Oceanography | Vol. 38, No. 2
14
GEOLOGY AND SEAFLOOR HABITAT
The Endeavour MPA hosts hydrothermal vent ecosystems
whose formation and persistence are directly linked to the
dynamic geological and tectonic processes of the Juan de
Fuca Ridge. Understanding this interplay through continu
ous, multidisciplinary monitoring is foundational to effective
MPA management.
The Endeavour Segment is an intermediate-rate spreading
center (full rate: ~52 mm yr–1) (DeMets et al., 2010; Krauss et al.,
2023) characterized by a 10 km long and 1 km wide axial val
ley flanked by rift crests rising 100–150 m above the valley floor.
Extensive and vigorous hydrothermal venting occurs within the
axial valley focused at five main active vent clusters spaced about
2–3 km apart (Figure 1; Kelley et al., 2012). The Main Endeavour
(MEF) and Mothra fields have received significant scientific
attention and are currently being monitored by sensors con
nected to the NEPTUNE observatory. The High Rise and Salty
Dawg fields (see Figure 1) are designated for minimally intru
sive studies and outreach opportunities (Fisheries and Oceans
Canada, 2010) and have no cabled sensors.
The uniqueness of hydrothermal venting regions, with respect
to other deep-sea benthic habitats, stems from the chemical flux
and exchange of heat between the ocean and the seafloor and
the geologically rapid change of the seafloor morphology due
to local tectonic dynamics. This leads to a chemically and phys
ically extreme environment that hosts the specialized life that
has physiologically and biologically adapted to the geologically
controlled environment. Although vent ecosystems are rare and
their global extent is small, their contribution to the understand
ing of life and their ecosystem functions and services are sig
nificant and are considered ideal candidates for designation as
Vulnerable Marine Ecosystems and recommended for Area-
Based Management Tools (e.g., Menini and Van Dover, 2019).
The Endeavour Segment features a combination of active and
inactive chimneys, edifices, and mounds along its axial valley.
The active structures cluster into the five major vent fields with
more than 400 inactive structures as well as the diffuse venting
sites interspersed among them. Conceptually, they are geolog
ically connected, and the entire ridge segment can be consid
ered a single temporally and spatially varying vent field driven
MONITORING
EQUIPMENT
PROPERTIES
MEASURED
VENT FIELD/
SITES
(See Figure 3)
SIGNIFICANCE
(Value in MPA management)
KEY PUBLICATIONS
DISCIPLINE: BIOLOGY
1. Video cameras
Video, paired with
other sensors
(i.e., temperature)
• MEF
• Mothra
Track biological community structure and
responses to venting physico-chemistry
dynamics.
• Cuvelier et al., 2014, 2017
• Lelièvre et al., 2017
• Carter, 2025
• Robert et al., 2012
• Lee et al., 2015
2. Biological samples
Whole specimens,
tissue, assemblages
and e-DNA
• High Rise
• MEF
• Mothra
Characterization of vent and vent-
periphery communities (from microbes to
megafauna).
• Perez and Juniper, 2016, 2017
• Perez et al., 2023
• Lelièvre et al., 2018
• Georgieva et al., 2020
3. Colonization
experiments
Community
recolonization/
ecological succession
• MEF
Investigate faunal colonization (from
microbes to macrobenthos) simulating
recovery from natural perturbations
(e.g., eruptions).
• Ongoing studies
4. Passive larval
trap collectors
Benthic invertebrate
larvae
• MEF
Larval ecology and genetic connectivity
among different vent, vent periphery,
and background deep-sea benthic
communities.
• Ongoing study
5. ROV video
surveys, including
photogrammetry
Habitat and benthic
community dynamics
• MEF
• Mothra
• High Rise
Track, at larger spatial scales, temporal
changes of vent community composition
and responses to natural perturbations.
• Neufeld et al., 2022
DISCIPLINE: SOUNDSCAPES
1. Cabled hydrophone
arrays
Intensity and direction
of broadband sound
• MEF
Vent activity monitoring, earthquake
detection (near and distal), marine-mammal
detection and monitoring.
• Smith and Barclay, 2023
2. Deep acoustic
lander (autonomous,
Dalhousie University)
Sound velocity,
pressure, conductivity,
temperature, salinity;
intensity and direction
of broadband sound
• MEF
Water-column properties affecting sound
propagation, vent activity monitoring.
• Smith and Barclay, 2023
TABLE 1. Continued…