16 research outputs found
Introducing Fiji and ICY image processing techniques in ichnological research as a tool for sedimentary basin analysis
Get PDFSome features of trace fossils are not easy to determine due to limited vissibility of trace fossils. Here, we applied two image processing techniques (Fiji and ICY) to ichnological studies and we compare them with the previously used high-resolution image treatment method. , discussing their usefulness for ichnological studies. Then, these are compared with a high resolution image treatment. These techniques are revealed as rapid alternatives for estimation of some ichnological features, being so useful for the first stages of research, when a detailed analysis is not needed
Complex sublinear burrows in the deep sea may be constructed by amphipods
Get PDFTrails, burrows, and other âlife tracesâ in sediment provide important evidence for understanding ecologyâboth of the maker and of other usersâand behavioral information often lacking in inaccessible ecosystems, such as the deep sea or those that are already extinct. Here, we report novel sublinear rows of openings in the abyssal plains of the North Pacific, and the first plausible hypothesis for a maker of these constructions. Enigmatic serial burrows have now been recorded in the Pacific and Atlantic deep sea. Based on image and specimen evidence, we propose that these Bering Sea excavations represent amphipod burrows, while the maker of the previously known Mid-Atlantic Ridge constructions remains undetermined. We propose that maerid amphipods could create the Pacific burrows by eatingâdigging horizontally below the surface along a nutrient-rich layer in the sediment, making the serial openings above them as they go, for conveniently removing excavated sediment as the excavation progresses. These striking structures contribute to local biodiversity, and their maker could be considered a deep-sea ecosystem engineer.publishedVersio
Key evidence for distal turbiditic- and bottom-current interactions from tubular turbidite infills
Get PDFLebensspuren and benthic fauna diversity and density data obtained from KuramBio 2012 expedition still images (50 still images per 8 deep-sea stations)
No full text<p>Lebensspuren and total benthic fauna diversity and density data generated by the random selection of 50 still images per station of the KuramBio 2012 expedition (Stations 3-6, 8-11; the depth of the stations ranged from 4,868 m to 5,768 m). Annotation and data reports were conducted with BIIGLE 2.0. Still images belong to videos where the Ocean Floor Observation System (OFOS) was deployed. For more information see the cruise report (RV Sonne cruise SO223; doi:10.1016/j.dsr2.2014.11.001) and Miguez-Salas et al., (2023).</p><p> </p>
Still images from the KuramBio expedition 2012 (Stations 3-6, 8-11) obtained with the Ocean Floor Observation System
No full text<p>Repository with still images obtained from the videos of the KuramBio 2012 expedition in 5 second intervals. Still images belong to deep-sea stations where the Ocean Floor Observation System (OFOS) was deployed and enough video survey was obtained (i.e., Stations 3-6, 8-11). The Station 7 survey length was enough but has no HD video. Thus, images were not retrieved since the quality does not allow accurate lebensspuren or benthic fauna identification. </p><p>The OFOS was lowered into the water at the CTD position. The first 300 meters lowering was conducted with 0.5 m/sec, and then the speed was increased to 0.8 m/sec while the ship was kept in position. At 500 meters above ground the speed was reduced to 0.5 m/sec, and further reduced to 0.3 m/sec at 200 meters above ground. As soon as visual contact with the bottom was established, the winch was stopped. The ship started moving with 0.5 knots in the appropriate direction, which was chosen depending on current and wind situation at the according station. The OFOS was kept in an appropriate distance to the seafloor, enabling the scientists to watch the macrofaunal organisms. The approximate size of the observed animals could be calculated with the help of two laser pointers having a distance of 10 cm between each other (see Fig. 1-3). Generally, the survey lasted slightly over one hour, then the ship was stopped and heaving of the OFOS started. This was first conducted at 0.5 m/sec and accelerated to 1.0 m/sec. For more information see the cruise report (RV Sonne cruise SO223; doi:10.1016/j.dsr2.2014.11.001).</p>
KuramBio 2012_Lebensspuren area data
No full textLebensspuren data genrated by the random selection of 50 frames per station of the KuramBio 2012 expedition (8 stations analyzed; the depth of the stations ranged from 4,868 m to 5,768 m). In these 400 frames, the area of 5,692 lebensspuren was measured and the lebensspuren were classified. Additionally, megabenthic fauna was quantified and classified as âfaunal coverageâ at each station, which was the area covered by all individual megabenthic organisms. This âfaunal coverageâ area is based on the measurements of 4,009 individual animals.The research was funded by a Humboldt Postdoctoral Fellowship from the Humboldt Foundation
Neoichnological analysis of sea stars in the deep sea near the Aleutian Trench: behavioral insights from in situ observations
No full textAbstract The study of biogenic structures (e.g. lebensspuren) produced by benthic fauna on the seafloor provides invaluable information about the behavior of their tracemakers. In the case of sea stars, most of the previous research has been focused on shallow-marine environments due to the extreme scarcity of data from deep-sea lebensspurens. Here, we examined sea star traces from six deep-sea stations (deeper than 4500Â m) near the Aleutian Trench (North Pacific). A total of six families were identified from still images. The majority of them were not observed producing any lebensspuren or just pentameral impressions related to resting and feeding activities. Two members of the families Pterasteridae and Porcellanasteridae could be clearly characterized by a composite behavior resulting in contrasting lebensspuren morphotypes. A morphotype belonging to the genus Hymenaster undet .produced pentameral impressions (related to predation) and punctuated trails (related to podia locomotion). Members of the family Porcellanasteridae produced oval to circular impressions (that may be related to burrowing trails for the detection of organic matter), flat-shallow trails (related to podia locomotion), and irregular M-ridged trails (related to locomotion while feeding through the sediment interface). There is a severe scarcity of data related to the locomotion of past deep-sea Asteroidea (i.e. trace fossils) and their ichnotaxonomical classification. We discuss the implications of our results for the ichnofamily Biformitidae, as well as the importance of considering other features (e.g. podia impressions) rather than just hook-shaped traces related to arm locomotion.SCOPUS: ar.jinfo:eu-repo/semantics/publishe
Comparison of rosette-shape traces in abyssal terrains: Environmental and faunal implications
No full textBiogenic traces (lebensspuren) result from the activity of benthic organisms on and within the seafloor and are a common feature of deep-sea environments. Rosette-shape traces (RSTs), also referred to as spoke burrows, are a commonly observed and distinctive trace, likely created by echiuran worms during feeding and burrowing. We conduct a quantitative morphometric assessment of RSTs from two contrasting sites at the Porcupine Abyssal Plain Sustained Observatory (PAP-SO; Northeast Atlantic) with similar physico-chemical conditions except for relative sediment compaction, but substantive differences in their megabenthic communities. We quantified RST abundance (numerical density and seafloor cover) and morphological characteristics (spoke number and overlap, spoke length and width, trace area and relative completeness) for 148 individual RSTs observed in some 6800 seafloor photograph (8788 mâ2 seafloor area) captured with an autonomous underwater vehicle. We derived two primary results between study sites: (a) individual spoke morphology exhibited no statistically significant differences, while (b) individual trace completeness was significantly different. The consistency in spoke morphometrics reflects our identification of a single RST morphotype, potentially representing a single functional group of echiurans. The difference in trace completeness between sites may have resulted from differences in competition for resource with other megabenthic surface deposit feeders, and not to be directly related to relative sediment compaction. By reference to literature data and observations of similar traces in other deep-sea settings, we further suggest that this connection between trace completeness and resource availability may be more generally applicable in both contemporary ecology and paleoichnology
