understanding and forecasting current and future consequences of coastal warming require a fine-scale assessment of the near-shore temperature changes. Here we show that despite the fact that 71% of the world's coastlines are significantly warming, rates of change have been highly heterogeneous both spatially and seasonally. We demonstrate that 46% of the coastlines have experienced a significant decrease in the frequency of extremely cold events, while extremely hot days are becoming more common in 38% of the area. Also, we show that the onset of the warm season is significantly advancing earlier in the year in 36% of the temperate coastal regions. more importantly, it is now possible to analyse local patterns within the global context, which is useful for a broad array of scientific fields, policy makers and general public.

Well-documented changes in species abundances and distributions coinciding with global warming have been increasing during recent years. A trend of raising sea-surface temperature has also been observed along the Portuguese coast which could affect intertidal species' ranges. The present study aimed at evaluating the direction and intensity of distribution changes of macroalgae in the area. The last 50-year trend of coastal air and sea temperature was reassessed, providing an accurate estimate of the warming process. Information on species' range shifts was obtained by comparing data from recent resurveys with historical records of algal distributions collected during the 1950s and 1960s. Although a prevalence of northward migrations was anticipated, this work showed a marked difference in the average direction of changes between cold-and warm-water species. Cold-water species, when considered together, showed no particular shifting trend, because the number of species that shifted north or south was the same. Contrarily, all shifting warm-water species expanded their range northwards. Therefore, generalizations about poleward range shifts due to increasing temperature should be made with caution.

Overfishing is arguably the greatest ecological threat facing the oceans, yet catches of many highly migratory fishes including oceanic sharks remain largely unregulated with poor monitoring and data reporting. Oceanic shark conservation is hampered by basic knowledge gaps about where sharks aggregate across population ranges and precisely where they overlap with fishers. Using satellite tracking data from six shark species across the North Atlantic, we show that pelagic sharks occupy predictable habitat hotspots of high space use. Movement modeling showed sharks preferred habitats characterized by strong sea surface-temperature gradients (fronts) over other available habitats. However, simultaneous Global Positioning System (GPS) tracking of the entire Spanish and Portuguese longline-vessel fishing fleets show an 80% overlap of fished areas with hotspots, potentially increasing shark susceptibility to fishing exploitation. Regions of high overlap between oceanic tagged sharks and longliners included the North Atlantic Current/Labrador Current convergence zone and the Mid-Atlantic Ridge southwest of the Azores. In these main regions, and subareas within them, shark/vessel co-occurrence was spatially and temporally persistent between years, highlighting how broadly the fishing exploitation efficiently "tracks" oceanic sharks within their space-use hotspots year-round. Given this intense focus of longliners on shark hotspots, our study argues the need for international catch limits for pelagic sharks and identifies a future role of combining fine-scale fish and vessel telemetry to inform the ocean-scale management of fisheries.animal telemetry | distribution | conservation | fisheries | predator-prey O ceanic pelagic sharks are iconic top predators with relatively low resilience to exploitation (1-3), yet many tens of millions of individuals are caught each year by high-seas fisheries (2) with significant reductions in catch rates documented for many species (4-6). This level of exploitation is especially problematic because the harvest of oceanic sharks remains largely unregulated (2, 7). For the majority of shark species that make up more than 95% of oceanic shark catches, no international or bilateral harvest limits have been imposed (2, 7). Consequently, analysis indicates that extinction risk in oceanic and coastal sharks and rays is higher than for most other vertebrates (3). Accordingly, there is a critical need and concern for improved management and conservation of oceanic sharks.Management action for oceanic sharks such as catch quotas, size limits, and/or area closures (i.e., marine protected areas, MPAs) is hampered by a paucity of high-quality data on total catches, landings, species identification, catch locations, and the susceptibility of sharks to fisheries (2, 4, 7). In addition, poor recordkeeping, a lack of reporting or deliberate underreporting of pelagic shark catches by the high seas longlining fleet and/or fishing nations (7), contributes to poor data quality that can lead to increased unce...

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Aim  We tested whether the contraction of the equatorward boundary of an intertidal organism, the blue mussel, Mytilus edulis, was due to high summer temperatures limiting mortality. Location  The Atlantic coast of the United States. Methods  Field transplant experiments were conducted at three locations along the US Atlantic coast. Survival and heat shock protein 70 expression were determined at biweekly intervals. Air and water temperature profiles were used to model current and historical patterns of mortality, and to determine rates of temperature change. Results  High levels of mortality and expression of the inducible heat shock protein 70 were observed after multiple consecutive aerial exposures of 32 °C or greater. Since 1960, seasonal air and water temperatures have increased along the eastern US seaboard, and south of Lewes, DE (38.8° N) summer sea surface temperature increases have exceeded the upper lethal limits of this organism. Main conclusions  Along the southern portion of its range, intertidal populations of M. edulis have experienced catastrophic mortality directly associated with summer high temperatures. Over the past 50 years, a geographic contraction of the southern, equatorward range edge of M. edulis has occurred, shifting the range edge approximately 350 km north of the previous limit at Cape Hatteras, NC (35.2° N).

Aim  Recent colonization of northern Portuguese shores by Patella rustica Linnaeus, 1758, led to the bridging of a historical gap in the distribution known since the 1900s. Long‐term oceanographic data collected over the last half‐century were examined in order to detect possible mechanisms for the observed change in its distribution. Location  This study was carried out along the entire Portuguese coastline, from 41°50′ to 37°06′ N. Time‐series of hydrographical variables (sea surface temperature and salinity) were derived for the Atlantic coast of the Iberian Peninsula. Methods  Abundance and size‐frequency distributions of the newly observed limpet populations were compared with those from well‐established populations in southern Portugal. Anomalies were computed for sea surface temperature (1950–2000) and sea surface salinity (1958–2001) data, covering the whole Atlantic coast of the Iberian Peninsula. An upwelling index (1967–2005) was derived for a single location within the distributional gap of P. rustica. Split moving window analysis was performed to detect significant discontinuities in hydrographical data sets. Results  Patella rustica has gradually been expanding in northern Iberia, and in the late 1990s the historical gap in distribution in northern Portugal was bridged. Size‐frequency distribution differed between historical and recent populations, the latter lacking small‐sized individuals. At the same time, several anomalous oceanographic events occurred off the Portuguese coast and were probably related to this expansion. Main conclusions  Although sea surface temperature might be a major determinant of the reproductive success of P. rustica and hence its dispersal potential, it is more likely that a coincidence of several factors occurring in the late 1990s provided exceptional conditions that allowed the geographical expansion of this species.

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