June 2025

Welcome to interactive presentation, created with Publuu. Enjoy the reading!

June 2025 | Oceanography

13

Operated by Ocean Networks Canada (ONC), the NEPTUNE

observatory comprises an 840 km fiber-optic cable extend­

ing from Vancouver Island across the North American and

Juan de Fuca tectonic plates to connect five major node sites

to power and the internet (Barnes et al., 2007). The western­

most Endeavour node supports the scientific sensors in the

heavily instrumented Endeavour Hydrothermal Vents MPA

(Table 1, Figures 3 and 4). Real-time data, archived data, and

data products from sensors in the axial valley and on the flanks

of the Endeavour Segment of the Juan de Fuca Ridge have been

available since 2010 through ONC’s digital infrastructure,

Oceans 3.0 (Owens et al., 2022). Regular expeditions using ships

and remotely operated vehicles (ROVs) to maintain infrastruc­

ture also collect observations and physical samples to ground

truth and complement the sensor data. Internet connectivity

from the ships allows the Canadian and international science

community to participate from shore to conduct experiments

and sampling strategies to aid in developing a more complete

understanding of the physical, geological, and biological pro­

cesses of this protected environment (Table 1).

TABLE 1. Summary of major disciplines, sensor technology, and geological, physical, chemical, and biological properties monitored and their scientific

and MPA monitoring impacts. MEF = Main Endeavour Field. RCM = Regional Circulation Mooring North and South.

MONITORING

EQUIPMENT

PROPERTIES

MEASURED

VENT FIELD/

SITES

(See Figure 3)

SIGNIFICANCE

(Value in MPA management)

KEY PUBLICATIONS

DISCIPLINE: GEOPHYSICS AND GEOCHEMISTRY

1. Seismometers and

accelerometers

Seismic ground

motions and

low-frequency

hydroacoustic signals

• RCM-N

• MEF

• Mothra

• Ridge Flank

• Node

Identify periods of seismic unrest driven by

tectonic spreading events that are linked

to changes in venting and/or eruptions.

Also, detect chimney collapses and activity

from baleen whales.

• Krauss et al., 2023

• Bohnenstiehl et al., 2004

• Smith and Barclay, 2023

2. Bottom pressure

recorders (BPR)

Vertical seafloor

movements and sea

level changes

• RCM-N

• MEF

• Ridge Flank

• RCM-S

• Node

• Mothra

Inflation/deflation can indicate changes

in the underlying magma chamber that

affects the hydrothermal system and can

precede spreading events.

• Barreyre and Sohn, 2016

3. Benthic and

Resistivity Sensors

(BARS), paired with

vent fluid samples

Temperature,

resistivity, and redox

potential

• MEF

• Mothra

Changes in chemical composition of

vent fluids over time, and the influence

of chemical and heat fluxes on the

composition and diversity of benthic vent

biological communities.

• Xu et al., 2017a

4. Vent imaging sonar

3D vent plume and

heat flux mapping

• MEF

Hydrothermal heat and chemical flux

variability is a fundamental control on the

ecosystem.

• Bemis et al., 2015

• Xu et al., 2014, 2017b

5. Serial gas tight

sampler

Fluid geochemistry

• MEF

Changes in chemical composition of vent

fluids over time, and the influence of

chemical and heat fluxes on the makeup

and diversity of benthic vent biological

communities.

• Seyfried et al., 2022

• Evans et al., 2023

6. Water samplers

(RAS-PPS)

Water geochemistry

and biology

• MEF

Diffuse venting and its effects on the

benthic ecosystem.

• Lelièvre et al., 2017

7. Sediment traps

Particulates from

vent plumes

• MEF

• West Flank

• South Axial

Hydrothermal venting and its effects on

the water column.

• Coogan et al., 2017

• Mills et al., 2024

• Beaupre-Olsen et al., 2025

DISCIPLINE: PHYSICAL OCEANOGRAPHY

1. Regional Circulation

Moorings

Ocean circulation

and water properties

(temperature, salinity,

and density)

• RCM-N

• NW Mooring

• RCM-S

• SW Mooring

Proxy measurement of the overall heat flux

variability to the ocean from hydrothermal

venting. Current circulation in and above

the axial valley controlling larval and vent

plume chemistry dispersal.

• Thomson et al., 2003

• Xu et al. 2014, 2017b

2. Conductivity,

temperature, and

depth (CTD)

Temperature, salinity

and density, dissolved

oxygen

• Node

Near seafloor water properties.

Continued on next page…

Made with Publuu - flipbook maker