Introduction
The domain of forensic sciences encapsulates a vast range of scientific fields. These fields are not only related directly to scientific knowledge concerning human issues but also to the big world in the form of environmental forensics. This deals with the flora and fauna around us, along with the essential non-living components of nature. One such specific area of environmental forensics is Marine forensics.
What is Marine Forensics?
Marine forensics deals with legal and forensic issues regarding various incidents and crimes involving water bodies such as lakes, oceans, and rivers. These incidents may range from a human accident or death to the illegal killing of endangered species in marine environments. It deals with protecting aquatic life from pollution and population decline due to human activities, and also the lives of humans engaged with various activities in the marine environment, like navigation.
While considering the forensic investigation in the marine environment, DNA analysis and the taphonomy (the process of fossilization) of dead decaying remains play a significant role.
History
The concept of protection of life in the marine environment came with the rise in pollution and other exploitative human activities like the illegal capturing of endangered species. This concern led to the enactment of the Marine Mammal Protection Act of 1972 in the USA.
Further scope of marine forensics was expanded by diving into aspects of marine forensic investigation that dealt with the loss of life and property at sea due to the sinking of a vessel/ship. It was first discussed in 1995 with the formation of the Marine Forensics Panel of ship structures Committee, later expanded to the Marine Forensics Committee of the Society of Naval Architects and Marine Engineers (SNAME).
SNAME organised the first International Marine Forensics Symposium in Washington, D.C. (2012) that discussed various aspects of Marine Forensics Investigation, including analysis of hydrodynamics of the water body, damage to hull structure, etc.
Issues and Cases in Marine Forensics
1. Protection of fisheries and endangered species in the legal jurisdiction of a nation.
2. Species substitution in the consumer market of a high market value species to a low economic value species (seafood business, wholesale markets).
3. Investigation of sunken vessels in the marine environment.
4. Recovery and examination of human remains under decomposition in any water bodies.
5. Underwater investigation in drowning cases or cases of accidents and mass disasters.
6. Tracing of species under threat using DNA.
7. Sampling of evidence in case of harmful incidents like oil spills.
8. Threat to flora and fauna of marine environment due to industrialization.
9. Keeping track of waterborne diseases through surveillance systems such as Waterborne Disease and Outbreak Reporting System (created in 1971) to protect marine life from diseases due to pollution and pathogens.
10. Overall examination of the marine environment by considering factors like temperature, the salinity of water, wind direction, tide patterns, etc., to better understand the policy actions and practical steps to be taken to protect human and marine lives.
Current Scenario
The current scene in the field of marine forensics seems promising. Along with the fields mentioned above, marine forensics has also come to include the pollution and harm caused by petroleum as a product and industry through natural seeps or oil spills during extraction or the transportation of petroleum products. National Oceanic and Atmospheric Administration (NOAA) lab in the US uses its forensic laboratory to analyse 85% of samples of NOAA fisheries due to the 1970 efforts of the congress to protect fisheries, marine mammals and endangered species. It maintains 10,000 samples. Some recent organisations and laboratories related to marine forensics around the world are-
1. Northwest Fisheries Science Center (NWFSC)
2. Virginia Institute of Marine Science (VIMS)
3. Marine Accident Investigation Branch (MAIB)
4. Office of the National Coordinator for Health Information Technology
These organisations look over commercial fisheries in protected environments, illegal capturing of endangered species or trespassing into zones of ecological significance.
The samples in the case of marine forensics range from freshly frozen fish fillets and pieces of bones to petroleum products. Hence, collecting these samples is done through various sample-specific methods and tools. The types of evidence encountered are-
• Fines, scales and heads of a marine organism
• DNA samples of animals that help, from bones, fish scales, processed seafood, dried tissues etc.
• Trace evidence in the form of dried blood spots on a fish hook, some of the canned food items
• Blood samples
• Samples of Coral reef
• Water samples
• Packed seafood samples
• Petroleum products
Freezing fish tissues, fins and scales and then using methods like air drying and sonication (applying sound energy for agitating sample particles to extract the desired component) in a dilute solution of lab-grade detergent before further sampling procedure can be used as a preservation method. In case of oil spills, sampling procedures are used for oils, sediments, and trace metals in the water column and hydrocarbons in water columns. Sampling is also done of unimpacted regions for checking background conditions at the ocean. Data quality objectives in such samples of petroleum products are done with the standard guidelines of the American Society for Testing and Materials (ASTM).
Sampling techniques used in the marine environment –
• Sample collection method- approaching a down current location for sampling
• Move from least to most contaminated locations
• Pre-cleaning of sampling equipment and use of decontamination methods
Analysis in Marine Forensics
The primary analysis of species in concern is done based on morphological features. And then, individualization of the identified species is done based on DNA extraction and sequencing. Tracing the species of marine environment that has been endangered through a particular incident is done by either taking the DNA from directly available species sample or the surroundings of the species (for example, sea, water) in the form of eDNA (environmental DNA). eDNA is a novel, quicker way to acquire DNA samples from animals that are present in a given habitat. In a natural setting, it aids in regulating species’ biomass and distribution and monitoring invasive species’ development. It may be utilised as a survey tool for environmental preservation. By using eDNA metabarcoding, which helps identify the number of marine species, collecting an eDNA sample will make it easier to analyse the dynamics of a particular ecosystem.
Analysis of blood and petroleum products follows its already existing protocols. For human bodies under decomposition in the marine environment, autolysis and putrefaction bring hindrances. Factors like the depth of the sea at the location, temperature, dissolved oxygen, the body being in a trapped environment (sequestered), and the existence of micro marine organisms affect the analysis.
Conclusion
In the case of marine forensics, the contamination of the incident location due to various geographical and ecological phenomena is significant. Moreover, almost 80% of marine incidents are human errors and have just happened near the water body without the intention of directly harming the marine environment. In this situation, marine forensic investigation needs to be combined with additional methods of examination in autopsy to come to a conclusive result. These challenges require the forensic investigator to be careful while examining a scene of the crime of marine forensics while considering the dynamic nature of the environment around them.
References
• Martlin, B. A., Anderson, G. S., & Bell, L. S. (2022). A review of human decomposition in marine environments. Canadian Society of Forensic Science Journal, 1-30.
• Wait, A. D., Tuit, C. B., & Maney, J. P. (2020). Forensic sampling practices for oil spills in the marine environment. Environmental Forensics, 21(3-4), 310-318.
• Kery, S. (2013). Introduction to the Marine Forensic Guidelines. Naval Engineers Journal, 125(1), 109-114.
• Marine Forensic Laboratory at the Northwest Fisheries Science Center 2023, accessed on 20 May 2023, < https://www.fisheries.noaa.gov/west-coast/science-data/marine-forensic-laboratory-northwest-fisheries-science-center>
• Liu, Y. (2022). Collecting Environmental DNA Samples on the 2022 Spring Ecosystem Monitoring Survey. Science blog NAOO Fisheries. < https://www.fisheries.noaa.gov/science-blog/collecting-environmental-dna-samples-2022-spring-ecosystem-monitoring-survey>
Authored By
The author, Mukti Chavda is a master’s student in Forensic Sciences at Rashtriya Raksha University (an Institute of national importance). She has always been a passionate writer and is now keen to improve her knowledge in her own subject and simultaneously share the same with the rest of the world to simplify access to information.
MCQs On Marine Forensics
1. Which of the following is not a primary goal of forensic marine investigations?
a) Determining cause of death
b) Identifying human remains
c) Assessing marine pollution
d) Establishing fishing regulations
Answer: d) Establishing fishing regulations
Explanation: Forensic marine investigations primarily focus on determining the cause of death, identifying human remains, and assessing marine pollution. Establishing fishing regulations falls under the purview of fisheries management and conservation, which is not a primary goal of forensic marine investigations.
2. When conducting a forensic investigation involving a deceased individual found in water, which factor is most likely to influence the rate of decomposition?
a) Salinity of the water
b) Depth of the water
c) Temperature of the water
d) Dissolved oxygen levels in the water
Answer: c) Temperature of the water
Explanation: The water temperature has the greatest influence on the decomposition rate in aquatic environments. Higher temperatures accelerate decomposition, while lower temperatures slow it down. Salinity, depth, and dissolved oxygen levels can also affect decomposition but to a lesser extent.
3. what is the purpose of using a sediment corer in forensic marine investigations?
a) To measure water depth
b) To collect sediment samples
c) To analyze water currents
d) To estimate time of death
Answer: b) To collect sediment samples
Explanation: A sediment corer is a tool used in forensic marine investigations to collect samples of sediment from the bottom of a body of water. The sediment samples can provide valuable information about the environment, potential pollutants, and the presence of any evidence or artifacts relevant to the investigation.
4. Which technique is commonly used to analyze stable isotopes in marine forensics?
a) DNA profiling
b) Radiocarbon dating
c) Gas chromatography
d) Stable isotope analysis
Answer: d) Stable isotope analysis
Explanation: Stable isotope analysis is a technique frequently employed in forensic marine investigations. It involves measuring the ratios of stable isotopes (such as carbon, nitrogen, oxygen, and hydrogen) in various samples, which can provide insights into the diet, movement patterns, and origins of organisms or substances in the marine environment.
5. What is the primary purpose of using side-scan sonar in forensic marine investigations?
a) Mapping the seafloor topography
b) Locating submerged evidence or objects
c) Detecting underwater noise pollution
d) Studying marine mammal behaviour
Answer: b) Locating submerged evidence or objects
Explanation: Side-scan sonar is a tool commonly employed in forensic marine investigations to locate submerged evidence or objects. It provides detailed images of the seafloor, allowing investigators to identify potential targets of interest and plan subsequent recovery or examination efforts.
