Seeking temporal refugia to heat stress: increasing nocturnal activity despite predation risk

Flexibility in activity timing may enable organisms to quickly adapt to environmental changes. Under global warming, diurnally adapted endotherms may achieve a better energy balance by shifting their activity towards cooler nocturnal hours. However, this shift may expose animals to new or increased environmental challenges (e.g. increased predation risk, reduced foraging efficiency). We analysed a large dataset of activity data from 47 ibex (Capra ibex) in two protected areas, characterized by varying levels of predation risk (presence versus absence of the wolf-Canis lupus). We found that ibex increased nocturnal activity following warmer days and during brighter nights. Despite the considerable sexual dimorphism typical of this species and the consequent different predation-risk perception, males and females demonstrated consistent responses to heat in both predator-present and predator-absent areas. This supports the hypothesis that shifting activity towards nighttime may be a common strategy adopted by diurnal endotherms in response to global warming. As nowadays different pressures are pushing mammals towards nocturnality, our findings emphasize the urgent need to integrate knowledge of temporal behavioural modifications into management and conservation planning.

Sleep, circadian activity patterns and postpartum depression: A systematic review and meta-analysis of actigraphy studies

Transition to motherhood is a period full of challenges and demands. In this review, we focused on the associations of sleep and circadian activity patterns during and after pregnancy with postpartum mental health factors. A systematic review and meta-analysis were conducted (PROSPERO reference 316,505). A search for articles was performed using PsycARTICLES, PsycINFO, PubMed, MEDLINE, Scopus, Cochrane, DARE, hand search, and citation tracking. The search was meant to identify peer-reviewed, experimental and observational studies reporting on women over 18 years old that assessed sleep and circadian activity patterns during pregnancy or postpartum using actigraphy, and investigated postpartum mental health factors. Nineteen relevant publications were selected. Postpartum total sleep at night was the indicator that was most closely related to the psychological functioning of women after childbirth. The results of the systematic review indicated that postpartum total sleep at night was related to postpartum fatigue, and the results of the meta-analysis suggested that total sleep at night was most strongly linked with postpartum depression. More studies are needed to estimate the associations of sleep-wake rhythm during pregnancy and in the postpartum period with postpartum mental health factors.

Use of a Fitbit-like device in rats: Sex differences, relation to EEG sleep, and use to measure the long-term effects of adolescent ethanol exposure

BACKGROUND

Sleep difficulties and rhythm disturbances are some of the problems associated with adolescent binge drinking. Recently, animal models of alcohol-induced insomnia have been developed. However, studies in human subjects have recently focused not only on nighttime EEG findings but also on daytime sleepiness and disrupted activity levels as typically measured by activity tracking devices such as the "Fitbit." We sought to develop and test a Fitbit-like device (the "FitBite") in rats and use it to track rest-activity cycles following adolescent alcohol exposure.

METHODS

The effects of 5 weeks of adolescent ethanol vapor or control conditions were evaluated in 48 male and female Wistar rats using FitBite activity while intoxicated, and during acute (24 h post-vapor exposure) and chronic withdrawal (4 weeks post-vapor exposure). Data were analyzed using activity count and cosinor analyses. Fourteen rats were subsequently implanted with cortical electrodes, and data from the FitBite were compared with EEG data to determine how well the FitBite could identify sleep and activity cycles.

RESULTS

Female rats were generally more active than males, with higher circadian rhythm amplitudes and mesors (rhythm-adjusted means) across a 24-h period. There were significant correlations between EEG-estimated sleep and activity counts using the FitBite. When the rats were tested during intoxication after 4 weeks of ethanol vapor exposure, they had significantly less overall activity. Disruptions in circadian rhythm were also found with significant decreases in the circadian amplitude, mesor, and a later shift in the acrophase. At 24 h of ethanol withdrawal, rats had more episodes of activity with shorter durations during the daytime, when rats are expected to spend more of their time sleeping. This effect remained at 4 weeks following withdrawal, but circadian rhythm disruptions were no longer present.

CONCLUSIONS

A Fitbit-like device can be successfully used in rats to assess rest-activity cycles. Adolescent alcohol exposure produced circadian rhythm disturbances that were not observed after withdrawal. Fragmentation of ultradian rest-activity cycles during the light period was found at 24 h and 4 weeks after withdrawal and support data demonstrating the presence of sleep disturbance long after alcohol withdrawal.

Fluctuations in the Rate of Radioactive Decay of the Natural Potassium-40 Isotope Can Potentially Affect the Periodic "Spontaneous" Activity of Animals

Body temperature rhythms of C57Bl/6 laboratory mice and common greenfinches (Chloris chloris) and feeding periods of common starlings (Sturnus vulgaris) were compared with the intensity of fluctuations in ⁴⁰К radioactive decay. Body temperature changes in greenfinches and mice were found to positively correlate with the intensity of fluctuations in ⁴⁰K radioactive decay. Superposed epoch analysis showed that an increase in mouse body temperature, which reflects the start of the active phase in the sleep-wake cycle, and food intake in starlings coincide with an increase in the intensity of ⁴⁰K radioactive decay. Thus, animal activity in the ultradian range of periods may be related to external quasi-rhythmic physical influences, rather than being determined only by endogenous processes. Given the extremely low dose of natural ⁴⁰К exposure, a factor responsible for radioactivity fluctuations may act as a biotropic factor.

Chronotypes and circadian rest-activity rhythms in bipolar disorders: a meta-analysis of self- and observer rating scales

OBJECTIVE

Chronobiological models postulate that abnormalities in circadian rest/activity rhythms (CRAR) are core phenomena of bipolar disorders (BDs). We undertook a meta-analysis of published studies to determine whether self- or observer ratings of CRAR differentiate BD cases from comparators (typically healthy controls [HCs]).

METHOD

We undertook systematic searches of four databases to identify studies for inclusion in random effects meta-analyses and meta-regression analyses. Effect sizes (ES) for pooled analyses of self- and observer ratings were expressed as standardized mean differences with 95% confidence intervals (CIs).

RESULTS

The 30 studies meeting eligibility criteria included 2840 cases and 3573 controls. Compared with HC, BD cases showed greater eveningness (ES: 0.33; 95% CI: 0.12-0.54), lower flexibility of rhythms (ES: 0.36; 95% CI: 0.06-0.67), lower amplitude of rhythms (ES: 0.55; 95% CI: 0.39-0.70) and more disturbances across a range of CRAR (ES of 0.78-1.12 for general and social activities, sleep and eating patterns). Between study heterogeneity was high (I²  > 70%) and evidence indicated a potential publication bias for studies using the Biological Rhythms Interview of Assessment in Neuropsychiatry. Meta-regression analyses suggested significantly larger ES were observed in studies using observer ratings or including BD cases with higher levels of depressive symptoms.

CONCLUSION

This meta-analysis demonstrates that BD is associated with higher levels of self- or observer-rated CRAR disturbances compared with controls. However, further studies should examine the respective performance of individual instruments when used alone or in combination, to clarify their applicability and utility in clinical practice.

Association between Rhythmic Variations of Mouse Body Temperature with 4-16-Minute Periods and Geomagnetic Undulations in Corresponding Frequency Range Pc5/Pi3

The rhythmic variations of body temperature in two groups of mice located in Moscow and Novosibirsk were compared with geomagnetic undulations within Pc5/Pi3 (1-5 mHz) range measured in Borok and Novosibirsk middle-latitude geophysical observatories located at the same longitudes as the examined mice. The spectral maxima of geomagnetic undulations and body temperature variations were observed with greatest probability at the frequencies of 1.6, 2.3, and 3.1 mHz. At this, the mean square of the distance between the frequencies of spectral maxima of simultaneous oscillations was smaller than that of random intervals favoring the hypothesis on geomagnetic undulations as the synchronizer of biorhythms. In both groups of mice, the share of intervals with a high spectral coherency between geomagnetic undulations and body temperature variations had common maximum in the pre-midnight sector of local time and it was higher for the large-scale geomagnetic undulations. Dependence of geomagnetic undulations on spatial scale suggests that body temperature is affected by electrotelluric field.

CLOCKWORK ORANGE promotes CLOCK-CYCLE activation via the putative Drosophila ortholog of CLOCK INTERACTING PROTEIN CIRCADIAN

The Drosophila circadian clock is driven by a transcriptional feedback loop in which CLOCK-CYCLE (CLK-CYC) binds E-boxes to transcribe genes encoding the PERIOD-TIMELESS (PER-TIM) repressor, which releases CLK-CYC from E-boxes to inhibit transcription. CLOCKWORK ORANGE (CWO) reinforces PER-TIM repression by binding E-boxes to maintain PER-TIM bound CLK-CYC off DNA, but also promotes CLK-CYC transcription through an unknown mechanism. To determine how CWO activates CLK-CYC transcription, we identified CWO target genes that are upregulated in the absence of CWO repression, conserved in mammals, and preferentially expressed in brain pacemaker neurons. Among the genes identified was a putative ortholog of mouse Clock Interacting Protein Circadian (Cipc), which represses CLOCK-BMAL1 transcription. Reducing or eliminating Drosophila Cipc expression shortens period, while overexpressing Cipc lengthens period, which is consistent with previous work showing that Drosophila Cipc represses CLK-CYC transcription in S2 cells. Cipc represses CLK-CYC transcription in vivo, but not uniformly, as per is strongly repressed, tim less so, and vri hardly at all. Long period rhythms in cwo mutant flies are largely rescued when Cipc expression is reduced or eliminated, indicating that increased Cipc expression mediates the period lengthening of cwo mutants. Consistent with this behavioral rescue, eliminating Cipc rescues the decreased CLK-CYC transcription in cwo mutant flies, where per is strongly rescued, tim is moderately rescued, and vri shows little rescue. These results suggest a mechanism for CWO-dependent CLK-CYC activation: CWO inhibition of CIPC repression promotes CLK-CYC transcription. This mechanism may be conserved since cwo and Cipc perform analogous roles in the mammalian circadian clock.

Spatiotemporal Overlap between the European Brown Hare and Its Potential Predators and Competitors

Analysis of spatiotemporal partitioning is pivotal to shed light on interspecific coexistence. Most research effort has involved large-sized carnivores and their prey, whereas little attention has been devoted to lagomorphs. We assessed spatiotemporal overlap among the European brown hare Lepus europaeus and its potential competitors and predators through camera-trapping in an area in Central Italy. We estimated the interspecific patterns of the spatiotemporal activity rhythms of brown hares, its potential predators (the red fox Vulpes vulpes, the pine marten Martes martes, the domestic cat Felis catus, and the domestic dog Canis familiaris), and a competitor, the roe deer Capreolus capreolus. Brown hare activity was studied in natural conditions as well as in a fenced area that excluded terrestrial predators and competitors. Free-ranging hares developed a more nocturnal behavior to avoid diurnal predators (i.e., domestic carnivores and martens). Although high temporal overlap was observed between free-ranging brown hares and both red foxes (82%) and roe deer (81%), hares avoided fox by being more active on darkest nights, as well as avoided roe deer through spatial partitioning. We suggest that hares may adapt their spatiotemporal behavior to avoid potential predators and competitors.

Closely Related Fruit Fly Species Living at Different Latitudes Diverge in Their Circadian Clock Anatomy and Rhythmic Behavior

Recently, we reported differences in the expression pattern of the blue light-sensitive flavoprotein cryptochrome (CRY) and the neuropeptide pigment-dispersing factor (PDF) in the neuronal clock network of high-latitude Drosophila species, belonging to the Drosophila subgenus ( virilis-repleta radiation), compared with cosmopolitan D. melanogaster flies, belonging to the Sophophora subgenus. Alterations in rhythmic patterns of activity due to these differences might have adaptive significance for colonizing high-latitude habitats and, hence, adjusting to long photoperiods. Here, we show that these differing CRY/PDF expression patterns are only present in those species of the virilis-repleta radiation that colonized high latitudes. The cosmopolitan species D. mercatorum and D. hydei have a D. melanogaster-like clock network and behavior despite belonging to the virilis-repleta radiation. Similarly, 2 species of the holotropical Zaprionus genus, more closely related to the Drosophila subgenus than to the Sophophora subgenus, retain a D. melanogaster-like clock network and rhythmic behavior. We therefore suggest that the D. melanogaster-like clock network is the "ancestral fly clock phenotype" and that alterations in the CRY/PDF clock neurochemistry have allowed some species of the virilis-repleta radiation to colonize high-latitude environments.

Cryptochrome Interacts With Actin and Enhances Eye-Mediated Light Sensitivity of the Circadian Clock in Drosophila melanogaster

Cryptochromes (CRYs) are a class of flavoproteins that sense blue light. In animals, CRYs are expressed in the eyes and in the clock neurons that control sleep/wake cycles and are implied in the generation and/or entrainment of circadian rhythmicity. Moreover, CRYs are sensing magnetic fields in insects as well as in humans. Here, we show that in the fruit fly Drosophila melanogaster CRY plays a light-independent role as "assembling" protein in the rhabdomeres of the compound eyes. CRY interacts with actin and appears to increase light sensitivity of the eyes by keeping the "signalplex" of the phototransduction cascade close to the membrane. By this way, CRY also enhances light-responses of the circadian clock.

The Circadian Clock of the Ant Camponotus floridanus Is Localized in Dorsal and Lateral Neurons of the Brain

The circadian clock of social insects has become a focal point of interest for research, as social insects show complex forms of timed behavior and organization within their colonies. These behaviors include brood care, nest maintenance, foraging, swarming, defense, and many other tasks, of which several require social synchronization and accurate timing. Ants of the genus Camponotus have been shown to display a variety of daily timed behaviors such as the emergence of males from the nest, foraging, and relocation of brood. Nevertheless, circadian rhythms of isolated individuals have been studied in few ant species, and the circadian clock network in the brain that governs such behaviors remains completely uncharacterized. Here we show that isolated minor workers of Camponotus floridanus exhibit temperature overcompensated free-running locomotor activity rhythms under constant darkness. Under light-dark cycles, most animals are active during day and night, with a slight preference for the night. On the neurobiological level, we show that distinct cell groups in the lateral and dorsal brain of minor workers of C. floridanus are immunostained with an antibody against the clock protein Period (PER) and a lateral group additionally with an antibody against the neuropeptide pigment-dispersing factor (PDF). PER abundance oscillates in a daily manner, and PDF-positive neurites invade most parts of the brain, suggesting that the PER/PDF-positive neurons are bona fide clock neurons that transfer rhythmic signals into the relevant brain areas controlling rhythmic behavior.

Rest-activity rhythm and sleep characteristics associated with depression symptom severity in strained dementia caregivers

Depression is associated with disturbances to sleep and the 24-h sleep-wake pattern (known as the rest-activity rhythm: RAR). However, there remains a need to identify the specific sleep/RAR correlates of depression symptom severity in population subgroups, such as strained dementia caregivers, who are at elevated risk for major depressive disorder. We assessed the cross-sectional associations of sleep/RARs with non-sleep depression symptom severity among 57 (mean age: 74 years, standard deviation: 7.4) strained dementia caregivers who were currently without clinical depression. We derived sleep measures from polysomnography and actigraphy, modelled RARs using a sigmoidally transformed cosine curve and measured non-sleep depression symptom severity using the Hamilton Depression Rating Scale (HRDS) with sleep items removed. The following sleep-wake measures were associated with greater depression symptom severity (absolute Spearman's correlations ranged from 0.23 to 0.32): more time awake after sleep onset (WASO), higher RAR middle level (mesor), relatively shorter active periods (alpha), earlier evening settling time (down-mesor) and less steep RARs (beta). In multivariable analysis, high WASO and low RAR beta were associated independently with depression symptom severity. Predicted non-sleep HDRS means (95% confidence intervals) in caregivers with and without these characteristics were: normal WASO/beta = 3.7 (2.3-5.0), high WASO/normal beta = 5.5 (3.5-7.6), normal WASO/low beta = 6.3 (3.6-8.9) and high WASO/low beta = 8.1 (5.3-10.9). Thus, in our sample of strained caregivers, greater sleep fragmentation (WASO) and less sustained/sharply segregated resting and active periods (low RAR beta) correlate uniquely with depression symptom severity. Longitudinal studies are needed to establish whether these independent sleep-wake correlates of depression symptoms explain heightened depression risk in dementia caregivers.

An RNAi Screen To Identify Protein Phosphatases That Function Within the Drosophila Circadian Clock

Circadian clocks in eukaryotes keep time via cell-autonomous transcriptional feedback loops. A well-characterized example of such a transcriptional feedback loop is in Drosophila, where CLOCK-CYCLE (CLK-CYC) complexes activate transcription of period (per) and timeless (tim) genes, rising levels of PER-TIM complexes feed-back to repress CLK-CYC activity, and degradation of PER and TIM permits the next cycle of CLK-CYC transcription. The timing of CLK-CYC activation and PER-TIM repression is regulated posttranslationally, in part through rhythmic phosphorylation of CLK, PER, and TIM. Previous behavioral screens identified several kinases that control CLK, PER, and TIM levels, subcellular localization, and/or activity, but two phosphatases that function within the clock were identified through the analysis of candidate genes from other pathways or model systems. To identify phosphatases that play a role in the clock, we screened clock cell-specific RNA interference (RNAi) knockdowns of all annotated protein phosphatases and protein phosphatase regulators in Drosophila for altered activity rhythms. This screen identified 19 protein phosphatases that lengthened or shortened the circadian period by ≥1 hr (p ≤ 0.05 compared to controls) or were arrhythmic. Additional RNAi lines, transposon inserts, overexpression, and loss-of-function mutants were tested to independently confirm these RNAi phenotypes. Based on genetic validation and molecular analysis, 15 viable protein phosphatases remain for future studies. These candidates are expected to reveal novel features of the circadian timekeeping mechanism in Drosophila that are likely to be conserved in all animals including humans.

Owls and larks in mice

Humans come in different chronotypes and, particularly, the late chronotype (the so-called owl) has been shown to be associated with several health risks. A number of studies show that laboratory mice also display various chronotypes. In mice as well as in humans, the chronotype shows correlations with the period length and rhythm stability. In addition, some mouse models for human diseases show alterations in their chronotypic behavior, which are comparable to those humans. Thus, analysis of the behavior of mice is a powerful tool to unravel the molecular and genetic background of the chronotype and the prevalence of risks and diseases that are associated with it. In this review, we summarize the correlation of chronotype with free-running period length and rhythm stability in inbred mouse strains, in mice with a compromised molecular clockwork, and in a mouse model for neurodegeneration.

Expression of clock genes period and timeless in the central nervous system of the Mediterranean flour moth, Ephestia kuehniella

Homologous circadian genes are found in all insect clocks, but their contribution to species-specific circadian timing systems differs. The aim of this study was to extend research within Lepidoptera to gain a better understanding of the molecular mechanism underlying circadian clock plasticity and evolution. The Mediterranean flour moth, Ephestia kuehniella (Pyralidae), represents a phylogenetically ancestral lepidopteran species. We have identified circadian rhythms in egg hatching, adult emergence, and adult locomotor activity. Cloning full-length complementary DNAs and further characterization confirmed one copy of period and timeless genes in both sexes. Both per and tim transcripts oscillate in their abundance in E. kuehniella heads under light-dark conditions. PER-like immunoreactivity (PER-lir) was observed in nuclei and cytoplasm of most neurons in the central brain, the ventral part of subesophageal complex, the neurohemal organs, the optic lobes, and eyes. PER-lir in photoreceptor nuclei oscillated during the day with maximal intensity in the light phase of the photoperiodic regime and lack of a signal in the middle of the dark phase. Expression patterns of per and tim messenger RNAs (mRNAs) were revealed in the identical location as the PER-lir was detected. In the photoreceptors, a daily rhythm in the intensity of expression of both per mRNA and tim mRNA was found. These findings suggest E. kuehniella as a potential lepidopteran model for circadian studies.

Depressive symptoms and circadian activity rhythm disturbances in community-dwelling older women

OBJECTIVES

Aging is associated with changes in circadian rhythms. Current evidence supports a role for circadian rhythms in the pathophysiology of depression. However, little is known about the relationship between depressive symptoms and circadian activity rhythms in older adults. We examined this association in community-dwelling older women.

METHODS

We performed a cross-sectional analysis of 3,020 women (mean age: 83.55 ± 3.79 years) enrolled in the Study of Osteoporotic Fractures. Depressive symptoms were assessed with the Geriatric Depression Scale categorizing participants as "normal" (0-2; referent group, N = 1,961), "some depressive symptoms" (3-5, N = 704), or "depressed" (≥6, N = 355). Circadian activity rhythm variables were measured using wrist actigraphy.

RESULTS

In age-adjusted and Study of Osteoporotic Fractures site-adjusted models, greater levels of depressive symptoms were associated with decreased amplitude (height; df = 3,014, t = -11.31, p for linear trend <0.001), pseudo F-statistic (robustness; df = 3,014, t = -8.07, p for linear trend <0.001), and mesor (mean modeled activity; df = 3014, t = -10.36, p for linear trend <0.001) of circadian activity rhythms. Greater levels of depressive symptoms were also associated with increased odds of being in the lowest quartile for amplitude (df = 1, χ(2) = 9240, p for linear trend <0.001), pseudo F-statistic (df = 1, χ(2) = 49.73, p for linear trend <0.001), and mesor (df = 1, χ(2) = 81.12, p for linear trend <0.001). These associations remained significant in multivariate models. Post-hoc analyses comparing mean amplitude, mesor, and pseudo F-statistic values pair-wise between depression-level groups revealed significant differences between women with "some depressive symptoms" and the "normal" group.

CONCLUSION

These data suggest a graded association between greater levels of depressive symptoms and more desynchronization of circadian activity rhythms in community-dwelling older women. This association was observed even for women endorsing subthreshold levels of depressive symptoms.

Natural history of the Neotropical arboreal ant, Odontomachus hastatus: nest sites, foraging schedule, and diet

The ecology of most arboreal ants remains poorly documented because of the difficulty in accessing ant nests and foragers in the forest canopy. This study documents the nesting and foraging ecology of a large (∼13 mm total length) arboreal trap-jaw ant, Odontomachus hastatus (Fabricius) (Hymenoptera: Formicidae) in a sandy plain forest on Cardoso Island, off the coast of Southeast Brazil. The results showed that O. hastatus nested in root clusters of epiphytic bromeliads, most commonly Vriesea procera (70% of nest plants). Mature O. hastatus colonies include one to several queens and about 500 workers. Foraging by O. hastatus is primarily nocturnal year-round, with increased foraging activity during the wet/warm season. The foragers hunt singly in the trees, preying on a variety of canopy-dwelling arthropods, with flies, moths, ants, and spiders accounting for > 60% of the prey captured. Although predators often have impacts on prey populations, the ecological importance of O. hastatus remains to be studied.

A new laboratory radio frequency identification (RFID) system for behavioural tracking of marine organisms

Radio frequency identification (RFID) devices are currently used to quantify several traits of animal behaviour with potential applications for the study of marine organisms. To date, behavioural studies with marine organisms are rare because of the technical difficulty of propagating radio waves within the saltwater medium. We present a novel RFID tracking system to study the burrowing behaviour of a valuable fishery resource, the Norway lobster (Nephrops norvegicus L.). The system consists of a network of six controllers, each handling a group of seven antennas. That network was placed below a microcosm tank that recreated important features typical of Nephrops' grounds, such as the presence of multiple burrows. The animals carried a passive transponder attached to their telson, operating at 13.56 MHz. The tracking system was implemented to concurrently report the behaviour of up to three individuals, in terms of their travelled distances in a specified unit of time and their preferential positioning within the antenna network. To do so, the controllers worked in parallel to send the antenna data to a computer via a USB connection. The tracking accuracy of the system was evaluated by concurrently recording the animals' behaviour with automated video imaging. During the two experiments, each lasting approximately one week, two different groups of three animals each showed a variable burrow occupancy and a nocturnal displacement under a standard photoperiod regime (12 h light:12 h dark), measured using the RFID method. Similar results were obtained with the video imaging. Our implemented RFID system was therefore capable of efficiently tracking the tested organisms and has a good potential for use on a wide variety of other marine organisms of commercial, aquaculture, and ecological interest.

The new Seafloor Observatory (OBSEA) for remote and long-term coastal ecosystem monitoring

A suitable sampling technology to identify species and to estimate population dynamics based on individual counts at different temporal levels in relation to habitat variations is increasingly important for fishery management and biodiversity studies. In the past two decades, as interest in exploring the oceans for valuable resources and in protecting these resources from overexploitation have grown, the number of cabled (permanent) submarine multiparametric platforms with video stations has increased. Prior to the development of seafloor observatories, the majority of autonomous stations were battery powered and stored data locally. The recently installed low-cost, multiparametric, expandable, cabled coastal Seafloor Observatory (OBSEA), located 4 km off of Vilanova i la Gertrú, Barcelona, at a depth of 20 m, is directly connected to a ground station by a telecommunication cable; thus, it is not affected by the limitations associated with previous observation technologies. OBSEA is part of the European Multidisciplinary Seafloor Observatory (EMSO) infrastructure, and its activities are included among the Network of Excellence of the European Seas Observatory NETwork (ESONET). OBSEA enables remote, long-term, and continuous surveys of the local ecosystem by acquiring synchronous multiparametric habitat data and bio-data with the following sensors: Conductivity-Temperature-Depth (CTD) sensors for salinity, temperature, and pressure; Acoustic Doppler Current Profilers (ADCP) for current speed and direction, including a turbidity meter and a fluorometer (for the determination of chlorophyll concentration); a hydrophone; a seismometer; and finally, a video camera for automated image analysis in relation to species classification and tracking. Images can be monitored in real time, and all data can be stored for future studies. In this article, the various components of OBSEA are described, including its hardware (the sensors and the network of marine and land nodes), software (data acquisition, transmission, processing, and storage), and multiparametric measurement (habitat and bio-data time series) capabilities. A one-month multiparametric survey of habitat parameters was conducted during 2009 and 2010 to demonstrate these functions. An automated video image analysis protocol was also developed for fish counting in the water column, a method that can be used with cabled coastal observatories working with still images. Finally, bio-data time series were coupled with data from other oceanographic sensors to demonstrate the utility of OBSEA in studies of ecosystem dynamics.