he input of solid waste from terrestrial sources to the world's oceans has become a major environmental threat, positioning marine litter and plastic pollution as priority issues in the international agenda [1][2][3][4] . If no effective measures are taken, the prospects for future growth in the production and use of plastics foresee an unsustainable increase in the amount of waste accumulated in terrestrial and aquatic ecosystems around the world 5-7 , with potential impacts on biodiversity and human health 8,9 . Jambeck et al. 10 provided a first approach to modelling mismanaged waste (MW), regarding items as waste if littered or inadequately disposed of on land. Considering the population within a 50-km distance buffer from the coast and assuming a range of conversion rates to marine debris of between 15 and 40% MW, the authors estimated a global annual input of 4.8-12.7 million tonnes (Mt) of plastic to the marine environment. This range of conversion rates of MW to marine debris (15-40%) was based on municipal water quality data gathered in the San Francisco Bay (California) watersheds. Field measurements of plastic input to the oceans are, however, essential for evaluating MW land-ocean transfer rates 6,11,12 , still leaving considerable room for improvement.Rivers act as conduits to the ocean, funnelling the waste dumped into the drainage basins and, as such, they contribute to better understanding the input of litter to the ocean from terrestrial sources. Lebreton et al. 11 and Schmidt et al. 12 estimated the export

North-east Atlantic mackerel spawning distribution has shifted northward in the last three decades probably in response to global sea warming. Yet, uncertainties subsist regarding on the shift rate, causalities, and how this species will respond to future conditions. Using egg surveys, we explored the influence of temperature change on mackerel's spawning distribution (western and southern spawning components of the stock) between 1992 and 2013, and projected how it may change under future climate change scenarios. We developed three generalized additive models (GAMs): (i) a spatiotemporal model to reconstruct the spawning distribution for the north-east Atlantic stock over the period 1992-2013, to estimate the rate of shift; (ii) a thermal habitat model to assess if spawning mackerel have tracked their thermal spawning-niche; and (iii) a niche-based model to project future spawning distribution under two predicted climate change scenarios. Our findings showed that mackerel spawning activity has shifted northward at a rate of 15.9 ± 0.9 km/decade between 1992 and 2013. Similarly, using the thermal habitat model, we detected a northward shift of the thermal spawning-niche. This indicates that mackerel has spawned at higher latitudes to partially tracking their thermal spawning-niche, at a rate of 28.0 ± 9.0 km/ • C of sea warming. Under future scenarios (mid and end of the century), the extrapolation of the niche-based model to coupled hydroclimatic and biogeochemical models indicates that center of gravity of mackerel spawning distribution is expected to shift westward (32 to 117 km) and northward (0.5 to 328 km), but with high variability according to scenarios and time frames. The future of the overall egg production in the area is uncertain (change from −9.3 to 12%). With the aim to allow the fishing industry to anticipate the future distribution of mackerel shoals during the spawning period, future research should focus on reducing uncertainty in projections.

Rivers are major pathways for litter to enter the ocean, especially plastic debris. Yet, further research is needed to improve knowledge on rivers contribution, increase data availability, refine litter origins, and develop relevant solutions to limit riverine litter inputs. This study presents the results of three years of aquatic litter monitoring on the Adour river catchment (southwest of France). Litter monitoring consisted of collecting all litter stranded on river banks or stuck in the riparian vegetation in defined areas identified from cartographic and hydromorphological analyses, and with the support of local stakeholders. Litter samples were then sorted and counted according to a list of items containing 130 categories. Since 2014, 278 litter samplings were carried out, and 120,632 litter items were collected, sorted, and counted. 41% of litter could not be identified due to high degradation. Food and beverage packaging, smoking-related items, sewage related debris, fishery and mariculture gear, and common household items represented around 70% of identifiable items. Overall, the present study contributes to our knowledge of litter sources and pathways, with the target of reducing the amounts entering the ocean. The long-term application of this monitoring is a way forward to measure societal changes as well as assess effectiveness of measures.