Deep-sea rhythms: effects on community evaluation and new study technologies

Special issue Llum, foscor i éssers vius.-- 6 pages, 6 figuresIn their behavioural, physiological and molecular functioning, animals follow temporal patterns collectively known as biological rhythms. Massive three-dimensional displacements of species occur at periodicities ranging from 12.4 h (tidal rhythms) and 24 h (day-night rhythms) to months (e.g. seasonal reproductive rhythms). This temporal adjustment of behavioural activity to geophysical cycles in light intensity, photoperiod length and hydrodynamism produces a strong and complex temporal variability in marine ecosystems, which complicates ecological studies focusing on populations and biodiversity assessments. Important constraints in sampling repeatability at statistically relevant frequencies limit the progress of marine ecology, especially in the increasingly anthropic-threatened but still largely unexplored deep sea (65% of the planet’s surface is below 1000 m depth). Within the framework of a novel seafloor video-cabled observatory technology that is progressively being installed in large oceanographic networks, it is now possible to explore and monitor ecosystems at sampling frequencies and over temporal durations never attained before. Fluctuations in video-counted individuals can be considered a proxy of populational behavioural rhythms in response to cycles of environmental parameters measured simultaneously through oceanographic, chemical and geologic sensors. Time-series analysis protocols can be implemented according to the following steps: i) periodogram analysis for the detection of significant periodicity; ii) waveform analysis for the measurement of rhythm phases (e.g. diurnal/nocturnal or monthly/seasonal peaks); and iii) integrated waveform analysis. In waveform analysis (step ii), data sets will be sectioned into segments of length equal to the periodicity of the geophysical cycle of reference (as assessed in step i). The values of all sub-sets will be averaged at corresponding timings to obtain a consensus curve (the waveform). The identification of a peak will be carried out to relate the significant increase in population activity to a particular moment in the fluctuation of the geophysical cycle. The integrated analysis of waveforms for all species (in step iii) and geophysical cycles will be carried out to evidence the temporal linkage among peaks, as an indication of a reliable cause-effect relationshipPeer Reviewe

Ritmes al mar profund: efecte sobre l’avaluació de les comunitats i noves tecnologies d’estudi

In their behavioural, physiological and molecular functioning, animals follow temporal patterns collectively known as biological rhythms. Massive three-dimensional displacements of species occur at periodicities ranging from 12.4 h (tidal rhythms) and 24 h (day-night rhythms) to months (e.g. seasonal reproductive rhythms). This temporal adjustment of behavioural activity to geophysical cycles in light intensity, photoperiod length and hydrodynamism produces a strong and complex temporal variability in marine ecosystems, which complicates ecological studies focusing on populations and biodiversity assessments. Important constraints in sampling repeatability at statistically relevant frequencies limit the progress of marine ecology, especially in the increasingly anthropic-threatened but still largely unexplored deep sea (65% of the planet’s surface is below 1000 m depth). Within the framework of a novel seafloor video-cabled observatory technology that is progressively being installed in large oceanographic networks, it is now possible to explore and monitor ecosystems at sampling frequencies and over temporal durations never attained before. Fluctuations in video-counted individuals can be considered a proxy of populational behavioural rhythms in response to cycles of environmental parameters measured simultaneously through oceanographic, chemical and geologic sensors. Time-series analysis protocols can be implemented according to the following steps: i) periodogram analysis for the detection of significant periodicity; ii) waveform analysis for the measurement of rhythm phases (e.g. diurnal/nocturnal or monthly/seasonal peaks); and iii) integrated waveform analysis. In waveform analysis (step ii), data sets will be sectioned into segments of length equal to the periodicity of the geophysical cycle of reference (as assessed in step i). The values of all sub-sets will be averaged at corresponding timings to obtain a consensus curve (the waveform). The identification of a peak will be carried out to relate the significant increase in population activity to a particular moment in the fluctuation of the geophysical cycle. The integrated analysis of waveforms for all species (in step iii) and geophysical cycles will be carried out to evidence the temporal linkage among peaks, as an indication of a reliable cause-effect relationship

Temporal Shape Changes and Future Trends in European Automotive Design

Evolution produces genuine novelty in morphology through the selection of competing designs as phenotypes. When applied to human creativity, the evolutionary paradigm can provide insight into the ways that our technology and its design are modified through time. The shape of European utilitarian cars in the past 60 years was analyzed in order to determine whether changes occur in a gradual fashion or through saltation, clarifying which are the more conserved and more variable parts of the designs. We also attempted to predict the future appearances of the cars within the next decade, discussing all results within the framework of relevant evolutionary-like equivalences. Here, we analyzed the modification in the shape of European utilitarian cars in the past 60 years by three-dimensional geometric morphometrics to test whether these changes occurred in a gradual or more saltatory fashion. The geometric morphometric shape analysis showed that even though car brands have always been preserving distinct shapes, all followed a gradual pattern of evolution which is now converging toward a more similar fusiform and compact asset. This process was described using Darwinian evolution as a metaphor to quantify and interpret changes over time and the societal pressures promoting them.This research was funded by project RITFIM (ref. CTM2010-16274, of the Spanish national RTD program. J. Aguzzi is a postdoctoral Fellow of the Spanish Ramón y Cajal Program (Spanish Ministry of Economy and Competitiveness).We acknowledge support by the CSIC Open Access Publication Initiative through its Unit of Information Resources for Research (URICI).Peer reviewe

Using ORB, BoW and SVM to identify and track tagged Norway lobster Nephrops norvegicus (L.)

Sustainable capture policies of many species strongly depend on the understanding of their social behaviour. Nevertheless, the analysis of emergent behaviour in marine species poses several challenges. Usually animals are captured and observed in tanks, and their behaviour is inferred from their dynamics and interactions. Therefore, researchers must deal with thousands of hours of video data. Without loss of generality, this paper proposes a computer vision approach to identify and track specific species, the Norway lobster, Nephrops norvegicus. We propose an identification scheme were animals are marked using black and white tags with a geometric shape in the center (holed triangle, filled triangle, holed circle and filled circle). Using a massive labelled dataset; we extract local features based on the ORB descriptor. These features are a posteriori clustered, and we construct a Bag of Visual Words feature vector per animal. This approximation yields us invariance to rotation and translation. A SVM classifier achieves generalization results above 99%. In a second contribution, we will make the code and training data publically available.Peer Reviewe

Video monitoring of Sparidae temporal rhythms: three-year study by OBSEA cabled observatory

Coco, S. ... et al.-- 7th International Workshop on Marine Technology – Martech Workshop 2016, 26-28 October 2016, Barcelona.-- 2 pages, 1 figure,1 tableThe abundance and composition of fish assemblages varies at different temporal scales as a product of diel and annual rhythms. In this study, we used a video-wired observatory (OBSEA, www.obsea.es) to monitor annual rhythms in a coastal fish assemblage with a 3-year data set (2012-2014). The photographs were acquired at 30 min frequency. Five species of the family Sparidae were studied (i.e. Dentex dentex, Diplodus sargus, Diplodus vulgaris, Diplodus annularis and Diplodus puntazzo) together with water temperature and daylength. The results of the annual rhythmicity analysis indicated that most of the peaks of abundance occured in the autumn months. Results suggest differentially temporal use of the reproductive or trophic nichePeer Reviewe

Integrating data from vessel monitoring system and fish landings in Menditerranean small fleets, using a PostgreSQL database with PostGIS extension

Geospatial technologies represent an advance in knowledge of marine ecosystems, allowing approach the study of the potential effect of world fishing fleets and their dynamics. Nevertheless, their application to fisheries biology is very recent and its use is generalizing when the ICES (International Council for the Exploration of the Sea) proposed one methodology to study fisheries and their impact in Atlantic Ocean ecosystems in the 2008 year. This procedure is based on the use of position data from the "blue boxes" (VMS-Vessel Monitoring System), mandatory since 2006 due to a European regulation, and it's present in most fishing boats. The junction of the VMS, fishing logbooks and landings data enables us to obtain among others results, maps of fishing effort, behaviour of fishing fleet and precise location of fishing grounds at the European waters. However, its design is made for large trawlers and longliners, and extensive Atlantic areas. This fact makes impossible its application for the study of the fleet and fisheries in Mediterranean waters. Because, the boats are much smaller, have lower mobility and they work in small fishing areas. The aim of this work has been to develop and apply a methodology (ICES based) to study fishing effort on species of commercial interest in Catalan coast, using scripting PL/SQL procedures of PostgreSQL system database with Post- GIS extension.Peer Reviewe

Global Deep-Sea Biodiversity Research Trends Highlighted by Science Mapping Approach

17 pages, 7 figures, supplementary material https://www.frontiersin.org/articles/10.3389/fmars.2020.00384/full#supplementary-material.-- All datasets generated for this study are included in the article/Supplementary Materia

Spontaneous internal desynchronization of locomotor activity and body temperature rhythms from plasma melatonin rhythm in rats exposed to constant dim light

BACKGROUND: We have recently reported that spontaneous internal desynchronization between the locomotor activity rhythm and the melatonin rhythm may occur in rats (30% of tested animals) when they are maintained in constant dim red light (LL(dim)) for 60 days. Previous work has also shown that melatonin plays an important role in the modulation of the circadian rhythms of running wheel activity (R(w)) and body temperature (T(b)). The aim of the present study was to investigate the effect that desynchronization of the melatonin rhythm may have on the coupling and expression of circadian rhythms in R(w )and T(b). METHODS: Rats were maintained in a temperature controlled (23–24°C) ventilated lightproof room under LL(dim )(red dim light 1 μW/cm(2 )[5 Lux], lower wavelength cutoff at 640 nm). Animals were individually housed in cages equipped with a running wheel and a magnetic sensor system to detect wheel rotation; T(b )was monitored by telemetry. T(b )and R(w )data were recorded in 5-min bins and saved on disk. For each animal, we determined the mesor and the amplitude of the R(w )and T(b )rhythm using waveform analysis on 7-day segments of the data. After sixty days of LL(dim )exposure, blood samples (80–100 μM) were collected every 4 hours over a 24-hrs period from the tail artery, and serum melatonin levels were measured by radioimmunoassay. RESULTS: Twenty-one animals showed clear circadian rhythms R(w )and T(b), whereas one animal was arrhythmic. R(w )and T(b )rhythms were always strictly associated and we did not observe desynchronization between these two rhythms. Plasma melatonin levels showed marked variations among individuals in the peak levels and in the night-to-day ratio. In six rats, the night-to-day ratio was less than 2, whereas in the rat that showed arrhythmicity in R(w )and T(b )melatonin levels were high and rhythmic with a large night-to-day ratio. In seven animals, serum melatonin levels peaked during the subjective day (from CT0 to CT8), thus suggesting that in these animals the circadian rhythm of serum melatonin desynchronized from the circadian rhythms of R(w )and T(b). No significant correlation was observed between the amplitude (or the levels) of the melatonin profile and the amplitude and mesor of the R(w )and T(b )rhythms. CONCLUSION: Our data indicate that the free-running periods (τ) and the amplitude of R(w )and T(b )were not different between desynchronized and non-desynchronized rats, thus suggesting that the circadian rhythm of serum melatonin plays a marginal role in the regulation of the R(w )and T(b )rhythms. The present study also supports the notion that in the rat the circadian rhythms of locomotor activity and body temperature are controlled by a single circadian pacemaker

Coastal observatories for monitoring of fish behaviour and their responses to environmental changes

The inclusion of behavioural components in the analysis of a community is of key relevance in marine ecology. Diel and seasonal activity rhythms or more longlasting changes in behavioural responses determine shifts in population, which in turn affect measurable abundances. Here, we review the value of cabled videoobservatories as a new and reliable technology for the remote, long-term, and highfrequency monitoring of fishes and their environment in coastal temperate areas. We provide details on the methodological requirements and constraints to appropriately measure fish behaviour at day-night and seasonal temporal scales from fixed videostations. In doing so, we highlight the relevance of an accurate monitoring capacity of the surrounding environmental variability. We present examples of multiparametric video, oceanographic, and meteorological monitoring made with the western Mediterranean platform OBSEA (www.obsea.es; 20 m water depth). Results are reviewed in relation to future developments of cabled observatory science, which will greatly improve its monitoring capability due to: i. the application of Artificial Intelligence to aid in analysis of increasingly large, complex, and highly interrelated biological and environmental data, and ii. the design of future geographic observational networks to allow for reliable spatial analysis of observed populationsPostprint (published version

Circadian oxygen consumption patterns in continental slope Nephrops norvegicus(Decapoda: nephropidae)in the western Mediterranean.

9 pages, 3 figures, 1 tableThe oxygen consumption of Nephrops norvegicus animals collected from the upper continental slope (400 m depth) in the northwestern Mediterranean was monitored under constant conditions of darkness and temperature. Two experiments were performed starting at the beginning of the expected day and at the beginning of the expected night phases, respectively. Mean oxygen consumption values recorded during the expected night were significantly higher than those recorded during the expected day. The slopes of the time series of oxygen consumption data of the two experiments were recalculated in consecutive 1-h intervals, being then averaged for corresponding 1-h time intervals. The plotting over a 24-h cycle of these mean hourly-values revealed a global nocturnal increase in the oxygen consumption in the laboratory. This result is discussed and compared with previously reported catch patterns accounting for emergence from burrows in the field, and locomotor and cardiac activity rhythms recorded in constant conditions in the laboratory in animals from the same depthThis research was funded by the Spanish CICYT programme (MAR-098-0935) to FSPeer reviewe