Deeper water fish and benthic surveys
in the Lord Howe Island Marine Park: February 2004

Methods

Survey design

The rapid ecological assessment reported here focused on representing depth strata between 30 and 200m at the cardinal points on both Lord Howe and Balls Pyramid Rises and the Commonwealth Sanctuary Zones (Fig. 1). With limited time available to undertake the work, local knowledge from resident fishermen was employed to target areas of bathymetric and piscatorial interest across both rises. Towed video, Baited Remote Underwater Video stations (BRUVS) and Remotely Operated Vehicle (ROV) equipment were shipped to the island on the 19 February 2004 and joined by staff on the 22 February to begin charter on a local boat, MV Kermadec, the following day and working through to the 6 March.

Adverse weather, in particular sea surface conditions, dictated when work could be carried out to the extent that 1 week passed before the survey work could begin. Subsequently, the wind rarely dropped below 15 knots and much of the work, limited to 6 days on the water out of 13 days on the island, was carried out in rough conditions. The need to manage the vessel with regard to swell direction and, in some places, a strong current meant that chosen stations had to be given up in favour of more accommodating conditions elsewhere. Gale-force winds prevented work planned in the Balls Pyramid Commonwealth Sanctuary Zone, although towed video and BRUVS sets were done across the shelf outside the northern boundary of this zone (Fig. 2). None of the sea conditions allowed the deployment of the ROV, which must be tethered to an anchored boat, and consequently detailed examination of the benthos was not achieved as planned.

December 18, 2008