There are various types of farmers' markets； depending on the type used, the markets have both advantages and disadvantages for fishing households. In reality, fishing households utilize multiple farmers’ markets as sales channels because utilizing multiple markets offers advantages for fishing households. However, previous research on direct sales using multiple different types of farmers' markets are limited. Taking the Tabuse Fisheries Improvement Group “Shinsen Tabuse” as a case and confirming the benefits and drawbacks of direct sales using multiple farmers’ markets as sales channels, we examined the significance of direct sales using multiple sales channels. The results revealed that there were both advantages and disadvantages for fishing households, depending on the characteristics of the farmers' markets that fishing households utilized. We also found that utilizing multiple sales channels in direct sales helped avoid the accumulation of product stock, and fishing households acquired more customers.

To ensure the stable supply of the euglenophyte Eutreptiella eupharyngea in the seed production of bivalves during the winter, we evaluated the growth potential of E. eupharyngea under low water temperatures through laboratory and outdoor experiments. In laboratory experiments, no significant difference was found in the maximum yield of E. eupharyngea between water temperatures of 10 and 20℃, whereas the maximum yield of the diatom Chaetoceros neogracile known as a common diet alga for the seed production of bivalves significantly decreased at 10℃ compared with 20℃. In an outdoor experiment on a 150-L scale at a salinity of 25, furthermore, E. eupharyngea grew well in mid-winter, and reached the maximum cell density of 3.7 × 10^5 cells mL^–1. During the outdoor experiment, water temperatures ranged from 0.5 to 23.7℃, with a mean of 10.7℃. Although the water temperature in the mass-culture tank fluctuated significantly with the weather and day or night, E. eupharyngea maintained more than 2.2×10^5 cells mL^-1 for 12 days. Therefore, E. eupharyngea may contribute to the stable supply of the feed throughout seed production of bivalves in late fall and spring.

The influence of temperature on the hemolymph CO_2 solubility coefficient (αco_2, µM/L/torr) was investigated in the marine bivalves, akoya pearl oyster Pinctada fucata martensii, Pacific oyster Crassostrea gigas and noble scallop Mimachlamys nobilis. Hemolymph samples were equilibrated with standard CO_2 gas mixtures to obtain expressions for αco_2 as a function of temperature. Relationships between hemolymph αco_2 and temperature (T) were expressed as follows： αco_2 = 76.88145 − 2.62637 ･ T + 0.036203 · T^2 (for P. fucata martensii), αco_2 = 94.2109 – 3.6252 · T + 0.0554 · T^2 (for C. gigas), αco_2 = 70.4591 – 1.5253 · T + 0.0103 · T^2 (for M. nobilis). In the distribution of hemolymph αco_2 values, there was no statistical significance across an interspecies comparison of αco_2. From this result, the regression was fitted using all values of αco_2 and temperature across the species, and the relationship was expressed as follows： αco_2 = 182.3717 – 24.3932 · T + 1.6396 · T^2 – 0.0492 · T^3 + 0.000536 · T^4. This polynomial is versatile equation and would yield the hemolymph αco_2 at arbitrary temperature, even with different species.

This study clarified the structures and seasonal changes of the annual Zostera marina population from April 2003 to November 2004, growing at Tategami-ura, Ago bay, Mie prefecture. Productive structures showed the graminous types excluding flowering period (May-June). Biomass and shoot density reached maximum values in May-June. At that time, over 80% of shoots were flowering shoots. And then, all shoots were disappeared in summer. From October-November, a lot of seedlings recruited and grew to flowering shoots by next spring. Maximum daily net production showed 4.50 g m^-2 day^-1 in June, which was similar level to that of the perennial Zostera marina population. However, yearly net production (305.0 g m^-2 year^-1) showed lower than that of the perennial type. Yearly maximum biomass was 152.6 g m^-2, and production/biomass (P / B) ratio was 2.0. It is necessary to more research in the production because the biomass and shoot density of the annual population verify drastically year to year.

We investigated the oxygen consumption and resistance for hypoxia in captivity of coral trout grouper Plectropomus leopardus. The fish with an average bodyweight 3 g consumed 515, 667 and 654 mg/kg/h of oxygen at water temperature 25, 27 and 30℃, respectively. On the other hand, one with an average bodyweights 5 g consumed 468 and 804 mg/kg/h at 25 and 30℃. The former groups recorded a decrease in oxygen consumption rate from 5 mg/L. The latter groups recorded from 4 mg/L. In a water temperature ranges from 25 to 30℃, 3 g fish began to die at dissolved oxygen levels of 0.99 to 1.06 mg/L (oxygen saturation of 15.4 to 16.0%), while at 0.73 to 1.15 mg/L (oxygen saturation of 11.0 to 18.8%), 5 g fish groups began to die. This is a significant result and gives a scientific impact on hypoxia for coral trout grouper aquaculture.