Protected Species and Marine Aquaculture Interactions

individual level, but requires permits and
may be unpopular.
Other Aquaculture Interactions
At marine fish farms, entanglement in the
cage or anti-predator nets poses the big -
gest threat to seabirds, especially those that
may dive to feed on fish or fouling organisms
(Belle & Nash 2008, Northridge et al.
2013). Seabirds are reported to congregate
near marine fish farms but are typically
considered a low risk in terms of preda tory
threat, though they may scavenge mortalities
or pick off fish during transfer or harvest (Pearson & Black 2001, Nash et al.
2005, Huntington et al. 2006, Rensel & Forster 2007). In contrast, the often significant
impacts to freshwater aquaculture (Goldburg & Triplett 1997, Belant et al.
2000, Snow et al. 2005) and fisheries (Karpouzi et al. 2007) by piscivorous birds like
cormorants and pelicans are better understood. Permits are available to implement
non-lethal predator controls to frighten birds away from cages and, because birds become
habituated to noise harassment, farms often use overhead netting or screens to
exclude seabirds from cage areas (Nash 2001, Huntington et al. 2006, Halwart et al.
2007). Siting of fish farms away from important seabird habitats is encouraged or required
in many countries (Bridger & Neal 2004, Borg et al. 2011) to minimize con -
flicts. Overviews of environmental impacts of marine aquaculture often refer to
seabirds as species of concern, but contain few specific examples
of measures implemented to aid in seabird conservation (Halwart
et al. 2007, IUCN 2007). A recent monitoring study at
south ern Chilean salmon farms found that bird abundance was
significantly higher near salmon farming areas than control sites
(Jiménez et al. 2013). However, the species composition of the
bird assemblages was different, with less diversity, and dominated
by opportunistic generalists like gulls, vultures and cormorants.
Hughes et al. (2014) collected video observations for
96 days at a pilot scale farm adjacent to land that cultivated
algae for biofuel production. They documented visits by birds,
sea otters and one sea lion. Birds tended to avoid any interaction with the farm gear,
but gulls and coots were most likely to interact with the farm gear. Overall, there
were no harmful interactions recorded, but the authors note they did observe that
even this pilot scale operation affected behaviors like feeding, grooming and social
activity.
A recent comprehensive report on the issue of seabird interactions with aquaculture
was recently conducted in New Zealand (Sagar 2013). There have been very few
American white
pelicans
Northern gannet
uSFWS
uSFWS
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