In this task, you are given a text of many news articles seperated by special token "|||||". Your task is to summarize them.

Remember the gray whale that was recently spotted off Israel? Its sighting was huge news because gray whales haven't been seen in the eastern hemisphere since at least the eighteenth century; the only gray whale populations remaining in the world are in the Pacific Ocean. The likeliest explanation for the whale's appearance in the Mediterranean was that, during a summer feeding season north of Alaska, it somehow made its way through either the Northeast or Northwest Passage before turning south into the Atlantic. 
  
 Well, the whale has been spotted again. 
  
 On May 30, at about 4.30 p.m. local time, researchers saw the whale off the coast of Spain, near Barcelona. Comparative photographs confirm it was the same one that was seen off Israel (then again, it would be an even more remarkable story if it were not, and there were more than one gray whale swimming around the Mediterranean). The whale, having somehow found its way through the Strait of Gibraltar and traveled east as far as it could, has now made it back to the western side of the sea. 
  
 Speculation alert: Right about now, its brethren in the Pacific population it has left behind are swimming north toward the Arctic; it is possible, perhaps even likely, that instinct is urging our wayward whale to do the same, and that it is looking for a way around the Iberian Peninsula in an attempt to do so. 
  
 TreeHugger: Gray Whale, Extinct for Centuries, Sighted in Mediterranean 
  
 In an email to Discovery News, Manel Gazo of Spanish cetacean research and conservation organization SUBMON said that coordinated efforts are underway to relocate the whale in order to track it, advise ship traffic to exercise caution in its vicinity, and secure a biopsy or a sample of sloughed skin to confirm the population whence the whale came. 
  
 In the meantime, thousands of miles from home, the whale swims on ... 
  
  
  
 Images courtesy Dr. Manel Gazo ||||| By Matt Walker 
  
 Editor, Earth News 
  
  
  
 The whale is seen again off Barcelona 
  
 A mysterious gray whale sighted off the coast of Israel in the Mediterranean Sea has been seen again off the north east coast of Spain. 
  
 The second sighting, made 23 days and 3000km after the first, has continued to perplex whale experts. 
  
 Gray whales were thought to be extinct across the Atlantic Ocean, so the appearance of an individual within the Mediterranean Sea was a major surprise. 
  
 Now it is not clear where the whale is heading or why. 
  
 Once, three major populations of gray (also spelt grey) whale existed: in the western and eastern North Pacific Ocean, and in the North Atlantic. 
  
 However, the North Atlantic population of gray whale became extinct sometime in the 17th or 18th Century, for reasons that are not clear. 
  
 No sightings of the species had been made in the Atlantic Ocean since. 
  
 That was until a single individual gray whale was sighted off the coast of Herzliya Marina, Israel on 9 May this year. 
  
 That sighting excited and bemused experts: it could either mean that the gray whale had recolonised the Atlantic Ocean, or that a single gray whale had shattered the record for the longest known migration by the species, which usually make a round trip of 15-20,000km each year. 
  
 Previous sighting off Israel 
  
 On 30th May 2010, members of SUBMON, a non-governmental organisation dedicated to the conservation and assessment of marine habitats, sighted a gray whale in front of Barcelona's harbour. 
  
 Whale expert Manuel Castellote at the US National Marine Mammal Lab compared photos of this whale with those taken earlier in May in Israeli waters. 
  
 These comparisons confirmed the match, the Whale and Dolphin Conservation Society (WDCS) have announced. 
  
 "It's wonderful news to hear of a resighting of this animal, where it's heading is the burning question," says Nicola Hodgins of the WDCS, which has its headquarters in Wiltshire, UK. 
  
 SOURCES 
  
 Visit the Whale and Dolphin Conservation Society 
  
 The whale appeared to be consistently heading south at a slow pace. 
  
 It is the first time a gray whale has been seen in the western Mediterranean Sea. 
  
 "Its likely route would be to leave the Mediterranean, and then head north along the coasts of Portugal and France, possibly coming as far north as the UK and North Atlantic waters" says Ms Hodgins. |||||
Gray whales became extinct in the Atlantic centuries ago, so experts believe the one that was spotted off Spain's Mediterranean coast recently is either incredible evidence of a recolonization, or incredibly lost. The whale is likely the same one seen off the coast of Israel last month, but experts have no idea where it's headed, the BBC reports. The most likely scenario is that the whale took a wrong turn during summer feeding season north of Alaska and headed south through the Northwest Passage. Its Pacific brethren will be swimming back to the Arctic around now, Discovery notes, so the whale may now be following its instinct to head north, but hasn't yet found a way around the Iberian peninsula.