Seasonal variation in total dietary fiber content of Delmarva seaweed

Seaweed is a cash crop industry used as a source of food all over the world in countries such as Japan, Ireland, and Scotland. Within the United States' Delmarva Peninsula, there is an abundance of seaweed that has not been used as a source of food or substance for bettering human health. In this study, a nutritional analysis of total dietary fiber (TDF) in three edible seaweeds, Fucus vesiculosus (Phaeophyta), Gracilaria tikvahiae (Rhodophyta), and Ulva lactuca (Chlorophyta) collected from Chincoteague Memorial Park, Chincoteague, VA, and Indian River Inlet, DE, was conducted to establish seasonality of TDF, and investigate site variations during summer, fall, and winter 2006 and spring 2007. Water quality data such as temperature, salinity, and pH were measured on each sample date with a multiparameter YSI unit. Water temperature varied from 20.4°C (DE) to 29.5 °C (VA) in summer 2006 and 1.1 °C (DE) to 3.2 °C (DE). Salinity varied from 18.7-30.38 ppt (DE) and 23.8-28.3 ppt (VA) while the pH remained constant between 7-8 at both sites. Fucus was a common species between the two sample sites, and varied in TDF from 40.12%-65.3% (DE) and 45.6%-76.8% (VA). Gracilaria, available at the Virginia site only, ranged from 47.2-55.3%, and Ulva ranged from 42.6%- 51.0% (DE) (not enough collected for Virginia site seasonal analysis). T-tests for paired samples (á=0.05) were conducted to investigate perceived seasonal differences in the fiber data. There was significance in fiber content as Delaware Fucus decreased between summer and fall 2006 and Virginia Fucus increased between winter 2006 and spring 2007. Additionally, fiber content of Virginia Fucus was significantly higher than Delaware Fucus in winter 2006 and spring 2007. As plant age is correlated to TDF content, it is possible that the ages of the samples collected in Virginia were older than that of Delaware.