scholarly journals A zero percent plastic ingestion rate by silver hake (Merluccius bilinearis) from the south coast of Newfoundland, Canada

2018 ◽  
Author(s):  
France Liboiron ◽  
Justine Ammendolia ◽  
Jacquelyn Saturno ◽  
Jessica Melvin ◽  
Alex Zahara ◽  
...  

AbstractSilver hake, (Merluccius bilinearis), contributes significant biomass to Northwest Atlantic ecosystems. The incidence of plastic ingestion for 134 individuals collected from Newfoundland, Canada was examined through visual examination of gastrointestinal contents and Raman spectrometry. We found a frequency of occurrence of ingestion of 0%. Through a comprehensive literature review of globally published fish ingestion studies, we found our value to be consistent with 41% (n=100) of all reported fish ingestion rates. We could not statistically compare silver hake results to other species due to low sample sizes in other studies (less than n=20) and a lack of standardized sampling methods. We recommend that further studies should 1) continue to report 0% plastic ingestion rates and 2) should describe location and species-specific traits that may contribute to 0% ingestion rates, particularly in locations where fish consumption has cultural and economic significance.

2018 ◽  
Vol 131 ◽  
pp. 267-275 ◽  
Author(s):  
France Liboiron ◽  
Justine Ammendolia ◽  
Jacquelyn Saturno ◽  
Jessica Melvin ◽  
Alex Zahara ◽  
...  

2012 ◽  
Vol 69 (10) ◽  
pp. 1710-1721 ◽  
Author(s):  
Elizabeth T. Methratta ◽  
Jason S. Link

Abstract Methratta, E.T., and Link, J.S. 2012. Feeding hotspots for four northwest Atlantic groundfish species. — ICES Journal of Marine Science, 69: 1710–1721. We used predator distribution and stomach content data to estimate the annual per capita rate of consumption for four representative predator species from the northwestern Atlantic Ocean, and considered how consumption is influenced by depth, bottom salinity, sediment grain size, location variables, and species-specific diet components. We found that geographic variables and species-specific prey resources were significantly associated with consumption rates, a pattern consistent with predator-prey theory. Prey categories comprised of fish were particularly important for a more mobile predator (silver hake Merluccius bilinearis), whereas benthic invertebrate prey were consistently important for a more sedentary predator (little skate Raja erinacea). Hotspots in consumption rates that overlap with particular prey resources were highlighted by the significance of location variables (longitude) for winter flounder Pseudopleuronectes americanus, silver hake, little skate, and sea raven Hemitripterus americanus. Depth was an important explanatory factor for consumption by little skate, but the explanatory value of abiotic habitat factors was low for the other three species. Greater emphasis on species-specific food habits, migratory patterns, and ecological interactions at the synoptic scales relevant to fisheries is needed for fisheries management.


1988 ◽  
Vol 45 (10) ◽  
pp. 1711-1719 ◽  
Author(s):  
Antoine Morin ◽  
Christian Back ◽  
Alain Chalifour ◽  
Jacques Boisvert ◽  
Robert H. Peters

Field experiments were performed in a gutter system to examine the effect of body size, water temperature, seston concentration, and particle type on the ingestion rate of Simulium venustum/verecundum larvae. Ingestion rates rose exponentially with increasing temperature between 9 and 19 °C (Q10 = 2.19, 95% CI 2.09–2.29) and rose asymptotically with seston concentration (range 0.7–30 mg∙L−1). Small larvae were more sensitive to variations in seston concentration than older instars. The type of particles offered also influenced the ingestion rate of larvae. Once corrected for body size, water temperature, and seston concentration, the data show that larvae ingested more of the natural seston and of a yeast suspension than of suspensions containing kaolinite. Ingestion rates of other simuliid species generally co-occurring at the outflow of lakes in early summer were of the same magnitude as those of S. venustum/verecundum, although significant differences were detected among species. Specific ingestion rates of simuliids decline with increasing mass, are similar to those measured for benthic detritivores, and tend to be higher than those of marine and freshwater zooplankton of similar size. The models are discussed with respect to black fly control with particulate larvicides.


2019 ◽  
Vol 49 (1) ◽  
pp. 3-10 ◽  
Author(s):  
Yanli Lei ◽  
Chengchun Li ◽  
Tiegang Li ◽  
Zhimin Jian

Abstract The majority of sediment-dwelling foraminifera are thought to be deposit feeders. They use their reticulopodia to gather sediment with associated algae, organic detritus, and bacteria. Uptake of diatoms by foraminifera have been observed but rarely quantified. We measured the clearance (gathering) rate and ingestion rate of diatoms by the common benthic foraminifer Quinqueloculina seminula using Nitzschia closterium as prey under laboratory culture conditions. Grazing experiments were performed to evaluate the effects of temperature (at 12, 15, 18, 21, and 24°C) and food availability (10 to 800 cells mm−2) on uptake rates of diatoms. The clearance rates, estimated from the disappearance of food items, were variable (0.59–4.4 mm2 foram−1 h−1) and did not show a clear relationship with food availability. The maximum clearance rates increased from 1.80 ± 0.21 to 2.69 ± 0.32 mm2 foram−1 h−1 when temperature increased from 12 to 18°C and decreased to 2.28 ± 0.25 mm2 foram−1 h−1 at 24°C. Ingestion rates varied from 1.0 to 43 × 103 diatoms foram−1 h−1, following a hyperbolic response to food concentrations at all experimental temperatures. The maximum individual ingestion rates increased from 842 ± 180 to 1648 ± 480 (mean ± SE) cells foram−1 h−1 and then decreased to 316 ± 54 cells foram−1 h−1 as temperature increased from 12 to 24°C. Experimental results revealed that 12–18°C was the optimal temperature range for Q. seminula feeding for specimens adapted to local conditions. Our study indicates that Q. seminula plays an ecological role by feeding upon benthic diatoms in marine benthic ecosystems.


1977 ◽  
Vol 34 (12) ◽  
pp. 2369-2373 ◽  
Author(s):  
Doris Fraser Hiltz ◽  
D. H. North ◽  
Barbara Smith Lall ◽  
R. A. Keith

Refrozen silver hake (Merluccius bilinearis), processed as fillets and minced flesh after thawing of stored round fish that had been frozen within 14 h of capture, underwent rapid deterioration during storage at −18 °C compared with once-frozen control materials from the same lot of fish. The estimated maximum storage life of silver hake refrozen as fillets after 3 and 6 mo storage of the round fish at −25 °C was reduced to about 4.5 and 1 mo, respectively, from 10 mo for once-frozen control fillets. Quality of the refrozen materials immediately after thawing and refreezing was similar to that of the round-frozen fish, except after 6 mo, where some initial deterioration occurred, particularly in minced flesh. Minced flesh was more unstable in frozen storage than fillets. In all once- and twice-frozen materials, formation of dimethylamine occurred concomitantly with decrease in protein extractability. Round-frozen fish underwent no loss in protein extractability during 6 mo storage at −25 °C, but some lipid hydrolysis occurred. These results suggest that the freeze–thaw–refreeze process as applied to silver hake will yield a final product of acceptable quality provided that storage of the round fish does not exceed 3–4 mo and that the refrozen materials are marketed within a month after processing. Key words: silver hake, Merluccius bilinearis, refrozen storage, dimethylamine, minced flesh


2021 ◽  
Vol 8 ◽  
Author(s):  
Sang Ah Park ◽  
Hae Jin Jeong ◽  
Jin Hee Ok ◽  
Hee Chang Kang ◽  
Ji Hyun You ◽  
...  

The newly described dinoflagellate, Shimiella gracilenta, is known to survive for approximately 1 month on the plastids of ingested prey cells during starvation, indicating kleptoplastidy. To understand the population dynamics of this dinoflagellate in marine planktonic food webs, its growth and mortality rate due to predation should be assessed. Thus, we investigated the feeding occurrence of eight common heterotrophic protists on S. gracilenta. We also determined the growth and ingestion rates of Oxyrrhis marina and the naked ciliate, Rimostrombidium sp. on S. gracilenta as a function of the prey concentration. The common heterotrophic dinoflagellates (HTDs) Gyrodinium dominans, O. marina, and Pfiesteria piscicida and a naked ciliate Rimostrombidium sp. were able to feed on S. gracilenta; whereas the HTDs Aduncodinium glandula, Gyrodinium jinhaense, Oblea rotunda, and Polykrikos kofoidii were not. Shimiella gracilenta supported positive growth of O. marina and Rimostrombidium sp. but did not support that of G. dominans and P. piscicida. With increasing prey concentrations, the growth and ingestion rates of O. marina and Rimostrombidium sp. on S. gracilenta increased and became saturated. The maximum growth rates of O. marina and Rimostrombidium sp. on S. gracilenta were 0.645 and 0.903 day−1, respectively. Furthermore, the maximum ingestion rates of O. marina and Rimostrombidium sp. on S. gracilenta were 0.11 ng C predator day−1 (1.6 cells predator−1 day−1) and 35 ng C predator day−1 (500 cells predator−1 day−1), respectively. The maximum ingestion rate of O. marina on S. gracilenta was lower than that on any other algal prey reported to date, although its maximum growth rate was moderate. In conclusion, S. gracilenta had only a few common heterotrophic protist predators but could support moderate growth rates of the predators. Thus, S. gracilenta may not be a common prey species for diverse heterotrophic protists but may be a suitable prey for a few heterotrophic protists.


2016 ◽  
Vol 63 (3) ◽  
Author(s):  
Jayasree Loka ◽  
K.K. Philipose ◽  
S.M. Sonali

Effect of marine microalgal diet on filtration and ingestion rates of Brachionus plicatilis was studied. Marine microalgae viz., Nannochloropsis oculata, Isochrysis galbana, Chaetoceros calcitrans and a combination of N. oculata and I. galbana (Nanno+Iso) at different cell concentrations were selected for the experiment and triplicates were maintained for each feed. Significant difference (p<0.05) was observed in the filtration and ingestion rates of B. plicatilis, between the treatments. Peak filtration rate of 12.2x10-5 cells ml-1 ind-1 min-1 was recorded in B. plicatilis fed with Nanno+Iso, followed by I. galbana. Ingestion rate was found to be significantly high (p<0.05) for those fed with C. calcitrans, followed by Nanno+Iso. Filtration rate was significantly high (p<0.05) in rotifers stocked at an initial density of 50 nos. ml-1 fed with Nanno+Iso. The results indicated that a combination of Nanno and Iso is the best suitable microalgal diet for rotifer with peak filtration (12.2x10-5cells ml-1 ind-1 min-1) and ingestion (5.4x10-3 cells ml-1 ind-1 min-1) rates during the first 60 min.


1999 ◽  
Vol 56 (2) ◽  
pp. 288-296 ◽  
Author(s):  
D M Gillis

The detailed spatial and temporal data collected for the regulation of the silver hake (Merluccius bilinearis) fishery on the Scotian Shelf provide a unique opportunity to test hypotheses about variability in catch rates on the scale of individual trawls. I used these data to examine vessel interactions and long-term temporal trends in catchability. An index of course linearity, derived from observed positions, times, and speeds of fishing vessels, indicated that interference competition was present in the fishery. However, catch rate did not decline with local vessel density. This apparent contradiction is consistent with fleet dynamic theory and suggests that the direct examination of catch rates is a poor test for interference in the retrospective analysis of fisheries data. The study of extended periods of high, localized fishing activity revealed a cycle in catch rates with periods of about 6 days. Such periods may represent an interaction between tidal, diel, and (or) technological factors. Although more study is required to identify the cause of these cycles, their existence should be considered in the design of surveys and other population studies using catch and effort data.


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