PILOT FLUVIAL SKELETAL TRANSPORT EXPERIMENTS
~1300 bones were soaked in water and chlorine (to reduce smell) for three months to ensure complete saturation. Bones continued to float into the second month, demonstrating bones can float for long (days to months) durations. Samples were transported to southern Utah in water, and were used in two seeding experiments in the East Fork Sevier River, after all twenty-five miles of the river upstream of Tropic Reservoir were walked and preexisting skeletal material removed. During bone removal from the river, all bones found on the flood plain were collected and kept.
A total of three river seeding experiments were initiated, two using presoaked bones, and one using the bones collected during river cleaning. The initial orientation, location, and state of articulation were recorded for all bones in each experiment. The first experiment utilized dry bones collected on the flood plain during the river cleaning, which were seeded in the river on a shallow bar. A deeper river reach was initially tried; however, all bones floated away during placement, so a shallower flow was required. Experiment two utilized only presoaked American alligator bones placed in an experimental array on the river bed in the thalweg. Lastly the majority of presoaked bones were seeded in a short stretch of river in shallow pools, on point bars, and in the thalweg.
Bones from all three experiments were recovered a year later, primarily large elements (limb bones). Bone deposition occurred on the upstream and downstream ends of bars (of any type), in pools, and generally at changes in flow competence. Skeletal material generally assumed the dip of the bed on which they were deposited, while elongate bones and fragments were generally parallel or perpendicular to flow. Bone interactions with the bed seemed to dominate transport and deposition, often involving bones caught in or on vegetation or large rocks. Skeletal material was often found in association with woody debris.