406
interest, this section will focus on the consequences of acoustic trauma. Noise from
anthropogenic sound sources can produce negative effects on fi shes ranging from
physical damage and death due to very intense sounds such as underwater explosions, sonar, pile driving, or seismic surveys (Popper et al. 2005 , 2007 ; Casper et al.
2012 , 2013a , b ; Halvorsen et al. 2012a , b ) to more subtle behavioral effects such as
reduced foraging, shelter maintenance, and predator defense (Purser and Radford
2011 ; Bruintjes and Radford 2013 ). The extreme effects of physical damage and
death have been recently reviewed elsewhere (Edds-Walton and Finneran 2006 ;
Popper and Hastings 2009 ), as have behavioral effects with potential long-term population level consequences (Slabbekoorn et al. 2010 ; Radford et al. 2014 ). Therefore,
we will focus here on the intermediate effect of anthropogenic sound, hearing loss.
In order to understand the effect of hearing loss on fi shes, one must fi rst assess
which types of acoustic stimuli are biologically relevant to them. One thing that
they listen to is other fi shes (both conspecifi c and heterospecifi c), as well as other
aquatic sound-producing organisms (Lagardère et al. 2005 ; Vasconcelos et al. 2011 ;
McIver et al. 2014 ). Fishes produce sounds in a variety of ways including drumming
of the swim bladder, stridulation of bones such as pectoral spines and pharyngeal
teeth, and vibration of tendons (Ladich and Fine 2006 ). Approximately 800 species
of fi sh from over 100 different families are known to produce sound (Ladich and
Fine 2006 ; Ladich and Bass 2008 ). Although the behavioral signifi cance of most of
these sounds has not yet been examined, it is known that some species use sound for
spatial orientation, defense from predators or competitors, reproductive behaviors
including courtship, mate choice and synchronization of gamete release, and alarm/
stress calls (Winn 1964 ; Tavolga 1971 , 1977 ; Hawkins 1993 ; Ladich 2000 ; Ladich
and Fine 2003 ; Ladich and Bass 1998 ). As sounds produced by fi shes can vary by
species, populations, gender, size, and motivation, they can provide useful information that might be used to modify fi sh behavior and thus infl uence their reproductive
fi tness (Hawkins and Rasmussen 1978 ; Myrberg et al. 1993 ; Parmentier et al. 2005 ;
Verzijden et al. 2010 ).
Intense sound exposure has been shown to elicit short-term physiological stress
responses and startle behaviors in fi shes (Skalski et al. 1992 ; Wardle et al. 2001 ;
Smith et al. 2004a ; Boeger et al. 2006 ; Wysocki et al. 2006 , 2007 ). Unfortunately,
there are few behavioral studies on the effects of anthropogenic sound on fi shes and
most of these studies have used test cages or tanks during the sound exposure
(McCauley et al. 2003 ; Boeger et al. 2006 ; Popper et al. 2007 ). Thus the behavioral
observations of these experiments may differ from how fi sh might react unrestrained
in the wild. More recent experiments have shown that background noise can affect
fi sh foraging and antipredator behavior (Purser and Radford 2011 ; Bruintjes and
Radford 2013 ), but in no behavioral experiment performed to date has hearing loss
been quantifi ed such that the relationship between hearing loss and specifi c behavioral defi cits can be elucidated. At this point, we can only speculate that hearing loss
in fi shes would produce similar disruptions in acoustic communication as in other
vertebrates (reviewed in Radford et al. 2014 ). Increased hearing thresholds would
mean that fi sh would have to be closer to sound-producing prey, mates, competitors, or predators before they could detect them. Hearing loss may also inhibit
M.E. Smith and J.D. Monroe
interest, this section will focus on the consequences of acoustic trauma. Noise from
anthropogenic sound sources can produce negative effects on fi shes ranging from
physical damage and death due to very intense sounds such as underwater explosions, sonar, pile driving, or seismic surveys (Popper et al. 2005 , 2007 ; Casper et al.
2012 , 2013a , b ; Halvorsen et al. 2012a , b ) to more subtle behavioral effects such as
reduced foraging, shelter maintenance, and predator defense (Purser and Radford
2011 ; Bruintjes and Radford 2013 ). The extreme effects of physical damage and
death have been recently reviewed elsewhere (Edds-Walton and Finneran 2006 ;
Popper and Hastings 2009 ), as have behavioral effects with potential long-term population level consequences (Slabbekoorn et al. 2010 ; Radford et al. 2014 ). Therefore,
we will focus here on the intermediate effect of anthropogenic sound, hearing loss.
In order to understand the effect of hearing loss on fi shes, one must fi rst assess
which types of acoustic stimuli are biologically relevant to them. One thing that
they listen to is other fi shes (both conspecifi c and heterospecifi c), as well as other
aquatic sound-producing organisms (Lagardère et al. 2005 ; Vasconcelos et al. 2011 ;
McIver et al. 2014 ). Fishes produce sounds in a variety of ways including drumming
of the swim bladder, stridulation of bones such as pectoral spines and pharyngeal
teeth, and vibration of tendons (Ladich and Fine 2006 ). Approximately 800 species
of fi sh from over 100 different families are known to produce sound (Ladich and
Fine 2006 ; Ladich and Bass 2008 ). Although the behavioral signifi cance of most of
these sounds has not yet been examined, it is known that some species use sound for
spatial orientation, defense from predators or competitors, reproductive behaviors
including courtship, mate choice and synchronization of gamete release, and alarm/
stress calls (Winn 1964 ; Tavolga 1971 , 1977 ; Hawkins 1993 ; Ladich 2000 ; Ladich
and Fine 2003 ; Ladich and Bass 1998 ). As sounds produced by fi shes can vary by
species, populations, gender, size, and motivation, they can provide useful information that might be used to modify fi sh behavior and thus infl uence their reproductive
fi tness (Hawkins and Rasmussen 1978 ; Myrberg et al. 1993 ; Parmentier et al. 2005 ;
Verzijden et al. 2010 ).
Intense sound exposure has been shown to elicit short-term physiological stress
responses and startle behaviors in fi shes (Skalski et al. 1992 ; Wardle et al. 2001 ;
Smith et al. 2004a ; Boeger et al. 2006 ; Wysocki et al. 2006 , 2007 ). Unfortunately,
there are few behavioral studies on the effects of anthropogenic sound on fi shes and
most of these studies have used test cages or tanks during the sound exposure
(McCauley et al. 2003 ; Boeger et al. 2006 ; Popper et al. 2007 ). Thus the behavioral
observations of these experiments may differ from how fi sh might react unrestrained
in the wild. More recent experiments have shown that background noise can affect
fi sh foraging and antipredator behavior (Purser and Radford 2011 ; Bruintjes and
Radford 2013 ), but in no behavioral experiment performed to date has hearing loss
been quantifi ed such that the relationship between hearing loss and specifi c behavioral defi cits can be elucidated. At this point, we can only speculate that hearing loss
in fi shes would produce similar disruptions in acoustic communication as in other
vertebrates (reviewed in Radford et al. 2014 ). Increased hearing thresholds would
mean that fi sh would have to be closer to sound-producing prey, mates, competitors, or predators before they could detect them. Hearing loss may also inhibit
M.E. Smith and J.D. Monroe