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There are numerous studies on the impacts of dams and other
infrastructure on hindering movements of salmonids, fish and
river dolphins (UNEP, 2001; WCD, 2000 ).
However, there has in recent years been far more focus on the
effect of noise pollution from shipping and recreational boats on
marine mammals, including both naval military sonar and other
anthropogenic sounds that can cause hearing damage or affect
fish and animal behaviour and communication in the ocean
(MacCauley
et al.
, 2003; Wellgart, 2007; Papanicolopulu, 2011;
Zirbel
et al.
, 2011). There is particularly increasing evidence on
behavioural changes in cetaceans – whale and dolphins – when
exposed to noise pollution (Nowacek
et al.
, 2007; Lusseau, 2008).
Odontocete cetaceans (toothed whales) use high frequency
echo-location sounds for navigating and foraging and are
highly sensitive to artificial sounds in the ocean, and have par-
ticularly the ability to detect and hear both very low and very
high frequencies, dependent upon species. Mass strandings
from a few to several hundred have occurred in numerous ce-
tacean species, including beaked whales following military ex-
ercises with sonar (Balcomb and Claridge, 2001), and of other
whales, dolphins and porpoises. The causes of mass strand-
ings are in all likelihood very diverse (Walker
et al.
, 2005).
Some may have been related to hearing loss possibly caused
by boat noise, pollution (from PCB) or other causes, while
others from a range of other factors including natural ones
(Mann
et al.
, 2010).
However, noise pollution from shipping may also have effects
other than mass strandings, namely through causing cetaceans
to avoid shipping lanes and harbours in previously important
habitat and migration routes. Artificial sound has even been
used effectively to deter killer whales from salmon farms (Mor-
ton and Symonds, 2002). Avoidance of cetaceans to even few
small-vessel tourist boats has been documented as a long-term
effect, with possible implications for local populations (Bejder
et al.
, 2006). More recent studies confirm substantial changes
in cetaceans’ behaviour when exposed to boat noise, greater
than previously suspected (Williams and Ashe, 2007; Bearzi
et
al.
, 2011; Seuront and Cribb, 2011).
Humpback whales (
Megaptera novaeangliae
) have been shown to
alter behaviour near vessels (Stamation
et al.
, 2010), and several
studies show dolphins avoiding areas with boat traffic (Bejder
et
al.
, 2006). There are numerous studies documenting changes and
Impacts of noise pollution and disturbance
by shipping