Growth rates of 7 species of Caulerpa were measured in sifu at depths of 20 m in Salt River canyon, St. Croix, US Virgin Islands. Mean stolon elongation rate for all species of Caulerpa studied was approximately 1 cm d-l. Dry biomass accumulated in this new growth was less than 10 mg d-', and specific growth rates were less than 10 % d-'; these values are low compared to rates of many benthic macroalgae. Macrofauna (conchs, ghost shrimp, hermit crabs, urchins, rays) were observed disturbing sediment. Plants were uprooted or buried by animals that foraged, burrowed, and made excavations or sediment mounds. Plants experimentally uprooted or burled to simulate effects of animal activities had significantly lower stolon elongation, biomass accumulation, and specific growth rates than control plants. We hypothesize that the productivity of these algae is limited in part by animal-mediated sediment disturbances.

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A marine biomass program was initiated in New York in 1980. Preliminary screening studies indicated that Laminaria saccharina L. is a good candidate for growth in seaweed/rope culturing systems. numerous laboratory tank and field raft‐culture experiments have examined the relationships between growth and ambient light, temperature and nitrogen levels throughout the year. Laminaria sporophytes appear in the field during the spring and late summer. Maximum growth rate (up to 8%•day‐1) occurs in the fall and spring. During the winter months, growth continues at 0.5 to l%•day‐1 while temperatures range from ‐1 to 4°C. A rapid increase in growth rate is observed when temperatures approach 6°C in late March. Growth ceases during the summer months and mature blades erode from distal portions. Much of the field population disappears during the summer months, while plants on rafts show greater survival. During the summer months of 1983, a small‐scale rope culture farm will be deployed and stocked with young Laminaria sporophytes.

A nonenzymatic technique using dilute salt solutions effected rapid release of viable protoplasts from mature bean (Phaseolus vulgaris L.) pollen. Protoplasm release started within 30 sec and was completed within 5 min in solutions of 0.02 to 0.06 m NaCl, or KCl, pH 6 to 9. The degree of release could be altered by changing the concentrations and ratios of CaCl2 and H3BO3 and by adding sucrose to either solidified or aqueous salt media. The surface of nonenzymatically released protoplasts was partially digested by short-time exposure to a mixture of cell wall-degrading enzymes and then examined by scanning electron microscope.