scholarly journals Feeding hotspots for four northwest Atlantic groundfish species

2012 ◽  
Vol 69 (10) ◽  
pp. 1710-1721 ◽  
Author(s):  
Elizabeth T. Methratta ◽  
Jason S. Link
Keyword(s):  
Benthic Invertebrate ◽  
Pseudopleuronectes Americanus ◽  
Sediment Grain Size ◽  
Northwest Atlantic ◽  
Predator Species ◽  
Consumption Rates ◽  
Prey Resources ◽  
Silver Hake ◽  
Species Specific ◽  
Merluccius Bilinearis

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.

Long-term shifts in the species composition of a coastal fish community

2008 ◽  
Vol 65 (7) ◽  
pp. 1352-1365 ◽  
Author(s):  
Jeremy S. Collie ◽  
Anthony D. Wood ◽  
H. Perry Jeffries
Keyword(s):  
Species Composition ◽  
Rhode Island ◽  
Chlorophyll Concentration ◽  
Taxonomic Diversity ◽  
Trawl Survey ◽  
Pseudopleuronectes Americanus ◽  
Nekton Community ◽  
Silver Hake ◽  
Merluccius Bilinearis ◽  
The University

To study decadal shifts in a coastal nekton community, we analyzed data on 25 fish and invertebrate species collected from 1959 to 2005 by the University of Rhode Island, Graduate School of Oceanography (Narragansett, Rhode Island, USA). This weekly trawl survey samples two locations: inside Narragansett Bay and in Rhode Island Sound. Over four decades, the community has shifted progressively from vertebrates to invertebrates and, especially since 1980, from benthic to pelagic species. Demersal species that declined include winter flounder ( Pseudopleuronectes americanus ), silver hake ( Merluccius bilinearis ), and red hake ( Urophycis chuss ); meanwhile warm-water fish (butterfish, Peprilus triacanthus ; scup, Stenotomus chrysops ) and invertebrates (lobster, crab, squid) increased with time. Total numbers reached a maximum in the 1990s, while mean body size decreased. Taxonomic diversity increased over time, as the community shifted from fish to invertebrates of several phyla. The shifts in species composition correlate most strongly with spring–summer sea surface temperature, which increased 1.6 °C over the 47-year time series. Species composition was also correlated with the winter North Atlantic Oscillation index and chlorophyll concentration, which has declined since the 1970s. Triggered primarily by rising temperatures, these decadal changes have altered the trophic structure of the nekton community, resulting in a shift from benthic to pelagic consumers.

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 ◽  
...  
Keyword(s):  
Sampling Methods ◽  
Ingestion Rate ◽  
Raman Spectrometry ◽  
Ingestion Rates ◽  
Economic Significance ◽  
Comprehensive Literature Review ◽  
Fish Ingestion ◽  
Silver Hake ◽  
Species Specific ◽  
Merluccius Bilinearis

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.

Storage Life of Refrozen Silver Hake (Merluccius bilinearis) Processed as Fillets am Minced Flesh from Thawed, Stored, Round-Frozen Fish

1977 ◽  
Vol 34 (12) ◽  
pp. 2369-2373 ◽  
Author(s):  
Doris Fraser Hiltz ◽  
D. H. North ◽  
Barbara Smith Lall ◽  
R. A. Keith
Keyword(s):  
Key Words ◽  
Frozen Storage ◽  
Storage Life ◽  
Freeze Thaw ◽  
Acceptable Quality ◽  
Frozen Fish ◽  
Silver Hake ◽  
Merluccius Bilinearis ◽  
Protein Extractability

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

Evidence supporting panmixia in Greenland halibut (Reinhardtius hippoglossoides) in the Northwest Atlantic

2014 ◽  
Vol 71 (5) ◽  
pp. 763-774 ◽  
Author(s):  
Denis Roy ◽  
David C. Hardie ◽  
Margaret A. Treble ◽  
James D. Reist ◽  
Daniel E. Ruzzante
Keyword(s):  
Population Structure ◽  
Population Genetic ◽  
Conservation Strategies ◽  
Greenland Halibut ◽  
Northwest Atlantic ◽  
Population Genetic Differentiation ◽  
Conservation Implications ◽  
Greenland Halibut Reinhardtius Hippoglossoides ◽  
Reinhardtius Hippoglossoides ◽  
Species Specific

Assessment of population structure is critical to the design and implementation of sound management and conservation strategies. However, population structure must be assessed using markers attuned to population genetic processes such as genetic drift and gene flow, which reflect actual levels of reproductive isolation among putative genetic clusters. This is critical for highly exploited, commercial species that form the backbone of regional and local economies. Here, we show extremely low levels of population genetic differentiation among Greenland halibut (Reinhardtius hippoglossoides) collected from throughout the Northwest Atlantic, which cannot be statistically differentiated from panmixia using 12 species-specific polymorphic microsatellite markers. In contrast, some previous studies have demonstrated significant differences among individuals collected from various parts of the species’ range using a variety of both genetic and nongenetic techniques. In accordance with other reports and consistent with the species’ life history, we demonstrate that the most parsimonious explanation reconciling observed patterns is a repeated high degree of local differentiation of new recruits and colonizers originating from a common gene pool. Such a scenario has important conservation implications in terms of devising more appropriate strategies balancing species persistence and replenishment with sustainable resource use.

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

2018 ◽  
Vol 131 ◽  
pp. 267-275 ◽  
Author(s):  
France Liboiron ◽  
Justine Ammendolia ◽  
Jacquelyn Saturno ◽  
Jessica Melvin ◽  
Alex Zahara ◽  
...  
Keyword(s):  
Ingestion Rate ◽  
South Coast ◽  
The South ◽  
Silver Hake ◽  
Merluccius Bilinearis

Behavioral inferences from regulatory observer data: catch rate variation in the Scotian Shelf silver hake (Merluccius bilinearis) fishery

1999 ◽  
Vol 56 (2) ◽  
pp. 288-296 ◽  
Author(s):  
D M Gillis
Keyword(s):  
Interference Competition ◽  
Temporal Trends ◽  
Catch Rate ◽  
Rate Variation ◽  
Scotian Shelf ◽  
Apparent Contradiction ◽  
Fishing Vessels ◽  
Catch Rates ◽  
Silver Hake ◽  
Merluccius Bilinearis

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.

Apparent digestibility coefficients of raw ground, acid and fermented silver hake (Merluccius bilinearis) feedstuffs for mink and an evaluation of the storage stability of the silages

1999 ◽  
Vol 79 (3) ◽  
pp. 375-381 ◽  
Author(s):  
M. B. White ◽  
D. M. Anderson ◽  
K. I. Rouvinen
Keyword(s):  
Formic Acid ◽  
Storage Stability ◽  
Storage Period ◽  
Apparent Digestibility ◽  
Standard Type ◽  
Randomized Design ◽  
Gross Energy ◽  
Silver Hake ◽  
Merluccius Bilinearis

A 3 × 4 factorial design experiment was conducted to determine digestibility coefficients (DC) of dry matter (DM), crude protein (CP), crude fat (CF), gross energy (GE) and amino acids (AA) in raw ground silver hake (RGSH), acid (ASHS) and fermented (FSHS) silver hake silages for mink. The ASHS was prepared with the addition of 2.5% (wt:wt) formic acid (85% concentration) and 200 ppm antioxidant (ethoxyquin) to the raw ground fish. The FSHS was produced with the addition of 1% Marisil® (Finn Sugar), 15% extruded wheat and 1% (wt:wt) formic acid (conc. 85%) to the raw ground fish. Twelve mature standard type male mink were confined to metabolism cages during the digestibility trial, which consisted of three experimental periods comprised of a 6-d adjustment period, followed by a 5-d collection period. Based on the total collection (TC) method and with graded levels (0, 15, 30 and 45%) of the test feedstuffs in the experimental diets, nutrient digestibilities in the pure feedstuffs were determined using a mathematical regression technique. The apparent digestibility (AD) of DM, CP, CF and GE were RGSH: 88.4, 93.6, 99.2 and 94.7%; ASHS: 90.6, 85.8, 96.1 and 87.2% and FSHS: 77.7, 84.5, 99.2 and 86.1%, respectively. The AD of all the AAs, except proline, in the RGSH was significantly higher (P < 0.05) than that in the ASHS and FSHS. A quality evaluation of the silages was conducted in a completely randomized design with two replications to determine storage stability of the silages, on 10 different sampling days, (3 sampling days for AAs), over the storage period. Quality of the silages was stable up to 90 days for the ASHS and 180 days FSHS based on increases in pH and total volatile nitrogen (TVN) content and decreases in N and AA content. The silver hake feedstuffs would provide a good source of highly digestible nutrients for mink and should be considered as opportunity feeds for these animals. Key words: Apparent digestibility, fish by-products, mink, silage, silage quality, silver hake

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