Field demonstration of a novel towed, area bubble-plume zooplankton (Calanus sp.) harvester

Grimaldo, Eduardo; Leifer, Ira; Gjøsund, Svein Helge; Larsen, Roger B.; Jeuthe, Henrik; Basedow, Sünnje Linnéa

doi:10.1016/j.fishres.2010.10.018

Cited by 13 publications

(9 citation statements)

References 33 publications

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“…Since the sonar beam only recorded the scattering layer along a single vertical profi le, it is not clear whether individual zooplankton from the disturbed layer remained redistributed throughout the water column or descended to their original depth following the interaction with the high-intensity rising bubble stream. Uplifting of a zooplankton layer was only observed with the more intense bubbles stream emissions, which should exhibit stronger entrained upwelling fl ows, a process that has been previously reported for engineered bubble plumes (Grimaldo et al, 2011). This suggests that the weaker upwelling fl ows of the less intense plumes and individual bubbles created insuffi cient advection to displace the biological scattering layer, or the zooplankton may have actively opposed the weaker entrained fl ow by swimming.…”

Section: Biology and Bubblessupporting

confidence: 52%

Behavior of methane seep bubbles over a pockmark on the Cascadia continental margin

et al. 2011

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A newly modifi ed acoustic method was used to derive time-dependent bubble emission size distributions and to monitor associated zooplankton behavior at a methane seep emitted from the northeast Pacifi c continental shelf in 150 m water depth near Grays Harbor, Washington State, USA. Instrumentation consisted of a seafl oor mooring with an upward-oriented 200 kHz sonar that imaged the column's lower 100 m for 33 h during September 2009. The profi ler observed several highly variable methane bubble streams venting from a large carbonate-lined pockmark. Other acoustic data and visual observations confi rmed that the gas bubbles reached the sea surface and were highly variable in nature. Individual bubble traces in the acoustic sonar images were used to derive vertical bubble velocities with a mean value of 24.6 ± 2.5 cm s-1 over the entire depth range. Some bubbles entering the acoustic image at shallower water depths exhibited a slower rise velocity of 22.2 ± 2.4 cm s-1 and likely originated from adjacent emission sites. Measured rise velocities were too slow to be clean, uncoated bubbles. We therefore assumed that the bubbles were surfactant coated with a Gaussian-shaped size distribution peaking at an observed radius of 7500 ± 100 μm. If the fl ux derived from these measurements was assumed to be relatively constant over time, total methane issuing from only one of the ~20 active bubble vents at the pockmark site is estimated as ~9 kg yr-1 , similar to the fl ux from other reported marine CH 4 vent sites.

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Section: Biology and Bubblessupporting

confidence: 52%

Behavior of methane seep bubbles over a pockmark on the Cascadia continental margin

et al. 2011

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“…The calanoid copepod, Calanus finmarchicus , which is present in large amounts in the North Atlantic and may be harvested in a sustainable way , has been suggested as a novel source of marine PUFA . In addition, oil from C. finmarchicus has a high content of stearidonic acid (SDA, 18:4n‐3) similar to that of some specialized seed oils, such as Echium oil .…”

Section: Introductionmentioning

confidence: 99%

Lipid profile of mice fed a high‐fat diet supplemented with a wax ester‐rich marine oil

Pedersen

Salma

Höper

et al. 2014

Euro J Lipid Sci & Tech

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Oil extracted from the marine copepod Calanus finmarchicus contains the long chain omega-3 fatty acids eicosapentaenoic acid and DHA in addition to stearidonic acid (18:4n-3). Unlike other marine lipids, the fatty acids in this oil are esterified with long chain fatty alcohols as wax esters. The aim of this study was to examine the fate of the wax esters in oil from C. finmarchicus when given as a 2% supplement in a high fat diet to C57BL/6J mice for 11 weeks. The study confirmed that feeding mice a high fat diet supplemented with a small amount of oil containing wax esters reduced the body weight gain. During digestion, wax esters were hydrolyzed and the fatty acids absorbed since the fatty acid composition of the adipose tissue and liver reflected the enrichment with the Calanus oil. The composition of the liver lipids demonstrated elongation and desaturation of the C18 omega-3 fatty acids from the feed and accumulation of longer chained omega-3 fatty acids. Elevated levels of FFA and FAOH in the feces suggest that the absorption process, not the hydrolysis, could be a rate limiting step in utilization of small amounts of wax esters included in high fat diets in mice.Practical applications: The limited amount of available fish oil has led to extensive search for alternative sources of long-chain PUFA. One suggestion is to harvest at lower trophic levels, like small crustaceans, which may be abundantly present in the oceans. In this investigation, we have studied the effects of including the astaxanthin-rich oil from the marine copepod C. finmarchicus in a high fat diet in mice. This oil is different from other marine oils since most of the fatty acids are esterified to long-chain fatty alcohols, not in TAG, and that stearidonic acid is the major omega-3 fatty acid present. The results provide knowledge and understanding of aspects related to digestion and possible physiological effects of including small amounts of marine wax esters in diets.Abbreviations: ALA, alpha linolenic acid; þCal, inclusion of 2% calanus oil; DPA, docosapentaenoic acid; EE, ethyl ester; EPA, eicosapentaenoic acid; eWat, epididymal white adipose tissue; FAOH, fatty alcohol; FFA, free fatty acid; HFD, high fat diet; HPLC-ELSD, HPLC coupled with an evaporative light scattering detector; LC-PUFA, long-chain PUFA; pWat, perirenal white adipose tissue; SDA, stearidonic acid; WE, wax ester 1718Eur.

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“…However, typical fisheries applications involve a towed bubble plume (Grimaldo et al, 2010). Potentially, there is a significant difference between a stationary (i.e., fixed) source bubble plume in a uniform horizontal current (Fig.…”

Section: Stationary Vs Towed Bubble Plumesmentioning

confidence: 99%

“…Two highly distinct approaches were used to generate bubble plumes during the two field test series in 2008 and 2009 (Grimaldo et al, 2010). One, a bubble raft with tow parallel sparging elements, used a flushed sparger that tended to produce very small bubbles (which a video camera mounted on the raft imaged as milky in appearance) (Fig.…”

Section: Towed Submerged Bubble Raftsmentioning

confidence: 99%

Commercial Exploitation of Zooplankton in the Norwegian Sea

Grimaldo¹,

Gjøsund²

2012

The Functioning of Ecosystems

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Field demonstration of a novel towed, area bubble-plume zooplankton (Calanus sp.) harvester

Cited by 13 publications

References 33 publications

Behavior of methane seep bubbles over a pockmark on the Cascadia continental margin

Behavior of methane seep bubbles over a pockmark on the Cascadia continental margin

Lipid profile of mice fed a high‐fat diet supplemented with a wax ester‐rich marine oil

Commercial Exploitation of Zooplankton in the Norwegian Sea

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