Seasonal comparison of beach litter on Mediterranean coastal sites (Alicante, SE Spain)

Presence of beach litter was assessed during spring and summer seasons 2018, at 56 sites along the coast of Alicante Province (SE Spain). Selected sites covered “remote” (9), “rural” (10) “village” (17) and “urban” (20) bathing areas. In an area of 201,700 m2, a total of 10,101 litter items (Avg: 0.062 items m-2) was counted in spring, and 20,857 (Avg: 0.116 items m−2) in summer. The most significant seasonal evolution was observed in the cigarette butt, group which increased from 4607 to 12843 units. Plastic represented the dominant material in both seasons (82.6 and 83.5% respectively). Litter items increased greatly during the summer season despite the increasing frequency of cleaning operations and were essentially related to beach users activities. Secondarily, beach litter was related to wastewater discharges and fishing activities. Beach litter management along investigated sites must be based on plans to reduce litter sources. For that, it is necessary to consider beach typology along with the seasonal influx of visitors to define the most appropriate management actions, not forgetting the implementation of environmental education, essential in schools and media

Characterization of plastic beach litter by Raman spectroscopy in South-western Spain

The characteristics and distribution of plastic litter were evaluated in October 2018 at 40 beaches along the coast of Cádiz Province, in Spain. A total of 14,261 plastic items, appertaining to 57 litter groups, were identified along the study area at different beach zones, i.e. at low tide water level (2%), along the foreshore (6%), at high tide water level (67%) and in the backshore area (25%). Plastic items have a great floatability, being this one of the main reasons for their proportional dominance among beach litter, especially in the wrack line. Hundreds of measurements were made of different items using Raman spectroscopy, an effective technique to determine the type of plastic. Cellulose acetate represented the most abundant material (79%) linked to cigarette butts, followed by polypropylene, 9% and polyethylene, 8%. The remaining were composed by polystyrene, polyethylene terephthalate and polyvinyl chloride. Smoke related items were the most common in the study area, followed by film and hard pieces, cotton bud sticks, fishing strings, food wrappers, caps/lids and single-use plastics. Beach litter can be related to beachgoers but some categories can be attributed to fishing activities or wastewater discharges. Plastics cause a multitude of damages to the coastal ecosystem, due to their toxic components and adsorbed substances and their facility of fragmentation and dispersion. Principal objective is the compositional characterization of plastic beach litter items and their spatial variability. It is therefore important to avoid unnecessary consumption, promote recycling and use other materials that are less harmful to the environment.With funding from the Spanish government through the "María de Maeztu Unit of Excellence" accreditation (MDM-2017-0737

Thick discs in galaxies were most likely not accreted

The origin of thick discs in galaxies remains shrouded in mystery. A variety of formation scenarios has been proposed. Here we aim to test one such scenario where the thick disc stars are proposed to be accreted from satellite galaxies. In this scenario, in at least some galaxies a fraction of thick disc stars would rotate in a retrograde way, which would cause a large thick disc velocity lag. Here, we compare the rotation curves of the thin and the thick discs of eight edge-on galaxies observed with MUSE at the VLT. We find that the velocity lags of the thick discs are compatible with those expected from asymmetric drift. If we consider the galaxies with thick disc rotation curves in the literature, only one in about fifteen shows clear signs of an accreted thick disc. Based on simulations in the literature we estimate that if thick discs were accreted, at least one in six would show clear signs of retrograde material. Thus, there is a growing tension between the observations and the hypothesis that thick discs are made of accreted stars