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Aspects of the life history of Porphyra dioica collected in Porto, Portugal, were investigated under laboratory and field conditions. This is one of the most common Porphyra species on the north coast of Portugal and can be found throughout the year. Field studies showed higher percentage cover, from 23% to 66%, from February to May in 2001 and 2002, compared to other times of the year. The effects of temperature, photon flux density (PFD) and photoperiod on growth and reproduction were tested. Zygotospores germinated fastest at 15°C and a PFD of 25 μmol photons m−2 s−1. Growth rate of the conchocelis was more affected by temperature than by photoperiod. In the three photoperiods tested, growth rate was maximal at 15°C, under 25–75 μmol photons m−2 s−1. Conchosporangium formation was greatest at 15°C, 25–75 μmol photons m−2 S−1 light and short-day, 8: 16 h light–dark conditions. In all conditions tested, conchosporangium formation was almost nonexistent in free-floating conditions. Optimal conditions for conchosporangium maturation (15°C, 8: 16 h light–dark and 5–25 μmol photons m−2 s−1) also promoted spore release after 18 weeks. Aeration appeared to be crucial for normal blade development. No archeospores were observed. Preliminary findings of the conditions for growth of the gametophyte stage are also discussed.

The sea urchin, Mesocentrotus nudus, is widely distributed in North West Pacific regions. It has a substantial impact on macroalgal communities as a generalist herbivore. This study examined various aspects of its feeding ecology, including algal preference, foraging behaviors, and possible effects of past feeding history on its algal preference. We used six common algal species (Ulva australis, Undaria pinnatifida, Sargassum confusum, Dictyopteris divaricata, Grateloupia elliptica, and Grateloupia angusta) from the east coast of Korea as food choice in a series of indoor aquarium experiments. The first choice of starved M. nudus was exclusively U. pinnatifida, followed by G. elliptica and S. confusum. Unlike large urchins, small urchins equally preferred U. pinnatifida and G. elliptica. On the other hand, Undaria-fed urchins preferred to feed only G. elliptica, although its preference slightly differed over time. We then grouped sea urchins into three categories (starved, Undaria-fed, mixed species-fed) to observe 12-days feeding preference as well as early foraging movements. Foraging behaviors of the three groups were distinctively different, although they could not completely reflect the actual consumption. For example, U. australis was highly attractive, but rarely eaten. Undaria-fed urchins seemed to stay with only S. confusum and U. australis. This study demonstrates that M. nudus shows high flexibility in food preference depending on past feeding history and body size. Its foraging behaviors are also affected by past feeding conditions, exhibiting active chemoreceptive movements.

The President’s Global Hunger and Food Security Initiative, titled “Feed the Future (FTF)”, has the overarching goal of sustainably reducing global poverty and hunger (www.feedthefuture.gov). Providing sufficient food to the world’s growing population will require a 70 percent increase in agricultural production by 2050 (Bruinsma 2009). To meet this food security challenge under constraints of limited agricultural land availability and increased climatic variability, the world will need to support and develop scientific and technological innovations that increase agricultural productivity in an environmentally sound manner while improving the availability of nutritious foods.

The food price spikes of 2006-2008 and that are resurfacing today underscore the fragility of global food security, with recent estimates that nearly a billion people are food insecure (Shapouri 2010), affecting families in the United States and around the world. While the causes were many, the underlying challenges are clear: the world cannot achieve the Millennium Development Goals (http://www.un.org/millenniumgoals/) relating to hunger, poverty, health, gender and the environment when the growth of agricultural productivity and income stagnates or is otherwise insufficient. The global research portfolio, presented here, serves as an integral strategy within the broader Feed the Future Initiative.

Consequences of congeneric quantitative variation in secondary metabolites of seaweeds on diet specificity and host association in specialist marine her- bivores have received little attention. We investigated quantitative variation in caulerpenyne and oxytoxin 1 in 7 species of green seaweeds from the genus Caulerpa, along with the feeding preferences and host associations of 4 co-occurring sacoglossan molluscs. C. taxifolia and C. sertularioides contained high concen- trations of metabolites and were preferred least by all herbivores. Algae with intermediate metabolite con- centrations (C. racemosa, C. serrulata, and C. cupres- soides) were preferred by Elysia tomentosa and Lo- biger viridis. Oxynoe viridis and Stiliger smaragdinus had strong preferences for different low concentration Caulerpa species (C. racemosa var. laetevirens and C. lentillifera), suggesting not all feeding preferences are based exclusively on the major metabolites. In situ host associations of L. viridis and S. smaragdinus mirrored their feeding preferences, but this was not the case for E. tomentosa. Furthermore, those algal species with the highest and lowest metabolite concentrations had the lowest overall densities of sacoglossans. The results im- ply that the direct influence of quantitative variation in Caulerpa chemistry may only be limited to host associa- tions in some sacoglossans. However, feeding pressure from multiple herbivore species with unique prefer- ences could still contribute to variation in chemical defence amongst congeneric algae.