Preprint volume - SIBM

Pre-print Volume - Posters
VARIOUS TOPICS
A. ARMANASCO, E. BOTTEON, D. SAVINI, S. NANNARELLI
Dipartimento di Ecologia del Territorio, Sez. di Ecologia, Università di Pavia, Via S. Epifanio, 14 – 27100 Pavia,
Italia.
elena.botteon01@ateneopv.it
FECAL PELLET ANALYSIS OF CARETTA CARETTA OUTPATIENTS
OF THE LINOSA ISLAND TURTLE RESCUE CENTER (SICILY, AG)
ANALISI DELLE FECI DI ESEMPLARI DI CARETTA CARETTA PAZIENTI
DEL CENTRO RECUPERO TARTARUGHE DELL’ISOLA DI LINOSA (SICILIA, AG)
Abstract – Preliminary data on Loggerhead sea turtle fecal pellets analysis conducted on hosts of the Sea
Turtle Recovery Center in Linosa Island (Agrigento Sicily) revealed strong impact of soft plastic floating
debris on diet. Fecal pellets can also be a good indicator of origin and movement of turtles in relation to
the habitat they have attended.
Key-words: fecal pellets, animal nutrition, rare species, marine debris.
Introduction – The Loggerhead sea turtle Caretta caretta is a protected species since
1973 (Endagered Species ACT- ESA). The Mediterranean Sea Turtle Recovery Center
of Linosa Island “Hydrosphera” (Agrigento, Sicily) has been conserving a collection of
dried fecal pellets from 60 turtles of 107 hosted in the center since 2006. Having the
opportunity of analyzing such an unusually large data set - i.e. published literature
reports similar analysis only for few specimens (Tomás et al., 2001; Frick et al., 2009)
- we report preliminary considerations on how fecal pellet can be used as reliable
indicator of diet, conservation status and habitat requirement for the species.
Materials and methods – A subsample of fecal pellet of 22 juvenile specimens of C.
caretta (Straight line carapace length: 27-63 cm), hosted in the Linosa’s Turtle
Recovery Center from 07.07.-25.08.2007, was analyzed under a dissecting microscope
(30×). Food and debris were classified in the following 11 categories (Fig.1): 1) fishes
(F); 2) molluscs (M); 3) crustaceans (C); 4) other undigested material of animal origin
(MA); 5) other undigested material of vegetal origin (MV); 6) hard plastic (HP); 7) soft
plastic (SP); 8) wood (W); 9) feathers (FE); 10) fishing lines and hooks (FL); 11) other
undigested material of anthropogenic origin (MAN). Each category was weighted
using an analytical scale (dwt; 0.001 g) and related to the total weight of the fecal
pellet. Moreover, plastic debris color was taken into consideration as a possible factor
determining ingestion preference.
Results – Soft plastic was the most frequent category of debris found in fecal pellets
(SP=91%) followed by undigested material of vegetal origin (MV=86%, mainly
Sargassum sp) and wood (W=45%). Amongst food, fish residue was the most recurrent
category (F=32%). Debris represented more than half of fecal pellets composition
(59±33% dwt/tot dwt*100). Transparent and white were the most frequently color of
plastic found in fecal pellet (25-30%). Most of the specimens (17 out of 22) were found
to have ingested Sargassum sp. algae.
41 st S.I.B.M. CONGRESS Rapallo (GE), 7-11 June 2010
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