ESONET—European Sea Floor Observatory Network

Friede, Imants G.; Mienert, J.; Person, Roland; Weering, Tjeerd C.E. van; Pfannkuche, Olaf; O'Neill, Nick; Thomsen, Laurenz; Favali, P.; Gasparoni, F.; Zitellini, Nevio; Millot, Claude; Gerber, Hans; Miranda, Jorge Miguel

doi:10.1016/s0422-9894(03)80047-8

Cited by 10 publications

(11 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…While the temporal resolution was not high enough to resolve the tidal or current controls, it was sufficient to begin to assess how sedimentary microbial processes might be affected by the variable methane flux. This work also highlights the importance of online observatories or lander deployments to obtain higher temporal resolution [e.g., Friede et al, 2003;Kasaya et al, 2009;Barnes et al, 2011].…”

Section: Discussionmentioning

confidence: 94%

Temporal variability of in situ methane concentrations in gas hydrate‐bearing sediments near Bullseye Vent, Northern Cascadia Margin

Lapham

Wilson

Riedel

et al. 2013

Geochem Geophys Geosyst

View full text Add to dashboard Cite

[1] To assess the temporal variability in the methane fluxes from marine sediments that overly gas hydrate bearing sediments and the factors that might control its rate, in situ methane concentrations were measured near Bullseye Vent on the Northern Cascadia continental margin. A long-term sampling device collected overlying water and pore-fluid samples from 25 cm above seafloor, at the sediment-water interface (SWI), and 7 cmbsf (centimeters below seafloor) over a 9 month period (August 2009-May 2010. These samples provide a record at $4 day resolution of in situ methane, ethane, propane, sulfate, and chloride concentrations, as well as stable carbon isotope ratios of methane ( 13 C-CH 4 ) and dissolved inorganic carbon ( 13 C-DIC). We show that pore fluids near the SWI are saturated or supersaturated with respect to methane ($80 mM) and the methane flux from the seabed is variable over time. We hypothesized that regional seismic activity controlled this variable CH 4 flux in the Northern Cascadia continental margin setting. However, we found no direct correlation between earthquakes and CH 4 flux. We also posited alternative controls on CH 4 flux variability, such as storms, regional oceanography and microbial activity. Again, no direct correlation was seen. This study takes first steps toward exploring which physical factors play a role in methane flux from hydrate-bearing sediments.Components: 9,035 words, 7 figures.

show abstract

Section: Discussionmentioning

confidence: 94%

Temporal variability of in situ methane concentrations in gas hydrate‐bearing sediments near Bullseye Vent, Northern Cascadia Margin

Lapham

Wilson

Riedel

et al. 2013

Geochem Geophys Geosyst

View full text Add to dashboard Cite

show abstract

“…Image acquisition occurred in a time-lapse mode at a 30 min frequency, with a light ON duration of few seconds. As already pointed out in video imaging studies with artificial lighting ON at night-time or constantly ON during the 24-h as in the deep-sea [ 11 , 19 , 28 ], attraction or repulsion in fishes may occurs after few seconds. In particular, Doya et al [ 29 ] estimated a suitable time of light attraction within the first 25 s of light ON at video recording in the deep-sea.…”

Section: Discussionmentioning

confidence: 99%

“…In this monitoring, automation in video imaging plays a key role, since cameras are the only sensor allowing the extraction of biological information at the complex ecological scale of animals and their communities [ 2 , 9 ]. Suitable automation may contribute to transform cabled observatories into permanent ecosystem monitoring tools [ 6 – 8 , 11 ], fulfilling the goals of major ongoing infrastructural projects of relevance for the future of European marine research [ 30 – 32 ].…”

Section: Conclusion/outlookmentioning

confidence: 99%

“…Unfortunately, major drawbacks in using still cabled observatories cameras chiefly refer to the need for manual processing of very large sets of images for animal detection, counting and when required, classification [ 9 ]. That drawback can only be overcome by implementing suitable automated-video imaging protocols, which have recently been customized for the study of activity rhythms with video-cabled observatories of aphotic deep-sea areas [ 9 – 11 ]. Such an effort has not yet been attempted in the shallow coastal zones, where the greater variability in environmental illumination and often complex background substrates (e.g., reefs or coarse bottoms) consistently complicate the elaboration of efficient protocols [ 2 ].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

A New Colorimetrically-Calibrated Automated Video-Imaging Protocol for Day-Night Fish Counting at the OBSEA Coastal Cabled Observatory

Rı́o

Aguzzi

Costa

et al. 2013

Sensors

View full text Add to dashboard Cite

Field measurements of the swimming activity rhythms of fishes are scant due to the difficulty of counting individuals at a high frequency over a long period of time. Cabled observatory video monitoring allows such a sampling at a high frequency over unlimited periods of time. Unfortunately, automation for the extraction of biological information (i.e., animals' visual counts per unit of time) is still a major bottleneck. In this study, we describe a new automated video-imaging protocol for the 24-h continuous counting of fishes in colorimetrically calibrated time-lapse photographic outputs, taken by a shallow water (20 m depth) cabled video-platform, the OBSEA. The spectral reflectance value for each patch was measured between 400 to 700 nm and then converted into standard RGB, used as a reference for all subsequent calibrations. All the images were acquired within a standardized Region Of Interest (ROI), represented by a 2 × 2 m methacrylate panel, endowed with a 9-colour calibration chart, and calibrated using the recently implemented “3D Thin-Plate Spline” warping approach in order to numerically define color by its coordinates in n-dimensional space. That operation was repeated on a subset of images, 500 images as a training set, manually selected since acquired under optimum visibility conditions. All images plus those for the training set were ordered together through Principal Component Analysis allowing the selection of 614 images (67.6%) out of 908 as a total corresponding to 18 days (at 30 min frequency). The Roberts operator (used in image processing and computer vision for edge detection) was used to highlights regions of high spatial colour gradient corresponding to fishes' bodies. Time series in manual and visual counts were compared together for efficiency evaluation. Periodogram and waveform analysis outputs provided very similar results, although quantified parameters in relation to the strength of respective rhythms were different. Results indicate that automation efficiency is limited by optimum visibility conditions. Data sets from manual counting present the larger day-night fluctuations in comparison to those derived from automation. This comparison indicates that the automation protocol subestimate fish numbers but it is anyway suitable for the study of community activity rhythms.

show abstract

“…Countries currently driving large international programmes aimed at creating underwater permanent cabled installations networks are Japan, Europe, the United States, and Canada. Japan is presently working on the development of alert systems for earthquakes and associated tsunamis, which is currently one of the major requirements in seismically active areas (reviewed by Priede et al 2004, Favali & Beranzoli 2006, Favali et al 2006a, Mikada et al 2010. The Dense Oceanfloor Network system for Earthquakes and Tsunamis (DONET 2011) consists of a network of seismic observational nodes along several locations in the Japan Trench (i.e., off-Tokachi-Kushiro, Suruga, Boso, Izu Peninsula, Sanriku, and in Sagami Bay).…”

Section: Spatial Coverage Of Existing or Planned Cabled Observatory Networkmentioning

confidence: 99%

Challenges to the assessment of benthic populations and biodiversity as a result of rhythmic behaviour: Video solutions from cabled observatories

2012

Oceanography and Marine Biology

View full text Add to dashboard Cite

All marine species studied thus far show rhythmic temporal patterns in their behavioural, physiological, and molecular functions, which are collectively known as biological rhythms. Biological rhythms are generated by biological clocks that time biological functions and are synchronised by geophysical cycles such as the solar lightdark cycle and tidal cycle. On continental margins, behavioural rhythms can be detected by diel (i.e., 24-h based) or seasonal periodical trawling as a consequence of massive inward and outward displacements of populations to and from the sample areas. As a result, significant errors in population/stock and biodiversity assessments performed by trawling may occur if timing of sampling is not taken into account. The increasing number of cabled and permanent multiparametric seafloor observatories now allows direct, continuous, and long-lasting monitoring of benthic ecosystems and analysis in relation to several habitat cycles. This review describes the adaptation of this technology to investigations of rhythmic behaviour by focusing on automated videoimaging. Diel fluctuations in the number of video-observed individuals can be used as a measure of average population rhythmic behaviour. The potential implementation of automated video image analysis in relation to animal tracking and classification procedures based on the combined use of morphometric tools and multivariate statistics is detailed in relation to populational and community studies. Based on video cameras mounted at multiparametric cabled observatories, an integrated time-series analysis protocol using chrono-biomedical procedures is proposed to place video-recorded bioinformation in an oceanographic context.

show abstract

ESONET—European Sea Floor Observatory Network

Cited by 10 publications

References 0 publications

Temporal variability of in situ methane concentrations in gas hydrate‐bearing sediments near Bullseye Vent, Northern Cascadia Margin

Temporal variability of in situ methane concentrations in gas hydrate‐bearing sediments near Bullseye Vent, Northern Cascadia Margin

A New Colorimetrically-Calibrated Automated Video-Imaging Protocol for Day-Night Fish Counting at the OBSEA Coastal Cabled Observatory

Challenges to the assessment of benthic populations and biodiversity as a result of rhythmic behaviour: Video solutions from cabled observatories

Contact Info

Product

Resources

About