US Navy Researches Biological ITL Ecosystems

Planktonic copepod, most likely Microsetella sp., with green and yellow fluorescence. Operation Deep Scope 2005 in Gulf of Mexico. (Credit: Dr. Mikhail Matz, NOAA)

By Kayla Matthews

Some of the U.S. Navy’s biggest tactical obstacles are tiny sea creatures. Intermediate trophic level (ITL) organisms can interfere with navigation and surveillance equipment, making it difficult to carry out some operations efficiently. To address the issue, the Navy started researching this marine life last year.

Naval Research Laboratory (NRL) oceanographer Brad Penta led the research project with a team of ocean biologists. Together with researchers from civilian institutions like the University of Mississippi, the NRL spent two weeks observing sea life off the coast of Delaware. The findings could improve both military operations and civilian research.

ITL Organisms’ Impact

ITL organisms are creatures that exist in the middle of the food chain, between autotrophs like plants and top predators. In the ocean, this trophic level includes various species of crustaceans and jellyfish. Typically, they don’t interfere with human activity, but they can disrupt some scientific instruments—such as those the Navy uses.

Many of these oceanic ITL organisms tend to congregate in swarms. When these swarms gather around equipment like sonar, they can interfere with the signals. Sonar waves bounce back and forth between these dense groupings of marine life, leading to unreliable readings.

Some of these creatures are also bioluminescent, meaning they emit light under some circumstances. These lights can disrupt navigational or surveillance tools. By better understanding marine ITL ecosystems, the Navy and other ocean vessels could learn how to work around them.

Research Tech

The NRL and its research partners used a variety of technologies to study ITL ecosystems. The three primary systems the study employed were an In-Situ Ichthyoplankton Imaging System (ISIIS), a Del Mar Oceanographic Wirewalker and camera-equipped aircraft.

The ISIIS is a submersible vehicle that researchers tow behind their ship. The device uses light-emitting diode (LED) lights and high-resolution cameras to capture images of plankton that could be invisible to the naked eye. The researchers also attached equipment to measure environmental factors to the ISIIS so they could understand the conditions in which these organisms gather.

On top of these ISIIS-attached sensors, the NRL used a Wirewalker, which sits just below the water’s surface and measures factors such as light, temperature, depth and oxygen levels as it moves with the current. These readings give ocean biologists an even more well-rounded idea of the environments marine ITL organisms inhabit.

The aircraft the researchers employed contained various cameras, including some equipped with LiDAR. Short for Light Detection and Ranging, LiDAR systems measure environments by reflecting a laser against them, like a radar that uses lasers instead of radio waves. The team designed their own LiDAR system, called Multi-Wavelength LiDAR for the Environment, or MUWLE. 

Unlike other LiDAR, the MUWLE can change the color of the laser it uses, making it more versatile. The MUWLE, Wirewalker and ISIIS gathered a vast amount of data, including millions of images, that researchers are still analyzing with the help of machine learning systems. 


Once the NRL and its cooperators thoroughly analyze the data, they’ll have a far better understanding of aquatic ITL organisms and their environments. Armed with this knowledge, they could better predict where swarms might be and develop equipment that can work around marine life.

The resulting Navy tech could help civilian work too. An increasing number of businesses are looking to employ military-grade equipment because of its resilience and accuracy. Private researchers could use sensors similar to the ones the Navy develops to improve the precision of their instruments.

Navigation systems like radar and sonar could improve with knowledge of how to account for ITL organisms. Naval ships aren’t the only ones who rely on these technologies, either. Fishing boats, cargo ships and recreational vessels could all benefit from more robust navigational equipment.

The tech made for this project could help future researchers, too. The MUWLE could replace the LiDAR systems scientists use now, leading to more discoveries in other fields.

The Navy may be spearheading this research, but everyone can benefit from the findings. By conducting this study, the Navy is making substantial strides in helping other maritime industries and related sectors make much-needed technological advancements.

Kayla Matthews is a technology journalist and writer. Her work has been featured in WIRED, VentureBeat, InformationWeek and Computerworld. To read more from Matthews, visit her blog, Productivity Bytes.

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