Mesozooplankton abundances with Copepoda detailed derived from Boka Kotorska Bay in 2008

Zooplankton samples were obtained at seven designated stations in Boka Kotorska Bay (Adriatic Sea), on 25th of each month in 2008, using plankton nets with 150 μm and 200 μm mesh sizes (57 cm in diameter and 250 cm length). The Bay is divided into 4 embayments labelled K (Kotor), R (Risan), T (Tivat) and H (Herceg Novi). The maximum depth was 10 m at shallow stations of the inner embayments (K2, K3, R2) or 20–30 m at central stations of each embayment (K1, R1, T1, H1). The plankton samples for qualitative and quantitative analyses were gathered by single net vertical tows. Additionally, single net oblique-stepped horizontal tows were conducted to assess taxa diversity. The net was pulled horizontally at a 25° angle, with the rope being shortened in 10-minute intervals over a total duration of 30 minutes, maintaining the vessel speed of 2 NM/h. Zooplankton specimens were preserved in a buffered 2.5% formaldehyde-seawater solution. A thorough analysis was conducted on the samples obtained in horizontal tows to ascertain species occurrences. Taxonomic identification and counting of individuals were carried out using Zeiss stereo microscope at 25× and 40× magnifications and an Olympus inverted microscope at 100× and 400× magnifications for smaller species. Quantitative analysis of zooplankton was conducted by partial counting 1/25 of each catch. Adult copepods were classified by species, whereas juveniles and nauplii were recorded as undifferentiated groups due to taxonomic resolution. Quantities are expressed as the number of individuals per square metre (ind/m2). Taxonomic identification was performed according to Rose (1933) and Trégouboff & Rose (1957), and scientific names were validated using the World Register of Marine Species (WoRMS).