Page 50: of Marine Technology Magazine (June 2012)

Case Study Across England and Wales, The Environment Agency moni- tors Þ sh life in rivers and waterways. They investigate rare and threatened species, such as eel and lamprey, and enumerate salmon and sea trout migrations. These agencies also investi- gate Þ sh behaviour around in-river structures like abstraction sites and pump houses, tidal ß ap structures and Þ sh passes to name a few applications. The Environment Agency already uses the DIDSON multi- beam sonar system for their Þ sh studies, which have proven to be highly effective in river monitoring. However, with The Environment Agency responsible for such a large area to mon- itor, demand has now outstripped the availability of the seven existing units and The Environment Agency Þ sheries techni- cal experts were keen to increase their remote non-invasive monitoring capacity. They have ordered new, additional sonar units through un- derwater technology supplier, MacArtney Underwater Tech- nology. MacArtney will supply three of the new generation sonar models from Sound Metrics Corp, the Adaptive Resolu- tion Imaging Sonar (ARIS) for their specialised Þ sh monitor- ing work. ÒThe higher resolution and lower power requirements of these short range units will be ideal for studying Þ sh move- ments in the turbid waters around tidal ß ap structures and Þ sh passes, particularly in remote locations that lack mains power supply,Ó explained Jon Hateley, Technical Advisor (Hy- droacoustics) at the Environment Agency. All the new ARIS Explorer range of sonarÕs are low pow- ered, drawing less than 15W Ð half the nominal 30W required for the current DIDSON. It also requires less maintenance as the sealed lens arrangement eliminates the need for a silt box and the internal focus drive mechanism avoids potential jam- ming issues.The DIDSON system is still a popular choice for imaging so-nar units for Þ sheries and Marine Scotland has recently placed an order for a standard 300m rated DIDSON system. This sys- tem will be used by the Scotland Freshwater Laboratory for Þ sheries investigation and Þ sheries research projects. MacArtney Underwater Technology will supply the DID- SON, a range of accessories, commissioning and training. The Environment Agency in Wales has also purchased a DIDSON LR (Long Range) imaging sonar. All ARIS and DIDSON system orders include the sonar, Pan & Tilt rotators, special lens items, commissioning and training if and as required.ARIS Sonar Imaging System ARIS Sonar Imaging System offers clearer details to The Environment Agency New generation sonar units from Sound Met- rics Corp. supplied by MacArtney will aid spe- cialized Þ sh monitoring work. Project at a GlanceProblem: Keeping up with monitor- ing of rare, threatened species in England & Wales Solution: Investment in additional Sound Metrics sonar unitswww.macartney.com June 201250 MTRMTR #5 (50-64).indd 50MTR #5 (50-64).indd 505/31/2012 1:15:42 PM5/31/2012 1:15:42 PM