IWDG surveying both visually and acoustically on the Marine Institute Blue Whiting Survey

1st Apr 2015

The IWDG are currently surveying for cetaceans onboard RV Celtic Explorer during the annual Marine Institute Blue Whiting survey.  For the first time both visual surveys and concurrent PAM, with the new IWDG towed hydrophone, are being carried out. The team comprise Aleksandra Borawska on Passive Acoustic Monitoring (PAM), Inge van de Knaap as MMO, Niall Keogh as seabird survey and Mairead O'Donovan (MMO and seabirds).  The team work at each station to maintain focus and gain experience.

Here an update from IWDG PAM operator Aleksandra Borawska:

Friday 3 April

Tonight common dolphins decided to make the Friday really good and had a proper mad karaoke party around the hydrophone. At times it seemed
like they must have clicked right at the hydrophone because it blasted the poor Pamguard out and sounded like someone was zapping it with a
taser. This was one of the most amazing experiences for me ever! Niall and Mairead did a rough count in the failing light and came up with 50+.

Wednesday 1 April

IWDG surveyors have joined the Marine Institute team onboard RV Celtic Explorer to collect acoustic and visual data of marine mammals during
the annual Blue Whiting acoustic survey (a species of mesopelagic fish). We have completed one and a half week of the survey so far. Together with the bird survey team, we have been carrying out as much survey effort as the conditions would allow, following a transect route off the west coast of Ireland, traversing the continental slope of the Porcupine Bank, continental shelf and the Rockall Trough.

Despite the adverse weather (wind force up to 9 at times) and having to run for shelter in north Donegal, we have had a number of sightings and acoustic detections. The highlights so far were the three encounters during which we simultaneously observed and recorded cetaceans, each of a species: the Common Dolphin, the Pilot Whale and the Bottlenose Dolphin. We also recorded a number of click detections that showed clear characteristics of the Sperm Whale (relatively well spaced out loud broadband clicks that are low enough frequency to be clearly audible through the headphones). The deeper waters just beyond the Porcupine Bank slope proved to be the hot spot on out transect line, with three or more individuals vocalising at the same time. We are now (Wed afternoon) on our way back out to sea,  and hoping for more encounters and detections off the continental slope off north Donegal, the Rockall Trough and the seamounts off the Hebrides.