scholarly journals Cetacean mortality due to interactions with fisheries and marine litter ingestion in the Croatian part of the Adriatic Sea from 1990 to 2019

2021 ◽  
Vol 91 (2) ◽  
pp. 189-206
Author(s):  
Martina Đuras ◽  
◽  
Ana Galov ◽  
Kim Korpes ◽  
Magdalena Kolenc ◽  
...  
Keyword(s):  
Adriatic Sea ◽  
Bottlenose Dolphins ◽  
Surveillance Program ◽  
Cetacean Species ◽  
Term Survival ◽  
Stenella Coeruleoalba ◽  
Marine Litter ◽  
Surveillance Programs ◽  
Fisheries Interactions

Various anthropogenic threats negatively influence the survival of cetaceans in all world seas. Thanks to a long-running marine mammal surveillance program, we are able to report the results of a detailed analysis of the influence of cetacean-fisheries interactions and marine litter ingestion on cetacean mortality in the Croatian part of the Adriatic Sea over the last three decades. The total number of dead cetaceans was 459, and included 334 bottlenose dolphins (Tursiops truncatus), 40 striped dolphins (Stenella coeruleoalba), ten Risso’s dolphins (Grampus griseus), six Cuvier’s beaked whales (Ziphius cavirostris) and four fin whales (Balaenoptera physalus). Three hundred of them were examined postmortally. Cetacean-fisheries interaction occurred frequently in the Adriatic Sea, being detected in 96 (20.9%) of the recorded cases. Bycatch was the most abundant cetacean-fisheries interaction, with 66 (14.4%) cases recorded. Good nutritional condition and evidence of recent feeding were the most common findings recorded in bycatch cases, followed by persistent froth in the airways, edematous lungs, bruises and an amputated fluke or tail. Cetacean-fisheries interactions other than bycatch affected 30 animals and included larynx strangulations, long-term tail entanglement and fishing gear in the stomach. Ingestion of marine litter that was not related to fisheries was recorded in four animals. This study reveals the considerable negative anthropogenic influence on cetaceans in the Adriatic Sea, especially the bottlenose dolphin that is considered to be the most numerous cetacean species therein, and demonstrates the need for the urgent development of a cetacean bycatch reduction program. Finally, it also shows the importance of sustaining national surveillance programs to gain scientifically based knowledge important for cetacean protection and prospects for their long-term survival.

scholarly journals Determinants of lungworm specificity in five cetacean species in the western Mediterranean

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Rachel Pool ◽  
Clara Romero-Rubira ◽  
Juan Antonio Raga ◽  
Mercedes Fernández ◽  
Francisco Javier Aznar
Keyword(s):  
Bottlenose Dolphins ◽  
Parasite Burden ◽  
Western Mediterranean ◽  
Host Size ◽  
Cetacean Species ◽  
Stenella Coeruleoalba ◽  
Species Similarity ◽  
Pilot Whales ◽  
Common Dolphins ◽  
Prey Overlap

Abstract Background Current data about Pseudaliidae show contrasting patterns of host specificity between congeneric species. We investigated how both contact and compatibility between hosts and parasites contributed to the patterns of lungworm infection observed in a community of five species of cetaceans in the western Mediterranean. Methods The lungs of 119 striped dolphins Stenella coeruleoalba, 18 bottlenose dolphins Tursiops truncatus, 7 Risso’s dolphins Grampus griseus, 7 long-finned pilot whales Globicephala melas, and 6 common dolphins Delphinus delphis were analysed for lungworms. Parasites were identified by morphology and analysis of ITS2 sequences using both maximum likelihood and Bayesian inference methods. Body length was used as a proxy for lungworm species fitness in different hosts and compared with Kruskal-Wallis tests. Infection parameters were compared between cetacean species using Fisher’s exact tests and Kruskal-Wallis tests. Phylogenetic specificity was explored by collating the overall lungworm species prevalence values in hosts from previous surveys in various localities. To explore the relative importance of vertical and horizontal transmission, Spearman’s rank correlation was used to look for an association between host size and lungworm burden. A Mantel test was used to explore the association between lungworm species similarity and prey overlap using dietary data. Results Halocercus delphini had higher infection levels in striped dolphins and common dolphins; Stenurus ovatus had higher infection levels in bottlenose dolphins; and Stenurus globicephalae had higher infection levels in long-finned pilot whales. These results are congruent with findings on a global scale. Morphometric comparison showed that the larger nematodes were found in the same host species that had the highest parasite burden. Lungworms were found in neonatal striped dolphins and a Risso’s dolphin, and there was a weak but significant correlation between host size and parasite burden in striped dolphins and bottlenose dolphins. There was also a weak but significant association between prey overlap and lungworm species similarity. Conclusions Data indicate that phylogenetic specificity has an important role in governing host–parasite associations, as indicated by the higher infection levels and larger nematode size in certain hosts. However, diet can also influence infection patterns in these preferred hosts and contribute to less severe infections in other hosts.

Behavioural changes and potential consequences of cetacean exposure to purse seine vessels in the Istanbul Strait, Turkey

2020 ◽  
Vol 100 (5) ◽  
pp. 847-856
Author(s):  
Cristóbal Olaya Meza ◽  
Aylin Akkaya ◽  
Flavio Affinito ◽  
Bayram Öztürk ◽  
Ayaka Amaha Öztürk
Keyword(s):  
Bottlenose Dolphins ◽  
Purse Seine ◽  
Traffic Density ◽  
Long Term Effects ◽  
Cetacean Species ◽  
Behavioural Changes ◽  
Fishing Vessels ◽  
Marine Traffic ◽  
Common Dolphins

AbstractMarine traffic has both short- and long-term effects on cetacean behaviour, yet fishing vessels present a unique situation as they disturb cetaceans whilst potentially offering alternative foraging opportunities. The Istanbul Strait is a key area for the study of anthropogenic disturbance on cetaceans due to heavy human pressure in a narrow space where at least three cetacean species are regularly encountered. The present study investigated changes in behaviour of bottlenose dolphins, common dolphins and harbour porpoises in relation to the presence of purse seiners using Markov chains analysis. The results revealed increased foraging in bottlenose and common dolphins' behavioural budgets and a decrease in the time spent foraging by harbour porpoises. Moreover, a loglinear model was used to analyse the effect of possible confounding variables on observed behaviours. The only variables found to be affecting behaviour were the previous recorded behaviour, seiner presence and marine traffic density. Consequently, the presence of purse seine vessels leads bottlenose and common dolphins to change their behaviour and are related with a decrease of energy intake in porpoises. The results of this study reveal that there is an effect of purse seine vessel presence on the cetaceans found in the Istanbul Strait with potentially significant impacts on their behaviour, therefore we suggest more research is needed in the area to identify the long-term impacts of these observed behavioural changes.

Influence of environmental factors on small cetacean distribution in the Spanish Mediterranean

2008 ◽  
Vol 88 (6) ◽  
pp. 1185-1192 ◽  
Author(s):  
A. Gómez de Segura ◽  
P.S. Hammond ◽  
J.A. Raga
Keyword(s):  
Linear Models ◽  
Bottlenose Dolphins ◽  
Chlorophyll Concentration ◽  
Spatial Models ◽  
Distribution Models ◽  
Cetacean Species ◽  
Stenella Coeruleoalba ◽  
Striped Dolphin ◽  
Environmental Features ◽  
Risso's Dolphin

Habitat distribution models are one of the most up to date methods to study the habitat usage of wildlife populations. They allow animal distribution to be related to environmental features and also the prediction of the distribution of animals based on this relationship. Seasonal aerial surveys were conducted in central Spanish Mediterranean waters from June 2000 to March 2003 to obtain information on the distribution of cetacean species. Data from the three most common cetacean species (striped dolphin, Stenella coeruleoalba, bottlenose dolphin, Tursiops truncatus, and Risso's dolphin, Grampus griseus) were related, using generalized linear models, to local environmental features: depth, slope, sea surface temperature and chlorophyll concentration. For bottlenose dolphins, no significant relationship was found with any covariate and no dolphins were observed in waters greater than 1000 m. The distribution of both striped and Risso's dolphin was significantly related to depth. The striped dolphin showed a preference for waters between 900 and 1500 m deep and Risso's dolphin for waters more than 1500 m deep. In addition, for the latest two species, maps of distribution were predicted by means of the spatial models. The areas of higher probabilities of occurrence coincide to a large extent with the marine protected areas previously proposed for the conservation of oceanic cetacean species.

scholarly journals Concentration of mercury and selenium in tissues of five cetacean species from Croatian coastal waters

2015 ◽  
Vol 67 (4) ◽  
pp. 1377-1389 ◽  
Author(s):  
Nina Bilandzic ◽  
Marija Sedak ◽  
Maja Djokic ◽  
Martina Djuras ◽  
Tomislav Gomercic ◽  
...  
Keyword(s):  
Coastal Waters ◽  
Tursiops Truncatus ◽  
Significant Positive Correlation ◽  
Adriatic Sea ◽  
Balaenoptera Physalus ◽  
Cetacean Species ◽  
Stenella Coeruleoalba ◽  
Positive Correlation ◽  
Grampus Griseus ◽  
Ziphius Cavirostris

Mercury (Hg) and selenium (Se) concentrations were measured in muscle, liver, kidney, spleen and lung tissues of five cetacean species, three dolphin (Stenella coeruleoalba, Tursiops truncatus and Grampus griseus) and two whale species (Balaenoptera physalus and Ziphius cavirostris), stranded along the Croatian coast during the period 1999-2002. Statistically significant differences in Hg concentrations in muscle, spleen and lung, and Se in liver and lung of the different dolphin species were observed. Mercury levels in liver and spleen and Se levels in liver differed between young and adult T. truncatus species. A significant positive correlation between different tissue types for Hg and Se concentrations was observed. In all tissues tested, the lowest Hg and Se concentrations were found in B. physalus. Mercury concentrations were positively correlated with Se in all tissues. The results present one of few studies related to lung and spleen tissues in these mammals, particularly in the Adriatic Sea. Since very little data are available, this research provides new data on concentrations of Hg and Se in five cetacean species from the Adriatic Sea basin.

scholarly journals How to Work on a Non-endangered Species and Contribute to Cetacean Conservation: An Example by the Sarasota Dolphin Research Program

2021 ◽  
Vol 8 ◽  
Author(s):  
Frances M. D. Gulland
Keyword(s):  
Endangered Species ◽  
Research Program ◽  
Bottlenose Dolphins ◽  
Cetacean Species ◽  
Sarasota Bay ◽  
Conservation Actions ◽  
Data Deficient ◽  
Iucn Red Data List ◽  
Term Data

The world’s most endangered small cetaceans are found in countries many miles from Sarasota Bay and its common bottlenose dolphins (Tursiops truncatus). Information on the ecology and threats to many of these endangered cetaceans is often far more limited than that on bottlenose dolphins, with the IUCN Red Data List describing many species as “data deficient.” In many developing nations where these rare species occur, resources for research and monitoring are scant, and logistical challenges further limit research into marine mammal health and population status and their threats. The Sarasota Dolphin Research Program (SDRP) has tackled this problem by using the bottlenose dolphin as a model for cetacean species in other parts of the world and using its resources to assist scientists working with more endangered species of cetacean. The celebration of 50 years of study by the SDRP exemplifies how using long-term data on known individuals can advance the fields of cetacean behavior, ecology, life history, physiology, toxicology, and medicine, all providing information for informing certain conservation actions. The Sarasota team has used their work to inform conservation policy both home and abroad.

scholarly journals Surveillance as Determinant of Long-Term Survival in Non-Transplanted Hepatocellular Carcinoma Patients

Cancers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 897
Author(s):  
Filippo Pelizzaro ◽  
Alessandro Vitale ◽  
Anna Sartori ◽  
Andrea Vieno ◽  
Barbara Penzo ◽  
...  
Keyword(s):  
Lead Time ◽  
Early Stage ◽  
Multivariable Logistic Regression Analysis ◽  
Term Survival ◽  
Long Term Survival ◽  
Inverse Probability Weights ◽  
Surveillance Programs ◽  
Baseline Characteristics ◽  
The Impact

Purpose: We aimed at assessing the impact of surveillance on long-term survival in HCC patients. Methods: From the ITA.LI.CA database, we selected 1028 cases with long (≥5 years, LS group) and 2721 controls with short-term survival (<5 years, SS group). The association between surveillance and LS was adjusted for confounders by multivariable logistic regression analysis. Survival of surveilled patients was presented both as observed and corrected for the lead-time bias, and the comparison of survival between surveillance and no surveillance groups was also performed after balancing the baseline characteristics with inverse probability weights (IPW). Results: LS patients were more frequently diagnosed under surveillance (p < 0.0001), and had more favorable baseline characteristics. Surveillance was an independent predictor of LS (OR = 1.413, 95% CI 1.195–1.671; p < 0.0001). The observed and the lead-time corrected survival of surveilled patients were significantly longer compared to the survival of not surveilled patients (p < 0.0001 and p = 0.0008, respectively). In IPW adjusted populations, no survival differences were demonstrated between the two groups (p = 0.30). Conclusions: Surveillance, increasing early-stage diagnosis and applicability of curative treatments, is a fundamental determinant of long-term survival in HCC patients. A wide implementation of surveillance programs should be pursued in order to improve HCC patients’ prognosis.

Host specificity ofOschmarinella rochebruniandBrachycladium atlanticum(Digenea: Brachycladiidae) in five cetacean species from western Mediterranean waters

2010 ◽  
Vol 85 (1) ◽  
pp. 12-19 ◽  
Author(s):  
P. Mateu ◽  
J.A. Raga ◽  
F.J. Aznar
Keyword(s):  
Host Species ◽  
Bottlenose Dolphins ◽  
Western Mediterranean ◽  
Its2 Region ◽  
Single Individual ◽  
Common Dolphin ◽  
Cetacean Species ◽  
Stenella Coeruleoalba ◽  
Pilot Whales ◽  
Common Dolphins

AbstractWe investigated patterns of specificity of liver flukes (fam. Brachycladiidae) in a community of cetaceans from the western Mediterranean. The liver and pancreas of 103 striped dolphins,Stenella coeruleoalba, 18 Risso's dolphins,Grampus griseus, 14 bottlenose dolphins,Tursiops truncatus, 8 common dolphins,Delphinus delphis, and 5 long-finned pilot whales,Globicephala melas, were analysed for brachycladiid species. Two species were found:Oschmarinella rochebruniin striped dolphins (prevalence (P): 61.2%; mean intensity (MI) (95% CI): 34.2 (25.7–45.6)), andBrachycladium atlanticumin striped dolphins (P: 39.8%; MI: 7.1 (4.8–13.1)) and a single individual of common dolphin (P: 12.5%; intensity: 19), which represents a new host record. A molecular analysis using the internal transcribed spacer 2 (ITS2) region of the rDNA gene confirmed that specimens ofB. atlanticumwere conspecific regardless of host species. Available dietary data suggest that Risso's dolphins, bottlenose dolphins and long-finned pilot whales would contact rarely, if at all, the infective stages ofO. rochebruniandB. atlanticum. Neither the prevalence nor the mean abundance ofB. atlanticumdiffered significantly between striped and common dolphins, but a principal component analysis using seven morphometric variables indicated that specimens collected from the common dolphin were stunted. These worms also had fewer eggs compared with specimens typically found in striped dolphins, although the size of the eggs was similar in both host species. Dwarfism and low fecundity have typically been found in helminths infecting unusual host species, and might reflect the lower compatibility ofB. atlanticumfor common dolphins. In summary, bothO. rochebruniandB. atlanticumappear to exhibit a narrow specificity for striped dolphins in the western Mediterranean.

Cetacean stranding and diet analyses in the North Aegean Sea (Greece)

2017 ◽  
Vol 98 (5) ◽  
pp. 1011-1028 ◽  
Author(s):  
C.B. Milani ◽  
A. Vella ◽  
P. Vidoris ◽  
A. Christidis ◽  
E. Koutrakis ◽  
...  
Keyword(s):  
Bottlenose Dolphins ◽  
Aegean Sea ◽  
Cetacean Species ◽  
Stenella Coeruleoalba ◽  
The North ◽  
Aegean Islands ◽  
North Aegean ◽  
Diet Analyses ◽  
North Aegean Sea ◽  
Common Dolphins

Cetacean stranding reports in the North Aegean Sea were recorded since 1998 from Strimonikos Gulf in Chalkidiki up to Alexandroupoli on the Turkish border and in a few northern Aegean islands. On site, the specimens were examined to identify species, gender, approximate age and, when possible, cause for stranding. A total of 26 filled stomachs of five cetacean species collected since 2002 were analysed: bottlenose dolphinsTursiops truncatus(N = 8), common dolphinsDelphinus delphis(N = 8), harbour porpoisesPhocoena phocoena(N = 5), striped dolphinsStenella coeruleoalba(N = 4) and Risso's dolphinsGrampus griseus(N = 1). From the analysed stomachs it was found that the bottlenose dolphins fed mainly on snake blennyOphidion barbatum(34%), bogueBoops boops(22%) and round sardinellaSardinella aurita(13%); common dolphins on round sardinella (17%), picarelsSpicaraspp. (10%) and Cocco's lantern fishLobianchia gemellaris(9%); harbour porpoises on Gobidae (four-spotted gobyDeltentosteus quadrimaculatus41% and black gobyGobius niger37%) and round sardinella (7%); striped dolphins on Myctophydae (Madeira lantern fishCeratoscopelus maderensis51%), and on Pfeffer's enople squidAbraliopsis morisii(10%) and bogue (8%); and Risso's dolphin exclusively on Teuthidae (31%), the umbrella squidHistioteuthis bonellii(30%) and the reverse jewel squidH. reversa(14%). The present work represents the first attempt to investigate the diet up to species level for several cetaceans in Greek waters and for harbour porpoises stranded in the Mediterranean Sea.

Abundance, site fidelity and range patterns of Indo-Pacific bottlenose dolphins (Tursiops aduncus) in two Australian subtropical estuaries

2008 ◽  
Vol 59 (11) ◽  
pp. 1015 ◽  
Author(s):  
Christine A. Fury ◽  
Peter L. Harrison
Keyword(s):  
Site Fidelity ◽  
Bottlenose Dolphins ◽  
River Mouth ◽  
Published Data ◽  
Term Survival ◽  
Tursiops Aduncus ◽  
Marine Habitats ◽  
South Wales ◽  
Abundance Estimates

Bottlenose dolphins are widely studied in marine habitats, but information on estuarine populations is very limited. The present study provides the first published data on bottlenose dolphins in Australian estuaries. Abundance estimates, site fidelity and individual ranging patterns were examined over a 3-year period for Indo-Pacific bottlenose dolphins (Tursiops aduncus) inhabiting the Clarence River (CR) and Richmond River (RR) estuaries in northern New South Wales, Australia. Mark–recapture analyses estimated 71 (62–81 95% CI) dolphins utilised the CR whereas 34 (19–49 95% CI) used the RR. Differences in site fidelity were observed between the estuaries, with 60% and 37% of identified dolphins determined as residents, 26% and 21% as occasional visitors and 14% and 42% as transients for the CR and RR respectively. Resource partitioning was apparent in both estuaries with the mean distance resident dolphins were found upstream from the river mouth being greater than occasional visitors and transients. The Clarence River sustains a larger, predominantly resident dolphin community compared with the Richmond River, which supports a relatively small dolphin community with lower site fidelity. Management of future increased anthropogenic disturbances is needed to ensure the long-term survival of these dolphin populations.

Caspases and apoptosis

2002 ◽  
Vol 38 ◽  
pp. 9-19 ◽  
Author(s):  
Guy S Salvesen
Keyword(s):  
Cysteine Proteases ◽  
Signalling Pathways ◽  
Term Survival ◽  
Mature Adult ◽  
Intracellular Signalling Pathways ◽  
Adult Cell ◽  
Caspase Family ◽  
Cell Fragments ◽  
Pro Inflammatory Cytokines

The ability of metazoan cells to undergo programmed cell death is vital to both the precise development and long-term survival of the mature adult. Cell deaths that result from engagement of this programme end in apoptosis, the ordered dismantling of the cell that results in its 'silent' demise, in which packaged cell fragments are removed by phagocytosis. This co-ordinated demise is mediated by members of a family of cysteine proteases known as caspases, whose activation follows characteristic apoptotic stimuli, and whose substrates include many proteins, the limited cleavage of which causes the characteristic morphology of apoptosis. In vertebrates, a subset of caspases has evolved to participate in the activation of pro-inflammatory cytokines, and thus members of the caspase family participate in one of two very distinct intracellular signalling pathways.

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