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Photographic and acoustic tracking observations of the behavior of the grenadier Coryphaenoides (Nematonurus) armatus, the eel Synaphobranchus bathybius, and other abyssal demersal fish in the North Atlantic Ocean

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Using an autonomous free-fall vehicle (AU-DOS), observations were made of demersal fish attracted to baits and baited acoustic transmitters at two stations in the North Atlantic Ocean. A comparison was made between Station PAP (4850N; 1630W), 4800 m deep on the Porcupine Abyssal Plain which is relatively eutrophic, and Station MAP (31N; 20W), 4900 m deep on the Madeira Abyssal Plain, which is oligotrophic. Experiments were conducted during summer, in 1989 and 1990. Four species of fish were observed at Station MAP, the grenadier, Coryphaenoides (Nematonurus) armatus, the eel, Synaphobranchus bathybius, and the ophidiids Spectrunculus grandis, and Barathrites sp. At Station PAP, C. (N.) armatus and H. (S.) bathybius were attracted to bait on all deployments and only two other individuals of different species, probably ophidiids, were seen. The mean first grenadier arrival time was 30 and 138 min at Stations PAP and MAP, respectively. Mean first eel arrival time was 29 and 151 min at Stations PAP and MAP, respectively. Estimated population densities of fish were 167 grenadiers km-2 and 180 synaphobranchid eels km-2 at Station PAP and 8 grenadiers km-2 and 7 eels km-2 at Station MAP. Only the grenadier C. (N.) armatus definitely ingested transmitters, and this species dominated fish activity around the baits. Mean time of departure of grenadiers with transmitters in their stomachs across an acoustic horizon at 1000 m range was 371 and 488 min at Stations PAP and MAP, respectively. Grenadiers had a longer mean staying time at the food source at the more oligotrophic Station MAP (364 min) than at Station PAP (141 min). This corresponds with predictions of optimal foraging theory.
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... anta go nisms: Harvey et al. 2007, Malcolm et al. 2007, McLean et al. 2016. The bait plume attracts fish through olfactory, auditory and behavioural cues which may result in stronger selectivity towards species with accurate sensory systems (Armstrong et al. 1992). Also, the use of bait has been shown to in crease the presence of predator species, which can influence species interactions (Armstrong et al. 1992, Jones et al. 2003, Cappo et al. 2004, Farns worth et al. 2007, Harvey et al. 2007, Stoner et al. 2008, Watson et al. 2010) and discourage some species from approaching the cameras (Jones et al. 2003) to avoid competition (Willis et al. 2003) or predation (Willis & Babcock 2000, Cappo et al. 2004, Harvey et al. 2007). ...
... The bait plume attracts fish through olfactory, auditory and behavioural cues which may result in stronger selectivity towards species with accurate sensory systems (Armstrong et al. 1992). Also, the use of bait has been shown to in crease the presence of predator species, which can influence species interactions (Armstrong et al. 1992, Jones et al. 2003, Cappo et al. 2004, Farns worth et al. 2007, Harvey et al. 2007, Stoner et al. 2008, Watson et al. 2010) and discourage some species from approaching the cameras (Jones et al. 2003) to avoid competition (Willis et al. 2003) or predation (Willis & Babcock 2000, Cappo et al. 2004, Harvey et al. 2007). This would result in underrepresentation of non-aggressive or lower trophic level species in BRUVS samples (Stoner & Ottmar 2003, Harvey et al. 2007, Malcolm et al. 2007, Stoner et al. 2008). ...
Article
Surf zones of sandy beaches are crucial environments for numerous fishes but one of the most challenging habitats when it comes to sampling, due to high-energy currents and waves. In this study, we compared the efficiency of 2 methods currently used to sample the biodiversity of shallow surf zone fish communities: the traditional method of beach seine nets and the more recently introduced surf zone Baited Remote Underwater Video Stations (surf-BRUVS). We applied both sampling strategies at 67 sites along 27 sandy beaches with different environmental characteristics in southeastern Brazil. We compared overall abundance, species richness, and beta (turnover) and functional trait diversity recorded from both methods. Our results showed that seine nets captured a higher species richness, greater abundance, greater functional richness and more functionally singular species than surf-BRUVS, particularly in areas with low wave energy. Beta diversity analyses, however, showed a clear difference in assemblage composition detected by each method regardless of environmental conditions, mainly driven by species turnover and variations in abundance. Only seine nets captured small species (<10 cm total length), while surf-BRUVS were more effective in recording larger species. Our results suggest that shallow surf zone assemblages sampled with surf-BRUVS and beach seine nets are almost totally taxonomically and highly functionally divergent, and the application of both methods provides complementary results. Additionally, the non-extractive nature of surf-BRUVS presents an opportunity for sampling vulnerable areas or species. However, when using a single method, researchers should take into consideration each method’s biases and be aware that biodiversity may be underestimated for certain groups.
... Compared to other deep-sea fishes, adult C. armatus appear to be particularly well-equipped to detect the location of such food-falls using olfaction as they possess relatively large olfactory bulbs (Wagner, 2001a(Wagner, , 2002. Moreover, in situ video recorded by baited cameras on landers (autonomous vehicles deployed on the seafloor) has revealed that C. armatus is often the first species to appear when baited cameras are deployed and is presumably attracted to the bait by a very sensitive olfactory system (Wilson and Smith, 1984;Priede et al., 1990Priede et al., , 1994Armstrong et al., 1992;Wagner, 2003). However, baits are predominantly taken only by large individuals (King et al., 2006), even in locations where trawls have demonstrated that smaller individuals are also present (Henriques et al., 2002;Collins et al., 2005). ...
... Olfaction appears to become far more important in these larger animals, and their well-developed olfactory system likely helps these fishes to locate sparsely distributed food-falls in the abyss. Indeed, as previously noted, large C. armatus are often the first fish to appear at baited cameras (Wilson and Smith, 1984;Priede et al., 1990Priede et al., , 1994Armstrong et al., 1992;Henriques et al., 2002;Wagner, 2003;Collins et al., 2005;Kemp et al., 2006;King et al., 2006). Wagner's (2003) results indicate that the ontogenetic shift in sensory capability in C. armatus occurs at a body size of between 400 and 500 mm SL, which is in agreement with the size range over which the shift in diet occurs in this species (Haedrich and Henderson, 1974;Martin and Christiansen, 1997). ...
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Many sensory systems are more commonly known than others, but all are critical for survival. These include those senses typically described by Aristotle around 300–400 Before the Common Era (BCE), such as sight (vision), hearing (audition), touch (somatosensation), smell (olfaction), and taste (gustation). However, many years of scientific endeavor have shown that these five senses represent only a part of the sensory abilities that are now known throughout the aquatic animal kingdom. The extended repertoire of senses includes the ability for vestibular control (equilibrioception), the sensation of temperature (thermoreception), postural awareness (proprioception), the monitoring of pain (nociception), the use of sonar (echolocation), and the detection of weak electric (electroreception) and magnetic (magnetoreception) fields. The papers presented in this Research Topic were greatly welcomed and consist of a collection of exciting and well-received articles that incorporated new knowledge on almost all of the known senses in a range of aquatic vertebrates, such as the sarcopterygian lungfishes, both freshwater and marine teleosts, elasmobranchs, marine reptiles, and cetaceans (marine mammals). The papers target many of the known senses in aquatic vertebrates, but are biased toward vision, which reflects the number of active research programs that concentrate on this sensory modality.
... El diseño de una escala de hendidura vertical 1 Depto. depende de la interacción de parámetros hidráulicos e biológicos, ya que las variables hidrodinámicas de la piscina (como la velocidad del agua) deben ser adecuadas a los requisitos de los peces (determinados por ejemplo por su resistencia o velocidad de natación). ...
... Algunas de las primeras aplicaciones de estas técnicas son la utilización de transmisores acústicos y una videocámara para observar el comportamiento de varias especies [1], o el uso de escáneres acústicos para monitorizar bancos de peces [10]. ...
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Resumen-En este trabajo se propone un algoritmo para analizar las trayectorias de los peces en el interior de escalas de hendidura vertical, construcciones hidráulicas que permiten a los peces sortear estructuras como presas que obstaculizan los procesos naturales en los ríos. Con la técnica propuesta se pretende estudiar el comportamiento de los peces en el interior de las escalas con el fin de conocer los requisitos de los animales e incrementar la eficacia de las mismas. La técnica propuesta calcula la posición del pez en cada instante a partir de una secuencia de imágenes adquiridas con cámaras de video utilizando Redes de Neuronas Artificiales (RNAs) y técnicas de visión artificial. Para evaluar la técnica propuesta, se han realizado diferentes ensayos en un modelo de escala de hendidura vertical de tamaño 1:1 y con peces vivos. Palabras clave-Visión Artificial, Redes de Neuronas Artificiales, Escalas de Peces, Seguimiento, Trayectoria I. INTRODUCCIÓN El ser humano ha modificado el régimen hidrológico de los ríos provocado transformaciones en la fauna y flora de los cauces fluviales. Estas transformaciones son especialmente destacables en el caso de los peces, más vulnerables que la vegetación cuando varían las condiciones hidráulicas del medio. Las escalas de hendidura vertical son estructuras hidráulicas que permiten el movimiento de los peces aguas arriba en los ríos, sorteando obstáculos como presas, centrales hidroeléctricas y otros. El diseño de una escala de hendidura vertical depende de la interacción de parámetros hidráulicos e biológicos, ya que las variables hidrodinámicas de la piscina (como la velocidad del agua) deben ser adecuadas a los requisitos de los peces (determinados por ejemplo por su resistencia o velocidad de natación). Hasta la fecha, existen diferentes trabajos donde se ha caracterizado el flujo en las escalas de hendidura vertical [13, 9, 11] y otros donde se ha estudiado la natación de los peces [6, 2]. Sin embargo no existen trabajos que conecten los estudios hidráulicos con los parámetros biológicos de los peces. Esta carencia pone de manifiesto la necesidad de completar la metodología a través de la integración con ensayos biológicos para determinar el comportamiento de los peces dentro de la escala. Debido a que el conocimiento del comportamiento de los peces en el interior de las escalas de hendidura vertical es muy escaso, en el diseño de las escalas se utiliza normalmente una aproximación basada puramente en la experiencia. Para solucionar este déficit, es necesario completar la metodología existente para el diseño de escalas con resultados experimentales con peces vivos. En estos ensayos, los peces se introducen en una escala de hendidura vertical de tamaño 1:1, como el mostrado en la Figura 1, y sus movimientos y comportamiento son analizados. Con este objetivo, el porcentaje de éxito al cruzar la estructura (la proporción de individuos que consigue cruzar la escala) debe ser evaluada junto con una medida del esfuerzo de los ejemplares basada en análisis sanguíneos. Además, es preciso realizar un análisis más detallado que permita analizar factores como las áreas y tiempos de descanso, velocidades, aceleraciones, tiempos de ascenso etc. De este modo, los resultados obtenidos pueden ser aplicados a la metodología de diseño de las escalas, estableciendo las condiciones hidráulicas que las especies objetivos pueden manejar, incrementando de este modo la eficiencia de la estructura. Sin embargo, realizar un seguimiento detallado de los peces en el interior de las escalas es una tarea compleja, que presenta numerosos inconvenientes Seguimiento visual de peces en escalas de hendidura vertical
... This methodology involves modelling the process of the detection, attraction and arrival of grenadiers at the baited underwater camera system using an inverse square relationship (Priede et al., 1990(Priede et al., , 1994. This method has proved successful in producing density estimates comparable to some trawl surveys (Armstrong et al., 1992;Priede and Merrett, 1996) but is restricted to sampling the area of influence of the emanating bait plume and to the scavenger species attracted. Echosounders however provide a means to monitor marine fauna within large volumes of water at a high spatial and temporal resolution (Benoit-Bird and Lawson, 2016). ...
... Ingestible transponders have allowed the behavior of two species of Grenadiers (C. armatus and C. yaguinae) swimming away from a bait sources to be observed (Priede et al., 1990;Armstrong et al., 1992). Wilson and Smith (1984) proposed that Coryphaenoides adopt a sit and wait strategy on the seafloor until the odor of a carcass is detected but further work has shown that grenadiers have a tendency to move across-current and swim independently of bottom currents to forage at a low continuous speed to reduce energy demands (Priede et al., 1990;Ruxton and Bailey, 2005). ...
Article
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Ecological and behavioral data on mobile, low density, benthopelagic animals is difficult to collect in the abyssal environment. However, these species occupy an important position in the abyssal food chain. At-depth ROV-mounted echosounder studies provide a powerful tool to gather in-situ information on abyssal benthopelagic assemblages and discern their distribution, behavior and habitat associations. This study presents a new perspective on mobile benthopelagic assemblages at the long-term study site, Station M (∼4000 m), using a Seabat T20-S MBES mounted on the ROV Doc Ricketts. The targets (∼45 m off the seafloor) are believed to be the abyssal grenadier of the species Coryphaenoides armatus or C. yaquinae, species known to dominate the mobile benthopelagic fauna at Station M. The swimming behavior of the targets indicated little evidence of avoidance or attraction to the slowly moving ROV and demonstrates the effectiveness of this platform to collect data on benthopelagic fish. The information on targets in close (<1 m) association with the seafloor from the MBES corresponded well to target densities recorded by the video transects. However, in addition the MBES resolved the distribution of targets up to 45 m above the seafloor. Target density had a small peak close to the seafloor (<1 m) but increased in density with height above the seafloor, exceeding the maximum near-bottom density by ∼50 times. ROV-mounted MBES surveys can effectively provide data on the distribution and behavior of benthopelagic fish and further understanding of the pelagic-benthic links in the abyssal deep-sea.
... Most of the above cited limitations and downfalls of UVC can be overcome with independent, non-destructive baited remote underwater video (BRUV) systems (Stallings, 2009;Langlois et al., 2010). Furthermore, the use of bait additionally reduces zero counts due to the active attraction of fishes and detect large, mobile species that avoid divers (Cappo et al., 2004) attracting them to the vicinity of the bait, independent of the effectiveness of the sample process (Armstrong et al., 1992). Such characteristics generate standardized surveys can be applied at any depth, in a variety of habitats, and by staff with relatively low levels of training (Brooks et al., 2011). ...
Article
While marine protected areas (MPAs) are increasing worldwide, it is still needed to assess the effectiveness of those already consolidated. Methods and ecological assessments to understanding integrated and habitat-specific management regimes are still scarce and insufficient for policy implications and biodiversity conservation. Through Baited Remote Underwater Video (BRUV), we used fish assemblages as proxy of ecological and managerial status in two reef habitat types along three protection levels at Abrolhos Bank - the largest and most biodiverse coral reef complex of the South Atlantic. We found completely distinct responses in the fish fauna between the top (shallow) and bottom (deep) habitats of the unique “chapeirões” pinnacle reef formations. In the most protected zone (no-take), higher richness and abundance of commercial fish and more diverse trophic structure was observed. Particularly, large (sharks and groupers) and small carnivores (snappers) were more abundant and distributed more homogeneously over both reef habitats in the strictly enforced no-take zone. Abundance of these top-predators decreased from the low enforcement no-take zone to the multiple use area, where they were often absent while their typical preys (primary and secondary consumers) were thriving, notably in the top habitats. These outcomes highlight the importance to focus investigations not selectively on a single habitat type or depth zone in order to properly assess MPA effectiveness. Consequently, the monitoring and protection of fish species supported by marine spatial planning may benefit from an improved understanding of ecological functioning provided by MPA performance.
... In open marine environments, this has traditionally been achieved by underwater visual census (UVC) via SCUBA, but is often criticized for regularly underestimating counts (Edgar et al., 2004). Remote underwater video survey (RUVS) methods have thus been employed regularly over the last 20 years as an alternative to UVC, particularly when targeting areas inaccessible to SCUBA divers (Armstrong et al., 1992;D'Onghia et al., 2015), highly mobile or cryptic species (Willis and Millar, 2000), and is able to minimize observer bias by allowing all analysis to take place ex situ, thus further creating a permanent survey record. The current standard for RUVS involves the addition of a form of bait (BRUVS) to act as an attractant for nomadic or cryptic species (Whitmarsh et al., 2016) and now is used universally. ...
Article
Understanding the composition and structure of marine animal assemblages across space and time is essential in the establishment of effective management frameworks, particularly for holistic approaches to ecosystem conservation. Baited remote underwater video (BRUV) surveys are a well-established tool used in assessing relative abundances of marine fauna but are not commonly used in enclosed environments such as lakes. Sweetings Pond is an anchialine lake situated on the island of Eleuthera in The Bahamas that remains relatively undocumented, with only a single census available from 1983, yet has experienced an increase in stress from anthropogenic activity. Here, we investigated differences in community composition between sites and attempted to identify the species/benthic components driving changes using baited video surveys, before exploring differences in community structure between day-night periods. Nine species were identified over the 3780 min of BRUV footage analyzed, which was comparable to 1983 estimates. No difference in animal assemblages was seen between sites and no correlation with benthic composition was present. However, nocturnal replicates displayed higher median animal abundance and species richness than diurnal replicates, potentially resulting from a sequential food web aggregation around the light source. A number of unique, opportunistic feeding behaviors were also observed which opens avenues for future study. Overall, this study presents BRUVS as a viable and streamlined tool for managers of enclosed aquatic ecosystems to rapidly assess the system's macrofauna across day-night periods, supporting the requirements of an ecosystem-based management approach.
... So, while some studies suggest relationships between abyssal fish community composition and density with food availability (e.g. Armstrong et al., 1992;Linley et al., 2017), a longitudinal driver may be more important in the CCZ. ...
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The abyssal seafloor of the Clarion Clipperton Zone (CCZ) in the central Pacific has the largest known deposits of polymetallic nodules and associated benthic faunal communities with high biodiversity. The environmental factors that structure these communities, both at regional and local scales, are not well understood. In this study, seabed image surveys were used to assess distribution patterns in invertebrate and fish megafauna (> 1cm) at multiple scales in relation to key environmental factors: food supply to the seabed varying at the regional scale (hundreds of km), seabed geomorphological variations varying at the broad local scale (tens of km), and seabed nodule cover varying at the fine local scale (tens of meters). We found significant differences in megafaunal density and community composition between all study areas. Variations in faunal density did not appear to match with regional productivity gradients, although faunal density generally decreased with water depth (from E to W). In contrast, geomorphology and particularly nodule cover appeared to exert strong control on local faunal abundance and community composition, but not in species richness. Local variations in faunal density and beta-diversity, particularly those driven by nodule presence (within study areas), were of comparable magnitude to those observed at a regional level (between study areas). However, regional comparisons of megabenthic assemblages showed clear shifts in dominance between taxonomic groups across the mid-eastern CCZ seabed, suggesting a higher regional heterogeneity than was previously thought.
... Fewer data are available for demersal fishes, although abundances have been correlated with spatial gradients in surface productivity (Armstrong et al., 1992;Thurston et al., 1995;Henriques et al., 2002), and with inter-annual variation in invertebrate and carrion availability (Drazen et al., 2012). Since demersal fishes within deep-sea ecosystems are typically predators or scavengers of large carrion (Drazen & Sutton 2017), such correlations are suggestive of strong bottom-up trophic control within deep-sea food webs. ...
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... BRUVs consist of an underwater camera focused on a standardized bait source positioned in the field of view (FOV), with the unit orientated down current from the camera. Individuals attracted to the bait that swim into the FOV are "captured" on camera (Armstrong, Bagley, & Priede, 1992), providing a permanent record of observations that can be reviewed multiple times. This record improves the accuracy of the data and allows for detailed analyses such as those required for examining animal behavior. ...
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