NOISE IMPACT ON MARINE SPECIESAJ Shockley

FROM LAST TIME..

This has a direct behavior andphysiological impact on marinespecies…

Ocean acidification is caused by uptake of anthropogenic CO₂

CO propagates ₂sound and lowers levels of sound dampening chemicals Ambient ocean noise is projected to increase by 2 dB by 2100.

INTRO

DU

CTION

Sounds from traffic, military, industrial and recreational activities have relatively low frequencies within the range of biotic sounds used to communicate.

This elicits both passive and active responses in marine life.

PASSIVE VS ACTIVE IMPACTS

Include involuntary responses in affected species like an increase in heart rate.

Include voluntary responses like avoidance of sound source.

Passive Active

ZEBRAFISH AS A MODEL

Neurochemical similarities to terrestrial

animals

Cheap and easy to

maintain

Readily reproduce

Small species that grows to about 2.5 inches

Zebra fish have grown in popularity as a model species for analyzing anxiety in behavioral studies.

NOVEL ENVIRONMENT EXPERIMENT A small group (6)

of fish was placed into the tank system, exposed continuous noise pulses as well as slow and fast pulse rates and their behavior assessed.

startle responses

erratic swimming movements/speed

accumulated swimming distance

group cohesion

freezing bouts

number of entries between tanks

total time spent in that same area relatively close to the surface

RESULTS

In both experiments swimming speed, group cohesion, and tendency to move up to the surface were effects.

While there are certainly implications more study is needed to draw direct links between experimental and natural environments in reference to spatial and temporal noise exposures. Captivity and natural environment are very different and yield different thresholds and physical impacts.

speciessexageseasonpredators present

METHOD

Exp 1: Moderate exposure levels of about 112dB in a single tank without acoustic escape.

Exp 2: Up to 140dB in a double tank system with possibility of acoustic escape via 35cm PVC tunnel.

SOURCES OF DEVIATION:

INTRO

DU

CTION

This experiment used sympatric species to study the effects of noise on anti-predation behaviors.

Exposure to additional anthropogenic sounds either causes:

Hypothesis: If exposure to additional noises causes a stress response resulting in reduced activity then the exposure will slow responses to predatory cues. However, if the exposure results in arousal then threats are more likely to be detected sooner and avoided.

Three-spined stickleback• Protective armor

European minnow • More sensitive

hearing (up to 5Hz)

Impacts on Anti-predator Behavior

Heightened alertness

Reduction in activity

and locomotion3

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SETUP AND METHODS

(PS) visual predatory stimulus, (LS) underwater loudspeaker, (X) focal fish position for predator release, (F) feeder, (P) artificial plant, (S) mesh separator and (D) opaque Correx dividers Control (30 min) and additional noises (15 min) were

recorded at 3 nearby ports. The experiment was conducted in a 150×30 cm glass

tank fitted with an upward facing loudspeaker. Experiments conducted at peak activity time (8AM to

6:30PM) with groups of 12 fish in at least 30 minute intervals.

In each trial control tracks were played for 30 min followed by either another control or an additional noise track.

1 min into the second track the predatory model was released and responses were video recorded with time stamps.

The videos were then muted and the freezing/startling responses were recorded by a single observer

RESULTS

With exposure to additional sounds Sticklebacks became more vigilant despite having protective factors.

Minnows were less responsive because they were more likely to be distracted by companion fish.

Despite their shared lineage these species responded quite differently from each other and from what was expected.

More study is needed within natural environments to provide more insight into the effects of additional noises on anti-predator behavior.

There was no significant difference in latency periods for minnows between control and additional noise tracks.

Sticklebacks a shorter latency period than Minnows with a shorter latency when exposed to additional noise.

BIBLIOGRAPHY http://www.newsweek.com/2014/04/11/whales-are-b

eing-killed-noise-pollution-248069.html http://ngm.nationalgeographic.com/2011/01/big-ide

a/noisy-ocean

Images http://

www.fishwallpapers.com/european-minnow/european-minnows-pic.html

http://animal-kid.com/three-spined-stickleback.html