SeaDoc Society and the OceanGate Foundation have partnered in support of deep exploration and research in the Salish Sea off the coast of British Columbia and Washington state. In September 2018 three teams of researchers will dive to depths as great as 200 m in Cyclops 1, a manned submersible owned and operated by OceanGate Inc.

During the week-long expedition starting Sept. 10, scientists will have the rare opportunity to directly observe two important components of the Salish Sea food chain: the feeding strategies of deep-dwelling red urchins and the behavior of Pacific sand lance, which hide in deep sand wave fields; and collect data to assess the costs/benefits of scientific trawling.

Deep-Dwelling Red Urchins

Urchins in the San Juan Islands play an important role in structuring seafloor communities and they represent a multimillion dollar fishery, but little is known about the populations that live below depths where kelp can survive, especially the ones so deep that they are not accessible to scuba divers. No human has ever seen a red urchin below 100 m, although unmanned cameras have documented them.

Kelp depends on sunlight for survival, but it’s also the main food source for red urchins, which can live to be 150 years old. This study will explore how these deep-dwelling urchins manage to feed at such depths, with a specific eye toward the role played by drift kelp, which urchins can grab with their long spines as it floats by.

Pacific Sand Lance Habitat

Sand lance are a small forage fish that play a crucial role in the food chain by converting plankton to fat that other fish, birds and mammals can access. They don’t have a swim bladder, which means they can’t stabilize themselves in the water column. They’re known for plunging their bodies into waves of sand at the seafloor as a mechanism for hiding or resting.

Beyond those basics, little is known about how they use this unique habitat. The sub will give scientists a front-row seat to observe these rolling sand waves, with real-time discussion inside the sub and peripheral vision to test several existing hypotheses and to document a far wider range than the camera alone could document.

Long-Term Impact of Scientific Trawling

For decades, scientists have trawled the ocean floor for valuable research purposes, but trawling is not without environmental effect. It can alter structure, decrease diversity and remove habitat for larger animals in the ecosystem.

The submarine will run transects in areas that have been trawled for scientific purposes up to 10 times per year for the past 30 years. Through observation and video documentation, the researchers will compare trawled sites to adjacent untrawled areas.

Scientists will make the resulting data available to the public with the goal of informing future policy decisions related to the effects of scientific trawling and the management of the Salish Sea environment. —OceanGate