June 2025 | Oceanography
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advancement in our understanding of the geophysics, vent biol
ogy, and oceanography of the MPA.
The observations collected by cabled sensors and during
the repeated visits for infrastructure maintenance are freely
available (unless there is a known student thesis that could be
affected by early release of the data). There is growing under
standing of hydrothermal ecosystems’ functions, their connec
tivity to other ecosystems, their benefit to humanity, and their
role in the ocean’s chemical balance. However, a clear picture of
the “value” of hydrothermal sites to weigh against disturbance,
for example by deep-sea mining or scientific sampling, is not
complete (Turner et al., 2019). The objective of continuous, long
time-series monitoring of vent sites by seafloor observatories is
to enable observation of natural disturbances and how succes
sion proceeds afterwards to understand what level of anthro
pogenic disturbance or scientific sampling might be tolerated.
In addition, real-time monitoring is essential for monitoring
episodic natural perturbations. A framework is being devel
oped among the Canadian government and scientific institu
tions for a rapid response to a perturbation of the hydrother
mal system at the Endeavour Segment to gain observations of
the changes in the water column chemistry and the benthic
and pelagic ecosystems.
The Endeavour MPA is remote, 300 km offshore and in
2.2 km of water, and seemingly clear of threats that impact
coastal oceans. However, it is not isolated from ocean acidifi
cation, microplastic pollution, hypoxia, and even storm inten
sity. Real-time data and regular, yearly maintenance visits to
Endeavour monitor change due to natural processes, pollution,
and climate change.
With the Endeavour MPA subsumed into the much larger off
shore TḥT MPA (Figure 6), now encompassing multiple eco
logically or biologically significant marine areas, remote moni
toring strategies are expected to change in accordance with new
MPA conservation and management goals. While the cabled
seafloor sensors will play a crucial role, other complementary
monitoring and infrastructure upgrades are needed to continue
increasing scientific understanding, to contribute to improved
management or conservation, and to monitor the effectiveness
of the new MPA protections.
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FIGURE 6. Map showing the boundaries (yellow polygon) of the offshore
TḥT MPA. Boundaries encompass all known hydrothermal vent fields
within Canada, at least 47 seamounts, and hundreds of seamount-like
features. The ONC observatories are delineated by orange squares.
Image credit: ONC