Browsing by Issue Date, starting with "2021-06-16"
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- The influence of the Sound scattering layers on the vertical behaviour of two mesopelagic sharksPublication . Saraiva, Bruno Miguel Monteiro; Queiroz, Nuno; Abecasis, DavidAs apex predators, large sharks sustain the structure and function of marine communities. However, due to the ever-increasing fishing pressure and their slow life-history traits, shark populations have drastically declined in the last decades. Thus, improved knowledge on shark movements is crucial to implement effective management actions to prevent biodiversity loss and the disruption of marine ecosystems. Vertical patterns of apex predators have regularly been associated with foraging behaviours, yet the direct connection with prey’s vertical distribution and availability is often missing. In the open ocean, large aggregations of zooplanktonic and micronektonic organisms produce two unique acoustical signatures known as sound scattering layers (SSLs), believed to be an essential food source for oceanic predators. The present study uses pop-up satellite archival transmitters data of 22 blue (Prionace glauca) and 17 shortfin mako sharks (Isurus oxyrinchus), tracked within the North Atlantic Ocean, to assess the SSLs influence on these species’ diel vertical migrations (DVM) and foraging patterns. The sharks’ vertical patterns followed the SSLs diel migrations, commonly exhibiting surface-oriented behaviour when daytime micronekton concentrations at the shallow scattering layer (SSL) were higher compared to the upper deep scattering layer (DSL). Also, both species seemed to use the SSLs as foraging grounds, yet, while the mako shark appeared to target non-migrant or semi-migrant prey at the DSL, the blue shark generally favoured higher micronekton concentrations. Nevertheless, temperature and oxygen levels limited the extent of the vertical movements and impact the time spent at depth, sometimes preventing the animals from reaching the DSL. Thus, considering the ongoing expansion of the oxygen minimum zones, some predators might lose access to highly energetic prey and subsequently decrease their fitness. The SSLs showed to affect the sharks’ vertical range and time spent at epipelagic waters, revealing a potential use to detect regions with increased fishing risk.
- Which way to cope with COVID-19 challenges? Contributions of the IoT for smart city projectsPublication . Fernandes, SilviaMany activities and sectors have come to a halt due to the COVID-19 crisis. People and workers’ habits and behaviors have changed dramatically, as the use of technologies and connections, virtual reality, and remote support have been enhanced. Businesses and cities have been forced to quickly adapt to the new challenges. Digital technologies have allowed people to have better access to public services due to improved use of resources. Smart cities have significant potential for linking people to work and services as never done before. Additionally, the technological convergence produces data that can enhance interactions and decisions toward the “new normal”. In this paper, the aim is to assess how Portugal is prepared to respond to the accelerated process that this context demands from cities. Portuguese SMEs have developed a good capacity for entrepreneurship and innovation; however, they are still behind in converting the knowledge acquired in sales and exports and there is still limited collaboration at the public-private level. The acceleration of smart cities through the Internet of Things (IoT) may encourage changes in these issues. A more assertive alignment between the emergent technologies and the digitization goals of companies is required. This paper opens a discussion around major needs and trends of IoT (and related technologies) since the pandemic has leveraged them. The relationship between innovation and city smartness is approached to assess main contributing and limiting variables (through the European Innovation Scoreboard), to clarify future directions toward smarter services. The tourism sector, as the largest export economic activity in the country, is addressed in this matter. An analytical framework (using, for example, Power BI and Azure IoT Hub) around this approach can choose and support the most suitable areas of development in the country.