We demonstrate a flexible strategy for local tsunami warning that relies on regional geodetic and seismic stations. Through retrospective analysis of four recent tsunamigenic events in Japan and Chile, we show that rapid earthquake source information, provided by methodologies developed for earthquake early warning, can be used to generate timely estimates of maximum expected tsunami amplitude with enough accuracy for tsunami warning. We validate the technique by comparing to detailed models of earthquake source and tsunami propagation as well as field surveys of tsunami inundation. Our approach does not require deployment of new geodetic and seismic instrumentation in many subduction zones and could be implemented rapidly by national monitoring and warning agencies. We illustrate the potential impact of our method with a detailed comparison to the actual timeline of events during the recent 2015 Mw8.3 Illapel, Chile, earthquake and tsunami that prompted the evacuation of 1 million people.

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Integration of technological solutions aims to improve accuracy, precision and repeatability in farming operations, and biosensor devices are increasingly used for understanding basic biology during livestock production. The aim of this study was to design and validate a miniaturized tri-axial accelerometer for non-invasive monitoring of farmed fish with re-programmable schedule protocols. The current device (AE-FishBIT v.1s) is a small (14 mm × 7 mm × 7 mm), stand-alone system with a total mass of 600 mg, which allows monitoring animals from 30 to 35 g onwards. The device was attached to the operculum of gilthead sea bream ( Sparus aurata ) and European sea bass ( Dicentrarchus labrax ) juveniles for monitoring their physical activity by measurements of movement accelerations in x - and y -axes, while records of operculum beats ( z -axis) served as a measurement of respiratory frequency. Data post-processing of exercised fish in swimming test chambers revealed an exponential increase of fish accelerations with the increase of fish speed from 1 body-length to 4 body-lengths per second, while a close relationship between oxygen consumption (MO 2 ) and opercular frequency was consistently found. Preliminary tests in free-swimming fish kept in rearing tanks also showed that device data recording was able to detect changes in daily fish activity. The usefulness of low computational load for data pre-processing with on-board algorithms was verified from low to submaximal exercise, increasing this procedure the autonomy of the system up to 6 h of data recording with different programmable schedules. Visual observations regarding tissue damage, feeding behavior and circulating levels of stress markers (cortisol, glucose, and lactate) did not reveal at short term a negative impact of device tagging. Reduced plasma levels of triglycerides revealed a transient inhibition of feed intake in small fish (sea bream 50–90 g, sea bass 100–200 g), but this disturbance was not detected in larger fish. All this considered together is the proof of concept that miniaturized devices are suitable for non-invasive and reliable metabolic phenotyping of farmed fish to improve their overall performance and welfare. Further work is underway for improving the attachment procedure and the full device packaging.

The eutrophication of sediments underlying marine fish farms is one of the major environmental concerns of the industry and regulatory agencies. In this study, a mechanistic model of sediment geochemistry was developed to: (1) determine maximum organic loads that can be degraded without leading to eutrophicated conditions, (2) predict the transition to suboxic conditions as a result of organic enrichment, and (3) predict sulfide levels in surface sediments, a key regulatory variable in Canada. A new definition is proposed for sediment assimilative capacity (AC) of marine fish farms, as the gross deposition rate of organic wastes that maximizes total organic carbon (C org ) degradation rates while preventing sediment sulfide accumulations in surface sediments (upper 2 cm) above regulatory limits (AC-H 2 S). Model results were consistent with empirical observations and highlight the influence that organic loading history, hydrodynamics, and microbial activity have on assimilative capacity. AC-H 2 S varied between 0.6 to 22.1 g C org m −2 d −1 in poorly flushed environments, with no upper limit defined in environments exposed to mean tidal currents > 9.5 cm s −1 (dispersion scenarios), where most fish farm organic wastes are dispersed to the far-field or resuspended after deposition below fish cages. The combination of diagenetic modelling and geochemical indicators may contribute significantly to the development of more effective tools for site selection and environmental management of marine fish farms. At this stage, the model should be considered as a proof of concept, developed with the purpose of verifying the utility of assimilative capacity for real-world application. Further validation is still required.