An analysis of temporal variability in abundance, diversity and growth rates within the coastal ichthyoplankton assemblage of South Georgia (sub-Antarctic)

Belchier, Mark; Lawson, Jennifer. 2013 An analysis of temporal variability in abundance, diversity and growth rates within the coastal ichthyoplankton assemblage of South Georgia (sub-Antarctic). Polar Biology, 36 (7). 969-983. 10.1007/s00300-013-1321-9

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Abstract/Summary

The study of spatial and temporal distribution and diversity of ichthyoplankton (fish eggs and larvae) can provide fisheries-independent information on the population dynamics and recruitment processes of marine fish species. Ichthyoplankton studies in the Southern Ocean have to date been largely constrained to the summer months. We analysed ichthyoplankton data collected from a year round, long term (2002–2008), plankton trawl sampling programme in a large fjord system (Cumberland Bay) at South Georgia, sub-Antarctic (54.25°S, 36.5°W) to assess temporal changes in larval fish diversity and abundance. Larvae of 22 species, representing nine families, were identified although three, Krefftichthys anderssoni (Myctophidae), Lepidonotothen nudifrons/Trematomus hansoni (Nototheniidae) and Champsocephalus gunnari (Channichthyidae), dominated abundance in all years. Significant seasonal and interannual differences in the larval fish assemblage were revealed by multivariate analyses. Estimates of larval growth are provided for five abundant species. Considerable inter-specific differences in relative larval growth rate were recorded but interannual variability within species was small. However, in the commercially important C. gunnari, multiple larval cohorts, representing a protracted spawning season, were observed to grow at different rates, and this may be related to temperature and/or food availability. A comparison with historical growth data from South Georgia suggests there has been little change in growth rate for the main species over the last three decades.

Item Type:	Publication - Article
Digital Object Identifier (DOI):	10.1007/s00300-013-1321-9
Programmes:	BAS Programmes > Polar Science for Planet Earth (2009 - ) > Ecosystems
ISSN:	0722-4060
Additional Keywords:	fish eggs, larvae, Ichthyoplankton, Sub-Antarctic, Notothenioidei, South Georgia, Larval growth, Fisheries
Date made live:	28 Aug 2013 13:06 +0 (UTC)
URI:	https://nora.nerc.ac.uk/id/eprint/503068

Item Type:

Publication - Article

Digital Object Identifier (DOI):

10.1007/s00300-013-1321-9

Programmes:

BAS Programmes > Polar Science for Planet Earth (2009 - ) > Ecosystems

ISSN:

0722-4060

Additional Keywords:

fish eggs, larvae, Ichthyoplankton, Sub-Antarctic, Notothenioidei, South Georgia, Larval growth, Fisheries

Date made live:

28 Aug 2013 13:06 +0 (UTC)