a colonial tunicate that floats in the water

A couple of weeks ago it was very common to see strange objects which looked
glass-like translucent and plastic, whilst others seemed softer, more
opaque and hairyer.  Not only were they littering the sea floor but were also driting in mid water.  On the whole the fish left them alone.

I touched one and it felt hard also as if it were made of plastic.  It was very strange.  So I emailed an image of one to our pal Andy to see if he knew what they were.

After a bit of hunting around he came back with an answer "I'm 100% sure that these tubes are Pyrosoma, and these ones
could possibly be 'Pyrosoma atlanticum".

Andy explained that my plastic tubes are also known to move and
die in large numbers and that they also use jet propulsion to move around.

Pyrosome, are colonial
tunicates that float in the water off the sea bed.

An example of a
tunicate is a sea squirt. They live mostly out in the open ocean and
can migrate a few hundred meters each day vertically. They are filter
feeders (hence the 2 holes either end). It's not too clear whether the images below have caught examples which are
alive or not… there might be some sort of a valve either end to
control filtering.

Andy suggested that the hairs on the outside might be used as
locomotion and that it might be able to use bioluminescence.

So, there you have it.  My mystery was easily explained so long as you know who to ask and how to structure the right question.

I thought the shots below were quite interesting.

300410 025

1. Anenome

300410 046 

2. Pyrosome

300410 044 

3. Anenome with Pyrosome

/0 Comments/by
,

light from the collapsing cavitation bubble

A month or so ago I met a great bloke called Andy who undertook a diving course with Calypso a couple of years ago.  Now he's back for more.

Andy and I completed our Rescue Diver course together and became pretty close, having to blow on each other foreheads for an afternoon and then share the experience of blowing on our instructors forehead a day later.  Andy also shared his air with me which is neither a metaphor nor a lifestyle choice.

As it happens Andy is from just across the water from where my sister lives on the West coast of Scotland;  I know, it's a small world.

Get to the point of all this finger tapping now, I hear you cry!

Well, Andy is studying Marine Biology and on his first day of this visit to Calypso Andy told us of the wonder of Snapping Shrimps.

The animal has one claw bigger than the other and snaps the big claw shut to make a noise in order to stun its prey.  Within the claw there is a plunger which as the claw snaps, the plunger moves out at incredible speed to create a cavitation bubble.

What this means is that the plunger pushes water out of the space within the claw faster than surrounding water can fill the void.  Being a fan of all things Star Trek and Dr Who I liked this bit most of all in that it reminded me of a black hole (but probably is nothing like it!).

The pressure is strong enough to kill small fish.

The snap can also produce light from the collapsing cavitation bubble. As it collapses, the cavitation bubble reaches temperatures equal to the surface temperature of the sun (estimated to be around 5,500 °C). The light is not visible to the naked eye.

All of this happens in less than a millisecond.  All that evolution for a spot of lunch!  What makes this even more incredible is that the sound is so loud that navel maps routinely detail beds of these creatures and when necessary commanders will lower their vessels down close to the colonies, in order to interrupt enemy sonar detection equipment, useless against the background noise of the snapping shrimp.

This last point was confirmed by Navy Mark who came and did his PADI Open Water with us.  He told me that rather than hide because of the noise, Russian subs would operate their radios at a Hz the same as the shrimps.  This was not by design but purely by chance.  When discovered this acoustic signature became known by western radio operators as the key to detection, either that or it turned out to be a bed of shrimp.

/0 Comments/by

swaying and dancing backwards and forwards

A couple of weeks ago, I was doing a dive at Puerto del Carmen.

As part of the DiveMeister course I have to practice, to demonstration standard, a host of skills, for example clearing the mask of water, removing and replacing the mask, pivoting on the fins, and removing and replacing the regulator (the breathing apparatus in the mouth).

200410 064 

200410 062

During this dive, we past a field of garden eels (my personal favorites) and a cuttlefish.

Then, Mr D decided to give me a treat and for about 10 minutes I was allowed to be distracted.  We looked in some ropes and found a little seahorse.

200410 045

200410 052

It was so very well camouflaged.  It was attached by its curling tail to some algae covered rope.

200410 057

It was tiny, no bigger than my thumb (about 5cm long) and so delicate.  It sat clinging to its rope haven swaying and dancing backwards and forwards in response to the subtle effects of the surge.

It was a real privilege to see the little creature.

I have been told that seahorses can be found in the waters near Dover harbour, which is great news and I cannot encourage divers enough, if you have not spent time looking up close at these majestic creatures, just do it!

For me, the 20° water has visibility in excess of 30 meters.  Given my current circumstances, I think I know where I would rather find them!

/2 Comments/by

lays like an old elephant carcass

On Tuesday mornings the scheduled dive at Calipso is the wrecks by the new harbour wall at Peurto del Carmen.

It requires a boat to travel to the entry point next to the wall which is used as a reference for decending the safety stop and for the acsent to the surface.

There are four wrecks in all.  As we decend we come across an imposing boat on its side.  It jutts from the wall, having been incorporated into the walls construction.  Time is not wasted on this wreck though as we drop off over the edge and swim slowly to the three as a greater depth of about 30 meters.

I am informed that all 4 boats are old working fishing boats the local authority sank on purpose specifically to support divers visiting the island.

290410 034

The deepest wreck lays like an old elephant carcass.  Its flesh eaten, rotted and scavenged from its bones.  Its ribs exposed and pointing skyward.   Made of wood, soon there will be nothing left of what used to harvest fish from this same sea.  In the meantime, it provides accomodation and food to a host of fish and other marine invertabrates.

290410 039

An old propeller sits on the sea bed.  Measuring about 2ft across, algae and corals cover the corroding metal as small atlantic damsels swim around to investigate the possability of food.

290410 038

Multi coloured turckish wrasse swim around the boats carcass weaving in and about flora covered wood.

290410 049

This wreck looks almost intact.  Its mast and rigging giving a ghostly feel to this man made environment.

290410 054

Up now to explore the first wreck we past.  It lays on its side.    It is much bigger than the others and sits on an imposing ridge overlooign the others.

290410 052

Looking at the wreck from below its bow, the light behind provides an eerie silluette.

290410 057 

Portholes look out from the bridge.  Fish swim to and fro through what once were wheather proof.

290410 058

Looking up I see a shoal of sardines swimming overhead.  Not yet baitballs, their numbers are swelling.

/0 Comments/by
, ,

the blue heart of our planet

These two TED talks feature the amzaing octopus.  I really enjoyed them and hope you do too.

Underwater filmmaker Mike deGruy has spent decades looking intimately
at the ocean. A consummate storyteller, he takes the stage at Mission
Blue to share his awe and excitement — and his fears — about the blue
heart of our planet.

David Gallo shows jaw-dropping footage of amazing sea creatures, including a color-shifting cuttlefish, a perfectly camouflaged octopus, and a Times Square's worth of neon light displays from fish who live in the blackest depths of the ocean.

You might also find this article interesting:

Davy Jones Garbage Dump (1975)

Deep Sea Dumping (2000)

WE SAY NO – Facebook group

/0 Comments/by

rubbish

Over the past few weeks I have been really shocked with the amount of rubbish that I have seen in the ocean when I have been diving.

I have decided to do something about it.

I searched the internet for schemes, projects or prgrammes which I might be able to obtain advice or guidlines for rubbish removal as a diver.  

Obviously I read about the PADI PROJECT AWARE Foundation where there is lots of encouragement to organise 'one off' events, which is great news when dealing with marine debris. 

You can find further information about Project Aware's support for volunteers who want to organise a clean up HERE. 

I also found lots of charity's doing their bit in different parts of the community, but it seems clear that there is not a systematic approach to get divers and the global diving community to simply remove little bits of rubbish whenever each and every diver goes underwater.

Maybe this is just another bee in my bonnet!  Who the devil knows?

I just think that picking up the odd cola can, drinks can ring pull, cigerette butt or plastic store bag to throw away after the dive is really simple for most PADI Open Water equivelent or more qualified divers to participate in. 

Although some individual divers do have a go routinly and some individuals or groups organise brillient events where tonnes of rubbish is removed from under the water in a bay or shoreline; I believe individual divers should be more pro-active in their chosen sport to clean up the environment and look upon it as an every day responsibility.

I will keep you informed of my progress as and when I do something.

/2 Comments/by
,

the slow rhythm of an aqua-blue sea

Best bit
of today was this morning when diving toward the pink coral at Puerto del
Carmen:

Refracted
beams of light shone down at strange angles through holes in the cloud high
above and then again through the water’s mirroring surface. The undulating
yellow sand below showed the surging effects of ebb and flow as the current
carried us through two shoals of small fish; which all at once parted, engulfed
and surrounded us, above and below.  Everywhere we looked orange/brown
Atlantic Damsels to our left and silver Sardines to our right moved with
collective intelligence, thousands of fish moving as if one organism to the
slow rhythm of an aqua-blue sea.

Although
the fish shimmer at the best of times, with this small forest of fifty, or so, narrow
intense rays of sun, single fish were sometimes caught, lit brighter than the
rest, as they swam through the spot lights.  Caught for a second, their
colours shone and glowed, before they quickly swam into the security of
obscurity amongst countless others that looked the same as them.

/2 Comments/by
,

Up and down I was sent and hauled

Today I learnt about rescue whilst observing the instruction style and participating in two elements of the BSAC Ocean Diver rescue dive, namely the 'air assisted assent' and the controlled buoyancy ascent.

I was asked to be the 'casualty' and after being shown by the instructor, the client was asked to perform the exercises. Up and down I was hauled and sent.  My right ear took a bit of a bashing, but even that was an interesting experience. 

Simon the client was a great guy and his beautiful family (wife and son) came along for the ride to the dive site.

Later I went on a pleasure dive with Simon and the instructor seeing:

•    - a cuttlefish
•    - 2 angel sharks
•    - grouper

Simon touched and held an Angel Shark's tail which made his wife and son very proud, when they were told after the dive.

Tonight I am going to visit Omar Sharif's house in Lagomar with a few of the guys I have met since arriving.  The gardens are meant to be amazing.

/1 Comment/by
,

fields of garden eels

Arriving early at work, today was spent doing two dives.

Two former members of the dive school staff, Marina and Jason joined us.  Jason is a qualified instructor and Marina worked as a Divemaster.

Back in the UK Jason now works as a forester and Marina works in catering.

Jason spoke to me about the effects of Red Band Needle Blight, a tree disease that is decimating the Corsican pine stocks.  Scots pine is as yet not so severely affected.

We also spoke about Sudden Oak Death and the growing experiments in the UK using Eucalyptus for bio fuels.  dead interesting!

In the morning I was 'buddied' with Dave who comes out here to Lanzarote diving and leaves his kit on the island between trips.  In the Afternoon I was with Stephen who I have mentioned before works with flight simulators.

Both dives were at Peurto del Carmen. 

200410 064

Although I saw dozens of fish, the new creatures of the day  included
fields of garden eels, poking their bodies out of their holes like
periscopes, their heads turned into the current.

Later I saw dozens of angel hair anemone, beautiful white delicate looking animals.

The afternoons dive was along the harbour wall and provided a close encounter with a cuttle fish, and still more sea cucumbers (which now I want to touch).  On the way back to the harbour stairs to exit the dive site, an angel sharks outline was spotted by Simon, the instructor/dive guide.

Simon carefully wafted some sand from the back of the shark and we were invited to stroke its pectoral fin.  The skin was rough like sandpaper.

I have been pretty tired today.  Not sure whether it is the heat, diving every day, the cycling or what.  I am eating well and sleeping just fine.  I will monitor the situation and report back.

/0 Comments/by
,

I turned into a one man kitchen disaster – 25 03 10

Today was a busy day.

It started with me learning the opening up procedure for the centre.

Essentially three cohorts of divers move through the school each morning and again after lunch.

At 8:30 experienced divers come in a get their kit, at 9:30 again slightly less experienced, and at 10:30 the new.

After each group comes through and collects their kit, the wet room is cleaned and mopped.  All the BCD's and wetsuits (left in a mess or from the day before) are re-wracked.

From 11:15 I was shown how to replace a valve within the BCD inflator which required periodic service/repair due to it having started to self-inflate.

I was then talked though the method of demonstrating a partial mask clearance and regulator recovery.

Patrick then demonstrated to me how to put an empty tank onto the compressor.

After an early lunch, Simon a Polish client who has lived in the UK for the last 6 years arrived for the sea based part of his BSAC course.

Simon is a nice chap.  He is married and has a 10 year old son, both here with him on holiday.  Although employed within an optics company, he operates his own online business selling, sunglasses, mini-scales and reading glasses.

I accompanied Patrick and Simon for this to witness the instruction of partial mask clearance and regulator recovery first-hand under water.

The bay we went to was very small and provides a maximum depth of 3m.  Very good for beginners.  Since the name of the beach does not appear printed on a map towel I bought, I canot tell you what it is called.  I will find out and report tomorrow.

Fish I saw:

  • A type of fish which I have not yet identified, but plentiful and friendly.
  • over a dozen sea cucumbers (The first one I saw, I thought was a big poo! They are brown, about 20cm long and appear motionless).

After the dive I went back to base, took a van for refueling and then spent the afternoon with Mr D learning about the rota and the challenges faced by him as the manager of the centre trying to manage a limited staff team.

After cycling home, I cooked carbonara, burnt it whilst I ran a bath, spilt food on the floor and could not find a mop.  In fact I turned into a one man kitchen disaster.

/0 Comments/by