@article{PAR00000586,
  title = {{C}haracterising and comparing the spawning habitats of anchovy {E}ngraulis encrasicolus and sardine {S}ardinops sagax in the southern {B}enguela upwelling ecosystem},
  author = {{T}watwa, {N}. {M}. and van der {L}ingen, {C}. {D}. and {D}rapeau, {L}. and {M}oloney, {C}. {L}. and {F}ield, {J}. {G}.},
  editor = {},
  language = {{ENG}},
  abstract = {{T}he spawning habitats of anchovy {E}ngraulis encrasicolus and sardine {S}ardinops sagax in the southern {B}enguela upwelling ecosystem were characterised by comparing their egg abundances with environmental variables measured concomitantly during two different survey programmes: the {S}outh {A}frican {S}ardine and {A}nchovy {R}ecruitment {P}rogramme ({SARP}), which comprised monthly surveys conducted during the austral summers of 1993/94 and 1994/95; and annual pelagic spawner biomass surveys conducted in early summer ({N}ovember/{D}ecember) from 1984 to 1999. {E}ggs were collected using a {C}al{VET} net. {P}hysical variables measured included sea surface temperature ({SST}), surface salinity, water depth, mixed-layer depth, and current and wind speeds; biological variables measured included phytoplankton biomass, and zooplankton biomass and production. {S}pawning habitat was identified by construction of quotient curves derived from egg abundance data and individual environmental variables, and relationships between these variables were determined using multivariate co-inertia analysis. {SARP} data showed that anchovy spawning was associated with cool water and moderate wind and current speeds, whereas sardine spawning was related to warmer water and more turbulent and unstable conditions (i.e. high wind speeds and strong currents) than for anchovy. {SARP} data also showed significant differences in selection of spawning habitat of the two species for all environmental variables. {T}he relationship between anchovy egg abundance and salinity was strongly positive, but strongly negative with water depth, phytoplankton biomass and zooplankton production. {S}ardine egg abundance was strongly positively related to current speed. {T}he spawner biomass survey data demonstrated that the spawning habitat of anchovy was characterised by warm water and high salinity, whereas sardine spawning was associated with cool water and low salinity. {T}he survey data showed significant differences in spawning habitat selection by anchovy and sardine for {SST}, salinity and zooplankton biomass, but not for the other environmental variables. {T}here was a positive relationship between anchovy egg abundance and {SST}, salinity and mixed-layer depth, and a negative relationship with water depth, phytoplankton biomass and zooplankton production. {F}or sardine there was a strong positive relationship between egg abundance and current speed and wind speed. {D}ifferences in the results between the two survey programmes could be attributable to differences in their spatio-temporal coverage. {S}pawning habitats of anchovy and sardine appear to be substantially different, with anchovy being more specific than sardine in their preference of various environmental conditions.},
  keywords = {anchovy ; sardine ; southern {B}enguela ; spawning ; upwelling},
  booktitle = {},
  journal = {{A}frican {J}ournal of {M}arine {S}cience},
  volume = {27},
  numero = {2},
  pages = {487--499},
  ISSN = {1814-232{X}},
  year = {2005},
  URL = {https://www.documentation.ird.fr/hor/{PAR}00000586},
}