Habitat Modification and Destruction
Mussel farming, in particular, is expanding rapidly in New Zealand
and is starting to compete for habitat with several whale and dolphin
populations. The Trust has carried out several assessments of the
effects of aquaculture on marine mammal populations, and is likely
to be increasingly involved in research in this area.
In general, this is much less of a problem in New Zealand than in
more heavily populated countries. Nevertheless, substantial parts
of the local marine environment have been changed dramatically through
port developments, reclamations and other uses like aquaculture.
Sand mining is another activity that could threaten New Zealand marine mammals. For example, there are plans for sand mining throughout the range of the North Island Hector's dolphin or Maui's dolphin. Typically, it takes between one and three years for the plants and animals that live in and on the sand to recover to the same distribution and total numbers after a sand mining operation. However, it can take much longer for the community composition to recover. For example, the removal of some organisms and crushing of others tends to attract scavengers into the area, changing the local ecology.
Publications and reports