Activity 1: Questions about SPLASH | Activity 2: Interpreting Graphs | Activity 3: Mark and Recapture | Activity 4: Estimating Humpback Population Growth | Activity 5: Whale Tails: Photo ID | Activity Answers
All whaling in the United States ended in 1972, when a whaling moratorium was passed. In 1978, whale biologists estimated that there were only 1,400 humpbacks still alive in the North Pacific. In 1991, the population was estimated to be roughly 10,000 whales. SPLASH study for 2006, estimates the population to be roughly 20,000 whales. ￼Earlier estimates set the pre-whaling population to be 15,000 whales. Although it appears that the current humpback population has exceeded its pre-whaling population, the estimate of 15,000 is based upon whaling records and is considered to be largely inaccurate.
The abundance estimates for Asia are very low, largely due to Japanese whaling that occurred there in the past. In addition, there appears to be a high level of mortality due to whales becoming entangled in fishing nets off the Asian coast.