Dolphins swimming in circle?

[glynd]

Just back from a lovely sail in Croatia, and saw something I've not come across before.

We had a large number of dolphins swimming / jumping fast in a circle, in about 80m of water right on our track.

I can only presume they were doing some kind of fishing, but it's not something I've seen before....

Sadly no video, but my mate might have a couple of good pictures (we bore away and passed about 15-20m away from this spectacle

Anyone come across this before?
Google finds video of something similar in shallow waters, but nothing showing this on the surface

 

[Hacker]

They will be circling a shoal to create a bait ball. Once they've got the fish in a ball then a quick swim through bets a good meal.

 

[glynd]

Aha - handy to know which term to search for!

It was pretty cool to see, and makes a difference to the usual swim along side

 

[Champagne Murphy]

Saw it in the bay at Achill Island a couple of years ago. It was the only time I've felt the need for a drone camera.

 

[Giblets]

I think it's a form of 'bubble netting' although this usually applies to whales.

https://www.youtube.com/watch?v=Q8iDcLTD9wQ

 

[glynd]

Saw it in the bay at Achill Island a couple of years ago. It was the only time I've felt the need for a drone camera.

I did wish I had a drone camera at the time, or maybe something attached at the spreaders...

Was on the helm at the time, so couldn't grab a camera myself :/

 

[westhinder]

I saw something similar when underway from Newlyn to Kilmore Quay: a pod of dolphins clearly hunting/fishing in group with a flock of birds overhead joining in the feast. We passed not far off, but the dolphins did not pay any attention to us. A quarter of an hour later we were joined by a pod of dolphins who stayed with the boat for half an hour. I have no way of knowing whether they were the same group who had finished their dinner and had come out to play, but it is a nice thought

 

[johnalison]

This is not something I expect to see in Essex, though I did see a harbour porpoise in the Orwell a couple of days ago, and off the Belgian coast a couple of weeks ago.

One thing I did watch fifteen years ago was a group of seals forming a semicircle at the shore of Hamford Water as they drifted with the flood tide, presumably round a shoal of mullet. Over the course of twenty minutes the semicircle shrank, but I was denied the chance to see the denoument by the onset of darkness.

 

[mjcoon]

... but I was denied the chance to see the denouement [corrected by spelling-checker] by the onset of darkness.

What would it be: an outbreak of seals clapping their flippers and barking?

Mike.

 

[johnalison]

What would it be: an outbreak of seals clapping their flippers and barking?

Mike.

No. they usually go in for a group hug.

Thanks for the spell-check. I thought it didn't look right.

 

[BelleSerene]

I am just reading Peter Nichols' A voyage for madmen about the 1968-9 Golden Globe race - Knox Johnston, Donald Crowhurst et al. At one point off an atoll near New Zealand, Bernard Moitessier (probably the most impressive sailor of the lot; would probably have been the fastest round had he not given up the race and his family to continue around the southern high latitudes to a life of solitude) saw a line of 25 porpoises swimming in the direction of his boat before turning to the right - repeatedly. The rest of the school was thrashing around in the middle of the circle. He took this manoeuvre to indicate concern and guidance to turn to starboard. On checking his compass he saw that the wind had backed and his self-steering gear was now pointing him towards the rocks; he turned right and the porpoises swam off.

Moitessier was prone to spiritualism. A far likelier explanation for the porpoises' behaviour is that they were creating and feeding on a bait ball.

 

[Ravi]

I am just reading Peter Nichols' A voyage for madmen about the 1968-9 Golden Globe race -

Great book!

There are many stories of dolphins (alone and in pods) 'guiding' ships to safety. Some-big ocean sailing friends insist that dolphins have warned them of (unforecast) bad storms by exhibiting unusual, frenetic behaviour.
Apparently, there is some old sailing adage along the lines of "When the sea pigs jump, tighten your sea cocks".