Painted Goby Larvae under High-CO2 Fail to Recognize Reef Sounds

Abstract

Atmospheric CO2 levels have been increasing at an unprecedented rate due to anthropogenic activity. Consequently, ocean pCO2 is increasing and pH decreasing, affecting marine life, including fish. For many coastal marine fishes, selection of the adult habitat occurs at the end of the pelagic larval phase. Fish larvae use a range of sensory cues, including sound, for locating settlement habitat. This study tested the effect of elevated CO2 on the ability of settlement-stage temperate fish to use auditory cues from adult coastal reef habitats. Wild late larval stages of painted goby (Pomatoschistus pictus) were exposed to control pCO2 (532 μatm, pH 8.06) and high pCO2 (1503 μatm, pH 7.66) conditions, likely to occur in nearshore regions subjected to upwelling events by the end of the century, and tested in an auditory choice chamber for their preference or avoidance to nighttime reef recordings. Fish reared in control pCO2 conditions discriminated reef soundscapes and were attracted by reef recordings. This behaviour changed in fish reared in the high CO2 conditions, with settlement-stage larvae strongly avoiding reef recordings. This study provides evidence that ocean acidification might affect the auditory responses of larval stages of temperate reef fish species, with potentially significant impacts on their survival.

Paradigm Lost: Ocean Acidification Will Overturn the Concept of Larval-Fish Biophysical Dispersal

“…Adding Castro et al (2017) to the relevant hearing studies listed by Ashur et al (2017) gives four studies covering four species of four families ( Table 1). One species is a Damselfish, plus one each Goby (Gobiidae), Croaker (Sciaenidae), and Barramundi (Latidae).…”

“…For swimming, six studies used CO 2 values for the middle to the end of the century (two had an effect, four did not), whereas four used values of 1400-1800 µatm (one had an effect, three did not). In some cases, higher CO 2 levels were selected based on regional differences in ocean pH such as upwelling (e.g., Castro et al, 2017), but in others, it was not clear upon what basis more acidic conditions were chosen. However, it does not appear that acidity very much higher than expected by 2100 is required for detrimental sensory performance or behaviours to be likely.…”

Ocean acidification effects on fish hearing

“…While the effects of elevated CO 2 on otolith FA remain poorly documented, there is increasing evidence that elevated CO 2 can affect auditory preferences of marine fishes [44,[47][48][49]. For example, larval clownfish reared at approximately 1000 µatm CO 2 had an impaired response to daytime reef sound [44] and late painted gobies reared at 1500 µatm CO 2 avoided reef sounds that attracted larvae reared in control conditions [50]. These alterations in auditory preference are thought to be linked to elevated CO 2 interfering with the function of GABA-A neurotransmitter receptors [51][52][53][54].…”

On the wrong track: ocean acidification attracts larval fish to irrelevant environmental cues

“…Sound is increasingly recognized as a cue used by dispersing propagules of tropical species because it propagates with little attenuation in water, is independent of currents and also carries information about the habitat type and its resident species community 2 , 7 . As a result of ocean acidification, larvae of the catadromous barramundi ( Lates calcarifer ) are deterred rather than attracted to the sound of their estuarine settlement habitat at settlement stage 8 , settlement-stage larvae of temperate gobies are deterred by reef soundscapes 9 , whilst post-settlement clownfish lose their avoidance response to reef sounds 10 .…”