A whale that took up residence in the Kishon Port in the Haifa Bay for five days swam back to the open sea on Tuesday morning, hours before scientists planned to coax him out.
On Sunday night biologists said they expected the whale, which apparently entered the port with a Russian ship, would leave with the ship after it unloaded its cargo and headed back to Turkey.
Biologists from the Israeli Marine Mammal Research and Assistance Center (IMMRAC), who spotted the whale five days ago in the port, questioned the ship's crew and found that the whale had followed it from Turkey all the way to Haifa.
However, the whale did not leave the port with the Russian ship, and biologists feared for the life of the marine mammal.
They said it was not clear what he fed on in the Kishon port's filthy water.
Four days ago the whale was initially identified as an adult Minke whale, whose maximum length reaches around 10 meters and which feeds on plankton and small fish.
However, with the help of IMMRAC experts currently participating in a scientific conference on marine mammals in France, the whale's pictures were reexamined and it was identified as a fin whale, a type of baleen whale.
The fin whale is at least twice as large as the Minke, reaching a length of 20 meters and a weight of 30 to 80 tons when full grown.
The fin whale calf is born 6.5 meters long and weighs up to two tons. It reaches puberty in eight to 10 years and lives to the age of 90 to 100 years.
The fin whale, which dives to a depth of 600 meters and feeds on krill, is common in the western Mediterranean and Atlantic Ocean.
According to the size of the whale cruising in the Kishon Port - slightly more than seven meters - this is apparently a calf that was only weaned a short time ago. IMMRAC biologists intend to create a kind of acoustic disturbance near the whale in an attempt to chase it out to sea.
They have not thought of another tactic to get the whale out of the harbor should this fail.