Dive Dry with Dr. Bill

108: Marine Biology the New Fashioned Way

The earliest marine biologists undertook their studies without the benefit of SCUBA equipment. Some studied the intertidal regions where the chances of being totally submerged were usually slim to non. In fact "Doc" Ricketts would probably never have taken to SCUBA since he reportedly hated to get his head wet and wore a hat while collecting (and some say even in the shower). Other ocean-going biologists like those on the Challenger Expedition from 1872 to 1876, the first true oceanographic voyage, worked entirely on ship. My early work in the 60's and 70's benefited from all three approaches.

However, when it came time to write my dissertation, my professor suggested I try using new computer-based technologies rather than writing up all the data I had gathered while teaching and researching here at Toyon Bay. Being a computer nut at the time, I decided I really wanted to incorporate this technology into my studies. I decided to merge images of kelp beds around Catalina acquired by orbiting satellites with the "new" technology of geographic information systems (GIS). It was a ground-breaking study with many interesting results.

After decades on Catalina, I knew that kelp beds around the island were very dynamic. Beds like those near Torqua Springs that were so thick decades ago that I had to dive down to the holdfast level to swim through them later disappeared. Each year I noticed that some beds were richer, and some thinner, than the year before. Kelp beds and ecosystems are dynamic (remember "shifting baselines?"). Using a GIS allowed me to take data from several different years and analyze it all at once. I could look at the shifting patterns of kelp distribution between years, and try to define areas where kelp persisted, and areas where it was only present sporadically, year-to-year.

Since data was hard to find in 1990, I needed to create my own Catalina GIS. To do so I spent months using a device similar to a computer mouse to trace the elevation contours for the whole island from a USGS map placed on a special sensor table. The result was a three-dimensional "digital" (computer) map of the topography of Catalina. I then "digitized" the submarine depths to create a continuous surface from the top of Mt. Orizaba down to 600 ft. below sea level around the island. From this I could create computer "maps" that showed the depth (or elevation) at any point, the slope of the underwater topography, the compass angle it faced (aspect), and other physical parameters of the environment. I even created a digital model of a storm event to look at wave exposure.

With these base data prepared, I looked for maps of the kelp beds around Catalina to add to my model. There was relatively little data available, but I did get a NOAA map from 1934, a 1980 map produced by Southern California Edison, and a 1979 map of the West End. To these I added kelp maps I created from the kelp visible in several satellite images. With these data, I then created a kelp "persistence" map by establishing whether kelp was present in 0, 1, 2 or up to 5 years in my study data. This new persistence map showed were kelp was present most frequently (values of 4-5) and least frequently (0-1) through the 60 years of the study. With this GIS, I was able to show correlations between a number of physical factors like depth or wave energy and the distribution or persistence of kelp, and write a 708 page dissertation that is an excellent door stop or cure for insomnia!

Much as I loved doing such groundbreaking research, it kept me in front of a computer screen or digitizing table too much of the time. I was studying electrons more than I was studying real kelp. I think this was a big part of my desire to get back into diving and see the real thing again. Now after five years of an intense return to SCUBA, I can integrate both the computer-based and diving-based perspectives for a more comprehensive picture as a scientist.

While a marine biology student at Harvard in the late 60's, my professor and I both discussed the concept of a computerized geographic information system very similar to today's GIS. In fact, we worked together on a computer program that took IBM punch cards and produced very early computer maps (using X's and O's) of starfish distributions in the world. Little did we know that nearby in Harvard's School of Design some of the early work on what would become GIS was being done by fellow student Jack Dangermond who founded Environmental Systems Research Institute (ESRI) that makes the GIS software I use today.

My march towards high tech marine biology was derailed for 20 years when I walked home from the Harvard Computer Center late one night and slipped on the ice and slush of Massachusetts Avenue, sending my freshly-punched deck of IBM cards flying all over the street. Remember the "don't bend, fold, staple or mutilate?" Well, they didn't say anything about slush. I put in an "all-nighter" in the Computer Center punching a new "deck of cards" since we had a 9:00 AM computer run and time was difficult to come by when there was only one behemoth computer on the entire campus! Things are much easier and more convenient today. Remember that next time you get Bill Gates' sinister Windows blue screen!

© 2004 Dr. Bill Bushing. Watch the "Dive Dry with Dr. Bill" underwater videos on Catalina Cable TV channel 49, 10:00 AM and 5:00 PM weekdays.

GIS map showing regions of high kelp persistence (brighter) around Catalina's West End.

This document maintained by Dr. Bill Bushing.
Material © 2004 Star Thrower Educational Multimedia