Out on a routine survey of dolphins along the southern Mediterranean coast of Ashkelon on Friday, researchers discovered a happy surprise – a tiny bottlenose dolphin calf, who is just a few weeks old.
While the species is relatively common on the coast – a stable population with 300 to 400 individuals – this was an exceptionally young and active calf, Dr. Aviad Scheinin, chairman of the Israel Marine Mammal Research & Assistance Center, told The Jerusalem Post on Sunday.
“Looking at the pictures and relative to the mother we think it’s a relatively young calf, though it has quite amazing acrobatic abilities,” said Scheinin, who is also the coordinator for the National Mediterranean Marine Biodiversity Program and a council member of the European Cetacean Society. “It was very exciting to see it during the survey.”
Of the 300 to 400 dolphins estimated to reside along Israel’s coast, the Marine Mammal Research & Assistance Center, which is located in Mishmoret, has catalogued about 150 individuals by their dorsal fins since the organization began tracking the animals in 1998.
On Friday, all five of the other dolphins surveyed were individuals the researchers had came across in the past, including Ban, the calf’s mother, Scheinin explained.
“The female is an interesting story because this is the third time we have seen her with a cub,” he said.
The first encounter with Ban was in 2007, when she swam with a calf a couple months old, and once again in 2010 when she escorted another calf, according to Scheinin.
“This time it was a very young calf, we reckon it is only a few weeks old,” said Scheinin. “During the first year when they suckle, they grow enormously quickly.”
The other dolphins in the group included Adi, whom researchers first identified 12 years ago and whom they think is a male, due to the animal’s scarring and characteristic behavior. Alongside Adi were also Natan, found in 2006, and Hooks, found in 2009 – named for the two hook-like shapes on his dorsal fin.
“We’re not sure if they’re young females or males,” Scheinin said, stressing that these two really tended to stick together.
“It could be that they are relatives. Usually if they are females they are relatives. If they are males they don’t have to be,” he added, citing research projects conducted in Florida and Australia.
A bit later in the journey, these five bottlenose dolphins were joined by yet another – a 2006 discovery named Joy, who is probably a male.
“Halfway through the survey suddenly we saw a big dolphin zooming to the group and the next thing we saw is we were left with only three dolphins,” Scheinin said.
The female and her cub left quickly, as did Adi, while Joy swam around with Natan and Hooks, though at a slight distance from them.
Researchers often sail their boat in the direction of fishing boats, which attract dolphins due to their ready availability of food. This time, with poor sea conditions for dolphin observation, the team did just that, and steered their Israel Nature and Parks Authority boat toward the fishing boats, where they found the dolphin group.
While fishing boats may help researchers find dolphins, they are also “the most dangerous cause of death for the local population,” according to Scheinin.
Three to four times a year, dolphins get caught in these nets in Israel.
Overall, every year an average of 15-20 dolphin and whale carcasses wash up on shore, due to a variety of causes. However, this year already 16 dolphins and whales – mainly dolphins – have washed up. Ten cases have occurred since summer began. Scheinin noted that this is the highest summer rate the researchers have ever experienced.
“This is the highest number of dolphins that washed ashore in the summer so we are quite worried that something is bad,” he said.
While the death rate of the bottlenose dolphins remain normal, the rise in dolphin deaths is mainly among the common dolphin, which has of late been coming from northern Sinai to Israel in increasing numbers. Five of them have died already, compared to last year’s one or two, according to Scheinin.
“In the last years we got quite a few sightings of this species, but only this year we got many dead dolphins from this [species of] dolphin,” he said. “The pictures are awful.”
The researchers have yet to determine the cause of death, because the bodies have been washing up too decomposed to perform an effective postmortem analysis, due to the warm water temperatures.
“We are not sure what’s causing it but it is something that is unusual,” he said.
Although throughout the world, the common dolphins are quite common, as their name states, in the Mediterranean region, the International Union of Conservation Legislators identified them as an “endangered population,” Scheinin explained. They have only recently started coming up from north Sinai, where they live and feed on small fish at the Nile delta.
“We didn’t see them in Israel,” he said. “When we saw them in the past it was very anecdotal. But in the last five years, since the Israel blockade on the Gaza Strip, what happened is there was a nature reserve caused by the Israeli Navy where nobody can fish.”
This reserve, west of Gaza, has led to a corridor for dolphins to move from Sinai to the Israeli southern shore, Scheinin added.
The mysterious trigger for their deaths could be some sort of disease, but the researchers are still working to determine where the deaths are coming from.
“We will do our best to give an answer because it is worrying us that we have Israeli common dolphins dying on the Israeli shore,” Scheinin said.