Wind Regulation of Emergence Times and Early Larval Survival in Capelin (Mallotus villosus)

1981 ◽  
Vol 38 (2) ◽  
pp. 215-223 ◽  
Author(s):  
Kenneth T. Frank ◽  
William C. Leggett
Keyword(s):  
Physical Condition ◽  
Population Biology ◽  
Larval Density ◽  
Larval Survival ◽  
Published Data ◽  
Mallotus Villosus ◽  
Good Physical Condition ◽  
Emergence Patterns ◽  
Capelin Mallotus Villosus ◽  
Larval Emergence

Factors regulating the emergence and survival of capelin (Mallotus villosus) larvae from their beach gravel nest sites were investigated in the spring and summer of 1978 and 1979. In both years, the pattern of larval emergence was characterized by intermittent abrupt increases in the numbers of larvae in the nearshore waters and corresponding precipitous declines in the density of preemergent larvae in the beach gravel. Both events were strongly correlated with onshore wind-induced wave action which disturbed the beach. Larval emergence patterns were unrelated to changes in tidal amplitude or day–night variation. The generality of this wind-induced larval emergence hypothesis was tested and confirmed using published data from two separate studies conducted at three different Newfoundland sites during 1927, 1929, 1930, and 1941. The density of larvae in the beach gravel was positively correlated with the length of time separating the occurrence of onshore winds. The result was a pronounced temporal clumping of larvae hatching at different times, periodic releases of large numbers of larvae into the aquatic environment, and a progressive deterioration in the physical condition of larvae emerging as beach residence time increased. The frequency of onshore winds during the hatching period was 50% greater in 1979 relative to 1978. Egg densities were similar in 1978 and 1979 but larval densities (no./m3) in the nearshore environment were 60% greater in 1979. This increase in larval density conformed to the increase in the proportion of larvae exiting the beach in good physical condition in 1979.Key words: capelin, Mallotus villosus; Newfoundland, larval emergence, larval survival, wind, population biology, beach spawning, coastal environments, year-class strength

Patterns of larval emergence of capelin (Mallotus villosus) and environmental cues at demersal spawning sites on the northeastern coast of Newfoundland

2008 ◽  
Vol 65 (6) ◽  
pp. 1135-1143 ◽  
Author(s):  
Paulette M. Penton ◽  
Gail K. Davoren
Keyword(s):  
Water Column ◽  
Good Condition ◽  
Larval Survival ◽  
Mallotus Villosus ◽  
Capelin Mallotus Villosus ◽  
Warm Surface Water ◽  
Larval Emergence ◽  
Wind Events ◽  
Northeastern Coast ◽  
Spawning Sites

At spawning beaches in Newfoundland, Canada, capelin ( Mallotus villosus ) larval emergence is triggered by coastal water mass replacement (CWMR). CWMR causes sharp but short increases in temperature in coastal areas by the transport of warm surface water to the coast during onshore wind events. Warm water temperatures stimulate the active emergence of capelin larvae into predator-poor and prey-rich conditions favourable for larval survival. We investigated whether wind events influenced (i) the thermal properties of the water column and (ii) the larval emergence patterns at five demersal (deep-water) spawning sites on the northeastern coast of Newfoundland during the posthatch periods in 2004–2006. Winds oriented along the shore caused frequent and sharp increases in bottom temperature at all sites but did not appear to stimulate the release of larvae into the water column. Instead, peaks in larval densities corresponded to predicted peaks in hatching. Because of this and the presence of recently hatched larvae (3–5 mm) primarily in good condition, we hypothesize that larvae simply emerged from the sediment upon hatching at these demersal spawning sites. We conclude that patterns of larval emergence at demersal sites in this region are different from those reported for the beach in other regions of Newfoundland.

Ecosystem changes and the effects on capelin (Mallotus villosus), a major forage species

2001 ◽  
Vol 58 (1) ◽  
pp. 73-85 ◽  
Author(s):  
J E Carscadden ◽  
K T Frank ◽  
W C Leggett
Keyword(s):  
Physical Environment ◽  
Population Biology ◽  
Single Species ◽  
Zooplankton Abundance ◽  
Mallotus Villosus ◽  
Northwest Atlantic ◽  
Commercial Fish ◽  
Commercial Exploitation ◽  
Capelin Mallotus Villosus ◽  
The Impact

Capelin (Mallotus villosus), an important forage and commercial fish in the Northwest Atlantic, has exhibited dramatic changes in its biology during the 1990s, coincident with extreme oceanographic conditions and the collapse of major groundfish stocks. Commercial exploitation has not been a serious factor influencing the population biology of capelin in the area. The overall consumption of capelin has declined as predator stock abundances have changed. Data on plankton are sparse, but there appears to have been a decline in zooplankton abundance during the 1990s, and at the same time, a phytoplankton index increased. The impact of the changes in the physical environment has been the subject of previous studies and these are reviewed. The relative impacts of four factors, commercial exploitation, predation, food availability, and the physical environment, on the changes in capelin biology are discussed in the context of capelin as a single species and in the context of the ecosystem. The overall patterns suggest the existence of a "trophic cascade" within the distributional range of capelin in the Northwest Atlantic during the 1990s primarily driven by declines in major finfish predators.

Capelin (Mallotus villosus) Spawning on the Southeast Shoal: Influence of Physical Factors Past and Present

1989 ◽  
Vol 46 (10) ◽  
pp. 1743-1754 ◽  
Author(s):  
J. E. Carscadden ◽  
K. T. Frank ◽  
D. S. Miller
Keyword(s):  
Surf Zone ◽  
Biological Data ◽  
Published Data ◽  
Physical Factors ◽  
Bottom Temperature ◽  
Mallotus Villosus ◽  
Term Survival ◽  
Grand Banks ◽  
Spawning Stock ◽  
Capelin Mallotus Villosus

Co-occurrence of beach- and offshore bottom-spawning populations of capelin (Mallotus villosus) in the Northwest Atlantic appears to be unusual. To explain the evolution of bottom-spawning in the offshore spawning population on the Southeast Shoal, we examined relevant substrate, water temperature, and biological data. Published data indicate that the Southeast Shoal was not glaciated during the Wisconsin glaciation (about 20 000 yr ago) and was above sea level. As the glaciers melted, this area was a surf zone before it became inundated. This suggests that this stock was once a beach-spawning stock and supports our hypothesis that substrate is the ultimate factor affecting spawning location. Analysis of 7 yr of distribution, maturity, and bottom temperature data showed that the variation in the final spawning location was not large and spawning occurred where bottom temperatures exceeded approximately 2 °C. We conclude that bottom temperature is a proximate factor influencing the final spawning location. Physical data for other areas of the Grand Banks indicate that only the Southeast Shoal has favourable substrate, bottom temperatures and environmental factors subsequent to spawning to allow the long-term survival of a capelin population.

Predation by Jellyfish on Larval Fish: An Experimental Evaluation Employing in situ Enclosures

1988 ◽  
Vol 45 (7) ◽  
pp. 1173-1190 ◽  
Author(s):  
Yves de Lafontaine ◽  
W. C. Leggett
Keyword(s):  
Functional Response ◽  
Larval Fish ◽  
Larval Mortality ◽  
Larval Density ◽  
Larval Survival ◽  
Exogenous Feeding ◽  
Larval Size ◽  
Capelin Mallotus Villosus ◽  
Jellyfish Species

Large in situ enclosures were used to investigate the mortality of yolk-sac larval capelin (Mallotus villosus) by four species of jellyfish predators. Daily instantaneous larval mortality increased linearly with predator density but was independent of initial larval density, indicating a linear functional response of the four jellyfish species. The addition of alternative prey did not modify the linearity of the functional response and did not significantly reduce or increase larval mortality imposed by two jellyfish species. The evidence of a linear response in large enclosures contrasts with the curvilinear (Type II) response previously reported in studies conducted in small laboratory containers. Larval mortality was strongly dependent on predator size within jellyfish species and increased with initial larval size. Larval capelin appeared more susceptible to predation at the time of transition from endogenous to exogenous feeding. Daily larval mortality rates due to predation varied between 0.015 and 1.58 depending on jellyfish species and appeared more strongly determined by body mass than differences in feeding appendages of jellyfish. Our results indicate that reduced larval mortality to jellyfish predation is achievable only by timing larval release in water mass where jellyfish numbers are naturally reduced. We estimated that macro invertebrate predation has the potential of being the primary regulator of larval survival and we hypothesized that large intra- and interannual variation in larval survival may be due to the variability in the emergence timing of capelin larvae relative to the growth trajectory of jellyfish.

Some observations on the population biology of capelin (Mallotus villosus) from Balsfjord, northern Norway

1988 ◽  
Vol 44 (3) ◽  
pp. 264-276 ◽  
Author(s):  
O. Nyholmen ◽  
C. C. E. Hopkins
Keyword(s):  
Population Biology ◽  
Mallotus Villosus ◽  
Northern Norway ◽  
Capelin Mallotus Villosus

Patterns of Larval Emergence and Their Potential Impact on Stock Differentiation in Beach Spawning Capelin (Mallotus villosus)

1987 ◽  
Vol 44 (7) ◽  
pp. 1326-1336 ◽  
Author(s):  
Louis Fortier ◽  
William C. Leggett ◽  
Serge Gosselin
Keyword(s):  
Dark Phase ◽  
Mallotus Villosus ◽  
Lawrence Estuary ◽  
Larval Stages ◽  
Abrupt Changes ◽  
Capelin Mallotus Villosus ◽  
Larval Emergence ◽  
Laboratory Emergence ◽  
St Lawrence Estuary ◽  
Stock Differentiation

The environmental cues triggering larval capelin (Mallotus villosus) emergence in the St. Lawrence estuary and in coastal Newfoundland are different. In the estuary, emergence from the intertidal and subtidal spawning grounds starts with dusk and ends with dawn, indicating an active response to low light intensity. In the laboratory, emergence from undisturbed sediments collected in the field is perfectly synchronized with the dark phase of the illumination cycle. Nocturnal emergence would represent an adaptation reducing vulnerability to visual predators. Previous work has shown that in Newfoundland, capelin emergence from intertidal beaches is triggered by abrupt changes in water temperature following the sporadic advection to the coast of surface water masses characterized by low predator and high prey abundances. We argue that regional differences in the emergence pattern of the species represent different strategies to avoid predation at the onset of the planktonic drift when the vulnerable yolk sac larvae are densely aggregated. Selection acting on the behaviour of the early larval stages could contribute to stock differentiation in capelin.

Meteorological and Hydrographic Regulation of Year-Class Strength in Capelin (Mallotus villosus)

1984 ◽  
Vol 41 (8) ◽  
pp. 1193-1201 ◽  
Author(s):  
W. C. Leggett ◽  
K. T. Frank ◽  
J. E. Carscadden
Keyword(s):  
Swimming Performance ◽  
Abiotic Factors ◽  
Larval Survival ◽  
Critical Periods ◽  
Mallotus Villosus ◽  
Large Spatial Scale ◽  
Spawning Stock ◽  
Class Strength ◽  
Capelin Mallotus Villosus ◽  
Parent Stock

Year-class strength (YCS) in eastern Newfoundland stocks of capelin (Mallotus villosus), a beach spawning osmerid, during the interval 1966–78 was strongly influenced by onshore wind frequency during the period immediately following hatching (WIND) and water temperatures experienced during the subsequent period of larval drift (TEMPSUM). The exact form of the relationship was ln YCS = 16.10 − 0.19WIND + 0.19TEMPSUM, R2 = 0.58. Wind conditions subsequent to hatching are known to influence both the timing of larval emergence from the beach spawning beds and the physical condition of larvae at emergence. Our analysis suggests that the influence of wind on early larval survival is also strong. The role of water temperatures during drift may be indirect, operating via its influence on food production. This could operate by altering mortality rates due to starvation or by altering growth rates which would influence swimming performance, predator avoidance, and time to metamorphosis. The strong influence of these abiotic variables, independent of parent stock size, adds further support to the hypothesis that abiotic factors operating at critical periods in larval development may be more important than spawning stock biomass as regulators of year-class size. Our findings also suggest that these critical periods must be identified and quantified at time scales relevant to individual larvae if reliable forecasting of year-class strength is to be achieved. On the other hand, the large spatial scale of the effects suggests that the space scale of individual larvae is of lesser importance in such analyses.

The population biology and exploitation of capelin (Mallotus villosus) in the barents sea

Sarsia ◽  
1998 ◽  
Vol 83 (6) ◽  
pp. 453-496 ◽  
Author(s):  
Harald Gjøsæter
Keyword(s):  
Population Biology ◽  
Barents Sea ◽  
Mallotus Villosus ◽  
The Barents Sea ◽  
Capelin Mallotus Villosus

scholarly journals Early life growth is affecting timing of spawning in the semelparous Barents Sea capelin (Mallotus villosus)

2021 ◽  
pp. 102614
Author(s):  
Florian Berg ◽  
Samina Shirajee ◽  
Arild Folkvord ◽  
Jane Aanestad Godiksen ◽  
Georg Skaret ◽  
...  
Keyword(s):  
Early Life ◽  
Barents Sea ◽  
Mallotus Villosus ◽  
Capelin Mallotus Villosus ◽  
Timing Of Spawning
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