Ocean Networks Canada (ONC) is extending its long-term continuous monitoring capabilities to support new marine protection efforts by deploying a sophisticated instrument package on Dellwood Seamount within the Canadian Offshore Pacific Area of Interest (Figure 1).
Figure 1. Dellwood Seamount is located within the Offshore Pacific Area of Interest, announced in May 2017 as the first step to establishing a large marine protected area under Canada’s Oceans Act. This unique seafloor ecosystem includes 17 named seamounts—with perhaps as many as 40 in total—and a series of hydrothermal vents.
Seamounts are submerged underwater mountains—often volcanic in origin. It is estimated that there are 100,000 seamounts around the globe, and over 30,000 of these are found in the Pacific Ocean. Despite their abundance, less than 0.01% of the world’s seamounts have been explored.
These biodiversity hotspots are home to corals and sponges, providing a mid-ocean nursery to a variety of marine life such as rockfish, sablefish, halibut and tuna, as well as marine mammals, seabirds and sharks.
Increasing our understanding of seamounts—which are critical to ocean health—is an important step on the path towards good marine management. Long-term continuous monitoring provides benchmark data that informs the science behind decision-making on further protection measures, such as the creation of a Marine Protected Area (MPA) and the development of MPA conservation objectives and management plans.
Dellwood Seamount was selected as the site to deploy ONC’s instrument package—an autonomous mooring—due to its extensive coral and sponge habitats, which were discovered during a Fisheries and Oceans Canada’s survey of the area in 2017 (Figure 2).
Figure 2. In July, ONC will deploy a nine metre autonomous mooring on the slopes of Dellwood Seamount at a depth of 825 metres, where corals and sponges provide a mid-ocean nursery for marine life.
An autonomous mooring is a self-contained, battery-operated string of sensors that gathers continuous data about the water column. These instrument packages can be up to hundreds of meters in height, held up by a float at one end and a bottom anchor at the other. Recent advances in sensors, data storage, battery technologies and robotics have greatly increased the capacity of these moorings to make different types of measurements and even collect samples in remote locations, helping us to understand our changing ocean and how it is impacting marine life (Figure 3).
Figure 3. ONC specially designed and built the Dellwood Seamount autonomous mooring to hold sensors several metres above the seafloor to monitor ocean conditions within the coral and sponge communities.
“It has been a real challenge to design a mooring that is compact and light enough to be maneuvered and precisely positioned by EV Nautilus’ remotely operated vehicle Hercules, yet robust enough to survive a year on this remote seamount in the northeast Pacific,” comments ONC’s chief scientist Kim Juniper. The Dellwood Seamount mooring is designed to hold sensors several metres above the seafloor at a depth of 825 metres, where coral and sponge communities thrive on the slopes of the seamount (Figure 3).
After being deployed in July 2018, the autonomous mooring will be recovered in summer 2019. An acoustic command will trigger the acoustic release to let go of the anchor, and the float will carry the instrument package and its recorded data to the surface where it will be recovered by a ship.
Once recovered, ONC will archive the data from the mooring and make it available for free on Oceans 2.0, ONC’s sophisticated data management and archive system. These data will enable Fisheries and Oceans Canada and other researchers to understand how habitat conditions vary throughout the year and, particularly, how the coral and sponge communities will be affected by future ocean change.
The Dellwood Seamount mooring is one of a small number of other seamount continuous monitoring projects currently underway worldwide, including several seamounts in the Azores Marine Protected Area, and another on the Axial Seamount on the Juan de Fuca Ridge where the US Ocean Observatory Initiative has a cabled observatory.
The Dellwood Seamount mooring is being deployed in July 2018 as part of Northeast Pacific Seamounts Expedition, an exciting 16-day voyage aboard state-of-the-art exploration vessel (EV) Nautilus to explore remote seamounts. ONC is partnering with Fisheries and Oceans Canada, the Haida Nation, and Oceana Canada in a collaborative effort to manage and protect these little-understood ocean biodiversity hotspots.
Join us live aboard EV Nautilus by watching the livestream 5-21 July, and learn more about this collaborative expedition: www.protectoceans.ca.
RELATED
Top Ten Species to on the During Northeast Pacific Seamounts Expedition
