Shoal behaviour and maturity relations of spawning capelin (Mallotus villosus) off Newfoundland: demersal spawning and diel vertical movement patterns

2006 ◽  
Vol 63 (2) ◽  
pp. 268-284 ◽  
Author(s):  
Gail K Davoren ◽  
John T Anderson ◽  
William A Montevecchi
Keyword(s):  
Surface Water ◽  
Deep Water ◽  
Movement Patterns ◽  
Gonadal Development ◽  
Vertical Movement ◽  
Suitable Habitat ◽  
Mallotus Villosus ◽  
Growth And Survival ◽  
Capelin Mallotus Villosus ◽  
Warm Surface Water

We investigated shoals of capelin (Mallotus villosus), the focal forage fish species in the Northwest Atlantic, in nearshore Newfoundland during spawning (2000–2003). Large shoals of maturing capelin were observed in warm (>0 °C), deep (>240 m) water. Smaller shoals of maturing fish were located in two specific areas closer to shore in shallower water (100–150 m). Shoals persisted in these staging areas in all years and moved into warm surface water during dark but remained in cold (<0 °C) deep water during daylight. These diel vertical movement patterns may reflect a trade-off between growth and survival, whereby cold, deep water allows reduced predation risk from visual, air-breathing predators while warm, surface water allows increased gonadal development. Shoals of spent capelin, mainly females, were also found in these areas. Sex-specific shoals were observed between staging areas and the coast. Closer to shore, mature, mixed-sex shoals revealed two previously undocumented demersal spawning sites (28–33 m). Suitable habitat for spawning and staging areas resulted in persistent aggregations of capelin shoals, reflecting key foraging areas for top predators and critical areas for conservation.

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.

Temperature-based spawning habitat selection by capelin (Mallotus villosus) in Newfoundland

2017 ◽  
Vol 74 (6) ◽  
pp. 1622-1629 ◽  
Author(s):  
Kevin A. Crook ◽  
Emily Maxner ◽  
Gail K. Davoren
Keyword(s):  
Habitat Selection ◽  
Deep Water ◽  
Environmental Conditions ◽  
Population Level ◽  
Life History Trait ◽  
Forage Fish ◽  
Spawning Habitat ◽  
Mallotus Villosus ◽  
Hourly Temperature ◽  
Capelin Mallotus Villosus

Abstract The location of reproduction is a key life history trait, as it influences the bio-physical conditions that offspring experience and, thus, fitness. Capelin Mallotus villosus is a small (&lt; 200 mm), short-lived forage fish that spawns in two habitats in coastal Newfoundland: warm beaches and cool, deep water (15–40 m). From 2009 to 2014, we investigated temperature-dependent spawning habitat use by quantifying hourly temperature at spawning sites during July within each habitat along with population-level spawning site use. Capelin did not spawn at sites with temperatures &lt;2 °C or consistently &gt;12 °C, supporting the estimated suitable spawning temperature range (2–12 °C). Spawning typically occurred exclusively at beaches early in July when deep-water habitat was too cold (i.e. &lt;2 °C), and then switched to deep-water habitat later in July when beaches became too warm (i.e. &gt;12 °C). Spawning overlapped for 1–3 d in both habitats when temperatures were within suitable ranges (2011, 2013), but capelin also spawned exclusively in one habitat when temperatures remained suitable in the other. The latter suggests that other factors influence spawning habitat selection, such as conspecific egg densities and other environmental conditions. Overall, the flexible use of spawning habitats, along with wide tolerance ranges of capelin eggs to environmental conditions, are likely key adaptations to maximize fitness and stabilize population dynamics of this important forage fish species in an unpredictable environment.

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

Channel head dynamics: capelin (Mallotus villosus) aggregation in the tidally driven upwelling system of the Saguenay - St. Lawrence Marine Park's whale feeding ground

2002 ◽  
Vol 59 (2) ◽  
pp. 197-210 ◽  
Author(s):  
Yvan Simard ◽  
Diane Lavoie ◽  
François J Saucier
Keyword(s):  
Circulation Model ◽  
Feeding Strategies ◽  
Total Biomass ◽  
Balaenoptera Acutorostrata ◽  
Mallotus Villosus ◽  
Tidal Dynamics ◽  
Lawrence Estuary ◽  
Fin Whale ◽  
Capelin Mallotus Villosus ◽  
Tidally Driven

Capelin (Mallotus villosus) tridimensional distribution at the head of the Laurentian Channel in the St. Lawrence estuary was investigated using 38- and 120-kHz acoustic surveys in the summers of 1994, 1995, 1997, and 1998. The results are interpreted with the help of a high-resolution tridimensional tidal circulation model. Total biomasses were small (93–4583 t) and showed rapid fluctuations, whereas mesoscale distribution was more constant. Capelin tended to occupy the very end of the channel head, especially the slopes and shallows surrounding the basins. This pattern did not coincide with the krill distribution, but the two total biomass series were significantly correlated. Capelin tidal dynamics is characterized by herding of capelin against the channel head slopes by the starting flooding currents, followed by an upwelling over the sills and shallows during maximum flood currents, and a return to the channel by the surface outflow during ebb. Each side of the channel head has a distinct capelin retention tidal cycle involving passive advection, swimming, and the two-layer estuarine circulation. This capelin distribution and tidal dynamics closely match the local fin whale (Balaenoptera physalus) and minke whale (Balaenoptera acutorostrata) distributions observed from the whale-watching fleet and typical tidal feeding strategies at the channel head.

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