Although both food availability and predation risk have been hypothesized to affect dolphin habitat use and group size, no study has measured both factors concurrently to determine their relative influences. From 1997 to 1999, we investigated the effect of food availability and tiger shark (Galeocerdo cuvier) predation risk on bottlenose dolphin (Tursiops aduncus) habitat use and group size in ...

Flow-induced bioluminescence provides a unique opportunity for visualizing the flow field around a swimming dolphin. Unfortunately, previous descriptions of dolphin-stimulated bioluminescence have been largely anecdotal and often conflicting. Most references in the scientific literature report an absence of bioluminescence on the dolphin body, which has been invariably assumed to be indicative ...

Observations suggest that dolphin sonars function well in the very shallow, reverberant, near-shore region of the ocean, and significantly out-perform man-made systems under such conditions. The echolocation characteristics of many small cetaceans have been measured directly and the high performance of biosonar systems is not in question, but explanations for their resolution, target detection,...

What is a dolphin? When you think of a dolphin you probably picture a bottlenose dolphin, Tursiops truncatus, the familiar star of oceanaria. But bottlenose dolphins are only one among sixtyseven living species in the fully aquatic mammalian order Cetacea and the diverse suborder Odontoceti (‘toothed whales’). In addition to possessing adult teeth, the many types of toothed whale are distinguis...

The causes of dolphin and whale stranding can often be difficult to determine. Because toothed whales rely on echolocation for orientation and feeding, hearing deficits could lead to stranding. We report on the results of auditory evoked potential measurements from eight species of odontocete cetaceans that were found stranded or severely entangled in fishing gear during the period 2004 through...

In order to evaluate the use of biopsy samples as non-destructive tool for assessing trace element concentrations in small cetaceans, the concentrations of 14 trace elements were determined in skin, blubber, liver and kidneys of four species of small cetaceans (i.e. common dolphin Delphinus delphis, harbour porpoise Phocoena phocoena, bottlenose dolphin Tursiops truncatus and striped dolphin St...

As top predators in the Pearl River Estuary (PRE) of China, Indo-Pacific humpback dolphins (Sousa chinensis) are bioindicators for examining regional trends of environmental contaminants in the PRE. We examined samples from stranded S. chinensis in the PRE, collected since 2004, to study the distribution and fate of total mercury (THg), methylmercury (MeHg) and selenium (Se) in the major tissue...

negotiators told a private meeting. Yet, in the event, climate change and the need for a 'green recovery' only made paragraph 27 and 28 of the 29-paragraph communiqué. Language, already weak in the final draft, was watered down even further by the leaders at the end of the summit and, after the initial euphoria, commentators have been increasingly concerned that the summit delivered too little ...

Hector’s dolphin is endemic to New Zealand, and listed as endangered on the IUCN Red List and equivalent New Zealand list of threatened species. The main threat to the species is entanglement in fishing gear, in particular gillnets. The Potential Biological Removal (PBR) method developed by the US National Marine Fisheries Service is a commonly used standard for determining a level of bycatch f...

Using polymerase chain reaction (PCR), a bottle-nosed dolphin (Tursiops truncatus) interleukin-4 (IL4) cDNA was cloned and sequenced. IL4 specific primers were based on the 5' and 3' untranslated regions of the human and murine IL4 gene. The dolphin IL4 cDNA is 528 base pairs in length and contains an open reading frame of 402 nucleotides coding an IL4 precursor of 133 amino acids, with the put...