Protected Species and Marine Aquaculture Interactions

GABRIEl BARATHIEu
activity (Keeley et al. 2009) with over 1100
currently active shellfish farms on leases covering
22,000 ha (National Aquatic Biodiversity
Information System 2015). One of the concerns
facing the industry is the impacts—real
and potential—to protected species including
marine mammals and seabirds.
In 2013, the government of New Zealand
issued a comprehensive summary report on
the effects of aquaculture on marine mammals
(Clement 2013). The report includes separate
analyses of farming of feed-added species
(fish) and filter feeders (shellfish). Clement (2013) summarizes the effects of aquaculture
to marine mammals and identifies three key areas of potential interactions—
competition for space, entanglement, and underwater noise disturbance (Tables 4– 7).
Impact of alterations in trophic pathways was identified as a fourth area of concern,
but a table was not included for that area. These interactions of concern are similar to
the potential impacts identified in the Lloyd (2003) assessment.
The potential harmful effects of aquaculture on marine mammals for habitat
modifications (Table 4) is not currently considered a high risk, as there is little overlap
in critical habitat and farm locations in New Zealand. There is awareness that industry
growth, both as an increase in the number of farms as well as expansion into
the open ocean, may increase the potential for both habitat exclusion and physical
interaction. Management strategies to avoid impacts are done on a case-by-case basis
primarily by siting in areas which minimize the likelihood of overlap with migration
routes or critical habitats. This may not always be possible in the United States. For
example, in New England, farms are being proposed in areas within whale and sea
turtle feeding grounds. The extent of possible overlap with protected species in that
region is unknown and depends upon which species are being considered and the
scale of the proposed project.
Several studies in Admiralty Bay, New Zealand have focused on potential habitat
exclusion of dolphins in nearshore waters. There is evidence that dolphins may be
Longline mussel farm
Protected Species & Mussel longline aquaculture interactions | 13