Nearshore abundance of zooplankton in relation to shoreline configuration and mechanisms involved

• Published in: Journal of plankton research 1998, Vol.20 (4), p.671-690
• Main Authors: Archambault, Philippe, Roff, John C., Bourget, Edwin, Bang, Bohuyn, Ingram, Grant R.
• Format: Article
• Language: English
• Subjects: Animal and plant ecology; Animal, plant and microbial ecology; Biological and medical sciences; Fundamental and applied biological sciences. Psychology; Marine; Sea water ecosystems; Synecology
• ISSN: 0142-7873; 1464-3774
• DOI: 10.1093/plankt/20.4.671

Zooplankton abundance was examined in relation to shoreline configuration. Four embayments (0.15, 1.5, 4 and 7 km opening) were each divided into three zones, corresponding to regions inside, outside and downstream. A portion of straight coast [˜12 km, Sainte-Flavie (SF)] was also divided into three zones. Only the largest embayment was sampled in 1993, but all embayments and SF were sampled in 1994. In 1993, zooplankton abundance was significantly higher within the embayinent than in external zones for six of seven dates. Zones inside the four embayments had generally higher zooplankton abundance than zones external to the embayments in 1994, but the opposite was observed during the first of two sampling dates for the largest embayments. No definite pattern was observed among zones along SF. Four hypotheses could explain the higher abundance of zooplankton inside embayments. Three were tested using meroplankton (M)/holoplankton (H) ratios. The M/H ratios confirmed hypotheses of retention and local production of meroplanktonic larvae inside embayments. Zooplankton abundance was lower inside than in zones external to embay ments only twice, and wind direction may have been responsible for these results. No embayment size effect on zooplankton abundance was detected. The patchy distribution of zooplankton may increase the difficulty of observing an effect of embayment size on zooplankton abundance.