CSI: Crime Scene Investigation (in the Pliocene)

Four million years ago a Pliocene dolphin Astadelphis gastaldii died. Its skeleton was recovered, then stored in an Italian museum where it lied unstudied for more than a century... until some researchers decided to have a deep look at it. The result was amazing.

Carved into the old dolphin bones, researcher Giovanni Bianucci and his colleagues from the University of Pisa, Italy, found visible shark bite marks. By carefully studying the morphology and disposition of the tooth marks, the authors managed to attribute the bites to the predation of a single shark, most likely a Cosmopolitodus hastalis.

Then Bianucci and colleagues reconstructed what probably happened during the attack:

"… the shark attached from below, biting into the abdomen. Caught in the powerful bite, the dolphin would have struggled, and the shark probably detached a big amount of flesh by shaking its body from side to side. The bite would have caused severe damage and intense blood loss, because of the dense network of nerves, blood vessels and vital organs in this area. Then, already dead or in a state of shock, the dolphin rolled onto its back, and the shark bit again, close to the fleshy dorsal fin".

This study reveals how much can be inferred from skeletal remains, and offers a glimpse on ancient animal behaviour.

Silvia Bonizzoni

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Drawing: Attack sequence as hypothesized by Bianucci et al.
A) the shark approached the prey; B) the shark bitted the abdomen of the dolphin; C) the dolphin, mortally injured, rolled to the left and the shark bitted adjacent to dorsal fin area.

For more information:
http://www.sciencedaily.com/releases/2010/03/100316142519.htm

Bianucci G., Sorce B., Storai T., Landini W. 2010. Killing in the Pliocene: shark attack on a dolphin from Italy. Palaeontology 53(2):457–470.
Abstract - Shark bite marks, including striae, sulci and abrasions, in a well-preserved fossil dolphin skeleton referred to Astadelphis gastaldii (Cetacea, Delphinidae) from Pliocene sediments of Piedmont (northern Italy), are described in detail. The exceptional combination of a fossil dolphin having a significant part of the skeleton preserved and a large number of bite marks on the bones represents one of the few detailed documentations of shark attack in the past. Most bite marks have been referred to a shark about 4 m long with unserrated teeth, belonging to Cosmopolitodus hastalis, on the basis of their shape and their general disposition on the dolphin skeleton. According to our hypothesis, the shark attacked the dolphin with an initial mortal bite to the abdomen from the rear and right, in a similar way as observed for the living white shark when attacking pinnipeds. A second, less strong, bite was given on the dorsal area when the dolphin, mortally injured, probably rolled to the left. The shark probably released the prey, dead or dying, and other sharks or fishes probably scavenged the torn body of the dolphin.

Bernd and Melany Würsig in Galaxidi

In these days Bernd and Melany Würsig are visiting the field station of Tethys in Galaxidi (Gulf of Corinth, Greece), spending a few days with researchers Silvia Bonizzoni and Giovanni Bearzi.

Bernd and Mel are good friends, long-time advisors and a bright example of commitment to cetacean science and conservation. They have done incredible work, and managed all that with much generosity, never taking themselves too seriously and always willing to share the fun.

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Bernd Würsig is regents professor at Texas A&M University, and chair of the Marine Biology Graduate Program. Melany Würsig is curriculum instruction specialist at Cloverleaf Elementary School in Houston, Texas. Bernd has been senior advisor to 65 graduate students since 1981, and authored or co-authored approximately 150 research papers and six books, including the second edition of the Encyclopedia of Marine Mammals (2009, with Bill Perrin and Hans Thewissen). Bernd and Melany co-authored The Hawaiian Spinner Dolphin (1994, with Ken Norris and Randy Wells) and The Dusky Dolphin: Master Acrobat off Different Shores (2010).

Fishing bans do work

Many are against fishing bans, or think that are useless. A study proved this kind of regulation works.

Australian researchers showed that strict fishing prohibition has helped to regenerate wildlife and coral on one-third of Australia's Great Barrier Reef. Laurence McCook, the lead author of the study, commented "The results are actually quite impressive. Having a higher proportion of protected areas is good for marine life, it's good for fish and it's good for people who rely on the reef for a living".

McCook and colleagues demonstrated no-take zones have less damaged coral, more and bigger fish (including sharks) in both reef and non-reef habitats, with benefits for fisheries as well as biodiversity conservation.

SB

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Photo: the Australian Great Barrier Reef

For more information:
http://www.telegraph.co.uk/news/worldnews/australiaandthepacific/australia/7290755/Fishing-ban-regenerates-Australias-Great-Barrier-Reef.html

The article:
L.J. McCook, T. Ayling, M. Cappo, J.H. Choat, R.D. Evans, D.M. De Freitas, M. Heupel, T.P. Hughes, G.P. Jones, B. Mapstone, H. Marsh, M. Mills, F.J. Molloy, C.R. Pitcher, R.L. Pressey, G.R. Russ, S. Sutton, H. Sweatman, R. Tobin, D.R. Wachenfeld, D.H. Williamson. 2010. Adaptive management of the Great Barrier Reef: a globally significant demonstration of the benefits of networks of marine reserves. PNAS doi: 10.1073/pnas.0909335107

Abstract - The Great Barrier Reef (GBR) provides a globally significant demonstration of the effectiveness of large-scale networks of marine reserves in contributing to integrated, adaptive management. Comprehensive review of available evidence shows major, rapid benefits of no-take areas for targeted fish and sharks, in both reef and nonreef habitats, with potential benefits for fisheries as well as biodiversity conservation. Large, mobile species like sharks benefit less than smaller, site-attached fish. Critically, reserves also appear to benefit overall ecosystem health and resilience: outbreaks of coral-eating, crown-of-thorns starfish appear less frequent on no-take reefs, which consequently have higher abundance of coral, the very foundation of reef ecosystems. Effective marine reserves require regular review of compliance: fish abundances in no-entry zones suggest that even no-take zones may be significantly depleted due to poaching. Spatial analyses comparing zoning with seabed biodiversity or dugong distributions illustrate significant benefits from application of best-practice conservation principles in data-poor situations. Increases in the marine reserve network in 2004 affected fishers, but preliminary economic analysis suggests considerable net benefits, in terms of protecting environmental and tourism values. Relative to the revenue generated by reef tourism, current expenditure on protection is minor. Recent implementation of an Outlook Report provides regular, formal review of environmental condition and management and links to policy responses, key aspects of adaptive management. Given the major threat posed by climate change, the expanded network of marine reserves provides a critical and cost-effective contribution to enhancing the resilience of the Great Barrier Reef.

Extinct and quickly forgotten

Many species became extinct because of us, but our impact on Planet Earth continues to be forgotten as we lose track of environment changes.

This is the conclusion of a recent study led by Dr. Samuel Turvey.

In 2006, Turvey participated in a Yangtze River expedition to asses the baiji (Lipotes vexillifer) population. The species was later declared ‘extinct’. Turvey returned in 2008 to interview locals about their knowledge of the baiji. The result was quite depressing: memories of this tremendous loss are quickly fading away.

Younger informants were less likely to know what a baiji was. While older people were aware of the historical decline of the baiji, younger fishermen from the same communities not only had never seen this animal, but had never even heard of it.

Soon, people will forget about the former existence of this cetacean species - once common in their environment. Progressively degraded environmental conditions and low biodiversity will come to be seen as normal.

"These shifts in community perception typically mean that the true level of human impact on the environment is underestimated, or even not appreciated at all, since the original environmental baseline has been forgotten” - Turvey commented.

Silvia Bonizzoni

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Drawing by Giovanni Bearzi

The article:
S.T. Turvey, L.A. Barrett, H. Yujiang, Z. Lei, Z. Xinqiao, W. Xianyan, H. Yadong, Z. Kaiya, T. Hart, W. Ding. 2010. Rapidly shifting baselines in Yangtze fishing communities and local memory of extinct species. Conservation Biology. doi: 10.1111/j.1523-1739.2009.01395.x

Abstract - Local ecological knowledge can provide a unique source of data for conservation, especially in efforts to investigate the status of rare or possibly extinct species, but it is unlikely to remain constant over time. Loss of perspective about past ecological conditions caused by lack of communication between generations may create "shifting baseline syndrome," in which younger generations are less aware of local species diversity or abundance in the recent past. This phenomenon has been widely discussed, but has rarely been examined quantitatively. We present new evidence of shifting baselines in local perception of regional species declines and on the duration of "community memory" of extinct species on the basis of extensive interviews with fishers in communities across the middle-lower Yangtze basin. Many Yangtze species have experienced major declines in recent decades, and the Yangtze River dolphin or baiji (Lipotes vexillifer) and Yangtze paddlefish (Psephurus gladius) may have become extinct during the 21st century. Although informants across all age classes were strongly aware of the Yangtze ecosystem's escalating resource depletion and environmental degradation, older informants were more likely to recognize declines in two commercially important fish species, Reeves' shad (Tenualosa reevesii) and Yangtze pufferfish (Takifugu fasciatus), and to have encountered baiji and paddlefish in the past. Age was also a strong predictor of whether informants had even heard of baiji or paddlefish, with younger informants being substantially less likely to recognize either species. A marked decrease in local knowledge about the Yangtze freshwater megafauna matched the time of major population declines of these species from the 1970s onwards, and paddlefish were already unknown to over 70% of all informants below the age of 40 and to those who first started fishing after 1995. This rapid rate of cultural baseline shift suggests that once even megafaunal species cease to be encountered on a fairly regular basis, they are rapidly forgotten by local communities

For more information:
http://news.mongabay.com/2010/0223-hance_shiftbaiji.html
http://news.bbc.co.uk/2/hi/science/nature/8530965.stm

The early ADP in Losinj, Croatia

One more video (Italian narration) bringing back memories of the early Adriatic Dolphin Project in Losinj, Croatia.

In the good old days

One more video from the good old days, posted by Drasko Holcer.

It features Tethys researchers working with 'eco-volunteers' back in the mid 1990s.

(Italian narration)

If you are interested in attending ongoing research courses by Tethys in Italy and Greece, please check:
http://www.tethys.org/tri_courses/courses_index_e.htm

Adriatic Dolphin Project video

Drasko Holcer, President of Blue World, posted a video collage with bits of history of the Adriatic Dolphin Project:

http://vimeo.com/9883799

There is a short part at the beginning which relates to the 14-year period (1987-2000) when the project was managed by Tethys.

Additional information about the Adriatic Dolphin Project can be found at:

http://www.tethys.org/projects/VDP/vdp_home.htm

Should killer whales not kill?

Killer whale kills SeaWorld trainer

Orca uccide addestratrice del SeaWorld



Why not let orcas kill their own prey in the wild, instead of using these top predators as toys and then be shocked if some of them, sometimes, behave as wild animals?

Giovanni Bearzi