Anthropogenic barriers to migration are traditionally mitigated for, by using fish passage structures. At a remote site in the North-Western United States ICER has undertaken research to understand the behavioural response of a culturally significant fish species to less used fish passes.

Fisheries scientists working with Pacific Lamprey (Lampetra tridentate) noticed rejection behaviour at a particular fish pass that was of similar design to others in the area. Between ICER and the local fisheries scientists it was hypothesised that this was due to acoustic signals generated by the fish pass in turbulent water. A research project was established in partnership between ICER and the United States Geological Survey (USGS) that aimed to improve the passage efficiency of upstream migrating Pacific Lamprey in the Columbia basin. Lamprey passes at various dams along the Umatilla River in Oregon, US were mapped for signs of potential acoustic disturbance to migrating Lamprey. Captive Lamprey were then exposed to broadband noise under laboratory conditions and their response measured. The current research focus is to quantify their behavioural differences under acoustic treatment.

It is hoped that understanding the acoustic conditions surrounding Lamprey passes and the associated behaviours will allow increased passage efficiency through better fish

pass design. A special thanks to the Confederated Tribes of the Umatilla Indian Reservation for allowing access to their land and Lamprey throughout the running of this project.

People:

Matt Short

Prof. Paul Kemp

Michael Hayes

Prof. Paul White

Dr. Mary Moser

Prof. Tim Leighton

 ICER researchers are exploring the influence of sound on the behaviour of fish groups. Building on previous research in the area of fisheries acoustics this study aims to quantify the extent to which being part of a school influences the reaction of fish to acoustic stimuli, using the minnow  (Phoxinus phoxinus) as the model species.

Using experimental facilities at ICER, and working closely with the Institute of Sound and Vibration Research (ISVR), acoustic fields are generated and mapped. The movements of the subject fish are recorded and tracked relative to alternative sound fields. By using state-of-art filming and particle tracking techniques,  reactions are observed and analysed relative to positional data of the fish to quantify how spatial distribution changes under different treatments in which acoustic pressure and particle motion is manipulated.  Further, in the aquatic environment fish frequently form aggregations. Existing research concerning fish and acoustic stimuli has traditionally focused on solitary fish or small groups.  Our research compares between the two. It is hoped that this research will lead to the development of more efficient environmental impact mitigation technology, such as behavioural fish screens / deterrents.

People:

Matt Short

Prof. Paul Kemp

Prof. Paul White

Prof. Tim Leighton

Research is being undertaken to explore the potential of a number of behavioural guidance devices at deterring seaward migrating adult European eel (Anguilla anguilla) from entering deleterious routes such as water abstraction and hydropower intakes. A series of field-based studies have been undertaken using sub-metre precision acoustic positioning telemetry to investigate the response of downstream migrating adult eels to an infrasound (< 20Hz) source at a redundant hydropower intake. Eel swim path characteristics when approaching the device during both ‘on’ and ‘off’ mode will be compared and analysed in the context of mapped acoustic environments.

The results of this research programme will be used to formulate a behavioural rule-base of values for developing efficient non-mechanical screening devices to prevent ingress of fish into hazardous areas.

People:
Dr Adam Piper
Prof Paul White
Dr Paul Kemp

Experimental research is investigating the fundamental hearing capabilities of a number of fish species of conservation importance, including the European eel (Anguilla anguilla) and river lamprey (Lampetra fluviatilis).A physiological approach will be undertaken, allowing the inferior limit of the audible detection range of a species to be quantified through the Auditory Brainstem Response method. This will enable the generation of accurate audiograms, a graphical representation of the lowest frequencies detectable by a fish, at the lowest intensity. In addition, a behavioural approach will further quantify how fish respond to detectable sounds. Behaviour will be video recorded during exposure to sound (e.g. ranging from 100 to 1000 Hz with an intensity range from 90 to 140 dB), and will be post processed using novel video tracking software.

Results from these experimental studies will inform our field based research into acoustic deterrents and have direct application to behavioural screening devices.

People:
Mathias Deleau

Prof Paul White

Dr Paul Kemp
Prof Tim Leighton

Low-frequency background noise in the ocean has increased 32-fold since the 1950’s. The most widespread source of marine anthropogenic noise pollution is from vessels: the worldwide commercial fleet has grown from approximately 30,000 vessels (~85,000,000 gross tons) in 1950 to 89,899 vessels (605,000,000 gross tons) in 2003. Worldwide non-commercial vessels, including recreational craft and private boats, have also increased, although no official log of actual numbers exists. Furthermore, port turn-around times are shorter resulting in ships spending more days per year at sea and vessels have greater average speeds, propulsion power, and propeller tip speeds.  Sound levels were seen to increase by 15 dB between 1950 and 1975 as a direct result of shipping activities. These trends are certain to continue, posing unique challenges for aquatic animals.

Infrastructure associated with shipping such as port development often uses pile driving during construction, an intense, impulsive sound source that has already been seen to affect many fish species.

Research at the ICER will investigate the effects of vessel related noise on fish; focusing on the impacts of noise, masking and vibrations on behaviours of keystone, commercial and conservational important species. This project will start by investigating an adaptation (the Lombard effect) that can overcome the effects of masking and allow the communication of biologically important signals between conspecifics to be heard, for example vocalisations used during courtship. The Lombard effect is the change in the intensity, pitch, duration or rate of vocalisations in the presence of background noise in order to maintain a constant signal to noise ratio. If it can be proven that fish utilise the Lombard effect to remain audible to conspecifics, then reproduction can occur unhindered. If, however, the Lombard effect is not observed in fish, then the masking of vocalisations by anthropogenic noise should be regarded as a serious threat to vocalising fish species.

This research will determine whether fish populations can adapt quickly enough to survive in areas of noise pollution. If they cannot, there may be serious consequences for marine food webs and the fisheries industry. This EPSRC and FugroEMU Ltd funded project will provide research to aid in setting criteria necessary for legislation to limit levels of noise pollution from anthropogenic activities.

People:
Sarah Neenan
Mr Rayner Piper
Prof Paul White
Dr Peter Shaw
Dr Paul Kemp
Prof Tim Leighton