Challenges Facing Ocean Scientists

diver1t.jpg (15317 bytes)
Diver working the kelp tank at
the Monterey Bay Aquarium

The fundamental goal of ocean science is to understand the ocean in its entirety. Ocean scientists, like all scientists, seek a kind of unified theory of how the ocean works.

But that's not so easy and it's not going to happen anytime soon.

The biggest obstacle to understanding the ocean is its complexity. Ocean processes are interdependent, meaning that one process affects another, which in turn may alter another, which may have ramifications for yet another. The ocean is one big web of physical, chemical, geological and biological processes that all depend on each other.

Unlike terrestrial environments where matter stays relatively put, the oceans are in constant motion. Physical forces cause movements of water, which carries with it chemicals and organisms that feed into geological processes. In this way, the ocean is a system of interdependent physical, chemical, geological and biological processes.

Understanding any one of these processes individually means that we have to isolate it from all the other processes, a scientific approach called the reductionist approach. But as soon as we isolate one component, we change it. It no longer reacts in concert with other processes. Thus, the reductionist approach doesn't allow us to examine the system as a whole.

An alternative scientific approach, the holistic or systems approach, has its own Medusa's head. So many things are happening at the same time that it's hard to say what is causing what. It's nearly impossible to follow the cause-and-effect of individual processes using the systems approach.

Their limitations notwithstanding, both approaches provide valuable information about the ocean. A reductionist approach allows us to isolate the "pieces" of the ocean and understand them bit by bit one at a time. Reductionists figure that once enough is known about the pieces, the whole picture will become more clear (kind of like the TV game "Concentration."). On the other hand, systems scientists subscribe to the belief that there are properties of the system that emerge as a whole. Discerning the system properties becomes the focus of their attention. The best example is the behavior of water, which could never be predicted by studying hydrogen and oxygen all by itself.

Like the National and American baseball teams, the rivalry between the two camps (the reductionists versus the holists) runs quite strong. Next time you meet a scientist, ask them whether they are a reductionist or a holist, then ask them what they think about the "other" guys. Who said scientists don't have strong feelings?

No matter how they feel, ocean scientists still face some pretty formidable operational challenges. The sea can be an angry mistress and more than one ocean scientist has returned home empty-handed and sorely disappointed.

A friend of mine works near Bermuda, where she deploys instruments called sediment traps, designed to collect the little bits and pieces of living and non-living things that sink through the water column. As she came onto station, her buoy, on which several of these sediment traps were deployed, was nowhere to be found. Turns out that another scientist working in the area was using the same code for his acoustic trigger, the series of beeps that tell the buoy to float to the surface. Unwittingly, he had released her buoy and it drifted away, unbeknownst to anyone. Fortunately, the buoy, worth more than $100,000 washed up on shore where a fisherman found it and called in for the $100 reward. Not all scientists are so lucky.

Consider the conditions under which an ocean scientist must work:

Oceanography would not be oceanography if it didn't have a bit of the hardy har-har to it. But the physical limitations posed by the ocean environment play a very large part in determining when, where and how ocean research is performed.

Aside from philosophical and operational challenges, what about the real challenges, the intellectual ones, the scientific ones, the raison d'etre of ocean science? What are the really cool things that ocean scientists are trying to figure out?

The list is almost infinite. Ask any oceanographer what's the most important scientific question facing oceanography today and you will probably get a different answer. I would tell you that accurate measurements of the rate of photosynthesis in the ocean are the most important challenge we face. Other ocean scientists might tell you that the bioluminescent bacteria that live in the photophores of small Hawaiian squid are important. Still others might say that creating mathematical equations to describe the physics of mixing of ocean waters are absolutely vital. The more politically minded might say that understanding the role of the oceans in global warming is critical. A general education oceanography student might tell you that understanding whales and dolphins is the most important thing that we can discover.

To get a firsthand idea of what's hot in ocean science research, march down to your local university and grab a scientific journal that reports the results of ocean scientists' research. You will find a plethora of research topics, some quite esoteric, others more mainstream. Here's a sampling of a scientific journal devoted to lakes and seas, called Limnology and Oceanography, published by the American Society of Limnology and Oceanography (or ASLO).

LIMNOLOGY AND OCEANOGRAPHY Vol. 44, No. 2, March 1999

CONTENTS

CAVENDER-BARES,KENT K., ELIZABETH L. MANN,SALLIE W. CHISHOLM,MICHAEL E. ONDRUSEK,

AND ROBERT R. BIDIGARE. Differential response of equatorial Pacific phytoplankton to iron fertilization

MOISAN,TIFFANY A., AND B. GREG MITCHELL. Photophysiological acclimation of Phaeocystis antarctica Karsten under light limitation

CARON,DAVID A., EMILY R. PEELE,EE LIN LIM, AND MARK R. DENNETT. Picoplankton and nanoplankton and their trophic coupling in surface waters of the Sargasso Sea south of Bermuda

WALLACE,BRETT B., AND DAVID P. H AMILTON. The effect of variations in irradiance on buoyancy regulation in Microcystis aeruginosa

JASSBY,ALAN D., CHARLES R. GOLDMAN,JOHN E. REUTER, AND ROBERT C. RICHARDS. Origins and scale dependence of temporal variability in the transparency of Lake Tahoe, California– Nevada

MURRELL, M. C., J. T. HOLLIBAUGH,M.W.SILVER, AND P. S. WONG. Bacterioplankton dynamics in northern San Francisco Bay: Role of particle association and seasonal freshwater flow

BOSCHKER, H. T. S., J. F. C. DE BROUWER, AND T. E. CAPPENBERG. The contribution of macrophyte- derived organic matter to microbial biomass in salt-marsh sediments: Stable carbon isotope analysis of microbial biomarkers

TRASK,JENNIFER L., AND CINDY LEE VAN DOVER. Site-specific and ontogenetic variations in nutrition of mussels (Bathymodiolus sp.) from the Lucky Strike hydrothermal vent field, Mid-Atlantic Ridge

KELLER,AIMEE A., CANDACE A. OVIATT,HENRY A. WALKER, AND JAMIE D. HAWK. Predicted impacts of elevated temperature on the magnitude of the winter-spring phytoplankton bloom in temperate coastal waters: A mesocosm study

SARNELLE,ORLANDO. Zooplankton effects on vertical particulate flux: Testable models and experimental results

RICHARDSON,ANTHONY J., AND HANS M. VERHEYE. Growth rates of copepods in the southern Benguela upwelling system: The interplay between body size and food.

And so on...

Interestingly (and entirely by random chance), I know a couple of the authors of the publications above. I've sailed aboard research vessels with Bidigare and Mitchell and the work of Van Dover we will encounter in a subsequent lecture. Given the hard work and dedication it takes to get something published in a scientific journal, I can imagine that any of the above authors would pick their research specialty as the most important challenge facing ocean science.

Still, this random listing of ocean research publications might not quite satisfy our urge to know what cool things ocean scientists are doing. Patience, young padwan. You have to know the force before you can play with the light saber.

For now, you'll just have to believe me that ocean scientists are working on some fascinating, mind-altering stuff. As you proceed in your ocean studies, you'll get a firsthand look at the many remarkable stories being uncovered in the sea.