Protected Species and Marine Aquaculture Interactions

equaling 19– 29 deaths per year (Robbins & Mattila 2001, Robbins et al. 2009). In
Argentina, of 9 southern right whale entanglement incidents from 2001– 2011 at
least 2 resulted from fishery gear including ropes, buoys and nets (Bellazzi et al.
2012). A third, possibly involved mussel spat collection lines, but this was not definitively
confirmed. Two involved rope which could not be attributed to a specific
human activity and the other 4 were due to vessel moorings.
A global summary of data on marine mammal bycatch in entangling fishing gear
(primarily gillnets) spanning from 1990 to 2010 was compiled by Reeves et al.
(2013). This study shows the significant risk that entangling gear poses for marine
mammals. The authors note that humpback, right and minke whales seem especially
prone to entanglement though the explanation for this is not clear. Johnson et al.
(2005) found that humpback whale entanglements were more likely to involve the
tail than right whales which tended to involve the mouth more frequently, although
the original gear configurations were not known in most cases.
Robbins and Kraus (2011) discuss numerous behavioral, sensory, and morphological
characteristics of right and humpback whales that may explain how these species
perceive and respond to fishing gear. For example, right whale mouth morphology
and feeding behavior suggest they often swim with their mouths open, putting them
Right whale entangled
in line
lessons lear ned from Fishery Gear & applications to aquaculture | 45