Eos, Transactions American Geophysical Union

Fishing trawler nets Massive “Catch” of methane hydrates



In November 2000, the commercial fishing vessel Ocean Selector recovered over 1000 kg of gas hydrate in a trawl net. The catch occurred in 800 m near the head of the deeply-incised Barcley Canyon off Vancouver Island (Figure 1). This is probably the largest recovery of gas hydrate ever reported from a marine setting.

Although methane hydrate is known to be stable at the sea floor for water depths greater than 500–600 m at temperate latitudes, observed outcrops of hydrate at the sea floor are rare and poorly understood. There is a very large disequilibrium between the concentration of methane in gas hydrate and in seawater. Therefore, one would expect that gas hydrate would sublime and dissociate when it comes in contact with seawater. Nevertheless, massive hydrate outcrops have been observed and sampled, most prominently at the Hydrate Ridge off Oregon [Suess et al., 1999] and in the Gulf of Mexico [MacDonald et al., 1994; Sassen et al., 2001].