Seasonal variations in abundance, development and vertical distribution of Calanus finmarchicus, C. hyperboreus andC. glacialis in the East Icelandic Current

Astthorsson, Olafur S.; Gíslason, Ástþór

doi:10.1093/plankt/25.7.843

Cited by 51 publications

(30 citation statements)

References 31 publications

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“…This may indicate that spawning of C. finmarchicus occurred later in the offshore areas south and west of Iceland compared with the other areas. This compares well with earlier findings, namely that the spring spawning is delayed with increasing distance from shore off the south and west coasts (Gislason & Astthorsson 1996;Gislason 2003), while this is not as evident in the subarctic waters off the north and northeast coasts (Gislason & Astthorsson 1998;Astthorsson & Gislason 2003).…”

Section: Discussionsupporting

confidence: 91%

Distribution patterns of zooplankton communities around Iceland in spring

Gíslason

Astthorsson

2004

Sarsia

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Gislason A, Astthorsson OS. 2004. Distribution patterns of zooplankton communities around Iceland in spring. Sarsia 89:467-477. SARSIAThis paper presents an analysis of zooplankton composition and abundance based on sampling over the depth range 0-50 m at nine transects (61 stations) during a hydrobiological survey of Icelandic waters in May-June 1992. Zooplankton abundance and species distribution is considered in relation to water masses and topography. The biomass of zooplankton was highest in the oceanic areas northeast of Iceland [$8-20 g dry weight (dw) m À2 ], whereas the lowest values were generally observed in the offshore areas southeast, south and southwest of Iceland (< 2 g dw m À2 ). Over the shelves, the values tended to be intermediate ($2-5 g dw m À2 ). In total, 93 species and identification groups were identified in the samples. Calanus finmarchicus was by far the most abundant species [about half of the total numbers of zooplankton if Calanus spp. nauplii ($20%) are included]. Less numerous groups were Oithona spp., cirripede larvae, euphausiid larvae (nauplii, calyptopis and furcilia stages), larvaceans, Pseudocalanus spp., C. hyperboreus, Acartia spp., and Temora longicornis. A cluster analysis was carried out in order to reveal relationships among stations in zooplankton abundance and species composition. The analysis classified stations into four groups, mainly defined by bathymetry and hydrographic conditions. In the coastal water south and west of Iceland, cirripede larvae were by far the most abundant group, followed by C. finmarchicus and euphausiid larvae (group A), while in the coastal water north of the country, C. finmarchicus, euphausiid larvae and larvaceans were most abundant (group B). In the offshore waters south of the island, C. finmarchicus, Oithona spp. and echinoderm larvae were most abundant (group C), whereas in the offshore area north of Iceland C. finmarchicus, Oithona spp. and C. hyperboreus were most abundant (group D).

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Section: Discussionsupporting

confidence: 91%

Distribution patterns of zooplankton communities around Iceland in spring

Gíslason

Astthorsson

2004

Sarsia

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“…The southern populations of C. glacialis and C. hyperboreus have probably been isolated from their main arctic populations for a very long time, which would facilitate evolutionary adaptations to their contrasting environments. Calanus finmarchicus and P. norvegica have more widespread distribution (Longhurst 2007), with populations in arctic waters more likely being influenced by gene flow from Atlantic waters (Astthorsson and Gislason 2003;Parent et al 2011), which might tend to counteract evolutionary adaptation to cold water. Consistent with this line of reasoning, the arctic and southern populations of the two latter species differed less in body size, possibly more influenced by phenotypic plasticity.…”

Section: Discussionmentioning

confidence: 99%

Inter‐ and intraspecific variation in body‐ and genome size in calanoid copepods from temperate and arctic waters

Leinaas

Jalal

Gabrielsen³

et al. 2016

Ecology and Evolution

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SummaryThe tendency of ectotherms to get larger in the cold (Bergmann clines) has potentially great implications for individual performance and food web dynamics. The mechanistic drivers of this trend are not well understood, however. One fundamental question is to which extent variation in body size is attributed to variation in cell size, which again is related to genome size. In this study, we analyzed body and genome size in four species of marine calanoid copepods, Calanus finmarchicus, C. glacialis, C. hyperboreus and Paraeuchaeta norvegica, with populations from both south Norwegian fjords and the High Arctic. The Calanus species showed typical interspecific Bergmann clines, and we assessed whether they also displayed similar intraspecific variations—and if correlation between genome size and body size differed between species. There were considerable inter‐ as well as intraspecific variations in body size and genome size, with the northernmost populations having the largest values of both variables within each species. Positive intraspecific relationships suggest a functional link between body and genome size, although its adaptiveness has not been settled. Impact of additional drivers like phylogeny or specific adaptations, however, was suggested by striking divergences in body size – genome size ratios among species. Thus, C. glacialis and C. hyperboreus, had fairly similar genome size despite very different body size, while P. norvegica, of similar body size as C. hyperboreus, had the largest genome sizes ever recorded from copepods. The inter‐ and intraspecific latitudinal body size clines suggest that climate change may have major impact on body size composition of keystone species in marine planktonic food webs.

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“…These genera form a central node in the structure and function of Arctic epipelagic ecosystems during spring and summer and have accordingly been the focus of most studies of Arctic zooplankton population dynamics. Most of these studies have focused primarily on processes governing population growth such as feeding (Båmstedt et al 1991, Turner et al 2001, egg production (Hirche 1989, Hirche et al 1997, Niehoff et al 2002, egg hatching or larval stage development (Astthorsson & Gislason 2003). All of these processes are equally important determinants of development of any population; however, the size of populations is determined not only by processes leading to increases, but also by mortality.…”

Section: Introductionmentioning

confidence: 99%

Mortality rates of epipelagic copepods in the post-spring bloom period in Disko Bay, western Greenland

Thor¹,

Nielsen²,

Tiselius³

2008

Mar. Ecol. Prog. Ser.

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Mortality rates of the copepods Calanus hyperboreus, C. glacialis, C. finmarchicus, Pseudocalanus sp. and Oithona similis were investigated during June 2001 in Disko Bay, western Greenland. These 5 species dominated the zooplankton community in the upper 75 m, contributing 89% of the total copepod biomass. Instantaneous mortality rates of copepodites of all 5 species and nauplii of Pseudocalanus sp. and O. similis were calculated using vertical life tables on abundances and published information on stage duration times. Compared with those covering a range of boreal habitats, the mortality rates were higher, with highest rates occurring in C. finmarchicus and C. glacialis copepodite stages I to III and Pseudocalanus spp. stage III (maximum = 0.18 d -1 ). Mortality rates remained lower in all stages of O. similis. When superimposing mortality rates for all species and stages on copepod size a significant peak at 1.3 mm prosome length was evident. This peak fitted a prey size dependent functional response of predation and the high mortality rates were, therefore, most probably attributable to size-specific predation.

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Seasonal variations in abundance, development and vertical distribution of Calanus finmarchicus, C. hyperboreus andC. glacialis in the East Icelandic Current

Cited by 51 publications

References 31 publications

Distribution patterns of zooplankton communities around Iceland in spring

Distribution patterns of zooplankton communities around Iceland in spring

Inter‐ and intraspecific variation in body‐ and genome size in calanoid copepods from temperate and arctic waters

Mortality rates of epipelagic copepods in the post-spring bloom period in Disko Bay, western Greenland

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