Spatiotemporal and Environmental Dynamics of Abundances and Diversity of Larval Fish in Artificial Reef Edge Habitats of Kitros, Pieria (Northern Aegean Sea, Eastern Mediterranean)

Abstract

Spatiotemporal and physiochemical influences on the abundances and diversity of ichthyoplankton were assessed in the Thermaikos Gulf and edge habitats surrounding the Pieria (Northern Greece) artificial reef complex. The collection of data was performed in edge habitats in the marine protected area near the artificial reef offshore of Kitros. Sampling trips occurred in each season of the spring, summer, and autumn in each year from 2015–2017. This artificial reef complex lies at a distance offshore of 11.5 km from Kitros and the delta of River Aliakmonas. A bongo net sampler was used to sample ichthyoplankton over a network of 16 sampling stations. Seventy species of larval fish were identified. The greatest measures of ichthyoplankton diversity were found during warmer seasons. Non-metric multidimensional scaling showed that seasons play a significant role in species assemblages, as months during the spring, summer, and autumn from different years clustered together. Ten groups of larvae were identified to the family or genus level, such as Arnoglossus spp., Callionymus spp., Crenilabrus spp., Gobius spp., Liza spp., Scorpaena spp., Solea spp., and Spicara spp. Overall, the species with the greatest abundance was the larvae of the European anchovy (Engraulis encrasicolus). The second genera (in order of highest abundance) were Gobius spp. followed by relatively abundant (but lesser numbers of) larvae representing the families Callionymidae, Centracanthidae, and Bothidae. The largest total abundances were found in July 2015 and September 2016. The biodiversity index indicated that measures of diversity were greater in July 2015, which was the only sampling performed in the middle of the summer, and indicated higher diversity in autumn 2015. The aim of this study was to present the assemblages of fish larvae in the marine protected area surrounding the artificial reef of Kitros Pierias as the result of a 3-year sampling program (2015–2017). The novelty of this study is that it is the only study of Ichthyoplankton ever performed in Greece with seasonal repetitions and densely located stations around a coastal marine protected area.