This is an article about the behavior of gulls attacking whales in Valdes Peninsula, published by Discover Magazine. The attack is constant throughout the season. Each year, an increasing number of gulls learn this pattern of behavior, and you can see it; in the whale watching tours.
Despite years of observations, no one knows whether the gull attacks are harming the whale populations beyond giving them some nasty sores. Certainly, the whale numbers are still going up, but it may take time before the true effects on these long-lived animals become clear.
The whales spend around a quarter of their daylight hours fleeing from the gulls’ attacks, which could conceivably rob them of valuable rest, and soak up their energy reserves. This might matter most for the calves, who are also robbed of important chances to socialise with their peers. Fazio is also worried that the gulls could carry skin infections, implanting bacteria from rubbish dumps and sewers into the skins of their unfortunate victims.