What a week! I finally had the chance to deploy my best piece of kit which has been carefully saved until we had tested new retrieval techniques (as it’s rather special and expensive!) So now we are deploying accelerometers on fish within the Tonnarella nets using the nets as a giant sea pen (344m wide by 80m deep), for approx. 4 hours before the harness pops off and the fish is then recaptured and lifted to true freedom at the next net haul.
The harness and tag then float at the surface so I have the best chance of finding it in one area before it drifts off! We deployed a CEFAS accelerometer this way (great piece of kit, how can you fit so many sensors into such a tiny object?!) and heard it on the radio receiver within 5 minutes of it arriving at the surface. Lawrence and I then kayaked out to collect it!
So I finally had the confidence to use the CATScam (Customised Animal Tracking Solutions camera) which is a bit larger with in-built accelerometer and video camera! This means the sunfish will film its day so we can visually validate all behaviours and get a fishes-eye view of the world!
Of course, even after months of background work, even the best laid plans can go astray… the tag deployed perfectly, the fish swam off into the nets… but after 4 hours there was nothing, no signal, no peep from the radio tag. Hours and then days passed, and the tag was nowhere to be found. Maybe the sunfish escaped the nets, maybe the tag drifted away really fast, maybe it was run over by a boat and sunk! Unlimited nightmare scenarios kept running through my mind… and when I had almost lost all hope: an email!! It was found by a member of the public in Portofino harbour! The labels and reward had worked and we now have full data from another sunfish including video footage! What a relief!
Our sunfish had filmed its day, including an encounter with another sunfish in the Tonnarella! The data we have received is really invaluable to my research and will help us to better understand this vulnerable species; how they travel, how much energy they need, what they eat and what the potential ecosystem-wide impacts might be if the current rates of mass removal of sunfishes continues. All this information will be useful for future management and conservation of sunfishes across the world, so I am really delighted!
Fingers crossed for more flat calm weather to get the next logger deployed soon!
Any comments/questions? Please get in touch!