142 research outputs found
Insights on Mediterranean fin whales feeding ecology through stable isotope analysis from skin biopsies.
No full textApproccio demografico allo studio della popolazione mediterranea di Balenottera comune (Balaenoptera physalus L 1758)
No full textIl lavoro di ricerca di questa tesi ha come scopo l’analisi demografica e l’applicazione di modelli adeguati alla popolazione mediterranea di balenottera comune. Il modello demografico si baserà, in particolare, sui dati raccolti dall’Istituto Tethys dal 1990 al 2007 nel Santuario Pelagos ed esaminati tramite foto-identificazione. Nel corso di questi 18 anni sono stati foto-identificati 431 individui diversi che rappresentano poco meno della metà degli individui stimati nel 1992 per la popolazione di balenottera comune del Santuario dei cetacei (circa 900 individui; Forcada et al., 1995). I dati del campione, stratificati per classi di taglia e di età, vengono utilizzati, insieme agli studi di Aguilar e Lockyer (1987) sulla popolazione atlantico-spagnola, alla letteratura riguardante le collisioni (Panigada et al., 2006) e gli spiaggiamenti (database CIBRA e database europei), al fine di ricostruire la life-table della popolazione. Su queste basi sarà possibile procedere alla messa a punto di una prima modellizzazione della popolazione mediterranea.
Questa tesi rappresenta l’inizio di un progetto di collaborazione a lungo termine tra il gruppo di lavoro di Zoologia del Dipartimento di Biologia, il settore di Demografia del Dipartimento di Economia dell’Università di Pisa e l’Istituto Tethys, volto allo studio demografico dei cetacei mediterranei
Demography and conservation of the Mediterranean fin whales (balenoptera physalus): what clues can be obtained from photoidentification data
No full textLong-lived and slow reproducing species, such as cetaceans, are among the most critical conservation units: a demographic approach can be very useful for their management and conservation. In the present work, we examined, by demographic tools, the most exhaustive photo-identifiation database available for the Mediterranean fi whale (Balaenoptera physalus) population, recorded by Tethys Research Institute between 1990 and 2007 in theWestern Ligurian Sea. A total of 31,782 km were covered and 548 fi whale sightings were recorded. The occurrence of the target species was uneven across the years and months: an anomalous reduction of sightings occurred between 2001 and 2004. Moreover, the target species is likely to
concentrate in the study area in the summer months and probably moves to other areas in the early autumn. Using the photo-identifiation technique, 431 diffrent individuals were photoidentifid, but only 318 of them were sized: 6 calves (≤10 meters), 33 immature (10-15 m), 261 adolescent-adult (>15 m) and 18 olds (≥20 m). For the fist time the size of the fi whale subpopulation in the Pelagos Sanctuary was obtained by photo-identifiation and mark-recapture techniques. These techniques were used to estimate the size of the sub-population composed by individuals >15 meters as 539 fi whales (95% confience interval = 345-732) over the period 1990-1999. The number of calves was likely underestimated, as the sighting period (late
spring-summer) was shifted with respect to the peak of births (late autumn). To fil this gap of knowledge we propose a simple mathematical model for the yearly dynamics of calves. After correcting the number of calves, a static life history table for the period 1990-2007 was set out. Our results highlight the highest survival proportions between calf and immature (61.1%) and the minimum between adolescent-adult and old (2.5%) vital stages. The overall life expectancy is estimated to be 6.3 years while the life expectancy of individuals entering the adolescent-adult stage is 14.3 years. This paper aims at providing a contribution for improving the conservation effrts and the demographic knowledge on fi whales in the Pelagos Sanctuary
Aerial survey abundance estimates of the loggerhead sea turtle Caretta caretta in the Pelagos Sanctuary, northwestern Mediterranean Sea
No full textAerial line transect surveys, totalling 16 590 km, were performed in winter and summer 2009 in the Pelagos Sanctuary, NW Mediterranean. A total of 207 loggerhead sea turtles were sighted, with only 9 sightings during the winter. In this season average raw 'surface' density (i.e. animals at or near the surface) was 0.002 turtles km -2, and on the basis of line-transect analysis, we estimated 237 specimens (CV = 34.33%; 95% CI = 122-461). The summer estimate resulted in 4083 animals at surface (CV = 14.59%; 95% CI = 3061-5466) in the study area, with a density of 0.046 km -2. Results indicated strong seasonal differences and lower densities than those found in comparable surveys in Spanish Mediterranean waters. Nevertheless, the ecological and oceanographic features of the Pelagos Sanctuary, established primarily for the protection of marine mammals, render it an important area also for Mediterranean loggerhead sea turtles. The potential for human-induced mortalities of turtles summering in the Pelagos Sanctuary is high. In this context, it is vital to obtain reliable estimates of absolute and relative abundance over time, monitor the status of loggerhead sea turtles and inform the development of effective conservation actions. This study illustrates the ability of aerial surveys to provide such data in this area. © Inter-Research 2011
An index based on the biodiversity of cetacean species to assess the environmental status of marine ecosystems
No full textThe Marine Strategy Framework Directive (MSFD) requires the assessment of the environmental status in relation to human pressures. In this study the biodiversity of the cetacean community is proposed as MSFD descriptor of the environmental status and its link with anthropogenic pressures is investigated. Functional groups are generally favoured over indicator species since they are thought to better reflect to anthropogenic stressors. Cetaceans are in many situations the most well known component of pelagic ecosystems. Their habitat requirements are known and can be used to evaluate the theoretical biodiversity that should be expected in a certain area. The deviations between the theoretical biodiversity and the actual biodiversity may be used to detect the impacts of human activities. Based on this analysis fishery resulted to be by far the most significant of the existing pressures. Among all the species, bottlenose dolphin was found the most correlated with the fishery sector dynamics
Fin whales (Balaenoptera physalus) as wide-scale sentinel of exposure to microplastic in marine environment: the case study of Mediterranean Sea and Sea of Cortez.
No full textPreliminary ecotoxicological data on C type killer whale (Orcinus orca) from Terra Nova Bay (Antarctica): Molecular biomarkers and persistent organic contaminants
No full textAmong killer whale forms, the type C is a fish eating form and the most common in the Ross Sea.
In the austral summer 2015 a study to evaluate the toxicological hazard C type killer whale faces in
the Antarctic ecosystem was conducted in Terra Nova Bay. Seven biopsy samples were collected
from adult specimens (5 males and 2 females) in the surroundings of the Italian research station
Mario Zucchelli by means of remote dart sampling from the pack ice.The accumulation levels of
persistent organic pollutants (POPs), including legacy (DDTs, PCBs, HCB) and emerging POPs
(PBDEs) were measured. Moreover, the protein expression of cythocrome P450 (CYP1A and 2B)
and the mRNA level variations of the peroxisome proliferator-activated receptors α and γ (PPARαγ) and the Estrogen Receptor α (ERα) were evaluated. PPARs are ligand-dependent nuclear
receptors involved in lipid homeostasis, inflammation and adipogenesis, and ERα is involved in the
estrogen pathways and induced by estrogen-like exogenous compounds such as OCs and PBDEs.
PCBs (twenty-one ortho PCB congeners), DDTs, HCB and PBDEs (fourteen congeners from tri- to
deca-substituted) were analyzed on freeze-dried blubber biopsy samples by GC-qMS. The protein
expression was evaluated by Western Blot and the mRNA levels were quantified by quantitative
Real-Time PCR. The average abundance pattern for the contaminants was
DDTs>PCBs>HCB>PBDEs. Contaminant levels resulted to be lower when compared to existing
data from Antarctic type C killer whales from Ross Sea (McMurdo Sound) and those reported for
the fish-eating resident or offshore killer whales, or feeding at higher trophic levels. Both protein
and gene expression biomarker responses were correlated to contaminant levels to evaluate the
biological responses to POPs. A comprehensive assessment of the ecotoxicological status of Ross
Sea killer whale will be undertaken by considering the satellite tracking and feeding ecology data
gained on the same samples
Do fin whales (Balaenoptera physalus) feed in microplastic impacted areas in the Pelagos Sanctuary
No full text
Proposal of early retreatment with iloprost in partially responsive patients with bone marrow edema syndrome: a case report
No full textBackground Avascular Necrosis (AVN) is defined as the cellular death of bone components due to an alteration of the blood supply, resulting in Edema of the Bone Marrow (BME), structural collapse and bone destruction. In advanced stages, AVN requires surgery. One emerging medical treatment for supporting osseous perfusion is the administration of iloprost.Materials and methods A 38-year-old woman presented with severe BME of the left hip (primary), persisting for 6 weeks. She was treated with iloprost iv at 2 ng/kg/min for 6 hours/day for 5 days, and after 4 weeks, the treatment was repeated at 1.5 ng/kg/min for 6 hours for 5 days because she exhibited only a partial response to the first treatment. Complete remission was obtained, documented clinically and on Magnetic Resonance Imaging (MRI). Her Harris Hip Score (HHS) increased from 29.90 to 97. No significant adverse events related to iloprost were registered. No surgical procedures were necessary.Conclusions In most cases, iloprost is administered in a single cycle of treatment over 5 days at 1-2 ng/kg/min for 6 hours/day, but no research has investigated the effectiveness of early retreatment after the first cycle results in only a partially response. Only a few studies examining small numbers of patients have evaluated iloprost in AVN/BME, preferring, in most cases, the dose of 1 ng/kg/min and obtaining clinical improvement both in BME and in AVN in times comparable to surgical core decompression. This case report demonstrates the safety and effectiveness of early repetition of the maximal dose of iloprost before BME evolves into AVN, as well as in cases initially appearing serious and requiring surgical procedures.</p
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