Seamounts and orange roughy

The introduction to the SIT level 4 marine ecology course relates to the formation of New Zealand’s coastline, its geology, geomorphology and processes.  One of the striking features of the submarine landscape is the seamount.  These are usually volcanic in origin and do not reach the ocean surface, but they can rise to 3 or 4 km from the ocean floor.  The Kermadec Ridge and Colville Ridge to the north of NZ’s North Island comprise many seamounts, the former being younger and still volcanically active, the latter being older and extinct. 

All seamounts are prize marine ecosystems because of their elevation, ocean currents around them, and, in the case of the Kermadec seamounts, the hydrothermal activity.  This means that they are target for the fishing industry and one species in particular is fast losing habitat due to the fishing methods used to harvest it. 

Orange Roughy are bottom dwellers.  Bottom trawling is used to catch them.  It is estimated that some 95% of the ecosystem is destroyed by this method that scrapes along the bottom, particularly on seamounts. 

This method has been described as bulldozing an orchard to harvest a few apples.

Take action by not purchasing orange roughy.  Make your vote count at the supermarket and fishmonger. 

http://www.forestandbird.org.nz/what-we-do/publications/-best-fish-guide-/orange-roughy

http://www.terranature.org/orangeRoughyCatch2007.htm

http://www.terranature.org/bottomTrawling_SouthPacificRFMO.htm