Observations of food falls off the Shiretoko Peninsula, Japan, using a remotely operated vehicle

Shifting feeding behaviour of deep-sea buccinid gastropods at natural and simulated food falls

“…These observations can be ecologically gene ralized to confirm the opportunistic mixed pre datory and scavenging be havioural guild for deep-sea buccinids. This is the first time that a natural food fall has been witnessed in the deep sea both prior to, and after , an animal has actually died (Yamamoto et al 2009). Our findings fr om simulated food-fall experiments with a lander wer e also surprising.…”

“…N atural food falls are extremely rarely observed with these in situ imaging-technologies as they ar e infrequent and unpredictable in space and time, making the pr obability of their detection extraordinarily low (Klages et al 2001, Soltwedel et al 2003, Yamamoto et al 2009). However, the incr easing number of per manent video-observatories on the deep seafloor is providing new possibilities of ecological monitoring at longer timescales than ever befor e (Aguzzi et al 2010,b, 2012, Matabos et al 2011, Ruhl et al 2011.…”

A Systematic Review of Remotely Operated Vehicle Surveys for Visually Assessing Fish Assemblages

“…Baker et al (2012) used a basic scale of attraction, avoidance and no reaction, whereas Adams et al (1995) used a scale that differentiated between weak and strong responses of attraction and repulsion. The type and severity of the reaction to the ROV can be influenced by a variety of factors, including the species, trophic position, and the body size and position of the individual relative to the seafloor as well as to different aspects of the ROV system (i.e., artificial lighting, thruster noise, speed) (Smale et al, 2001;Lorance and Trenkel, 2006;Stoner et al, 2008;Yamamoto et al, 2009;Söffker et al, 2011;Mapula et al, 2016). For example, Laidig et al (2012) found that more fish reacted to the regular-sized observation-class ROV (57%) than to a larger, manned submersible (11%).…”

“…The length of the umbilical tether and the current-induced drag on the tether cord (Ajemian et al, 2015b) can influence the distance the ROV can travel from the operating vessel. A "live-boat" technique, in which a clump weight is attached to the umbilical tether a short distance above the seafloor (Amend et al, 2001;Bryan et al, 2013;Haggarty et al, 2016), can be used to maintain the ROV at depth (Yamamoto et al, 2009) while allowing the unanchored vessel to move freely with the ROV during deployment (Pacunski et al, 2008). For locations that require additional stabilization from the current, particularly for systems with shorter tethers, and are at depth shallow enough to anchor the vessel, clump weights can be used to secure the umbilical tether to the seafloor, where it acts as a central starting point for radial transects.…”

Food falls in the deep northwestern Weddell Sea

“…Reports of natural medium-sized food falls, and their scavenging communities and rates, residence time, and estimated carbon contribution, at the moment of writing include carcasses of fish (Smith, 1985;Soltwedel et al, 2003;Yamamoto et al, 2009;Aguzzi et al, 2012;Higgs et al, 2014;Amon et al, 2017), cephalopods (Hoving et al, 2017), crustaceans (Christiansen and Boetius, 2000;Klages et al, 2001), jellyfish (Yamamoto et al, 2008;Sweetman and Chapman, 2011), and tunicates (Henschke et al, 2013;Stenvers et al, 2021). While for whale carcasses, the residence time, succession and consumption, scavenging communities and carbon contribution have been studied, both via naturally and experimentally deposited carcasses around the world (Fujiwara et al, 2007;Lundsten et al, 2010b;Lundsten et al, 2010a;Amon et al, 2013;Smith et al, 2014b;Smith et al, 2014a;Smith et al, 2015), descriptions of whale falls are still worthwhile to report.…”