scholarly journals Variation in size and growth of West Greenland capelin (Mallotus villosus) along latitudinal gradients

2010 ◽  
Vol 67 (6) ◽  
pp. 1128-1137 ◽  
Author(s):  
R. Hedeholm ◽  
P. Grønkjær ◽  
A. Rosing-Asvid ◽  
S. Rysgaard
Keyword(s):  
Size Distribution ◽  
Somatic Growth ◽  
Latitudinal Gradients ◽  
Mallotus Villosus ◽  
West Greenland ◽  
The North ◽  
Growth Difference ◽  
Capelin Mallotus Villosus ◽  
The Difference ◽  
Average Size

Abstract Hedeholm, R., Grønkjær, P., Rosing-Asvid, A., and Rysgaard, S. 2010. Variation in size and growth of West Greenland capelin (Mallotus villosus) along latitudinal gradients. – ICES Journal of Marine Science, 67: 1128–1137. Capelin (Mallotus villosus) is the dominant pelagic species in the West Greenland ecosystem. Historical data are re-examined and new data are presented on the size distribution and the growth pattern of capelin along latitudinal gradients of temperature and other growth factors extending over a distance of 1300 km. The average size of capelin increases with latitude. Fish 3 years old were 48 mm larger (54%) at the secondmost northern station compared with the most southern one. Otolith analysis revealed a significant effect of age as well as area on back-calculated growth. Hence, at all ages, fish grew faster in the north than in the south. Average somatic growth across areas in the first and fourth years was 56 and 15 mm, respectively. Temperature data suggest a 2°C difference in temperature between areas, temperatures being warmest in the north. Hence, the increase in temperature with latitude explains much of the latitudinal growth gradient and suggests a growth difference in West Greenland capelin of 0.4–0.6 cm °C−1 year−1. However, the difference in growth and size distribution between northern and southernmost stations, where temperatures are similar, suggests that other factors, such as differences in available prey and diet composition, also contribute to the differences.

scholarly journals Lifetime residency of capelin (Mallotus villosus) in West Greenland revealed by temporal patterns in otolith microchemistry

2022 ◽  
Vol 247 ◽  
pp. 106172
Author(s):  
Peter Fink-Jensen ◽  
Karin Hüssy ◽  
Tonny Bernt Thomsen ◽  
Simon Hansen Serre ◽  
Jens Søndergaard ◽  
...  
Keyword(s):  
Temporal Patterns ◽  
Otolith Microchemistry ◽  
Mallotus Villosus ◽  
West Greenland ◽  
Capelin Mallotus Villosus

Lack of genetic divergence in capelin (Mallotus villosus) spawning at beach versus subtidal habitats in coastal embayments of Newfoundland

2014 ◽  
Vol 92 (5) ◽  
pp. 377-382 ◽  
Author(s):  
Paulette M. Penton ◽  
Craig T. McFarlane ◽  
Erin K. Spice ◽  
Margaret F. Docker ◽  
Gail K. Davoren
Keyword(s):  
Local Adaptation ◽  
Genetic Divergence ◽  
Geographic Area ◽  
Mallotus Villosus ◽  
The North ◽  
Coastal Embayments ◽  
Fish Spawning ◽  
Capelin Mallotus Villosus ◽  
Unpredictable Environment ◽  
Spawning Sites

Capelin (Mallotus villosus (Müller, 1776)), a focal forage fish in the north Atlantic, spawn on both beach and demersal (deep-water) sites throughout their circumpolar distribution. Although these habitats rarely occur in close proximity, demersal spawning sites within 4 km of beach spawning sites (subtidal) have recently been discovered in two coastal embayments in Newfoundland, Canada. The physical environment differs considerably between beach and subtidal spawning sites, creating the potential for local adaptation and genetic divergence of capelin from the two habitats, but this has never been investigated on a fine spatial scale. We use eight microsatellite loci to test for genetic divergence between capelin spawning at beach and subtidal sites within these two coastal regions in Newfoundland. We found no genetic differentiation between fish spawning at beach and subtidal sites or between the two regions. The results from this fine-scale study are in agreement with the lack of habitat-based structure reported in other studies examining beach and demersal sites separated by a larger geographic area. We suggest that instead of showing site fidelity and local adaptation, the facultative use of alternate spawning habitats may be a more successful strategy in an unpredictable environment.

scholarly journals In situ measurements of capelin (Mallotus villosus) target strength in the North Pacific Ocean

2008 ◽  
Vol 66 (2) ◽  
pp. 258-263 ◽  
Author(s):  
Michael A. Guttormsen ◽  
Christopher D. Wilson
Keyword(s):  
Pacific Ocean ◽  
North Pacific ◽  
North Pacific Ocean ◽  
In Situ Measurements ◽  
Target Strength ◽  
Mallotus Villosus ◽  
The North ◽  
Capelin Mallotus Villosus ◽  
The North Pacific

Abstract Guttormsen, M. A. and Wilson, C. D. 2009. In situ measurements of capelin (Mallotus villosus) target strength in the North Pacific Ocean. – ICES Journal of Marine Science, 66: 258–263. In situ measurements of capelin (Mallotus villosus) target strength (TS) were collected during summer 2001–2003 near Kodiak Island in the Gulf of Alaska, using a calibrated EK500 echosounder with 38 and 120 kHz split-beam transducers. Targets were detected over dispersed, night-time aggregations using standard acoustic methods, then filtered using a quality-control algorithm to reject invalid targets. The 38 kHz-based, fitted model estimate was TS = 20 log10L− 70.3 (r2 = 0.30), where L is total length of fish. Compared with other studies, the TS-fitted model at 38 kHz was similar to that calculated from swimbladder morphology measurements from St Lawrence estuary capelin (TS = 20 log10L− 69.3), but resulted in greater estimates than models based on in situ measurements of capelin TS in the Barents Sea (TS = 19.1 log10L−74.0) and northern Atlantic Ocean (TS = 20 log10L − 73.1). The large intraspecific variability exhibited in the fitted TS – L models for this species suggests the use of TS measurements from the geographic region where the data were collected.

scholarly journals Capelin (Mallotus villosus) distribution and climate: a sea “canary” for marine ecosystem change

2005 ◽  
Vol 62 (7) ◽  
pp. 1524-1530 ◽  
Author(s):  
G.A. Rose
Keyword(s):  
Temperature Change ◽  
North Atlantic ◽  
Marine Ecosystem ◽  
Predatory Fish ◽  
Ecosystem Change ◽  
Monitoring Methods ◽  
Mallotus Villosus ◽  
The North ◽  
Capelin Mallotus Villosus ◽  
The North Atlantic

Abstract Capelin (Mallotus villosus) is a classic “r” adapted pelagic species that inhabits the northern boreal oceans at the margins of cold Arctic waters. The species originated in the North Pacific and colonized the North Atlantic at least once during interglacial periods of the past few million years. Capelin became the main forage species for many larger predatory fish, and also for seabirds and marine mammals. The colonizing abilities of capelin have been noted in historical anecdotes, typically in concert with climate variations. In this paper, all known shifts in distribution are catalogued. Shifts have taken place at the larval and adult stages, and some result in new spawning locations, others do not. Displacement distance relates to temperature change: log10(distancekm) = 0.28 × temperature change + 2.16 (p < 0.05, r2 = 0.91). The persistence of the shifts relates to the displacement distance: log10(persistencey) = 2.62 × log10(distancekm) − 6.56 (p < 0.05, r2 = 0.83). The quick and consistent response of capelin to temperature change, its importance to the North Atlantic foodweb, and established monitoring methods suggest this species as a sea “canary” for northern boreal marine ecosystem responses to climate variability and change.

Feeding ecology of capelin (Mallotus villosus Müller) in West Greenland waters

Polar Biology ◽  
2012 ◽  
Vol 35 (10) ◽  
pp. 1533-1543 ◽  
Author(s):  
R. Hedeholm ◽  
P. Grønkjær ◽  
S. Rysgaard
Keyword(s):  
Feeding Ecology ◽  
Mallotus Villosus ◽  
West Greenland ◽  
Capelin Mallotus Villosus

Particulate Size Distribution in the Haze and Non-Haze Episodes at Shijiazhuang City, China

2014 ◽  
Vol 955-959 ◽  
pp. 1297-1300
Author(s):  
Zan Hong Wang ◽  
Zhi Po Hao
Keyword(s):  
Size Distribution ◽  
Mass Concentration ◽  
Negative Relationship ◽  
Particulate Size ◽  
Visibility Range ◽  
Haze Episode ◽  
The Difference ◽  
Haze Formation ◽  
Average Size ◽  
Shape Curve

Aimed at detecting the particulate size distributions in the typical air pollution city of Shijiazhuang, China, this research collected samples in haze episode and non-haze episode separately and found the difference between the two situations. In non-haze episode, the average size distribution is a U-shape curve both lifting at the size minimum and maximum, with slightly higher frequency in the size below 0.65μm (grade 1 and grade 2); but in haze episode, the frequency of 0.43~0.65μm (grade 2) and 0.65~1.1μm (grade 3) increase evidently. By the correlation coefficient calculation, the mass concentration of PM0.43~0.65 has strong negative relationship with visibility range, which should be responsible for the low visibility formation. The fitting function demonstrates that the mass concentration of PM0.43~0.65 must be limited below 0.117 mg/m3 if the visibility range reaches 10km (“medium”), and below 0.006 mg/m3 over 19km (“good”). And there is a inflection point around 0.01 mg/m3 of PM0.43~0.65 as for the visiblity variation, in which the visiblity range decreases rapidly with slight increase of PM0.43~0.65 when below 0.001 mg/m3. PM0.43~0.65 is conclusively regarded as the feature size of particulate responsible for the haze formation in Shijiazhuang, China.

Beach and demersal spawning in capelin (Mallotus villosus) on the northeast Newfoundland coast: egg developmental rates and mortality

2012 ◽  
Vol 90 (2) ◽  
pp. 248-256 ◽  
Author(s):  
P.M. Penton ◽  
G.K. Davoren ◽  
W.A. Montevecchi ◽  
D.W. Andrews
Keyword(s):  
Rapid Development ◽  
Survival Rates ◽  
Mallotus Villosus ◽  
The North ◽  
Spawning Site ◽  
Slow Development ◽  
Capelin Mallotus Villosus ◽  
Developmental Rates ◽  
Incubation Temperatures ◽  
Limited Oxygen

Timing of spawning and site selection in fish are important fitness-related traits that ultimately influence reproductive success. Capelin ( Mallotus villosus (Müller, 1776)), a key forage fish in the north Atlantic, spawn eggs that adhere to sediments on beaches and in demersal (deep-water) habitats throughout their geographic range, resulting in divergent thermal regimes for the incubating eggs. We compare the timing and duration of spawning of capelin and its influence on the developmental and survival rates of eggs between a beach and a demersal spawning site on the northeast Newfoundland coast in 2004 and 2005. Spawning events at the beach were at least 10 days earlier and shorter (2–3 days) relative to the demersal site (8–12 days). Hourly and mean daily incubation temperatures at the beach were higher and more variable relative to the demersal site, resulting in two distinct developmental strategies: low to high mortality and rapid development (beach) versus low mortality and slow development (demersal). Higher egg mortality at beach sites was explained by higher and more variable temperatures and potentially limited oxygen replenishment relative to demersal sites. The divergent biology of beach and demersally spawned eggs suggest that each will respond differently to environmental change and, thus, require different approaches for successful management.

Application of the Foreshock Traffic Light System to the 2019 Ridgecrest sequence

2021 ◽  
Author(s):  
Laura Gulia ◽  
Stefan Wiemer ◽  
Gianfranco Vannucci
Keyword(s):  
Size Distribution ◽  
Reference Value ◽  
B Value ◽  
Aftershock Sequence ◽  
Traffic Light ◽  
Natural Systems ◽  
Background Value ◽  
Light System ◽  
The North ◽  
Average Size

&lt;p&gt;The relative earthquake size distribution, or b-value of the Gutenberg and Richter relationship, can act as an indirect stress meter in the earth crust, a finding confirmed in numerous laboratory studies but also in diverse natural systems. &amp;#160;In 2018, we analysed the average size-distribution of about 60 well-monitored earthquakes sequences showing that, after a mainshock with M&gt;=6, the b-value increases by about 20% respect to the background reference value.&lt;/p&gt;&lt;p&gt;In 2019, based on such result, we hypothesized and demonstrated that it may be possible, under specific circumstances, to discriminate if an ongoing sequence is representing a typically decaying aftershock sequence or rather foreshocks to an upcoming larger event. &amp;#160;We proposed a simple traffic light classification to assess in near real-time the level of concern for subsequent larger event, and tested it against 58 sequences, reaching a classification accuracy of 95%.&lt;/p&gt;&lt;p&gt;The Foreshock Traffic Light System (FTLS) has been implemented in a pseudo-prospective test to the 2019 Ridgecrest sequence. Results are fully in line with the hypothesis: in this Ridgecrest case study, after analyzing carefully the magnitude of completeness of the sequences, we find that in the hours after the first Mw6.4 Ridgecrest event, the b-value drops by 23% on average, when compared to the background value, resulting in a red foreshock traffic light. Spatially mapping the changes in b, we identify an area to the north of the rupture plane as the most likely location of a subsequent event. After the second, magnitude-7.1 mainshock, which did occur in the low b-value region, the b-value subsequently increased by 26% over the background value, triggering a green traffic light setting. Here we will report on these findings, discuss additional case studies, criticisms raised and discuss physics-based mechanics that may allow us to understand and model the observations.&lt;/p&gt;

Sex-specific life history strategies in capelin (Mallotus villosus)?

1998 ◽  
Vol 55 (3) ◽  
pp. 631-638 ◽  
Author(s):  
Geir Huse
Keyword(s):  
Life History ◽  
Barents Sea ◽  
Gonadosomatic Index ◽  
Somatic Growth ◽  
Life History Strategies ◽  
Mallotus Villosus ◽  
Offspring Production ◽  
Darwinian Fitness ◽  
Capelin Mallotus Villosus ◽  
Batch Spawning

The life history of capelin (Mallotus villosus) is presently suggested to be sex specific: while males follow a semelparous batch-spawning strategy, females are iteroparous. This hypothesis is based on predictions from a life history simulation model of Barents Sea capelin that shows that iteroparity is more profitable than semelparity for females, but for males, semelparity with several matings with females may be as profitable as iteroparity. These predictions are supported by (i) reports of males mating with several females during a spawning season, (ii) males having a lower gonadosomatic index than females and instead spending their energy on mating and somatic growth, and (iii) an observed higher mortality for males after spawning. The Darwinian fitness of female capelin is limited by the amount of eggs they can carry, and offspring production may only be increased by undertaking several spawning seasons with yearly intervals. Added together, these indices suggest that male and female capelin follow different life history strategies.

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