Early Online Release | Oceanography
all too familiar fashion, it did not take long to learn that human
activities are a source of ocean soundscape pollution that can be
injurious to marine wildlife (e.g., Hildebrand, 2009). Although
the notion of an ocean soundscape is ancient, and its use in ocean
studies has long been the subject of intensive research and devel
opment, we continue to make remarkable discoveries by simply
listening with increasingly sophisticated means for doing so.
Today, detailed observations of the comings and goings of
marine animals is greatly enhanced by soundscape analysis
(e.g., Oestreich et al., 2022, 2024; Ryan et al., 2022, 2025). The com
bination of passive and active acoustic observations has proven
useful in investigating predator foraging behaviors and the ecology
of fear (e.g., Benoit-Bird et al., 2019; Urmy and Benoit-Bird, 2021).
“Listening with light” by way of using fiber-optic cables as vibra
tion sensors—a technique known as distributed acoustic sens
ing (DAS)—is the latest evolution in the ongoing push to broaden
access to and analysis of the ocean soundscape (Saw et al., 2025).
By combining fleets of ASVs and AUVs equipped with acoustic,
imaging, and water sampling payloads, a new perspective on the
movements of animals traversing the environment in response to
ever changing ocean conditions is emerging, including by tracking
the traces of “genetic soup” shed in their wakes (e.g., Zhang et al.,
2021b; Figure 7).
The use of organisms’ DNA and RNA (and other methods) to
reveal what species are present and how they are responding to
their environments has advanced in concert with the develop
ment and application of ocean imaging and acoustics. The tools
and techniques employed have storied pasts and spring from the
creativity and insights of many investigators over decades. What
has come to be known as “ecogenomics” is deeply rooted in sub
cellular biological studies and molecular analytical methods for
detecting and decoding the very essence of life itself. Just as under
water imaging and soundscape analysis grew from industrial uses
and for purposes unrelated to ocean ecology, molecular biology,
nucleic acid sequencing, bioinformatics, and other methods unre
lated to marine science were adopted for ocean applications, for
ever altering the course of modern marine biology. Microbial ecol
ogists arguably led the way (e.g., Pace, 1985; Karl, 2014).
In a surprising twist, Ficetola et al. (2008) discovered that DNA
shed by frogs could be detected in the environment in which
they lived even when you could not see the animals themselves,
sparking an environmental DNA (eDNA) forensics revolution
(e.g., Kelly et al., 2014; Stoeckle et al., 2024). The analysis of eDNA
offers a noninvasive method for assessing biodiversity and track
ing animal movements by collecting samples of water and sequenc
ing the recovered material, enabling simultaneous detection of
marine organisms across multiple trophic levels (e.g., Chavez et al.,
2021b). As eDNA analysis has evolved, our eyes have been opened
to the notion of “genetic dark matter” that is recoverable from the
environment but has no described source or, in some cases, no
well-characterized function (e.g., Venter et al., 2004; Roux et al.,
2015; Delmont et al., 2022). Analysis of the sea’s genetic soup tells
us that there is a great deal of marine life and genetic capacity that
has not yet been characterized.
Just as machine learning and artificial intelligence have played
a huge role in analyzing and reacting to ocean imagery and sound,
they are likewise fueling the analysis of eDNA to synthesize an
integrated picture of a complex web of life. Although the detec
tion and real-time analysis of imagery, sound, and other bulk water
properties are now commonly employed to guide autonomous
platforms during targeted field observations, devices that enable
in situ, “hands off,” real-time analysis of eDNA and other cellu
lar metabolites are still very much in their infancy (e.g., Scholin
et al., 2017). With a few notable examples (e.g., Truelove et al.,
2019; Peter Thielen et al., Johns Hopkins University, pers. comm.,
2025), marine eDNA surveys rest largely on the acquisition, pres
ervation, and return of samples for shoreside analysis (Yamahara
et al., 2019; Zhang et al., 2021a; Truelove et al., 2022; Preston
et al., 2023). Despite the progress, scaling up the use of robots
that enable integrated optical, acoustic, and “omic” characteriza
tion of the sea presents a very significant technological challenge
when compared to using profiling floats to conduct global scale
biogeochemical observations.
TO THE SEAFLOOR
Descending to the seafloor, whether using a crewed submers
ible or an ROV, has been likened to being dropped into a pitch-
black room and using only a flashlight to see what lies ahead.
Remarkable discoveries have been made by picking dive sites that
are known to offer different types of terrain that might lead to find
ing something novel. The discovery of the “octopus garden” near
the base of Davidson Seamount offers an excellent, recent exam
ple of using ship-acquired bathymetry to guide an exploratory
ROV dive that serendipitously uncovered something remark
able (King and Brown, 2019). No doubt that method works, but
the area that can be covered is limited, and for the most part, you
have no detailed map to lead the way. AUVs are changing that
FIGURE 7. A fleet of long-range autonomous underwater vehicles (AUVs;
Hobson et al., 2012) fitted with different imaging, water sampling, and eDNA
collection payloads are lined up alongside a Liquid Robotics Wave Glider, all
readied for deployment in Monterey Bay. The fleet of vehicles allows coor
dinated observations for extended periods to provide a multifaceted view of
dynamic ecosystem processes. After Zhang et al. (2021a,b). Susan von Thun
© 2017 MBARI