveys in other geological settings of the Cascays Canyon are required to understand more comprehensively the diversity of its sessile and vagile biodiversity

Ludwig Koch and the Music of Nature

Ludwig Koch was a pioneer of outside broadcast, natural history recording in the first half of the 20th century. This programme explores his methods, techniques and personality through archive recordings and interviews, and includes attempts t recreating his experiments using modern equipment

High interannual variability in connectivity and genetic pool of a temperate clingfish matches oceanographic transport predictions

Adults of most marine benthic and demersal fish are site-attached, with the dispersal of their larval stages ensuring connectivity among populations. In this study we aimed to infer spatial and temporal variation in population connectivity and dispersal of a marine fish species, using genetic tools and comparing these with oceanographic transport. We focused on an intertidal rocky reef fish species, the shore clingfish Lepadogaster lepadogaster, along the southwest Iberian Peninsula, in 2011 and 2012. We predicted high levels of self-recruitment and distinct populations, due to short pelagic larval duration and because all its developmental stages have previously been found near adult habitats. Genetic analyses based on microsatellites countered our prediction and a biophysical dispersal model showed that oceanographic transport was a good explanation for the patterns observed. Adult sub-populations separated by up to 300 km of coastline displayed no genetic differentiation, revealing a single connected population with larvae potentially dispersing long distances over hundreds of km. Despite this, parentage analysis performed on recruits from one focal site within the Marine Park of Arrabida (Portugal), revealed self-recruitment levels of 2.5% and 7.7% in 2011 and 2012, respectively, suggesting that both long-and short-distance dispersal play an important role in the replenishment of these populations. Population differentiation and patterns of dispersal, which were highly variable between years, could be linked to the variability inherent in local oceanographic processes. Overall, our measures of connectivity based on genetic and oceanographic data highlight the relevance of long-distance dispersal in determining the degree of connectivity, even in species with short pelagic larval durations

Characterization of 15 polymorphic microsatellite loci in the temperate reef fish Lepadogaster lepadogaster, developed using 454-sequencing

Abstract The clingfish, Lepadogaster lepadogaster is a reef fish species, abundant in temperate nearshore rocky reefs of the Eastern Atlantic and central and Eastern Mediterranean. To study genetic variability and population connectivity of this species, we developed fifteen polymorphic microsatellite markers. These were tested in one population and all but one, showed no departure from Hardy–Weinberg equilibrium. Average overall observed heterozygosity was 0.66 and allelic richness was 8.9. Two primer pairs revealed possible linkage disequilibrium. These markers open perspectives for population genetic studies of this species to unravel connectivity and population biology, vital information for future conservation studies

Marine Litter Distribution and Density in European Seas, from the Shelves to Deep Basins

Anthropogenic litter is present in all marine habitats, from beaches to the most remote points in the oceans. On the seafloor, marine litter, particularly plastic, can accumulate in high densities with deleterious consequences for its inhabitants. Yet, because of the high cost involved with sampling the seafloor, no large-scale assessment of distribution patterns was available to date. Here, we present data on litter distribution and density collected during 588 video and trawl surveys across 32 sites in European waters. We found litter to be present in the deepest areas and at locations as remote from land as the Charlie-Gibbs Fracture Zone across the Mid-Atlantic Ridge. The highest litter density occurs in submarine canyons, whilst the lowest density can be found on continental shelves and on ocean ridges. Plastic was the most prevalent litter item found on the seafloor. Litter from fishing activities (derelict fishing lines and nets) was particularly common on seamounts, banks, mounds and ocean ridges. Our results highlight the extent of the problem and the need for action to prevent increasing accumulation of litter in marine environments

Litter densities (number of items ha⁻¹) in different locations across European waters according to their closest distances from land.

<p><i>x</i> axis is in a Log₁₀ scale. A.S  =  Anton Dohrn Seamount, B.C  =  Blanes Canyon (NW Med.), C.C  =  Cascais Canyon, C.S  =  Condor Seamount, D&E.C  =  Dangeard & Explorer Canyons, D.M  =  Darwin Mounds, G.L.C  =  Gulf of Lion canyons (NW Med.), G.L  =  Gulf of Lion, G.C  =  Guilvinec Canyon, H.B  =  Hatton Bank, H.IV  =  HAUSGARTEN, station IV, J.S =  Josephine Seamount, L.C =  Lisbon Canyon, N.C  =  Nazaré Canyon, N.C-G  =  North Charlie Gibbs Fracture Zone, N-E.F.C  =  North-East Faroe-Shetland Channel, N.F.C  =  North Faroe-Shetland Channel, N.W =  Norwegian margin, P.D.M  =  Pen Duick Alpha/Beta Mound, R.B  =  Rockall Bank, Ros.B  =  Rosemary Bank, S.C  =  Setúbal Canyon, S.C-G  =  South Charlie Gibbs Fracture Zone, W.C  =  Whittard Canyon, W-T.R  =  Wyville-Thomson Ridge.</p

Mean litter density (± standard error) in A = number of items ha⁻¹ and B = in kg of items ha⁻¹, across different physiographic settings in European waters.

<p>Mean litter density (± standard error) in A  =  number of items ha⁻¹ and B  =  in kg of items ha⁻¹, across different physiographic settings in European waters.</p

Litter items on the seafloor of European waters.

<p>A  =  Plastic bag entrapped by a small drop stone harbouring sponges (<i>Cladorhiza gelida</i>, <i>Caulophacus arcticus</i>), shrimps (<i>Bythocaris</i> sp.) and a crinoid (<i>Bathycrinus carpenterii</i>) recorded by an OFOS at the HAUSGARTEN observatory (Arctic) at 2500 m; B  =  Litter recovered within the net of a trawl in Blanes open slope at 1500 m during the PROMETO V cruise on board the R/V “García del Cid”; C  =  “Heineken” beer can in the upper Whittard canyon at 950 m water depth with the ROV Genesis; D  =  Plastic bag in Blanes Canyon at 896 m with the ROV “Liropus”; E  =  “Uncle Benn's Express Rice” packet at 967 m in Darwin Mound with the ROV “Lynx” (National Oceanography Centre, UK); F  =  Cargo net entangled in a cold-water coral colony at 950 m in Darwin Mound with the ROV “Lynx” (National Oceanography Centre, UK).</p

Composition of litter (%) in different locations on the seafloor of European waters.

<p>*Numbers in parentheses refer to trawl surveys.</p