Composition and dynamics of the Black Sea benthopelagic plankton and its contribution to the near-shore plankton communities.

At a shallow (7 m) near-shore sampling site in the Black Sea we analyzed composition, abundance, and biomass of benthopelagic organisms and the contribution these animals make to the total plankton. The site was monitored across several years (1996-2001; 2006-2007) whilst for 1999-2000 the seasonal variations were analysed. A total of 321 samples from Golubaja Bay near Novorossiysk (44°34'31.04″ N, 37°58'45.11″ E) in 1996-2007 were taken with a Judey net. The benthopelagic fauna was represented by 69 taxa, a diversity comparable to similar shelf areas. The benthopelagic component played an important role in near-shore plankton communities in the Black Sea accounting for 50% of the total zooplankton biomass at night during all seasons. Abundance and biomass of the benthopelagic animals showed seasonal fluctuations, the highest biomass being recorded during winter (>75% of the total zooplankton biomass) and early spring due to large amphipods, whilst the highest abundances occur during late summer because of numerous young stages of various taxa. Amphipods, mysids, and decapods are the main contributors to the plankton biomass and abundances. Both night and daytime samples are strongly recommended for the adequate description of the near-shore plankton communities

Sampling site (Golubaja Bay).

<p>Red circle: sampling site 44°34′31.04″ N, 37°58′45.11″ E, depth 7 m. This figure is similar but not identical to the original image generated by Google, and is therefore for representative purposes only.</p

Seasonal variations of biomass of the total zooplankton (<i>black circles</i>) and of the benthopelagic component (<i>diamonds</i>).

<p>Seasonal variations of biomass of the total zooplankton (<i>black circles</i>) and of the benthopelagic component (<i>diamonds</i>).</p

Typical overnight dynamics of abundances (a–d) and biomass (e–h) of the major benthopelagic taxa: March 2–3, 2000 (a, e), July 24–25, 2000 (b, f), October 18–19,1999 (c, g); December 8–9, 1999 (d, h).

<p>Typical overnight dynamics of abundances (a–d) and biomass (e–h) of the major benthopelagic taxa: March 2–3, 2000 (a, e), July 24–25, 2000 (b, f), October 18–19,1999 (c, g); December 8–9, 1999 (d, h).</p

Average contribution (%) that major taxa made to the total biomass (a-d) and abundances (e–h) of the benthopelagic animals during various seasons of 1999–2000 in the Golubaja Bay: March 2–3, 2000 (a, e), July 24–25, 2000 (b, f), October 18–19, 1999 (c, g); December 8–9, 1999 (d, h).

<p>Colour legend as in Fig. 3.</p

Presence of the major taxa of the benthopelagic animals in the water column of the Golubaja Bay during the season 1999–2000.

<p><i>1</i>– surface temperature.</p

List of benthopelagic animals.

<p>Bold type: first record of diurnal vertical migrations.</p

Overnight dynamics of abundances (a–d, red line), biomass (e–h, pink line), and contribution to the total plankton biomass (e–h, blue line) of benthopelagic animals: March 2–3, 2000 (a, e), July 24–25, 2000 (b, f), October 18–19,1999 (c, g); December 8–9, 1999 (d, h).

<p>Overnight dynamics of abundances (a–d, red line), biomass (e–h, pink line), and contribution to the total plankton biomass (e–h, blue line) of benthopelagic animals: March 2–3, 2000 (a, e), July 24–25, 2000 (b, f), October 18–19,1999 (c, g); December 8–9, 1999 (d, h).</p

Day-and-night stations.

<p>Day-and-night stations.</p