|Wilcox planned to observe the San Clemente farm for two years.
However, in January 1975, a corner anchor broke loose from the bottom and
the submerged rope grid floated to the surface, where it was destroyed
by a passing ship or by wave action. The other two farms experienced
similar fates: the Corona Del Mar structure disappeared without a trace
and the Catalina farm grid was destroyed by wave action. Although
none of these early ocean farm experiments were successful, North was able
to accumulate some data on nutrient uptake in an open ocean setting.
More importantly, an increasingly realistic interpretation of farm structure
design, construction, and particularly anchoring requirements was gained.
Preliminary results also indicated that fish grazing pressures were low
on the farm, compared to those in natural beds nearby.
Phase two of Wilcox's plan called for the construction of a Quarter Acre Module (QAM), designed to accommodate kelp plants in deep water. In the future, Wilcox envisioned that many of these modules would be combined to form a large marine farm. The QAM design was much sturdier than the grids of 1974 and included diesel engines to pump nutrient-rich water from depth to feed the plants. The Gas Research Institute (GRI), a research arm of the American Gas Association, engaged the General Electric Corporation (GE) to build the QAM. QAM's design resembled an open umbrella, suspended point first beneath the surface. During the first six months of 1978, the final design of the test farm was completed, along with plans for its construction and deployment.
The test farm was composed of four major sections: mooring, machinery buoy and substrate arms, upwelling pipe, and a protective curtain. The mooring system, designed to hold the QAM in place five miles off of Laguna Beach, CA, was composed of three sixteen-foot-diameter buoys, each connected to a 15,000 pound anchor. The three anchors were placed at the vertices of an equilateral triangle that was 550 feet on each side. The main part of the QAM structure consisted of the machinery buoy and substrate arms. The buoy contained two diesel engines used for artificial upwelling, and also provided support for the substrate arms that were designed to hold up to 150 adult kelp plants. The substrate arms consisted of six sixteen-meter-long, tapered stainless steel poles, attached to the base of the machinery buoy. Strands of polypropylene line connected the arms to each other and also served as a substrate for the kelp seedlings. Together, the machinery buoy and attached substrate arms had a dry weight of 110,000 pounds.
The third section was a 1,465-foot upwelling pipe, designed to draw 8,900 gallons per minute of nutrient-rich water from a depth of 1,500 feet. The final component added to the test farm was a current-retarding curtain, which was designed to act as a barrier around the machinery buoy, reducing surface currents and helping concentrate nutrients in the vicinity of the kelp plants. By August 1978, the QAM mooring system was installed and in September, the machinery buoy/substrate assembly and upwelling pipe were anchored in 1,800 feet of water off Laguna Beach, CA. North then assembled a team of divers to attach 100 adult plants to the QAM during the first week of December. Shortly afterwards, North's research group began collecting data, including weekly growth measurements of juvenile fronds, analysis of dissolved nutrients in water samples, and blade tissue analysis.
Immediately after installation of the QAM, the protective curtain began tearing at the points of attachment, and by the end of December, it was completely gone. The effect of December storms on the now unprotected farm was devastating. Strong waves and currents produced abrasion between the plants and the farm structure, until by February there were no transplants left. This first test of the QAM farm structure demonstrated a need for modification in order to minimize plant abrasion and for a stronger current-inhibition system. Researchers also recognized that improved plant selection, transplanting, and attachment techniques would improve chances of survival. Most importantly, it was realized that further date were required to understand the hydrodynamics of the kelp plants relative to wave-induced motion of the QAM (pitching and heaving). These factors were obviously crucial to successful cultivation of kelp on an artificial substrate in the open ocean.
Studies of methane production from kelp were more successful than the kelp farming efforts. In 1977, General Electric explored methods for transforming organic matter (kelp) into methane by micro-organisms in the absence of air. This anaerobic microbial process is called anaerobic digestion, by which organic matter is decomposed and bioconverted into biogas—a mixture of methane and carbon dioxide. Researchers found that kelp was readily degradable in saline culture and that addition of supplementary nutrients to the bioreactor (a tank in which the digestion occurs) was not necessary. The kelp digestion rate was insensitive to drastic reductions in particle size, and methane yields approached 71% (methane) per pound of kelp, greater than any other known biomass source at the time.
The QAM was originally scheduled to be a two-year project. However, the winter storms and the resulting loss of all adult plants limited the project to a two-month period. Nonetheless, between May and August of 1979, juvenile plants appeared on the QAM, presumably offspring arising from spores liberated by the adult transplants attached five months previously. North took advantage of this unexpected source of data and measured growth rates, plant mortality, and nitrogen content of the juvenile plants. He was also able to determine which of the farm's components provided the best surfaces for plant attachment. Although a higher survival rate was recorded for plants on the substrate arms and planting buoys, the best survival rate was among those plants attached to the moderately rough surface of the polyester support ropes. Although the QAM was able to provide anchorage for a number of juvenile kelp plants, these fell prey almost immediately when a population of fish grazed on the structure. Unfortunately, before any significant collection of growth data, the QAM disappeared during a storm in 1979.
Although the QAM generated useful data on substrate engineering, General Electric was unable to meet the goal of obtaining data on yield potential of adult giant kelps. The lack of data may in part be attributed to the gap between engineering and biological approaches to the farming problem. This was particularly evident in the QAM experiment, where the structure destroyed the plants. In fact, movement of the structure caused plants to wrap around the arms, where they were abraded and beaten into pieces. Without growth data for farmed Macrocystis there was no way to determine whether Wilcox's projected energy yields were possible.
Near Shore Farming
In order to guarantee adequate growth data, the Gas Research Institute (GRI) also contracted with Michael Neushul, a marine biologist at U.C. Santa Barbara, who began farming marine algae off the coast of Santa Barbara in 1978. Neushul joined the marine biomass program after the grid and QAM experiments. In 1980, Neushul Mariculture, Inc. (NMI) installed a near-shore farm in thirty feet of water, on a sixteen acre lease site at Elwood Beach in Goleta, CA. Two plots were installed (control and experiment), each consisting of a sixty by forty meter combined chain and rope grid. The chains were attached to concrete "slab" anchors. A total of 722 Macrocystis were planted at intersections of rope and chain using eighty pound gravel bag attachments. Plants on the perimeter of the plot were spaced one every sixteen square meters. Further in, the medium density plants were spaced one every four meters. The highest-density sector was located at the center of the plot, with plants spaced one every square meter. A drift cable was installed on the seaward side of the two plots in order to prevent plants torn from natural beds from entangling and detaching farm plot plants.
The Elwood farm was ideally located due to its isolated location and the close proximity of the Arco Oil pier. Most importantly, kelp grew naturally in these waters and the plants were not subject to the rough water experienced in the previous offshore experiments. NMI's objective was to record the effects of transplanting, handling, cultivation, density, fertilization, and harvesting on a population of farmed giant kelps. Ultimately, the near shore experiment was designed to obtain growth data for farmed marine biomass.
NMI's near shore farm, GRI's final project, was the most successful experiment in the marine biomass project. Harvest data from the experimental plots were collected up until 1985. During the final years of the biomass program, NMI also completed a comparative study of the effects of environmental conditions on natural and cultivated beds of Macrocystis. They also continued their research on genetically engineered kelp. Michael Neushul took the position that Macrocystis was itself an ideal farm structure with floats, lines, and even anchors produced vegetatively. NMI's genetic research demonstrated that the basic structure of the kelp plant could be drastically changed, creating marine algae with larger floats and stronger stipes. This caused NMI to conclude that perhaps it would be easier to genetically fabricate or engineer open ocean farms rather than to grow the existing algae on man-made structures.
Review of the Marine Biomass Program
Howard Wilcox's estimation of the prospects for farming the ocean were based upon a 2% efficiency for converting solar energy into plant material, a 5% efficiency for production of human food, and a 50% efficiency for the production of fuel and other products. Assuming these numbers are correct, one square mile of sea surface would produce enough food to feed 3,000 to 5,000 persons, and enough energy to support more than 300 persons at current U.S. per capita consumption levels. Since the oceans contain 80 to 100 million square miles of arable surface water, the marine farms could support a world population of more than twenty billion persons. NMI's estimate of 1% efficiency for solar conversion into marine biomass was considerably more conservative than Wilcox's earlier number. This number was later confirmed by harvest data taken from the Elwood farm.
The contrast between optimistic and conservative views of maricultural potential is summarized by illustrations of existing and future farms that have been published. These serve as "samples" of past views and draw attention to specific aspects of the GRI program. For example, in 1974, an illustrated article in Newsweek carried the heading "Four-H Frogmen" and a quotation from Wilcox that "It's not high technology... we're just talking about plain old plants growing." Wilcox's initial optimism and "low tech" approach was misleading, to say the least, especially considering that the 1972 program began with the primary objective of proving that macroalgae (kelp) could be farmed. It was not until 1982-83 that NMI produced the first (and only) yield data. Unlike the Wilcox/GE group, NMI began their experiments with the assumption that Macrocystis was exceedingly complex and hence difficult to cultivate. NMI's results justified this approach, as they concluded that the success of marine farms hinged upon a sound program of hydrodynamic measurements. In other words, marine farming entailed a lot more than simply tying a plant to a structure anchored in the ocean.
Criticism of the GRI project also demonstrated the general lack of knowledge in the U.S. about marine farming. For instance, a Washington Post cartoon appearing during the project, highlighted the loss of 100 kelp plants attached to Wilcox's first test farm. What the author failed to understand was than even though giant kelp are large and tree-like, they are really ephemeral. In fact, up to a third of all plants in California beds are annually lost to storm and grazing damage. The loss of all plants in an experimental planting is not unusual, depending upon the environmental conditions. Here again, the focus on farm structure as opposed to the actual crop drew attention away from the most important aspect of marine farming—the plants themselves.
Despite the misconceptions that plagued the Ocean Food and Energy Farm, Wilcox's projection of 2% efficiency in conversion of sunlight to energy was not realistic. As mentioned above, NMI's near-shore growth data demonstrated a 1% efficiency (conservative estimate), a number that confirms the viability of marine biomass as a source of energy. NMI also demonstrated that Macrocystis has an exceedingly high rate of biomass production (fifteen dry ash-free tons per acre per year), and that the plants can withstand quarterly harvests where up to half of the biomass is removed. Furthermore, survival of plants following repeated harvesting showed that substantial yields were possible without changing the standing crop.
Review of the marine biomass program provides valuable lessons for future development of marine farming. Of the many difficulties that plagued initial efforts to farm the sea, one in particular, stands out—the lack of communication between engineering and biological communities. The project began with the assumption that marine farming would not be technically difficult. Wilcox's statement that "It's not high technology... we're just talking about plain old plants growing," illustrates this lack of understanding. Ten years later, after the work of two contractors and several major experimental farming efforts, there was still no yield data for farmed Macrocystis. Plants were entangled with the farm structures, consumed by fish, infected, or dislodged and destroyed by storms. By 1980, it was apparent that building a "false bottom" for kelp plants in the open-ocean was not a "low-tech" task. Attempts to protect the structures with a fabric current shield (ripped away) also met with failure. While marine engineers learned from the QAM and grid experiments, biologists were unable to obtain any significant growth data from the experiments.
Many of the problems associated with marine farming were due to constraints on the overall Marine Biomass Program. In particular, Wilcox's original concept required an enormous amount of marine biomass, near-shore work was not deemed to be worthwhile. This resulted in an approach that required both engineers and biologists to "walk before they could crawl," an obstacle that contributed to the lack of data generated by the early open-ocean experiments. Without this crucial growth data, there was no way of testing Wilcox's theory about the biomass potential of marine farming. NMI produced these data by planting and harvesting a near-shore marine farm. Current efforts to revive the program should take particular care not to overlook the experience of earlier investigators. Marine plant specialists must be involved from the very beginning and should play an active role in the design of farming structures. From an engineering perspective, the grid and QAM experiments were somewhat useful in that they highlighted the many problems encountered in placing artificial substrates in deep water. However, the lack of significant growth data demonstrated that the success of marine farming did not hinge solely upon the ability to anchor the structures in the ocean. In particular, engineers needed to account for the hydrodynamic requirements of the marine plants that they were attempting to grow. Future project managers must place the plants first in order to succeed in the production of marine biomass.
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