E-Locus - Institutional Repository of the University of Crete

Home Search

Results - Details

Search command : Author="Καρακάσης" And Author="Ιωάννης"

Current Record: 9 of 53

[Add to Basket]

Identifier

000449279

Title

Βενθικές κοινότητες σκληρού υποστρώματος σε επιλεγμένα λιμάνια και μαρίνες της Ελλάδας με έμφαση στην καταγραφή αλλόχθονων ειδών

Alternative Title

Benthic communities of hard substrates in selected ports and marinas of Greece focusing on non-indigenous species

Author

Ράλλης, Ιωάννης Ν.

Thesis advisor

Αρβανιτίδης, Χρήστος
Χατζηγεωργίου, Γιώργος

Reviewer

Κασαπίδης, Παναγιώτης
Καρακάσης, Ιωάννης

Abstract

The Greek Seas are characterized by increased maritime traffic. Ship hulls and ballast waters are important means of transport for non-indigenous species (NIS). Ports and marinas receive a multitude of anthropogenic impacts, including biological invasions via transport-stowaway. Therefore, these areas can function as stepping stones for the dispersal of NIS in nearby natural habitats. Nevertheless, to date there is no systematic monitoring in Greek ports regarding benthic species. The objective of this Master’s thesis is to describe the biodiversity patterns in artificial hard substrates and to record NIS found in seven ports and marinas across the southern Greek Seas. Thus, a rapid assessment survey was applied using non-destructive sampling (photoquadrats) and complementary qualitative samples. The artificial hard substrate at a shallow depth was examined in three sampling events during years 2020 and 2021. In total, 95 photoquadrats were analyzed resulting in significant differences in the community structure of the ports and marinas. among the native invertebrates, the bryozoan Schizoporella errata and the sponges complex Spirastrella cunctatrix / Crambe crambe were constantly present. Additionally, visual surveys provided new data regarding the presence of NIS. In total, 16 NIS were identified with some being characterized as invasive (e.g., Stypopodium schimperi, Pinctada radiata, Synaptula reciprocans). The most widely distributed were the bryozoan Amathia verticillata and the ascidian Herdmania momus with presence in five of the seven sites. Differences in biodiversity patterns indicate the unique profile of each study area. The presence of NIS in ports and marinas should be monitored at a regular basis in order to develop early warning systems to prevent their dispersion during early stages of succession. Visual census can be an effective tool for this purpose.

Language

Greek

Subject

Alien

Photoquadrats

Port

Αλλόχθοναα είδη

Λιμάνι

Ξενικά

Σκληρό υπόστρωμα

Φωτογραφικά πλαίσια

Issue date