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Biodiversity in marine zones with different protection levels
in the marine protected area of the Egadi Islands (South Italy)

A. M. Beltrano, S. Vitale, L. Cannizzaro, G. Bono, A. Milazzo

Istituto di ricerche sulle Risorse Marine e l'Ambiente (IRMA) - Consiglio Nazionale delle Ricerche (CNR), sez. (IAMC)
Via L. Vaccara, 61- Mazara del Vallo (TP), Italia
e-mail:annamariabeltrano@hotmail.com

Introduction
The institution of MPA provides mainly the protection and conservation of the environment and a sustainable use of resources. In the framework of the
researches realised in the Marine Protected Area of the Egadi Islands a study on the coastal community was conducted in order to value the biodiversity in
zones characterised from different levels of protection and to determine the conservation state of the resources.

Material and methods
The study area was the Marine Protected Area of the Egadi Islands, localized in the Southern Italian coast,
characterised from 4 zones with different levels of protection (A,B,C,D). Experimental fishing surveys (37) were
carried out during 3 seasons, from autumn 2002 to spring 2003, by trammel net, along the coast of the Favignana
and Marettimo Islands.

The survey was carried out considering the zones with total protection (A) and
with reduced protection (B and C). The zone D was not considered as it was
very deep for fishing by trammel net. All specimens caught were identified to
species and a sub-sample was collected for further investigations. The
abundance per each species was calculated (N=number of specimens per m2 of
net).

The most common biodiversity indices were used: richness (S), Shannon-Weaver’s index (H), Simpson’s index (D) and
the evenness (J). The χ2 test of Pearson, applied to the richness, were used to test the differences among the zones
A, B, C.

Results
46 species were recorded. In all, 40 species were found in Marettimo, 32 in Favignana, among Osteychthyes, Mollusca
Cefalopoda, Condroicthyes, Crustacea.
The richness values, analysed in the different seasons, presented values ranging between 17 and 19 in Favignana. While, in
Marettimo the richness values ranged between 18 e 29. Particularly, the richness resulted highest in the winter season
(S=29).

Moreover the comparison among the different zones showed that the highest value of richness was in the zone A (S=27) in Marettimo. In the zone B and C,

the richness presented higher values in Favignana (SA, B=13) than Marettimo (SB=9; SC=11).
The χ2 test, applied to the richness values, showed significant differences among the zones A, B, and C (χ22 = 12,43 p<0,001).
The values of S, H’, D, N and J calculated for all seasons considered and in the zones (A, B, C) have been indicated in table 1 and 2 respectively.

In Favignana, in the all seasons Scorpaena porcus Islands Szone A Szone B Szone C H’zone A H’zone B H’zone C Dzone A Dzone B Dzone C Nzone A Nzone B Nzone C JA JB JC

(DA=0,152; DW=0,159; DS=0,034) was the dominant Favignana - 13 13 - 2,20 2,22 - 0,15 0,14 - 0,015 0,016 - 0,86 0,87
species, representing about 37% of the catches; Marettimo 27 9 11 2,01 1,79 2,15 0,28 0,24 0,13 0,147 0,010 0,025 0,61 0,81 0,90
The dominant species were both in autumn and in winter
Tab. 1 - Richness (S), Shannon-Weaver diversity index (H’), Dominance index (D) and Abundance (N=number of
were: Symphodus sp. (DA=0,039; DW =0,012;), Diplodus specimens per m2 of net), recorded for each season at Favignana, Marettimo and Levanzo Islands.
annularis (DA=0,010; DW=0,006), Diplodus vulgaris (DA=
Islands Sautum Swinther Sspring H’autum H’winther H’spring Dautum Dwinther Dspring Nautum Nwinther Nspring Jautum Jwinther Jspring
0,005; DW=0,006).
Favignana 18 17 19 1,99 2,20 2,50 0,21 0,19 0,11 0,084 0,044 0,030 0,69 0,78 0,85
In spring, the dominant species were: Scorpaena scrofa Marettimo 22 29 18 2,45 2,09 2,45 0,15 0,26 0,11 0,065 0,157 0,044 0,79 0,62 0,85
(DS =0,033), Scorpaena notata (DS =0,016), Pagellus
acarne (DS =0,0148). Tab. 2 - Richness (S), Shannon-Weaver diversity index (H’), Dominance index (D) and Abundance (N=number of
specimens per m2 of net), recorded in the zone with different protection levels (A,B,C).
In Marettimo, autumn was dominated by: Pagellus acarne
(DA=0,0116), present with the 35% of the catches, Boops In all seasons, the Shannon-Weaver diversity index (H’), ranged between 1,99 and 2,50.
boops (DA=0,008), Scorpaena scrofa (DA=0,005). Particularly, in Favignana H’ value was high in spring, whereas in Marettimo it was high in
In winter, dominant species were: Boops boops autumn and spring. The H’ value resulted lowest in zone B in Marettimo.
(DW=0,243), Euthynnus alletteratus (DW= 0,007) that
represented the 48% of the catches and Labrus merula The evenness resulted similar in every seasons, ranging from
0,62 to 0,90. The high values of J indicated a good
(DW=0,005). distribution of the specimens among species.
The abundance showed highest values in winter season, in
In spring, Symphodus tinca (DS=0,034), Scorpaena scrofa Marettimo. Similar values were recorded in the other seasons,
(DS=0,021), Scorpaena porcus (DS=0,021), Sepia in both Islands; moreover a high value of N was observed in
officinalis (DS= 0,012) and Palinurus elephas (DS=0,008) zone A and quite similar values in the other zones.

prevailed.

Conclusions

In conclusion, in Marettimo the richness and abundance were higher than in Favignana.
Particularly, we consider the following observations: - in Favignana there isn’t the zone with total
protection (A); - the highest value of S and N were recorded only in zone A. Therefore, these
preliminary results suggest that the total protection applied to the zone A allows an increase of the
biomass and contemporary the protection of the alieutic resources. It would be interesting to
monitor the effect of the protection for a long time.

This study was realised in the framework of the project "Caratterizzazione dell'ambiente
marino, della comunità ittica e dell'attività di pesca della Riserva Naturale Marina delle
Isole Egadi (Trapani) ai fini della realizzazione della zonazione e cartografia mediante
GIS" (AMPEGA), financed by IRMA-CNR and the Italian Ministry of Environment.