Observing animal behavior underwater presents several challenges not faced by those in the terrestrial world. For bird-watchers, all you really need is patience and a good set of binoculars. Any decent sized sea cliff in the UK will attract a horde of twitchers, cameras and lenses at the ready, who can blissfully watch birds taking off, landing, feeding their chicks, and arguing over nesting spots. Similarly, back-garden bird watchers may have to contend with shyer species more likely to take off when noticed, but a diversity of feeders and nest sites (and an absence of cats) can reliably guarantee that some bird behavior will be seen.
Underwater, the biggest challenge is time... depending upon your equipment and depth you may have anything between ten minutes and two hours to observe as much as you can. Finding fish or other sea life that are doing anything interesting (e.g., not simply swimming or resting) becomes a race against time with your air supply the limiting factor. Diving a wreck, or a site known for a given species can up the odds significantly, but for some of the more interesting animals, it all comes down to luck.
Unless you are using a rebreather, you are also noisy as hell under water and likely to disturb or scare off the animals you are trying to observe. Take a look at the octopus and the seal in the prior two videos... both animals are well aware of me, and neither is particularly happy that I'm around. The octopus is fleeing from me and sees me as a predator. The seal is taking a more wait-and-see attitude, but is clearly not comfortable being cornered by two divers. There is no sound on either video, but if I had left the sound in, you would hear the very loud sound of my breathing and exhaling through my respirator. Rebreather divers have an advantage here, as they are virtually soundless, and they are the equipment of choice for professional underwater photographers for this reason... ...but with a cost of roughly £5,000 for the kit and training, this presents a substanial barrier to entry.
Finally, its gets dark underwater, particularly in the UK, and its easy to miss a lot of what is going on around you. The seal and octopus videos were taken off the NE coast of England at around 10 meters... visibility is still good. This below is more typical:
Note how much darker everything is outside of the beam of the torch... (also the noise I'm making!) That means that a school of fish can be 10 meters away from you, just at the edge of your visibility, and deliberately avoiding this noisy invader of the deep! Quite a few times I have seen interesting shadows swimming at the edge of my vision, or just glimpsed something disappearing into a crevice, meters away from me but too far to see clearly in the murk.
Showing posts with label UK. Show all posts
Showing posts with label UK. Show all posts
Monday, 6 January 2014
Sunday, 5 January 2014
A Kraken from the Deep (English Style)
A chance encounter with the Curled Octopus (Eledone cirrhosa) near Sunderland on the NE coast of England. Seeing octopi in the med or the Canaries is quite common, but seeing them off of UK coasts is a rare treat. They aren't actually rare here, but given the circumstances of UK diving, they aren't often seen.
Wednesday, 5 October 2011
Color in the depths
The Spiny Squat Lobster (Galathea strigosa) is one of the more striking denizens of the depths in UK waters. This specimen I photographed at the Farnes was not to keen to pose, but I was able to capture some of the brilliant blue patterning that characterizes this species.
Its interesting to speculate what the purpose is of the bright blue lines, considering that without the benefit of a camera flash, the murk and darkness soaks up much of the color and that these crustaceans are most active at night. The key, I suspect, is that the color blue is one of the last colors to fade out as you go deeper, and would be one of the few still visible at depth (the orange, in contrast, would be indistinguishable from other nearby colors). Some crabs have been shown to make use of coloration patterns to distinguish conspecifics and to evaluate potential rivals, while the lines (appearing as dark streaks on a light background) could help confuse predators by breaking up the body pattern. Other than some speculative observations on the related Galathea intermedia I haven't come across any studies that try to test this, however.
Its interesting to speculate what the purpose is of the bright blue lines, considering that without the benefit of a camera flash, the murk and darkness soaks up much of the color and that these crustaceans are most active at night. The key, I suspect, is that the color blue is one of the last colors to fade out as you go deeper, and would be one of the few still visible at depth (the orange, in contrast, would be indistinguishable from other nearby colors). Some crabs have been shown to make use of coloration patterns to distinguish conspecifics and to evaluate potential rivals, while the lines (appearing as dark streaks on a light background) could help confuse predators by breaking up the body pattern. Other than some speculative observations on the related Galathea intermedia I haven't come across any studies that try to test this, however.
Sunday, 8 May 2011
Its been a while
Diving season is back, no more quarries, actual sea life!
Most divers go for the rocky terrain, and why not? Lots of nooks and crannies for things to hide in, and good attachment surfaces for the more sessile marine dwellers. But this fellow I found in the open sand. This is a little cuttlefish (Sepiola atlantica) which was hiding in the sand until I disturbed it. To give some sense of scale, he is about the length of my thumb.
This is him in action.
Most divers go for the rocky terrain, and why not? Lots of nooks and crannies for things to hide in, and good attachment surfaces for the more sessile marine dwellers. But this fellow I found in the open sand. This is a little cuttlefish (Sepiola atlantica) which was hiding in the sand until I disturbed it. To give some sense of scale, he is about the length of my thumb.
This is him in action.
Thursday, 14 October 2010
Crab porn
Two mating velvet crabs, not particularly happy to be interrupted. The male (the larger one) is 'mate guarding' the female... basically standing over her to protect her (mating takes place after the female moults, when her exoskeleton is still soft and she is vulnerable to predators) and to ensure no other male gets any ideas.
The video was taken at a depth of about 15 to 18 meters at St. Abbs, Scotland.
The video was taken at a depth of about 15 to 18 meters at St. Abbs, Scotland.
Wots that fish?
It happens to everyone... your cruising along at 18 meters through the pea soup that passes for ocean water in the North Atlantic when suddenly you spot a few colorful fish in your beam, darting in and out of the sea weed...
... or maybe its just a single fish, examining you from the security of a rock cleft....
... or possibly its a discoloration of the sand, that swims away as you pass over (after a bit of prodding with your torch, anyway)
You reach for your handy guide to the fish of the northern Atlantic waters (in my case a 40 year old copy of Collins Guide to Sea Fishes) and ignoring the difficult interactions of paper with water at depth, you flip to the appropriate page and quickly realize that you are seeing....
... well, no, actually, its not that clear... The difficulty of many of these fish guides is that they make a few assumptions about your situation, namely that you are viewing the fish from the side, in good light, on the surface, while the fish in question sits perfectly still with its fins outstretched. The pictures in the guides vary from black and white sketches (not good if the obvious difference between species is color pattern), paintings (often taken from dead and slightly faded fish) or pictures of pickled specimens. It gets worse if you go to the technical literature... Handbook of the Marine Fauna of North-West Europe is one of the best books for identifying UK sea life, but unless you regularly take a dissecting microscope and a jug of formaldehyde on your dive trips its not going to be much use (who can count fin rays at depth, anyway?) I have a personal rule about collecting live specimens (that is, I won't) so I'm limited to either a photograph or a short movie clip taken under what I would politely call less than ideal conditions.
Fortunately, there seems to be more sea life publications written by divers for divers in recent years, with photos taken from life rather than illustrations or images of dead specimens. Without such aids, I would have been hard-pressed to identify either of these fish, as they belong to the Gobies, one of the more difficult fish groups.
The species, incidentally, are female Two-Spotted Gobies and a lone Common Goby.
... or maybe its just a single fish, examining you from the security of a rock cleft....
... or possibly its a discoloration of the sand, that swims away as you pass over (after a bit of prodding with your torch, anyway)
You reach for your handy guide to the fish of the northern Atlantic waters (in my case a 40 year old copy of Collins Guide to Sea Fishes) and ignoring the difficult interactions of paper with water at depth, you flip to the appropriate page and quickly realize that you are seeing....
... well, no, actually, its not that clear... The difficulty of many of these fish guides is that they make a few assumptions about your situation, namely that you are viewing the fish from the side, in good light, on the surface, while the fish in question sits perfectly still with its fins outstretched. The pictures in the guides vary from black and white sketches (not good if the obvious difference between species is color pattern), paintings (often taken from dead and slightly faded fish) or pictures of pickled specimens. It gets worse if you go to the technical literature... Handbook of the Marine Fauna of North-West Europe is one of the best books for identifying UK sea life, but unless you regularly take a dissecting microscope and a jug of formaldehyde on your dive trips its not going to be much use (who can count fin rays at depth, anyway?) I have a personal rule about collecting live specimens (that is, I won't) so I'm limited to either a photograph or a short movie clip taken under what I would politely call less than ideal conditions.
Fortunately, there seems to be more sea life publications written by divers for divers in recent years, with photos taken from life rather than illustrations or images of dead specimens. Without such aids, I would have been hard-pressed to identify either of these fish, as they belong to the Gobies, one of the more difficult fish groups.
The species, incidentally, are female Two-Spotted Gobies and a lone Common Goby.
Sunday, 5 September 2010
Shore diving
Diving the british coast can be an amazing experience, with a diversity of life unlike anything you'll find in the tropics. You just have to be willing to brave cold waters, bad weather, and a visibility measured in inches instead of meters.
This weekend I was at St. Mary's Lighthouse, north of Newcastle. This is how the tourists see St. Mary's:
and this is how I saw it:
Probably due to the shallowness of the dive site and the proximity of a sandy beach, there was not as much life as at places farther north up the coast, but there were still crabs, lobsters, turban snails, and sea anemones. The high point of the dive was finding a small blenny curled in an S shape, hoping not to be noticed, then darting off when it realized it had an audience! The low point (or sad point, really) was coming across a large lobster trapped in an abandoned lobster pot... if I had thought to bring a dive knife I could have cut it free, but as it was, I had to leave it behind. There something about seeing these large, beautiful crustaceans when they are alive and in their native habitat that makes it seem like such waste to trap and eat them.
The visibility in the water was too poor for most of my attempts at photography, but I did manage a short film clip of a crab scuttling away from us. It also gives you a bit of an idea of the visibility I had to deal with. Getting lost was a constant risk, even with a compass, and we had to surface several times just to figure out where we were!
This weekend I was at St. Mary's Lighthouse, north of Newcastle. This is how the tourists see St. Mary's:
and this is how I saw it:
Probably due to the shallowness of the dive site and the proximity of a sandy beach, there was not as much life as at places farther north up the coast, but there were still crabs, lobsters, turban snails, and sea anemones. The high point of the dive was finding a small blenny curled in an S shape, hoping not to be noticed, then darting off when it realized it had an audience! The low point (or sad point, really) was coming across a large lobster trapped in an abandoned lobster pot... if I had thought to bring a dive knife I could have cut it free, but as it was, I had to leave it behind. There something about seeing these large, beautiful crustaceans when they are alive and in their native habitat that makes it seem like such waste to trap and eat them.
The visibility in the water was too poor for most of my attempts at photography, but I did manage a short film clip of a crab scuttling away from us. It also gives you a bit of an idea of the visibility I had to deal with. Getting lost was a constant risk, even with a compass, and we had to surface several times just to figure out where we were!
Wednesday, 1 September 2010
A good day for butterflies
A recurring theme of mine is how few insects there are in the UK, compared not only with areas of similar climate in North America, but also with the UK of 100 or even 50 years ago. A quick glance at old identification guides or museum collections show just how much diversity has been lost, and how the numbers of many species have crashed. No surprise given the changing land use in this country... hedgerows, for example, have been lost at an alarming rate, despite their role as wildlife refuges in the otherwise monoculture environments of England.
This weekend was one of those rare days when I've seen a lot of insect life. The Yorkshire Dales are one place you would think would be a good place for seeing butterflies and moths, given the diversity of habitats and the smaller scale of farming, but years of bad weather have, I suspect, knocked down the numbers of leps in this region. Yet this weekend, on a nice warm day near Hawes, I saw more butterflies (and more numbers of butterflies) than at any other time in the years I've lived here.
On top of the more common Small White and Green-veined White, there were the less-seen Large Whites, Small Tortoiseshells, Peacock butterflies and even a Red Admiral, but the prize for the day was seeing a Fritillary, a rare sight at the best of times. Unfortunately, I was too slow with my camera (and the butterfly itself was in no great shape) so I don't know what type it was, but if I had to guess I would say it was a Silver Washed Fritillary. Hopefully when I can look up some range information I'll have a better idea.
Some of the butterflies I saw:
Small Tortoiseshell
Large White
Peacock
Red Admiral
This weekend was one of those rare days when I've seen a lot of insect life. The Yorkshire Dales are one place you would think would be a good place for seeing butterflies and moths, given the diversity of habitats and the smaller scale of farming, but years of bad weather have, I suspect, knocked down the numbers of leps in this region. Yet this weekend, on a nice warm day near Hawes, I saw more butterflies (and more numbers of butterflies) than at any other time in the years I've lived here.
On top of the more common Small White and Green-veined White, there were the less-seen Large Whites, Small Tortoiseshells, Peacock butterflies and even a Red Admiral, but the prize for the day was seeing a Fritillary, a rare sight at the best of times. Unfortunately, I was too slow with my camera (and the butterfly itself was in no great shape) so I don't know what type it was, but if I had to guess I would say it was a Silver Washed Fritillary. Hopefully when I can look up some range information I'll have a better idea.
Some of the butterflies I saw:
Small Tortoiseshell
Large White
Peacock
Red Admiral
Saturday, 15 May 2010
In the garden
I've been reading the book Garden Natural History which has inspired the latest round of backyard photography. Its fascinating how much goes on in the garden that most people aren't aware of - all the more so given my habit for letting it run a bit wild. Most of the activity is below the surface - mites, burrowing insects, worms, and other scavengers of the soil (and the creatures who prey on them) but there is a host of activity going on above the surface - aphids, parasitoid wasps, flies and butterflies, and of course the host of mosses, lichens, fungi and other less-visible plants that along with the grass and garden plants are the basis of this ecosystem. Its unfortunate that I'm probably one of the few people who appreciate all the activity going on in the back-yard... most people in England seem to want that perfect lawn (in other words a grass monoculture trimmed to resemble a sheep-grazed field, without the benefit of sheep dung or the various plants that thrive in sheep fields) while others have taken to removing the grass entirely and replacing it with stones or tiles. Its almost as though the urban biodiversity of this nation is at the mercy of home-owners with an obsessive-compulsive view about tidiness and order.
Friday, 14 May 2010
Silent Night II
By coincidence I came across an advertisement for this new book out Silent Summer which goes into detail what I've been noticing in the past few years - how the various insect and other invertebrate species are dying out in this country. Sixteen years ago I visited the UK as a budding young entomologist and returned home with several specimens of what were at the time unprotected species, but which are now on the endangered list, if not actually extinct in this country. Sixteen years is not a long time... barely a generation... yet in this time 5 species of butterfly have gone extinct here, and the majority of the remaining species are endangered.
I'll need to get myself a copy of that book... I don't think it will make happy reading.
I'll need to get myself a copy of that book... I don't think it will make happy reading.
Thursday, 13 May 2010
Silent Night
I miss cicadas.
I don't think most people in this country realize how noisy the countryside should be, or would think something is wrong when walking through a silent field at night. There is only one species of cicada in England and its restricted to the New Forest in the south. There are several species of crickets and grasshoppers as well, but I have only rarely seen them (again in the south) and never heard one calling. To someone who grew up in the colonies, its horribly unnatural to hear so little of the night chorus and highlights the degree to which this country has extirpated its local fauna. One of the saddest aspects is that thanks to Victorian and Edwardian collectors and enthusiasts, there is no country with a better record of the species of insects and other invertebrates that live here, and yet this record makes it painfully clear just how much the native species have been extinguished from this island with so many species either locally extinct, pushed into patches of marginal territory, or in the case of the once common freshwater pearl mussel (Margaritifera margaritifera) and several of the oak species, only ancient individuals remain with no young having been recruited for decades. Changing climates (and a run of bad summers) is expected to put several of the rarer butterfly species here at risk of extinction from these islands, but as these species have become so restricted in their locations, I'm not sure anyone but a handful of experts will notice that they are gone.
...and that of course is the problem. Its been a slow and gradual process of loss, such that the scale has not been apparent to the average resident. Most Englanders my age think that what they run across (or more, what they don't run across) when out in the countryside is "normal". Their parents may remember there being more butterflies or more of some flowers (perhaps they once saw a lady slipper orchid in the woods - now these flowers are so rare they need police protection) but its been such a gradual process that even they have largely accepted it. Its only once you look back at the old records - descriptions of clouds of moths surrounding gas lamps, or boxes containing hundreds of faded moth specimens - that you appreciate the scale of the loss.
The picture, by the way, is a cicada molt skin photographed in a small Myrtle Beech forest in south Australia. I've still never had the luck to find one here in England.
Thursday, 29 April 2010
A brief detour from the reef
Just taking a little break from the tour of the museum to discuss my foray into the world of local politics. I've just returned from a "hustings" with our four local candidates. This isn't intended to be a political blog, but given the somewhat small turnout and the gravity of the topics under discussion I felt I needed to make a few comments on what I saw.
My main interest in attending was to see first hand our local MP, one Philip Davies (Con) who up to now I had heard little about, but was now regularly sending me flyers in which he made his fight against "political correctness" one of his main campaign planks. Now, I can see why some people might think there is a bit too much political correctness, but its an odd thing to put in big letters on your campaign literature... and to be honest, in the part of the world where I come from, when a candidate talks loudly about political correctness he isn't advocating Chubby Brown play the Apollo... its a code word for the sort of soft racism that will let a black man sit at the front of the bus, so long as he doesn't have any asparations to drive it. I was half expecting a posher version of Nick Griffin to be honest, and was somewhat pleasantly surprised to find that he didn't meet my initial expectation, but I have to say he reminded me very strongly of the American style right-wing rebel... a british John McCain if you will.
Now a bit of rebellion is a good thing - there are far too many yes-men elected to public office - but its only good being a rebel if you actually know what your talking about. No real surprise, but Philip doesn't believe in global warming and even cited the East Anglia stolen emails as evidence, as though that was some silver bullet, clearly unaware of how East Anglia had been exonerated from any wrong doing. He was also a big fan of nuclear power, while at the same time he kept going on about the high cost of green technologies.... except aren't nuclear power plants very expensive to build, expensive to run, and even expensive to decommission? A glance at wikipedia (yes, I know...) indicated that the cost per reactor could vary between 100 million to 500 million euros or more.
Overall not a good sign from our local MP... its a short distance from rebel-without-a-cause to rebel-without-a-clue.
As for the other candidates...
John Harris (Lib Dem) came off as an academic... seemed to know his stuff, but his presentation skills could use some polish. I like that he is a biology teacher though... the more people in parliament with a grounding in science the better.
Kevin Warnes (Green) was much more polished, also a teacher, and has a PhD in political science... also seemed to know his stuff, and admitted that he is prepared to listen to the experts. (though couldn't we get a few actual experts into the house, once in a while?)
Susan Hinchcliffe (Labour) came off well, but I can't help thinking she is pretty naive about her own party. I think the funniest moment for me was when she mentioned the Freedom of Information Act as one of the good things Labour has done. Now, I briefly worked in the civil service and one of the first things I was taught was all about avoiding FOI requests by not keeping records, self-censoring emails, selective minuting , and when all else fails, delay tactics. I'd be curious to see how aware she is of the inner workings of her own government, but then at the civil service we were quite good at hiding what we were really up to.
My main interest in attending was to see first hand our local MP, one Philip Davies (Con) who up to now I had heard little about, but was now regularly sending me flyers in which he made his fight against "political correctness" one of his main campaign planks. Now, I can see why some people might think there is a bit too much political correctness, but its an odd thing to put in big letters on your campaign literature... and to be honest, in the part of the world where I come from, when a candidate talks loudly about political correctness he isn't advocating Chubby Brown play the Apollo... its a code word for the sort of soft racism that will let a black man sit at the front of the bus, so long as he doesn't have any asparations to drive it. I was half expecting a posher version of Nick Griffin to be honest, and was somewhat pleasantly surprised to find that he didn't meet my initial expectation, but I have to say he reminded me very strongly of the American style right-wing rebel... a british John McCain if you will.
Now a bit of rebellion is a good thing - there are far too many yes-men elected to public office - but its only good being a rebel if you actually know what your talking about. No real surprise, but Philip doesn't believe in global warming and even cited the East Anglia stolen emails as evidence, as though that was some silver bullet, clearly unaware of how East Anglia had been exonerated from any wrong doing. He was also a big fan of nuclear power, while at the same time he kept going on about the high cost of green technologies.... except aren't nuclear power plants very expensive to build, expensive to run, and even expensive to decommission? A glance at wikipedia (yes, I know...) indicated that the cost per reactor could vary between 100 million to 500 million euros or more.
Overall not a good sign from our local MP... its a short distance from rebel-without-a-cause to rebel-without-a-clue.
As for the other candidates...
John Harris (Lib Dem) came off as an academic... seemed to know his stuff, but his presentation skills could use some polish. I like that he is a biology teacher though... the more people in parliament with a grounding in science the better.
Kevin Warnes (Green) was much more polished, also a teacher, and has a PhD in political science... also seemed to know his stuff, and admitted that he is prepared to listen to the experts. (though couldn't we get a few actual experts into the house, once in a while?)
Susan Hinchcliffe (Labour) came off well, but I can't help thinking she is pretty naive about her own party. I think the funniest moment for me was when she mentioned the Freedom of Information Act as one of the good things Labour has done. Now, I briefly worked in the civil service and one of the first things I was taught was all about avoiding FOI requests by not keeping records, self-censoring emails, selective minuting , and when all else fails, delay tactics. I'd be curious to see how aware she is of the inner workings of her own government, but then at the civil service we were quite good at hiding what we were really up to.
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