Overview of sperm whale Physeter macrocephalus mortality events in the Adriatic Sea, 15552009
The following article has become available online: Overview of sperm whale Physeter macrocephalus mortality events in the Adriatic Sea, 1555-2009 Giovanni BEARZI, Nino PIERANTONIO, Marco AFFRONTE, Draško HOLCER, Nicola MAIO, Giuseppe NOTARBARTOLO DI SCIARA Mammal Review (2011) doi: 10.1111/j.1365-2907.2010.00171.x ABSTRACT 1. In the Mediterranean Sea, the sperm whale Physeter macrocephalus is one of eight regular cetacean species. Poor knowledge of its ecology and status, together with suspected decline in numbers, make studies of historical and present occurrence especially relevant. Long-term time series of stranding events are the most reliable data to provide a scientific framework for testing hypotheses that seek to explain the mechanisms responsible for cetacean strandings. 2. We present a comprehensive overview of cases of sperm whale mortality and human response to such events encompassing five centuries (1555-2009) within a portion of the Mediterranean Sea that offers a wealth of historical information - the Adriatic Sea. 3. A total of 36 mortality events were validated, involving 68 animals. Two findings of skeletal materials are also reported. The geographic distribution of strandings within the basin clearly was uneven: 44% of records (n = 16) were clustered along a 280km portion of the western Adriatic coast. A relatively high number of mortality events occurred along gently sloping sandy beaches away from suitable sperm whale habitat. 4. Until the first half of the 20th century, live-stranded animals were routinely killed: all but one cases with known human response elicited killing attempts. Starting from the 1980s, killing was replaced by efforts to rescue the animals. 5. Mass strandings of sperm whales have occurred since historical times in the Adriatic Sea. Mortality events involving multiple individuals accounted for at least 17% of the total sample (6 of 36 mortality events). At least 29% of live strandings (6 of 21) involved more than one individual. 6. This study contributes a long-term dataset based on careful validation of historical information, suitable for hypothesis testing aimed at investigating spatial and temporal correlates of sperm whale strandings - particularly live strandings - as a clue to their causes. --- A pdf copy can be obtained from the journal's web site (subscribers only): http://tinyurl.com/4sg6xuc or from me: giovanni.bearzi@gmail.com <mailto:giovanni.bearzi@gmail.com> - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Giovanni Bearzi http://www.coastaldolphins.org/giovanni_bearzi.htm <http://www.coastaldolphins.org/giovanni_bearzi.htm>
The following article has become available online: Striped dolphins and short-beaked common dolphins in the Gulf of Corinth, Greece: abundance estimates from dorsal fin photographs Giovanni BEARZI, Silvia BONIZZONI, Stefano AGAZZI, Joan GONZALVO, Rohan J.C. CURREY Marine Mammal Science (2011) doi: 10.1111/j.1748-7692.2010.00448.x ABSTRACT Capture-recapture methods relying on dorsal fin natural markings have never been applied successfully to striped dolphins, Stenella coeruleoalba, and were rarely used to assess abundance of short-beaked common dolphins, Delphinus delphis. We used digital photo-identification to obtain abundance estimates of striped and common dolphins living in mixed groups in the Gulf of Corinth, Greece. The proportion of either species was calculated based on the relative number of photographs of adult animals showing relevant portions of their body during conspicuous surfacings. Striped dolphins and common dolphins averaged 95.0% and 3.2% of all individuals, respectively. Animals showing intermediate pigmentation accounted for another 1.8%. Striped dolphin numbers were relatively high, with a point estimate of 835 animals (95% CI = 6311,106). Common dolphins numbers were low (point estimate 28 animals; 95% CI = 1173) and individuals were scattered within striped dolphin groups, indicating that this common dolphin population may be nonviable. Within a semiclosed Gulf exposed to considerable anthropogenic impact, the future of both dolphin species is of concern due to their suspected geographic isolation and restricted extent of occurrence. Information provided here can be used to inform timely conservation efforts. --- A pdf copy can be obtained from the journal's web site (subscribers only): http://tinyurl.com/4hmzyvb <http://tinyurl.com/4hmzyvb> or from me: giovanni.bearzi@gmail.com <mailto:giovanni.bearzi@gmail.com> - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Giovanni Bearzi http://www.coastaldolphins.org/giovanni_bearzi.htm <http://www.coastaldolphins.org/giovanni_bearzi.htm>
participants (1)
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Giovanni Bearzi