Josephine Seamount in Atlantic

95% of ecological damage at seamounts is done by bottom trawling.

navama supports projects to understand bottom trawling activities of fishery vessels at seamounts all around the globe.

Source: www.oceanservice.noaa.gov

Source: www.oceanservice.noaa.gov

A seamount (see Wikipedia) is a mountain rising from the ocean seafloor that does not reach to the water’s surface, and thus is not an island. Seamounts are typically formed from extinct volcanoes that rise abruptly and are usually found rising from the seafloor to 1,000–4,000 metres in height. They are defined by oceanographers as independent features that rise to at least 1,000 metres above the seafloor, characteristically of conical form. The peaks are often found hundreds to thousands of meters below the surface, and are therefore considered to be within the deep sea. During their evolution over geologic time, the largest seamounts may reach the sea surface where wave action erodes the summit to form a flat surface. After they have subsided and sunk below the sea surface such flat-top seamounts are called “guyots” or “tablemounts”.

AIS signal points around Josephine Seamount © WWF & navama

AIS signal points around Josephine Seamount
© WWF & navama

A total of 9,951 seamounts and 283 guyots, covering a total of 8,796,150 km2 have been mapped (based on  Wikipedia) but only a few have been studied in detail by scientists. Seamounts and guyots are most abundant in the North Pacific Ocean, and follow a distinctive evolutionary pattern of eruption, build-up, subsidence and erosion. In recent years, several active seamounts have been observed, for example Loihi in the Hawaiian Islands.

Because of their abundance, seamounts are one of the most common oceanic ecosystems in the world. Interactions between seamounts and underwater currents, as well as their elevated position in the water, attract plankton, corals, fish, and marine mammals alike. Their aggregational effect has been noted by the commercial fishing industry, and many seamounts support extensive fisheries. There are ongoing concerns on the negative impact of fishing on seamount ecosystems, and well-documented cases of stock decline, for example with the orange roughy (Hoplostethus atlanticus). 95% of ecological damage is done by bottom trawling, which scrapes whole ecosystems off seamounts.

seeOcean has a global data set of seamounts build in to analyse vessel traffic and potential bottom trawling activity in the surrounding.

Fishery patterns at Josephine Seamount isolated from AIS data sets © WWF & navama

Fishery patterns at Josephine Seamount isolated from AIS data sets
© WWF & navama

Analytics of AIS  patterns showed strong indication of fishing activities from vessels equipped with bottom trawling gear in sensitive marine ecosystems like the Josephine Seamount in Atlantic. A region where by international agreements bottom trawling is not allowed.

Additional sources:

Wikipedia

NOAA

 

 

 

 

The analytics where done by navama within seeOcean  based on  AIS  data from ORBCOMM satellites.