When a body enters the ocean, it undergoes natural processes influenced by the unique marine environment. These processes involve interactions with water, temperature, pressure, and marine life, contributing to its transformation. The fate of remains in the vastness of the ocean is highly variable, depending on numerous interconnected factors.
Initial Buoyancy and Sinking
Upon entering the water, a body’s initial buoyancy is determined by several factors. The amount of air in the lungs plays a significant role; a body with lungs full of air may initially float. Body fat content also influences buoyancy, as fat is less dense than muscle and water, aiding flotation. Clothing can trap air, further contributing to initial buoyancy.
However, the human body is slightly denser than seawater, and significantly denser than freshwater, causing it to sink if no air is trapped. A body that has drowned, with lungs filled with water, will sink faster. As decomposition begins, gases accumulate within the body from bacterial activity, which can reduce the body’s density and cause it to resurface, sometimes days after submersion. This re-floating is temporary, as the gases eventually escape, leading the body to sink again.
Decomposition Processes Underwater
Decomposition in an aquatic environment differs from that on land due to factors such as temperature and oxygen levels. The process begins with autolysis, cells’ self-digestion, followed by putrefaction, the breakdown of tissues by bacteria. Bacteria naturally present in the gut proliferate after death, producing gases like methane and carbon dioxide, which cause bloating.
Decomposition proceeds more slowly in water, especially in colder temperatures and low-oxygen (anaerobic) conditions. The rate of decomposition is also affected by salinity, with saltwater potentially slowing the decay process compared to freshwater, though temperature is a more significant factor.
Marine Scavenger Activity
Marine organisms play a substantial role in the breakdown and dispersal of remains. Various scavengers are attracted to a body, including fish, crabs, and other invertebrates. Smaller bony fish, crabs, and shrimp are known to feed on human remains. These creatures contribute to the rapid consumption of soft tissues, often leaving only skeletal remains.
Scavenger activity varies with depth and oxygen levels. In low-oxygen environments, larger scavengers may be less active, allowing smaller organisms to feed, though some smaller creatures may struggle to penetrate the skin. Scavenging can lead to the disarticulation and dispersal of body parts, such as feet washing ashore, often still contained within footwear due to their protective nature.
Environmental Influences and Preservation
Ocean conditions influence the decomposition process and can lead to the preservation of remains. Cold water temperatures slow bacterial activity, delaying decomposition. Deep-sea environments, with cold temperatures and high pressure, can further inhibit decay. Low oxygen levels, or anoxic conditions, also hinder decomposition by limiting aerobic bacteria.
A form of preservation in aquatic environments is adipocere formation, also known as “corpse wax.” This waxy, soap-like substance forms from the body’s fat through saponification, occurring in moist, anaerobic conditions. Adipocere acts as a protective barrier, slowing further decomposition and preserving the body’s form for extended periods, sometimes for decades or even centuries.
Discovery and Retrieval
The discovery of remains in the ocean can occur in several ways. Bodies may resurface due to gas accumulation during decomposition and be found floating. Ocean currents can carry bodies over long distances, causing them to wash ashore. Remains might also be discovered by divers or submersibles in deeper waters.
Retrieving bodies from the ocean presents numerous challenges due to the vastness and depth of the marine environment. Decomposition, scavenging, and the effects of water can alter the condition of remains, making identification difficult. Specialized techniques and equipment, including sonar and remotely operated vehicles, are necessary for locating and recovering submerged remains. DNA analysis and dental records are used for identification.