Out of Water (video) - With estimates of a global temperature
increase of between 3 and 10 degrees over the next century, many
people are simply planning to turn up the air conditioner. But
what if youâ€™re a fish? (5/24/02)
Tracker - Scientists from the Monteray Bay Aquarium are using
satellites to track endangered bluefin tuna. (9/04/01)
Elsewhere on the web
Bay National Marine Sanctuary
- Communication Partnership for Science and the Sea
While we humans debate the politics of global warming, it appears that nature—in
some places—is already looking for cooler weather.
Two studies—60 years apart—show that sea life is already dramatically
changing along one spot in northern California.
The Tides of Time
The question of global climate change is a politically charged issue that
has scientists worldwide trying to assess what is going on and why. But, itâ€™s
difficult for scientists to accurately measure an extremely large and complex
event. Instead, they must observe many little events. For example, they might
measure the size of a glacier and compare it to historical records. They could
count the plants and animals somewhere, and try to decide if thatâ€™s
different from the way things were in the past. From many smaller observations
like these they can build the overall picture.
To be accurate, scientists canâ€™t confine those smaller observations just
to the land or the air. Since two-thirds of the earthâ€™s surface is covered
by water, they also need to try measuring changes in sea life.
Thatâ€™s not an easy job. Waves and currents are always stirring the seas.
Life beneath the waves is also constantly on the move.
Furthermore, you have to conduct your “sea census” where some other
scientist already counted, and the original survey needs to be old enough
and accurate enough to offer some perspective. Also, the spot must still be
in essentially the same condition as the first survey. Since global climate
change is a relatively new concern, such survey sites are hard to find.
At Hopkins Point in Monterey,
California, researchers have been taking the oceanâ€™s temperature
since 1891. The area is a picturesque, rocky tide pool and home to Stanford
Marine Station (the first marine laboratory on Americaâ€™s Pacific
coast). The Monterey Bay Aquarium
and the Monterey Bay Aquarium
Research Institute are also nearby. Birds wait on the rocks for low tide,
hoping to feed on the abundant life below.
Low tide is also a chance for scientists to examine that life, a chance to
count and categorize the snails, mollusks, anemones and other creatures hiding
in the rocks.
The first ocean scientist to conduct a survey here was Willis
G. Hewatt in 1931. The doctoral student laid out a series of 1-yard by
1-yard squares among the rocks in an area that had been made a marine reserve
earlier that same year. He used brass bolts to mark the area. For two years
he patiently counted all the life in those squares and earned his degree.
Not only did he create a detailed written record of what he found; he left
those four brass bolts firmly anchored in the rocks of Hopkins Point.
Sixty years later, under the direction of Jim
Barry of the Monterey Bay Research Institute and Chuck Baxter from Hopkins
Marine Station, Stanford University undergraduate students Rafe
Sagarin and Sarah
Gilman decided to follow up on Hewattâ€™s study. They wanted to know
if the temperatures around Hopkins Point had changed, and whether that changed
the life in this tidal pool.
The first step was to check a hundred years worth of daily air and sea temperatures,
do the math, and see if there had been a change. They found that the average
sea temperature was up about 1 1/2 degrees, and the average air temperature
up about four degrees.
They then found those four bolts and, like Hewatt, spent two years hunched
over the rocks repeating his sea survey.
According to their study, published in the journal Science,
Sagarin and Gilmore “counted and identified over 58,000 individuals…in
35 resurveyed plots.” They chose 45 species and assigned each to one
of three range categories. The northern range species tended to live near
Monterey and further north. The southern species range was from Monterey southward.
The range of the cosmopolitan species was centered on the waters off the coast
They found that the sea life at Hopkins point had changed quite a bit since
According to their study, “Of the 45 species analyzed, 32 exhibited statistically
significant relative changes in abundance.” Of the nine southern species,
eight had, “increased significantly.” Of the eight northern species,
five had “decreased significantly.”
Dr. Steven Webster, senior marine biologist of the Monterey Bay Aquarium, said
the statistics, “are pretty solid data to indicate that over that period
of 60 years, now 70 years, this area is coming to be much more like a southern
While this is only one study of one small tidal pool among all the oceans of
the world, the study is strong statistical evidence that some sea life is
already seeking somewhere new to play it cool.