Tidally Driven Exchange in an Archipelago Strait: Biological and Optical Responses

Measurements in San Bernardino Strait, one of two major connections between the Pacific Ocean and the interior waters of the Philippine Archipelago, captured 2-3 m s(-1) tidal currents that drove vertical mixing and net landward transport. A TRIAXUS towed profiling vehicle equipped with physical and optical sensors was used to repeatedly map subregions within the strait, employing survey patterns designed to resolve tidal variability of physical and optical properties. Strong flow over the sill between Luzon and Capul islands resulted in upward transport and mixing of deeper high-salinity, low-oxygen, high-particle-and-nutrient-concentration water into the upper water column, landward of the sill. During the high-velocity ebb flow, topography influences the vertical distribution of water, but without the diapycnal mixing observed during flood tide. The surveys captured a net landward flux of water through the narrowest part of the strait. The tidally varying velocities contribute to strong vertical transport and diapycnal mixing of the deeper water into the upper layer, contributing to the observed higher phytoplankton biomass within the interior of the strait.

Impacts of Technology Adoption: Comparing Returns to the Farming Sector in Maine under Alternative Technology Regimes

This thesis tests if certain technology choices are associated with a reduction in the proportion of farming activities in the agro-food system in Maine. Goodman, Sorj, and Wilkinson define appropriationism as the replacement of farming sector activities by industrial inputs. Based on the concept of appropriationism, industrial fanning systems using large amounts of synthetic inputs contribute less to fanning than more agrarian systems, like organic fanning. Thus, returns to the farming sector should be greater for organic compared with conventional potato fanning in Maine since organic farming uses fewer industrial inputs. Goodman et. al. define substitutionism as the displacement of farming sector commodities and activities by industrial processes in the marketing sector. Based on the concept of substitutionism, returns to the farming sector should be greater for Lay's Classic®™ potato chips made from natural potatoes compared with Baked Lay's®™ potato crisps manufactured from processed dehydrated potatoes. Returns to the farming sector are defined as returns to the farmer or farm family from farming activities, returns to farm labor, and returns to farmers and farm labor producing inputs used on the farm. Results show absolute returns to the farming sector are less for organic compared to conventional tablestock potato farms in Maine. However as a proportion of farm revenues, large organic farms that market at least 25% of their produce to retail stores or directly to consumers do as well as conventional farms. When comparing returns as a proportion of consumer expenditures, these organic farms do better than conventional farms. Returns to the farming sector are less for organic because of yield penalties, cost of marketing services, and diseconomies of size for organic tablestock potato farms. Expanding acreage and reintegrating livestock with cropping systems may increase returns to the fanning sector. Organic farming demonstrates difficulties in providing marketing services at the farm level. Providing marketing services limits the ability to expand production to capture economies of size. Maine organic potato farmers emphasize non-monetary values such as supporting sustainable agriculture, self-sufficiency, the intrinsic value of work, and close community and family connections. Returns to the farming sector as a proportion of consumer expenditures are about three times greater for Lay's Classic®™ potato chips than for Baked Lay's®™ potato crisps, since the value that farmers receive for potatoes used to produce dehydrated potato flakes in one pound of crisps is about half of the value that farmers receive for potatoes used to make one pound of chips. However, this assumes farmers assign a cost to producing low-grade potatoes for dehydration proportionate to their value. Premium potatoes are used to produce potato chips. Low-grade potatoes are used to produce the dehydrated potato flakes used to make potato crisps. Returns to the farming sector are slightly greater for potato crisps if no costs are allocated to producing low-grade potatoes for dehydration. A shift in consumer preferences from potato chips to crisps may result in a geographical shift of potato production from Maine to the Pacific Northwest assuming no food-grade dehydration facilities are built in Maine.