Mesozooplankton as a possible quality indicator of marine water

Postgraduate Thesis uoadl:2631598 634 Read counter

Unit:
Κατεύθυνση Βιολογική Ωκεανογραφία
Library of the School of Science
Deposit date:
2018-01-24
Year:
2018
Author:
Theodorou Iason
Supervisors info:
Δρ. Τσιρτσής Γεώργιος, Καθηγητής, Τμήμα Επιστημών Θάλασσας, Πανεπιστήμιο Αιγαίου
Δρ. Ζερβουδάκη Σουλτάνα, Ερευνήτρια Β΄ ΕΛΚΕΘΕ
Δρ. Βερροιόπουλος Γεώργιος, Καθηγητής, Τμήμα Βιολογίας, ΕΚΠΑ
Original Title:
Το μεσοζωοπλαγκτόν ως πιθανός δείκτης ποιότητας θαλάσσιων υδάτων
Languages:
Greek
Translated title:
Mesozooplankton as a possible quality indicator of marine water
Summary:
Introduction/Aim: The MSFD aims to achieve good environmental status (GES-MSFD) in marine waters by 2020. To help achieve GES-MSFD, eleven descriptors of the state of the environment have been defined. Zooplankton can be used as an Indicator of water quality assessment in Descriptors 1 and 4. Zooplankton is considered to have great potential as an "observer" of "environmental changes and pressures" (Beaugrand et al., 2010). In spite of the several published works of Mediterranean zooplankton time series, only one of them attempts to develop a zooplankton based indicator, until now (Serranito et al. 2016). This is were this particular study comes in. The main target of this work was to examine whether the changes in the composition of the mesozooplankton biological communities can be an indicator of environmental quality in coastal waters of the Aegean. Several side goals were set in this direction concerning the ability of spotting the difference between two well studied “control” samples of bad and good environmental status, the time differentiation for each station, the spatial differentiation for each time period, as well as the production of a method capable of evaluating the state of new samplings of the study area.
Methods: The study concerns stations S2 (24 samplings) of Elefsina gulf, S7 (31 samplings) and S11 (84 samplings) of Saronikos gulf, at years 1987-2010. Each sampling corresponds to a vertical trapping of a zooplankton with a "mesh" aperture of 200 μm. A total of 139 mesozooplankton samplings, where 104 taxa (copepods and cladocera) have already been identified in previous studies. The study was conducted per station for the whole year and also for the hot (May-September) and the cold season (October-April) separately, for all three different periods (F0: 1987-1994, F1: 1995-2004, F2_3: 2004-2010), related to the different phases of Psyttalia’s Biological Cleaning Unit development. As a “control” sample of bad and good quality, F1 period (1998-2004) of S2 station and F2_3 period (2005-2009) of S11 station were chosen respectively. Biodiversity indexes (17 diversity, 7 species evenness and 2 dominance) (Karydis and Tsirtsis, 1996, Washington, 1984), the statistical processing (Shapiro's test, Bartlett's test, Anova, Kruskal Wallis, PCAs, LDAs) and the graphs were obtained using the “R” language. Initially, the existence of statistically significant differentiation was examined using Anova or Kruskal Wallis (differentiation between good-bad quality “control” samples, time differentiation analysis for each station and spatial differentiation for each period). Greater importance was given to the results of ANOVA concerning the whole year. Based on the above, PCAs were produced to show how the various indexes selected were grouped together. Finally, LDAs were developed to distinguish between groups of different quality and evaluate new samplings.
Results: From the biodiversity indexes -whose variation were in cases statistically significant- 20 "positive" indicators of diversity and species evenness (Margalef, Gleason, Menhinic, Shannon, HillN0, HillN1, HillN2, Chao2, Odum, Pie, M, Tu, Brillouin, Camargo Diversion , Camargo Evenness, Fisher's α, E1, E2, E3, E5) always increased in the direction of the good “control”. On the contrary, the 5 "negative" indexes of diversity evenness of species, as well as the dominance ones (Simpson, Kothe, Redundancy, Berger Parker, McNaughton) always showed elevated values in the direction of the bad “control”. An LDA was produced with 100% correct repositioning of the control samples in the two discrete groups, based on diversity indices showing statistical differentiation between the two "control" through Anova for the whole year. It was used to evaluate the remaining 111 samplings. Of these, 7 were placed in the “bad quality” group and 93 in the “good” one with posterior probabilities greater of 95%. Looking at spatial variation, a deviation of the S2 station is detected by the other two. Concerning the temporal differentiation of S7 (closest to Psittalia), Odum only shows a statistically acceptable result. The evenness indexes E1, Redundancy (all year) and E2, E3 (summer) are also marginally acceptable. They detect, to some extent, a gradual improvement from 1998 to 2009.
Main Conclusions: Mesozooplankton reflects the difference between two well-known samples with different water quality, through a range of biodiversity indexes at a statistically significant level (> 95%), and can therefore be used as a marker of marine water quality. Good environmental status (GES) is characterized by higher numbers of species with high level of evenness, high diversity and low dominance. The LDA that has been produced can be used for future water quality assessments of this area, based on the biodiversity of copepods and cladocera. This study aims to get one step further the effort of developing zooplankton indicators for monitoring and assessing marine waters’ quality, within the framework of the MSFD.
Main subject category:
Science
Keywords:
Ecology, Quality Assessment, Mesozooplankton, Aegean, Saronic Gulf, Elefsina Gulf, Biodiversity
Index:
Yes
Number of index pages:
1
Contains images:
Yes
Number of references:
162
Number of pages:
77
Theodorou I. MSc thesis.pdf (3 MB) Open in new window