Read the following article about numbers of sea otters remaining in California. Use the information in the article and table to answer the questions.

Sea Otter Census Shows Big Population Jump

From a story by News Reporter Tony Russomanno (September 2003)

 It seemed that everywhere scientists looked this year -- especially in Monterey Bay-- they saw sea otters.

"Silver headed male is coming in" says a counter.

Up and down the California coast, federal, state and private researchers turned their eyes to the water for the annual spring sea otter count.

"That's three resting plus one small" say a counter.


The results returned numbers so high that scientists believe they're misleading.


 

"The spring count this year is the highest we've ever had since 1983," said Greg Sanders of the U.S. Fish and Wildlife Service. "So that's encouraging."

2,505 otters were counted in this year's census, up 17% from last year. But the count only reflects otters that were observed. Scientists say the observing conditions this year were very good and more otters have congregated in Monterey Bay, where they are easily seen.

"I have no confidence that the population really is increasing now," said Dr. Jim Estes, an ecology researcher with the U.S. Geological Survey and one of the leaders of the annual count. "I think it's roughly stable."

On the chart, the raw numbers show this year's spike. But when the counts are displayed as a three year running average, the increase levels out.

Scientists believe a harsh early winter combined with increased food attracted many more otters close in to Monterey Bay, where they could be seen and counted. This also may explain what appeared to be a mystery in April.

This spring, an exceptionally large number of dead and dying sea otters were found around Monterey Bay. There were reports that a disease carried by cat faeces contributed to the deaths. But the explanation offered now is quite a bit simpler.

"It's simply that there are a lot of live ones out there and thus [are] a lot of dead ones accumulating as a result of all these live ones," said Estes.

The increase in dead otters is proportional to the increase in live ones -- meaning that the so-called unusual deaths reported in April were not unusual at all.

Scientists say if the otter count shows an increase over the next several years, they'll know the downward population trend that began in the mid-1990s has actually reversed. Despite the increase this year, the 2,505 otters counted are still a fraction of the 18,000 to 20,000 believed to have lived along what is now the California coast (among about 250,000 worldwide) before they were hunted to near-extinction.