Tale 3 of whales 
     
    
   
   
    
     BY DAVID CAIRNS 
     
    
   
   
    
     Prince Edward Island is famous for lobsters, oysters and many 
     
     other forms of marine life, but whales are not prominent among our 
     
     salt—water attractions. But a recent influx of the big mammals off 
     
     Murray Harbour shows that whales will indeed come here when the 
     
     conditions are right. 
     
    
   
   
    
     For whales, conditions are right when there is lots of food, and 
     
     they can catch that food. Each year, millions of herring spawn on 
     
     Fisherman's Bank, a shallow plateau in the Northumberland Strait about 
     
     14 kilometers off Murray Harbour. The herring lay their eggs on the 
     
     bottom in broad carpets that look, to a diver, like fields of newly— 
     
     fallen snow. The egg beds can be several centimeters thick and cover 
     
     many hundreds of hectares. To this inviting feast come hordes of cod, 
     
     flounder, mackerel and cunners, all gorging themselves on the egg 
     
     smorgasbord. And when the great whales arrive, the predators 
     
     themselves become the prey. 
     
    
   
   
    
     I first saw whales on the Bank on 31 August this year, a day after 
     
     beginning a spawning bed study for the Department of Fisheries and 
     
     _0ceans. The whales were minkes (pronounced mink-ee). Minkes are small 
     
     as whales go, and the biggest we saw were at most 9 meters long. The 
     
     minkes were surfacing and diving in exactly the area where our echo— 
     
     sounder showed the herring were concentrated, and the whales were 
     
     doubtlessly filling themselves with herring and the other predators 
     
     which came to fill their bellies with herring eggs. At the Same time, 
     
     majestic gannets wheeled overhead in search of a herring or mackerel 
     
     that strayed up in the water column, and gulls were in constant patrol 
     
     for any bits of food that might find their way to the surface. 
     
    
   
   
    
     Our surveys on Fisherman's Bank continued until 20 September, and 
     
     we saw minkes on most days. On some days there were probably a dozen or 
     
     more of them on the Bank. Twice we saw fin whales as well. Fins, 
     
     which are often more than 20 m long, are second only in size to the 
     
     giant blue whale. The first sighting (on 2 September) was of a mother 
     
     and her calf, and the second (on 10 September) was of a single adult. 
     
    
   
   
    
     To see whales surface to breathe is impressive, but to see them 
     
     jump clear of the water is nothing short of spectacular. On 2 
     
     September, as we approached Murray Harbour at the end of the day, we 
     
     were treated to the sight of a minke whale repeatedly breaching. The 
     
     whale came hurtling from the water, and then fell back on the sea with 
     
     a resounding splash. It repeated this process at least four times. 
     
     The significance of breaching behaviour is uncertain, but it may have a 
     
     communication function. Breaching is relatively common in humpback 
     
     whales, which are abundant in Newfoundland waters, but it is unusual 
     
     behaviour in minkes. 
     
    
   
   
    
     The waters of the northern Gulf of St. Lawrence and Newfoundland 
     
     teem with seabirds and whales; why are these animals relatively 
     
    
   
   
    
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