Like aliens from a tropical paradise they come, small, seemingly insignificant marine species whose presence may nevertheless indicate a fundamental change in the waters of the Monterey Bay. Working in conjunction with the researchers at the Hopkins Marine Station in Pacific Grove, Stanford University seniors Sarah Gilman and Rafe Sagarin earlier this year replicated a study of marine ecology in the waters of the Monterey Bay conducted in 1934 by Stanford graduate student Willis Hewitt.
What the Stanford students found were some significant increases in the numbers of warm water invertebrates and a corresponding decrease in cold water marine invertebrates – as compared to the 1934 study – suggesting that a permanent warming of the waters of the Monterey Bay may be taking place. The average temperature of the water also climbed from 12.8 degrees Celsius 60 years ago to 13.5 degrees today.
“While it’s premature to say whether our study confirms that a permanent long-term increase in ocean temperature is occurring, Rafe and I feel that water temperature increase is the big factor behind our findings,” says Gilman. “If the local waters keep warming at the same rate, in another 60 years this area could look more like Southern California in marine composition.”
Few environmental issues have generated as much public debate and controversy as global warming – the theory that increased production of human-generated carbon dioxide has created a blanket-effect that is causing temperatures on earth to rise.
While scientists have been tracking the apparent increase in marine and atmospheric temperature averages over the past 10 years, there is little consensus as to whether measured increases can be attributed to global warming or to natural fluctuations in global temperatures.
Some oceanographers and meteorologists theorize that global warming may account for certain oceanic and atmospheric anomalies that have occurred in recent years. Of particular concern to scientists here on the Monterey Peninsula is the possible effect a prolonged period of global warming could have on marine ecosystems and coastal weather patterns.
“We seem to be entering a critical, transitional climate period that may very well reflect a response to global warming,” says Kenneth Parker, a biological oceanographer with the National Oceanic and Atmospheric Administration (NOAA) here in Monterey.
“What we hope to know by improved weather observation and marine study is whether these apparent changes are natural or man-made, and whether they point to a permanent change in the environment. The specific study of the biological response of the coastal waters to these environmental changes may give us the best insight into tracking and understanding the long term effects of global warming.”
It is this very question of the potential relationship between global warming and the abundance of coastal marine organisms that prompted Gilman and Sagarin’s study. Working with the actual charts, sketches, and notes from the Hewitt study that took place 60 years ago, Gilman and Sagarin were able to survey the identical coastal sections Hewitt studied in 1934.
“The Hewitt study was essential because no one else had conducted a large study of invertebrates in the intertidal zone since Hewitt,” explains Sagarin, who became interested in marine biology as a youngster living on Cape Cod. “His study provided the essential baseline data with which to compare our findings, and allows us to pinpoint the exact locations where he took samples.”
“The most difficult part of our research project was trying to find the brass markers Hewitt had placed in the rocks that showed where he conducted his survey,” recalls Gilman with amusement. “A lot of rock surfaces Hewitt descried in his notes had changed significantly in 60 years. It took us almost four days searching at low tide to find the markers. Locating the markers was critical to the accuracy of our study.”
Of the 108 years initially studied by Hewitt, Gilman and Sagarin duplicated 19 square yards of the study. After checking tide charts and the maps to confirm the locations to be studied, Gilman and Sagarin went out at low tide, oftentimes at three or four in the morning with wet suits and flashlights, to place a frame of PVC pipe measuring one square yard over the precise areas of rock and ocean Hewitt studied.
Once the frame was in place, Gilman and Sagarin counted marine organisms found within it and logged the information into computers back at the lab.
Of the 190 different species of invertebrates recorded by Hewitt, Gilman and Sagarin discovered changes in the populations of 49 species, of which 29 species showed significant differences.
Especially interesting were increases of several types of warm-water sea anemones. One such anemone, Corynactis Californica increased from zero to 134 organisms. Another, Anthopleura Elegantissima, increased from 10 to 101.
Gilman and Sagarin also noted an increase in a type of warm-water barnacle – from zero to 900 specimens – and a major increase in the presence of Serpulorbis, a warm-water snail most commonly found off the coast of Baja and Southern California not even recorded in the original Hewitt study.
It was the abundant presence of Serpulorbis that prompted the replication of the Hewitt study, according to Chuck Baxter, a retired Stanford biology lecturer and Hopkins researcher who acted as an advisor for Gilman and Sagarin’s study.
“About four years ago, while conducting class exercises with students in the waters near Hopkins, I began to notice a dramatic increase in the Serpulorbis snail, a somewhat rare, but no unknown presence in the waters of the Bay.” Baxter explains, adding, “what’s important with the study done by Rafe and Sarah is the unexpected bias towards warm-water species.
“This suggests that big changes in the structure of the intertidal community are taking place.”
Aside from global warming another possible explanation for the increased presence of warm-water invertebrates found in the Hewitt replication study can be found in El Nino – a subtropical atmospheric effect resulting from shifts in barometric pressure, that in turn create erratic weather patterns and shifts in warm ocean currents from the south and west.
NOAA’s Parker says El Nino typically affects the ocean waters on the surface, creating a surface layer of warm water that traps colder subsurface water. But out in the deeper ocean waters of the Bay, Monterey’s commercial fisherman have noted significant changes in their catch over the past 10 years, suggesting that the increased presence of warm-water invertebrates may not e an anomaly caused solely by El Nino and that warming may not be limited to coastal waters.
“Ever since the El Nino in 1982, the waters in the Bay have been much more erratic than usual and still haven’t settled,” says Joe Pennisi, the 20-year owner of Royal Seafood Co. Pennisi, who has been involved in the local fishing industry for more than 30 years. He says that while quantities of fish caught haven’t been markedly affected by these changes, fishermen have been forced further north and west for certain catches.
“A lot of fish usually caught closer to shore like snapper, salmon, and sole are not as available because of the warmer water temperatures,” says Pennisi.
The longer-term effects of changing ocean temperature are still open to debate.
“The feedback globally could be enormous,” says Sagarin, who adds that new species introduced rapidly into an area “could take over an ecosystem – or have no effect.”
“Certain fish, like sardines, do benefit from warmer waters because their eggs mature quicker,” says Pennisi. “While this has been a plus for some fishing companies, this hasn’t helped guys in the salmon business. We’ve been fishing the waters off the San Francisco Bay a lot more because they have been more productive for cold water fish.”
Baxter believes the results of the new study suggest more is happening to the waters by the Bay than a temporary or isolated warming trend caused by El Nino.
“The significant increase in the presence of these warm-water invertebrates also suggests that a progressive change in global temperatures is occurring as opposed to some aberration or accidental change in climate,” he says.
While the results and implications of the newest Monterey Bay study are compelling, certain elements point to the inconclusive nature of research into localized, casual effects of globally generated environmental phenomenon.
Part of the difficulty scientists have in asserting the global temperatures are increasing is that the interaction of oceanic and atmospheric forces is an extremely complex dynamic. Local weather and ocean activity is often generated by events happening thousands of miles away. The El Nino of recent years, for example, cannot be understood without studying the entire global weather phenomenon.
“El Nino is not a local effect but a subtropical phenomenon with global effects,” says Robert Haney, chairman of the Meteorology Department at the Naval Postgraduate School.
“The most important thing meteorologists have come to understand is how the weather in one part of the global affects conditions farther away,” says Haney. “It is our understanding of this remote weather effect as it pertains to El Nino that has enlarged our understanding of global weather patterns. Ironically, El Nino has made the meteorologist’s job much harder because it has generated much more unstable and unpredictable weather patterns.”
Obtaining a significant statistical database is another difficulty confronting scientists trying to ascertain whether extended or permanent environmental changes are taking place in the earth’s atmosphere and ocean waters.
Without a satisfactory database, scientists cannot know for sure whether detected increases in atmospheric temperatures, for example, represent a steady increase over time or merely reflect peak temperatures along naturally fluctuating curves.
Sagarin acknowledges that the 60 year disparity between the two Bay studies does call into question the implications of the new data.
“The gap in time does create some uncertainty in terms of what we’ve found,” he says. “There isn’t enough statistical correlation, between studies for us to be able to stay with certainty that the increases in warm water marine invertebrates can be accounted for solely because of El Nino or global warming. There aren’t enough data points since Hewitt to know for sure how or when the changes began to occur.”
“While this study doesn’t prove global warming, it does demonstrate significant faunal changes attributable to a major temperature change,” says Baxter. “And it does provide some significant hard data that can be used as indices of global warming.”
Baxter, Sagarin and Gilman’s look at warming trends are just one among many research projects going on at 12 different local institutions.
The area boasts a 100-year tradition of pioneering oceanic and atmospheric research that began with the founding of the Hopkins Marine Station in Pacific Grove in the spring of 1892 at the very first marine laboratory built on the Pacific Coast.
Area oceanographers and meteorologists working for a diverse group of academic, private, and government research institutions are at the vanguard in the design, testing, and application of highly technical monitoring devices and computer-generated global weather models that will hopefully provide data to better understand the interaction of ocean and atmosphere.
“Many people are predicting that by the year 2000, Monterey will be this country’s major center for oceanographic and atmospheric study,” says Parker of NOAA. “This is a vigorous, productive, and exciting place to be for oceanographic research.”
For Parker as well as for many other locally based oceanographers, the establishment of the Monterey Bay National Marine Sanctuary has contributed significantly towards making the Monterey area even more ideal for studying the effects of ocean and atmospheric warming.
“The designation of the Bay as a marine sanctuary keeps our ‘laboratory’ natural and helps minimize the influence of man’s activities,” says Parker. “By eliminating unwanted drilling, shipping, and dumping off our coastal waters, our scientific findings will be more representative of what would be found in a completely natural ecosystem.”
The very existence of so many research institutes also works to facilitate the examination of the effects of warming on the earth’s oceans.
Francisco Chavez, an associate scientist at the Monterey Bay Aquarium Research Institute (MBARI) for the past six years, says the geographic proximity of so many different research institutes has led to the emergence of the Monterey area as a leading center of scientific study.
“This area is unique because it is small enough geographically to allow various disciplines to work together more readily,” says Chavez. “It’s much easier to share information and ideas. There’s a lot of contact here you don’t find elsewhere.”
Chavez is one of the leading researchers in the study of El Nino and the relationship between phytoplankton productivity and changes in atmosphere and ocean temperature. He is currently at work developing mooring systems with on-board computers, sensors, and instrumentation that can monitor physical, chemical, and biological changes in the ocean.’
“Currently, our ability to measure is not as good as it can be,” said Chavez. “With these new remote monitoring systems, scientists will be able to obtain up-to-date information on an hourly basis by a simple cellular phone call.”
For researches at MBARI and the Moss Landing Marine Laboratories (MLML), the proximity to shore of the 4,000 meter deep Monterey Submarine Canyon has greatly facilitated testing of the deep water monitoring devices needed to examine warming trends out in the open ocean.
Operated by a consortium of six campuses of the California State University, MLML is currently completing testing of the fiber optical system of computer software of the Marine Optical Buoy (MOBY), which is designed by MLML staffers to measure the productivity of phytoplankton in the ocean waters.
Upon completion of testing early next year, MOBY will be moored permanently off Lanai in the Hawaiian Islands, where it will be used to help calibrate a new generation of satellites designed to measure ocean color, sea surface temperature, and phytoplankton concentrations.
“The main goal of the MOBY and satellite project is to track future ocean warming and plankton growth from space to see if phytoplankton growth increases with increases in ocean temperature,” explains William Broenkow, an MLML professor and researcher at MLML who supervised the MOBY project.
Phytoplankton, the microscopic marine plant life at the origin of the food chain, has become the focus of research for MLML scientists. Phytoplankton are responsible for absorption of carbon dioxide (CO2) in the atmosphere, which is believed by many scientists to be a major cause of global warming.
We hope to predict how much CO2 will be removed from the earth’s atmosphere, by tracking global, phytoplankton productivity,” says Broenkow.
Meanwhile, the work of United States Navy scientists in Monterey over the past 30 years has already provided an invaluable source of marine and weather data for civilian researchers. Beginning next year, the Fleet Numerical Oceanography Center will join forces with NOAA and the National Weather Service to form the Marine Prediction center and create what John Hovermale, superintendent of the marine meteorology division of the Naval Research Lab, calls “…the best data base in the world for oceanographic and atmospheric information.
“While the exact nature of the relationship and some classification issues are still to be resolved in Washington, the Navy and National Weather service will exchange data and share a common database,” Hovermale added.
“The creation of the Marine Prediction Center reflects the general spirit at the top of the local research community that wants to make the Monterey Peninsula an even greater center for scientific excellence.”
Like the rest of his colleagues, MBARI’s Chavez hopes the improved monitoring devices will provide greater insight into the interaction of ocean and atmosphere.
“So far there have been no major breakthroughs,” says Chavez. “We can’t say with certainty that we are in a warming trend.”
As a result of their initial findings, both Gilman and Sagarin see a need for additional data to create a clearer picture of the changes taking place in the coastal environment of Monterey Bay
“The biggest implication of our study is that species composition can be very useful in measuring long-term environmental changes,” says Gilman
“We need to do this study on a consistent basis,” adds Sagarin. “I hope this project will continue.”