Copepod biomass, size composition and production in the Southern Benguela: Spatio–temporal patterns of variation, and comparison with other eastern boundary upwelling systems

Coupled physical/biogeochemical modeling including O<sub>2</sub>-dependent processes in the Eastern Boundary Upwelling Systems: application in the Benguela

“…To convert the copepod abundance (number of individuals per m 2 : no m −2 ) from Kreiner and Ayon (2008) in biomass (mmol N m −2 ), we used a mean dry weight of individual animal of 40.75 µg for each individual. It corresponds to a mean dry mass for Calanoides carinatus (juvenile and adult stages) as estimated by Huggett et al (2009), a major copepod species in the Namibian system. The abundance was converted into terms of carbon by assuming that 40 % of the dry weight was carbon (Peterson et al, 1990).…”

Summer and winter differences in zooplankton biomass, distribution and size composition in the KwaZulu-Natal Bight, South Africa

“…Many of these as well as other studies indicate elevated zooplankton biomass associated with upwelling events or seasons, as well as changes in community structure in response to upwelling events (e.g. Pillar 1986;Verheye et al 1992;Huggett et al 2009). Depending on when these seasonal events occur, the biomass reacts accordingly, in response to nutrients concentrated in deep water that are brought up onto the shelf by various processes.…”

“…The maximum biomass recorded for the Northern Benguela by Kollmer (1963) was double that recorded in the KZN Bight. Mean copepod biomass in the southern Benguela during annual autumn and summer surveys over a 16-year time-series was similarly higher (Huggett et al 2009). There are very few data available on zooplankton biomass in other western boundary current systems.…”

Reviewing evidence of marine ecosystem change off South Africa

“…Zooplankton vary both spatially and temporally around the South African coastline, with inshore diversity being generally higher and biomass lower along the East Coast than the West Coast (Verheye et al 1994). Seasonal zooplankton maxima appear in spring/summer, related to indices of wind-driven upwelling (Richardson et al 2003, although winter copepod production also contributes significantly to annual production (Huggett et al 2009). A long-term increase in the abundance of zooplankton in St Helena Bay on the West Coast from 1951-1996 (Verheye et al 1998) was reflected in an increase in copepod biomass for the entire West Coast since the 1970s (Huggett et al 2009).…”

“…Seasonal zooplankton maxima appear in spring/summer, related to indices of wind-driven upwelling (Richardson et al 2003, although winter copepod production also contributes significantly to annual production (Huggett et al 2009). A long-term increase in the abundance of zooplankton in St Helena Bay on the West Coast from 1951-1996 (Verheye et al 1998) was reflected in an increase in copepod biomass for the entire West Coast since the 1970s (Huggett et al 2009). Since the mid-1990s, the long-term increasing trend in zooplankton abundance in St Helena Bay has reversed ( Figure 5), but this pattern is not uniform along the West Coast and western Agulhas Bank.…”