Unprecedented sand eel numbers great news for whale watching in West Cork

As predicted in my previous log, we now have an intense bloom of plankton in full swing, and the sea is green, far more than blue, with rich phytoplankton. Not predicted, is the incredible amount of lesser sand eels that have assembled to feed on the bloom in West Cork waters. I have never seen them so abundant at any time in the past 40 years. Having looked at several samples of them, it is very clear that the vast majority of them are two year old fish, showing that the wet summer of 2012 must have suited their spawning activity very well, in some unexplained way. All fish species spawn annually, but very often there is no regeneration, and all the larval fish perish, with no survivors at all. Then, every now and again, all works according to plan, and there are millions of new recruits to add to the stock, such as there is this year.

All this abundance has not gone unnoticed and a good number of minke whales, and a lot of sea birds have been gorging themselves on sand eels, as well as all the predatory fish in the area. It’s a tough life, being a sand eel. There seems to be more minkes about than is usual, with a good showing of calf size animals, as there was last year. It is good to see plenty of young whales about, proving they are still breeding successfully. It is these youngsters that have a preponderance for visiting boats, and will spend up to half an hour, circling the boat and passing under the hull, sometimes upside down, showing off their swimming skills. An absolute delight for whale watchers and the only time you get to see the exquisite, streamlined shape of a minke whale’s tail.

A good showing of basking sharks over the last few weeks, in spite of poor conditions for bringing them to the surface. A combination of strong sunshine and warm, balmy air is the ideal for them, and such weather is forecast for the week ahead. A lot of the sharks are young, relatively small for their species, but here and there you find a whopper……

In 1974, I was crewing on a local boat, drift netting for salmon off Toe Head. It was a warm sunny day in June with light south east wind. Not far away from us, in near the rock we saw a distress flare go off. We motored in towards the flare and discovered a local boat with steering disabled about to destruct on the rocky shoreline. We threw a tow line and pulled the boat away from the rocks. They were then able to fix the rudder problem and returned to their nets so we returned to ours, except that they had vanished! We had about 1,500 yards of drift net, moving very slowly to the west, a good sized poly-form buoy, marked each end, with a large cork every 2 metres all along the net, a lot of buoyant material, vanished without trace.

A calm blue sea, superb visibility, we motored east and west, searching for our gear, in disbelief that it could just disappear in the short period we left them unattended. After two hours searching we spotted one of the end buoys, and caught hold of it, to see all our netting was being pulled under by some mysterious force. We tried towing the net to free it. With an almost new 120 horse power engine we were able to pull ahead for a bit, then back up, recovering the net, piece by piece. At times the boat was pulled backwards with engine going full ahead, and the ropes from the net sank into the hardwood gunnel under the pressure. After about two hours of this activity, we had recovered more than two thirds of our gear, and peering down into water below, could see the tail of a colossal basking shark, which dwarfed any that I had seen before, and they were abundant in the seventies.

The shark finally broke free of the net. I never saw the whole shark, its body hidden in the gloom of the water, but I did see clearly that it was close to 12 feet from the tip of one tail lobe to the other. It looked as big as any large whale shark, its tropical counterpart, the world’s largest fish. I’ve never seen another even approaching the size of it.

It is often in June when the first sightings of fin whales occur and with plenty of plankton and fish activity, I will be surprised if that is not the case this year. The sea is notably warmer this year than last, with everything happening on time, and in season, so I will bet there will be blows to be seen in June.

Colin Barnes

Skipper, MV Holly Jo

Ed note….Based on body length ratios of basking sharks, if Colin’s length estimation of 12ft between tips of tail fin is correct, this shark could quite easily have been in the 40-45ft length range. Such a large specimen has to the best of my knowledge never actually been measured properly in Irish waters (with a tape and along the ground). But basking sharks of these humpback whale proportions have been referred to in Gavin Maxwell’s classic 1952 book “ Harpoon at a Venture”, which tells the story of the basking shark fishery in the Scottish Outer Hebrides. So Colin’s observation back in 1974 is not without precedent.