All the relevant information was synthesized and interpreted in a technical review and in the form of an ecological risk assessment for SBF discharges to deep offshore waters of the Gulf of Mexico. Bulk SBF s are not permitted for discharge to waters of the Gulf of Mexico, but SBF cuttings are. Discharged SBF cuttings usually contain 5-15 percent adhering SBF s. The SBF cuttings form clumps in the receiving waters and quickly settle to the bottom following discharge to the ocean. The SBF s are biodegradable.
Esters degrade most rapidly.
Biodegradation often causes depletion of oxygen in sediments. The SBF s have a low toxicity to water column and sediment-dwelling marine organisms. However, high concentrations of SBF s in sediments produce adverse effects in benthic communities. The usual response is the loss or decrease in abundance of several species of benthic fauna and an increase in the abundance of a few opportunistic species, leading to an overall decrease in species diversity. This effect is probably caused by organic enrichment of the sediments with biodegradable SBF, leading to sediment hypoxia.