Two Decades of Coastal Dolphin Population Surveys in Israel, Eastern Mediterranean.

Along the Mediterranean coast of Israel, two near-shore dolphin species are prevalent; Tursiops truncatus (least concern, IUCN) and Delphinus delphis (endangered, IUCN). Ship-board surveys and sporadic sightings over the last two decades have shown that the two differ in distribution-T. truncatus is found along the entire coast and D. delphis only in the south. The environmental and anthropological factors affecting these species' spatial distribution and determining their habitat preferences in this area are largely unknown. This work is a first attempt at summarizing 20 years of observations and studying habitat preferences for both species, by use of Generalized Additive Models. T. truncatus was found to be present in all areas of the continental shelf where survey effort coverage was sufficient, with a high affinity towards bottom trawlers. Model results showed D. delphis distribution to be associated to (shallow) water depths, though the factors driving their limited latitudinal distribution currently remain unknown. It is evident that T. truncatus and D. delphis are present in segregated areas of the Israeli continental shelf and T. truncatus currently sustains a delicate balance with continuously shifting human activities, while the drivers of D. delphis distribution are more specified, yet still not fully understood.

Photobacterium damselae subspecies damselae Pneumonia in Dead, Stranded Bottlenose Dolphin, Eastern Mediterranean Sea.

Photobacterium damselae subspecies damselae, an abundant, generalist marine pathogen, has been reported in various cetaceans worldwide. We report a bottlenose dolphin in the eastern Mediterranean Sea that was found stranded and dead. The dolphin had a severe case of chronic suppurative pneumonia and splenic lymphoid depletion caused by this pathogen.

Detection of Toxoplasma gondii in three common bottlenose dolphins (Tursiops truncatus); A first description from the Eastern Mediterranean Sea.

Toxoplasma gondii has been described in several marine mammals around the world including numerous species of cetaceans, yet infection and transmission mechanisms in the marine environment are not clearly defined. The Israel Marine Mammal Research and Assistance Center has been collating a database of all marine mammal stranding events along the country's national coastlines since 1993. In this study, we describe the molecular detection and characterisation of T. gondii in three common bottlenose dolphins (Tursiops truncatus) including one case of coinfection with herpesvirus. The animals were found stranded on the Mediterranean coast of Israel in May and November 2013. In one of the three cases, the dolphin was found alive and admitted to intensive care. To our knowledge, this is the first report of T. gondii infection of marine mammals in the Eastern Mediterranean Sea. As this parasite acts as an indicator for marine pollution and marine mammal health, we believe these findings add important information regarding the state of the environment in this region.

Trace elements in striped dolphins (Stenella coeruleoalba) from the Eastern Mediterranean: A 10-years perspective.

Concentrations of Hg, Se, Cd, Cu, Zn, Fe, Mn and As, in kidney, liver, muscle and blubber from 7 specimens of Stenella coeruleoalba, stranded along the Israeli Mediterranean coast (IMC) from 2006 to 2011 (2011-series) were determined and compared to previous data on S. coeruleoalba from the IMC (2001-series). No differences were observed in essential and toxic elements concentrations, between the two series, except for hepatic Mn which was higher in the latter. Hg/Se molar ratios in blubber, kidney and liver increased linearly with log Hg concentrations, while muscle was more heterogenic in this respect. Means (±SD) of hepatic Hg concentrations (134±89 and 181±200mgkg(-1), from the 2011 and 2001 series, respectively) were similar to that found in 2007-2009 specimens from Spain, possibly reflecting the relatively high natural background levels of mercury in the Mediterranean Sea.

Trace elements in tissues of cetacean species rarely stranded along the Israeli Mediterranean coast.

In this paper we present the concentrations of Hg, Cd, Se, Pb, Cu, Mn, Zn and Fe in organs of 6 non-common specimens of cetaceans that were stranded along the Israeli Mediterranean coast (IMC), during 2002-2010: two fin whales, one minke whale, one Cuvier's beaked whale, one rough-toothed dolphin, and one Risso's dolphin. Most of the specimens were calves stranded by accident. Concentrations of Hg and Cd were low in tissues of the baleen whales and higher in the toothed whales, with maximum concentrations of 1067 mg kg(-1) Hg in the liver of the Risso's dolphin and 29 mg kg(-1) Cd in the kidney of the Cuvier's beaked whale. As far as we are aware, this is the first report of trace elements in baleen whales in the Eastern Mediterranean, and the first report of trace elements in minke whale and rough-toothed dolphin in the Mediterranean.

Risso's dolphin (Grampus griseus) stranding on the coast of Israel (eastern Mediterranean). Autopsy results and trace metal concentrations.

The stranding of Risso's dolphin (Grampus griseus) on the Mediterranean coast of Israel is reported in this study. High concentrations of trace metals (Hg, Cd, Zn, Fe and Se) were found in the various tissues analyzed, while Cu and Mn concentrations were naturally low. The specimen was found alive, but died a day later. The cause of death was attributed to bacterial bronchopneumonia in combination with endotoxemia, resulting in disseminated intravascular coagulation. Plastic bags found in its stomach contributed to the dolphin's poor physical condition. No connection was found between the high concentrations of trace metals in the internal organs and the cause of death. It is assumed that the high concentrations were a result of the high trophic level of this species, its diet and its advanced age. Anthropogenic influence could not be assessed due to the sparse database of trace metals for this species, in particular knowledge of the natural levels.