331
possibly causing behavioral changes that affect their distribution and survival
(Scheidat et al. 2004; Carrera et al. 2008; Popper and Hawkins 2016).
Therefore, the whale watching activity can be indicated as a threat to marine
animals (Coscarella et al. 2003; Popper and Hawkins 2016), requiring increased
attention for the subject, control of the activity and management in areas in which it
is held, since positive results have been shown in some locations (eg Tosi and
Ferreira 2009).
13.1.3.4 Dredging and Port Activities
Dredging procedures are usually performed adjacent to the coast, where the depth
needs to be increased (as the entrance of the Caravelas estuary, Bahia State, to
ensure efficiency of ports operations). Many negative environmental impacts are
related to this activity, such as increased turbidity, resuspension of pollutants, habitat destruction, alteration of hydrodynamics, changes on sound propagation and
intense sound noise during dredging activities (Torres-Guijarro et al. 2013).
A dredger used on sandy bottoms is the Trailing Suction Hopper Dredger. This
type of dredger generates noises from different sources, as illustrated on the picture
below (Fig. 13.8).
Fig. 13.8 Dredging activity is very common and has many different sources of sound, may causing acoustic impact where it occurs (From: Reine et al. 2014)
13 Anthropogenic Noise and Guiana Dolphins (Sotalia guianensis) in Brazil…
possibly causing behavioral changes that affect their distribution and survival
(Scheidat et al. 2004; Carrera et al. 2008; Popper and Hawkins 2016).
Therefore, the whale watching activity can be indicated as a threat to marine
animals (Coscarella et al. 2003; Popper and Hawkins 2016), requiring increased
attention for the subject, control of the activity and management in areas in which it
is held, since positive results have been shown in some locations (eg Tosi and
Ferreira 2009).
13.1.3.4 Dredging and Port Activities
Dredging procedures are usually performed adjacent to the coast, where the depth
needs to be increased (as the entrance of the Caravelas estuary, Bahia State, to
ensure efficiency of ports operations). Many negative environmental impacts are
related to this activity, such as increased turbidity, resuspension of pollutants, habitat destruction, alteration of hydrodynamics, changes on sound propagation and
intense sound noise during dredging activities (Torres-Guijarro et al. 2013).
A dredger used on sandy bottoms is the Trailing Suction Hopper Dredger. This
type of dredger generates noises from different sources, as illustrated on the picture
below (Fig. 13.8).
Fig. 13.8 Dredging activity is very common and has many different sources of sound, may causing acoustic impact where it occurs (From: Reine et al. 2014)
13 Anthropogenic Noise and Guiana Dolphins (Sotalia guianensis) in Brazil…