Kemp's Ridley Sea Turtle Waste Characterization Study: Precursor to a Recirculating Holding System Design

The decreasing population of the endangered Kemp's ridley sea turtle ( Lepidochelys kempi ) has necessitated research into more cost effective captive nurseries. Captive nurseries are an attempt to increase the survival of the Kemp's ridley past the first year of life. Presently, Kemp's ridleys are reared in captivity at the Headstart rearing facility in Galveston, Texas. This facility consists of a labor intensive, flow-through system. Alternatively, recirculating systems permit development of inshore facilities with decreased labor and operating costs. This paper presents baseline excretion data necessary for designing filtration units required for water quality maintenance in recirculating holding systems. The total ammonia nitrogen excretion rate based on a 24 hour isolation period (fed) was fairly constant at 0.19 mg N/g-turtle-day, while the BOD₅ loading rate was highly variable, averaging nearly 0.50 mg O₂/g-turt1e-day. In addition, comparisons of filtered versus nonfiltered samples suggest that a suspended solids removal mechanism prior to the filtration unit would dramatically decrease BOD₅ and, thus, improve filter efficiency and increase its capacity.