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John Blatchford's BlogPosted by John Blatchford Inspiration for insect articles came from local specimens, but researching material and images about marine biology while living far away from the sea and reference libraries needs internet research.
Fish and Insect Themes When I was the Feature Writer for ‘Fish and Insects’ at Suite101 I found that most of my articles were born out of interesting observations. Wandering through the countryside, or sitting reading in my garden would suddenly expose a fascinating insect. Sometimes I was able to get a good photo, and then my curiosity would lead me to researching the species. (Praying Mantis and Mole Crickets are good examples). Marine Biology Themes My ‘first loves’ and all my academic qualifications are in Marine Biology – and my research work was related to adaptations to rocky shores. I think this means that my articles in ‘Marine Biology and Oceanography’ are possibly more authoritative, but when I find myself sitting at a computer inland (either here in France or at home in Yorkshire) it is difficult to stroll by the seaside or go out in boats. Occasionally a holiday will provide this sort of opportunity (as with my visit to Vancouver Island this spring), and these occasions generate enthusiasms in much the same way as with the insects. 'Vancouver Island Marine Biology’ and ‘Botanical Beach Vancouver Island’ are good examples of ‘interesting place or observation leads to an article’. When I am not close to the sea and boats I seem to write what is, in effect, a series of articles about any one topic. This is because, in my mind, ‘one thing leads to another' – and also because it is very difficult to cover any topic adequately in one short article. My series about whales is a good example of this. Posted by John Blatchford Two Types of Marine Reptile Sea Snakes There are over sixty species of snake that live more or less permanently in the sea. They are highly venomous and eat fish. All breathe air and need to surface at intervals (like whales), and some need to come ashore to breed. Sea Turtles Seven species of turtle a fully marine, but like the snakes they breathe air and come up regularly. They lay their eggs on sandy beaches, and often migrate over long distances to return to the place where they hatched. While writing about these Marine Reptiles I began to think about marine amphibians. One Type of Marine Amphibian While there are a number of very well adapted sea-going reptiles (snakes and turtles) there are no truly marine amphibian – only one species of frog comes close. Frogs and Toads The Crab-eating Frog - Fejervarya cancrivora formerly Rana cancrivora lives in the mangrove swamps of south east Asia, and as its name suggest it will eat crabs. It is the only known modern species of amphibian that can tolerate saltwater conditions. The Marine Toad - Bufo marinus, despite its name does not live in or near the sea. It is purely terrestrial, and goes to freshwater to breed. (My old article about French Frogs and Toads looks at a few of the common modern ones.) Newts and Salamanders None of the family Salamandridae goes anywhere near the sea. Most live in or near freshwater, and a few have become terrestrial in damp places, but they cannot tolerate salt. My article about French Newts and Salamanders introduces the group. Posted by John Blatchford Whales communicate with one-another, and recording the sounds they make alongside what they were doing at the time could help us understand what they are saying. Hydrophones Rugged underwater microphones are now available at reasonable cost. Some allow recorded sound data to be analyzed later on a computer, meaning that it is possible to use information about whale signals outside the frequency range that humans can hear. Many devices are battery operated and fully portable and the microphone can simply be dropped into the water beside the whale watching boat, while the engine is off, of course! Video Recording Most digital cameras have video capability, and many can accept an external microphone input (hydrophone in this case). This means that it is possible to record whale behaviour along with the sounds they were making underwater at that time. Naturally the only behaviour that can be videoed will be whatever takes place at the surface, while sounds made underwater might be associated with other activities. Camera Binoculars One of the main problems with watching whales is the unpredictability of exactly when and where they will next surface. Continuously scanning the area with good marine binoculars is the usual way to overcome this problem, but there will rarely be time to put down the binoculars and get the camera ready before they submerge again. This is where instant replay camera binoculars become extremely useful. (Some earlier blogs discuss the additional equipment that might be of interest to whale watchers, including one about image stabilization for binoculars.) Posted by John Blatchford Binoculars will always shake a bit when they are hand-held, and if the ‘platform’ you are on is also vibrating the situation becomes much worse. Using binoculars on a boat watching whales will involve movements caused by the waves and vibration caused by engines as well as the inevitable shaking. They are also very likely to get wet! Waterproof Stabilized Binoculars The military sometimes need to use binoculars in small craft at sea, and very rugged waterproof binoculars are available with internal gyroscopic stabilization. They are much heavier than regular binoculars, and can be incredibly expensive (thousands of dollars!) – but the electrically driven gyroscopes effectively damp down most movement and vibration to give a steady, clear image. Attaching a Gyroscope to the Tripod Mount An alternative solution to the problem would be to attach a small battery-driven gyroscope unit to standard waterproof binoculars. This has the advantage that the gyroscope can be used when at sea whale watching, and then detached for times when a tripod is used, or when the binoculars are not being used from a bouncing boat. Still an expensive toy though! Non Gyroscopic Image Stabilization There are a couple of alternatives to the use of rather heavy gyroscopes to stabilize images, one uses a built-in microcomputer to fiddle around with lenses and prisms when motion is detected, and the other suspends the prisms in a very clever way that reduces movement. Waterproof Stabilized Digital Camera Binoculars These would be the ultimate tool for whale watching, but unfortunately I have not been able to find any on sale. If any reader knows better, then please leave a comment! Posted by John Blatchford My two (old) articles about snakes in France ('Harmless French Snakes' and 'Venomous French Snakes') seem to be very popular, particularly with readers in France, so I decided to move away from Marine Biology for a bit and do one about French Lizards. Walking in France When you explore the French countryside on foot, and if you walk quietly and keep your eyes open, you can expect to come across snakes and lizards. Usually they will be gone before you can identify them, but returning to the same spot later (and more carefully!) will often allow you to watch them closely. It is a good idea to use binoculars at first, and then creep up on them very slowly. Snakes There is really nothing to fear as long as you don't attempt to catch them. If you try this then many will bite (two spwecies injecting rather nasty venom), and those that don't bite might well cover you in foul-smelling stuff or whip you vigorously with their tail. Lizards Any holiday in rural France will expose you to lizards. They like the sun as much as holidaymakers! None are dangerous, but the big ones can, and will, bite. What is probably more distressing is the fact that they are all capable of shedding their tails. Trying to catch a lizard will usually result in a damaged lizard and a wriggling tail with lots of blood. Eventually a new tail will grow - but it is never as good as the first. Many wall lizards that you see will have stumpy tails which tell of their recent encounters (often with cats). Never try to catch a lizard, but feel free to photograph them if you can! Posted by John Blatchford I have now written a few articles suggesting places that marine biologists might like to visit while staying on Vancouver Island, and what equipment they should take. Pacific Rim Park This is a must! All the way along from Ucluelet to Tofino there are trails providing easy walking with good views out to sea and access to the best beaches. It really requires several days, but my article suggesting where to visit gives a few ideas for those short of time. Botanical Beach An article about three unusual animals found in tide pools begins to describe this amazing rocky beach. The tide pools (rock pools) here are world famous. It is a protected area, but that does not stop you looking and taking photographs. Equipment to Take I recently wrote a blog about equipment for amateur marine biologists, and there is an article about hand lenses. There is no mention anywhere of clothing, but so much depends on the weather! Stout walking shoes or boots are of course a good idea, and a hat is usually advisable. In terms of protection from the sun it is easy to forget how much gets through even on cloudy days spent ferreting around on the beach, so an effective sun cream is strongly advised, whatever the weather looks like. Posted by John Blatchford After a few articles about some of the equipment amateur marine biologists might require I decided to write about the ways in which expertise can be built up in a number of popular specialisms. Whale Watching How to become a whale expert stresses reading as much as possible about then, in print or online, and then actually watching them at sea whenever possible. Seashore Ecology How to become a sea shore expert is much more ‘hands on’. Summer holidays take many people to the coast, and exploring the shore fits in well with relaxed lounging on the beach. The rest of the family can sunbathe while the naturalist ‘does his (or her) thing’. It is possible to build up impressive expertise with minimal equipment, and those who live near the sea, or holiday regularly in the same location on the coast, can become genuine experts on the ecology of their chosen location. Marine Biology Appreciating the grandeur of whales and becoming aware of the myriad life-forms found on the beach are probably the two most common ways in which young (and not so young) people get drawn into a career in some aspect of marine biology. How to become a marine biologist considers routes into both academic and non-academic careers working with marine animals. Posted by John Blatchford In a much earlier article I suggested presents suitable for young naturalists, and I have now picked up this theme again – but aimed more at older amateurs this time. This article looks at some of the important details that should be borne in mind when binoculars are purchased specifically to watch whales from a boat. ‘Presents for Whale Watchers’ also looks at telescopes, hydrophones and field guides. Choosing and purchasing a suitable field guide adds much to a holiday on the coast for any amateur marine biologist, allowing identification of the plants and animals observed, and also giving interesting additional information about them. In addition to discussing the various types of field guide that exist there are a couple of suggestions about how and where to find them. Here advice is given about suitable specifications for a small plankton net suitable for amateur use. This could be used from the shore, the end of a pier or jetty, or from a small boat to capture samples of plankton. There are also a couple of suggestions for how to transport these samples in good condition and how to look at them later. Similar Equipment Articles I have a few ideas of my own for future articles about equipment for amateurs, but I would also be delighted to respond to any readers’ requests. The best way to make such a request would be to either comment on one of the above articles, or to email me direct. Posted by John Blatchford Every cell of an animal is actually a co-operative venture between organisms – the powerhouses (mitochondria) came onboard when animal cells first made their appearance on the planet. With such an intimate relationship within every cell of an animal it should not surprise us when we find strange associations of whole animals themselves – but it does! Coral reefs are extremely old – the habitat they provide has been around for ages. Many animals have adapted to profit from this very stable and predictable environment, and the various cleaner fish (and cleaner shrimps for that matter) show just how far behaviours can be modified if there is the potential for mutual gain. The Cleaner Fish have found a niche where they eat the parasites of other fish – many other species of big fish use the services of the cleaners, and in return do not eat them! This sort of co-operative behaviour is ‘hard-wired’ and written into the DNA of the species involved. A ‘Cleaner Fish’ does not decide to behave in this way – it’s just what it is and what it does. Helpful Whales There is a completely different type of association between animals, where animals with intelligence and self-awareness actually decide to become involved. We know this full-well for ourselves – we can make a choice as to whether we help out or not. But what about dolphins, for example? Did ‘Pelorus Jack’ make a conscious decision to help sailing boats? Do dolphins who help swimming humans and other whales know what they are doing? I would like to think they do, maybe we have moved on to a whole new ball-game with some of the more intelligent creatures on the planet actually deciding to work together. This would be good news! Posted by John Blatchford My most recent article, about scuba diving and underwater photography, looks at the way that a hobby (or obsession!) can help conservation. In this case it is the economic importance of ecotourism that does the trick, with the additional possibility of an increasingly aware section of the public being inspired to act politically. This is very similar to the way in which whale watchers often become keen advocates for the marine environment. Great Apes Human Rights and Whales In an article in the New Scientist back in 1997 I argued that the Great Apes should be given limited ‘Human Rights’ (granting them the rights to life and a home at least). Maybe something similar would be appropriate for the Great Whales also? The article goes on to talk about the ways in which ecotourism helps habitat conservation, and surely this is equally the case where whale watching and reef diving are concerned. Flagship Species and Habitat Conservation If sufficient habitat is conserved to guarantee the survival of the Great Apes, then the habitat necessary for literally millions of other species is also kept. What is true for the Great Apes on land is equally true for the Great Whales and their habitat, and for Coral Reefs and theirs. Concentrating on the critical habitats for a few, well-loved, species (Apes, Whales and Corals) is an excellent first steps towards the protection of biodiversity globally. Posted by John Blatchford I have written a number of articles in ‘Marine Biology and Oceanography’ about individual whale species, and a few about aspects of their lives (such as ‘Whale Evolution and Classification’ and ‘Whale Brain and Intelligence’). Following the internal links within these two will take you on to most of the whale articles, or they could be found through this list. Other writers on Suite101 have also written about whales – notably by Dawn Smith in ‘Wildlife Preservation’ – part of the ‘Plants and Animals’ section. Why Write About Whales? Whales have come to be symbols of the unspoilt oceans in much the same way that the Giant Panda has come to symbolise the conservation issues on land. Add to that the fact that the lives of whales are very different from our own, and that much mystery still surrounds them, and you have a very heady mix. We suspect that some whales are highly intelligent, and some even suggest that they might have genuine languages. People are fascinated by captive cetaceans (usually Belugas, Dolphins and Killer Whales), but I have tried to write more about their lives in the wild, and Dawn Smith writes more about the conservation issues that affect particular species. Posted by John Blatchford While staying with friends in Nanaimo I was lucky enough to visit the Pacific Biological Station. This is where most of the marine research for the Canada’s Pacific Ocean is carried out. The station was established in 1908, so there was due to be ‘open house’ from 23-27 April 2008. Although I had to leave the island a couple of days before, I managed a ‘sneak preview’. Schools Programme In addition to academic research the Biological Station maintains a few tanks of the more robust sea creatures that volunteers take out regularly to local schools. I took part in one of these visits, and was very impressed to see the way the (young in this case) students reacted. They were obviously fascinated by the animals and understood that they should be handled with care. (Fortunately they did not realise that animals captured from a variety of places should never be released back into the wild – there is too great a risk of them carrying one or more of the diseases or parasites that have been unwittingly introduced to a number of locations in the past – usually ‘hitching a ride’ on deliberately transplanted shellfish.) Collections of Whale Identification Photos Among many other areas of research the PBS has collections of photographs of the fins of ‘resident’ Killer Whales in the area, allowing individuals to be identified. Those who go whale watching out of Victoria and take photos will find this very interesting. Posted by John Blatchford I was recently fortunate enough to visit Vancouver Island. My friends in Nanaimo have a unique knowledge of the wildlife, since Paul has been involved in forestry for many years and has spent hours alone in some of the remotest areas. Long Beach As a European I found the scale of things in Canada overwhelming at first. Long Beach, for example, is much bigger than anything I have ever seen in Britain (although Scarista Beach on the Isle of Harris, where I once lived, comes close!) – but where I would expect to find driftwood there were hundreds of entire tree-trunks. Where I would expect to find a little detached seaweed along the strand line there were enormous piles of Bull Kelp (up to 30 metres long!). Wickaninnish and Giant Barnacles Further south along the beach there are rocky outcrops near the low-water line, here I found the creature of my dreams – Balanus nubilis, the Giant Acorn Barnacle. This huge barnacle (over 3 inches tall and more than 4 inches across!) had me chuckling with delight. I managed to resist the temptation to take one away with me, but only just. They are so big that they were roasted and eaten by First Nation people in the past, and I would love to know what they taste like! Posted by John Blatchford In my article ‘Collecting Olive Shells’ I have suggested that distribution data and information about species variability in any location should be published somewhere – so that others can access it. Distribution Data Amateur collectors are in an ideal position to amass data about the distribution of the species that interest them. In a sense any data about marine mollusc distribution is useful, but those who specialise in a particular group (be it the olives, cones, cowries, or whatever) are likely to have a more complete picture. Best of all is the information that comes from individuals who specialise in a single (or few) species. Knowing the current range of any particular species gives a ‘base-line’ against which future changes can be measured. The effects of habitat loss, pollution and global warming will have something to be measured against. Variability Data For shells which show a lot of individual variation within the species it is very useful to know which forms are found where. This sort of data can help untangle the thorny problem of ‘what is each variety adapted to’, and can even help elucidate some of the tantalising questions about speciation. In the absence of detailed genetic information the way in which populations vary across their range can be very instructive. Where to Publish I have started a discussion where people who have already published their data, or are about to do so, can help those who are considering it. Posted by John Blatchford Ever since I did some of the editorial research for Pete Dance’s ‘Encyclopedia of Shells’ (back in 1973) I have been fascinated by the cowries. I have my own small collection – all of them obtained from unwanted museum specimens (which means that someone else bears the responsibility for any environmental damage!). Scientific Value More serious collectors, who actually travel around and find their own specimens, can add much to scientific knowledge. This is particularly true when we are looking at the distribution of any species, but it will also be useful in the future by providing a sort of ‘base-line’. Future changes in distribution (say as a result of global warming or habitat damage) will have a point of comparison. For this to be of any use it is important that each shell is individually labelled (or recorded somehow) for both date and location of capture. Aesthetic and Commercial Value I find shells beautiful, particularly the cowries. When they are displayed appropriately they can become almost ‘works of art’. Some of the rarer shells can also be quite expensive. I was once lucky enough to handle a 200 year old Cypraea aurantium in the Natural History Museum (London) which had attained its famous golden sheen. This specimen must be almost priceless! Not only of value to collectors – cowries (particularly C. moneta) have actually been used as currency in the past. Posted by John Blatchford Many strange animals are kept as pets. Some have become domesticated over thousands of years, while others are taken from the wild. Domestic Animals
Wild Animals How much cruelty is involved depends on two factors, how the animals are fed and housed, and how intelligent they are. It is difficult to imagine ways in which a pet insect might suffer – we do not credit them with much intelligence, and assume they have no self-awareness. Intelligent animals (such as the Chimpanzees and Killer Whales) are certainly aware of themselves and can suffer pain and feel emotions. Keeping any of the Great Apes or Whales in captivity can easily become cruel – they need to be with other members of their own species and to have enough space to behave naturally’. In my own opinion intelligent wild animals should only be removed from their natural environment if there are very good reasons. Posted by John Blatchford Planktonic organisms are technically ‘those which are made to drift’ by water movement. Some of the larger animal plankton might be able swim reasonably well, but even so they are very much at the mercy of the ocean currents. Daily Vertcal Movement Even very poor swimmers can manage to move up and down in the water column. Many phytoplankton move down during the night, and then back towards the light during daytime to allow photosynthesis. Most zooplankton (animals) move up at night to feed, and then return to deeper water during daylight hours to avoid predators (or at least to make it harder for predators to find them!). Daily Horizontal Movement Ocean currents typically flow in different directions as you move vertically through the water column. This means that any animal that has the ability to descend during the day will come up into a new part of the sea next evening – giving it new pastures to graze. Going up and down regularly (relatively short distances) can lead to an efficient zigzag movement through new feeding areas. Seasonal Movements Plants need nutrients and sufficient sunlight to photosynthesise. Away from the tropics, as day-length increases the phytoplankton ‘blooms’ and populations of zooplankton feeding on these plants explode. When the nutrients have been used up many of the phytoplanctonic organisms sink and enter a resting period – waiting for upwelling currents to replenish the surface waters and for sufficient daylight to return. Many of the animals also move away from the surface until next season (Antarctic Krill, for example, hide away under the pack-ice.) Posted by John Blatchford Whalebone The Baleen Whales do not have teeth; instead they have fringed plates made of keratin (the material that makes hair and finger nails). These ‘baleen plates’, also known as ‘whalebone’, are used to sieve small animals from the water. Right Whales and Bowheads feed by swimming along with the mouth open and straining out small animal plankton, Gray Whales scoop up sediment from the ocean floor and feed on the small crustaceans that live in the mud and sand, and Pygmy Right Whales probably feed on copepods – although very little is known about them. Rorquals All other Baleen Whales have pleats in the throat to allow the mouth to expand, and they are known collectively as the ‘rorquals’. They do not so much skim the water as gulp it, with the ‘pleats’ stretching to form an enormous mouth which can hold up to 100 tons of food and water in the case of the Blue Whale. Blue Whales, Fin Whales, Sei Whales and the small Minke Whales all eat plankton, but Bryde’s Whale, the Pygmy Bryde’s Whale and the Humpback prefer fish. That is all of the rorquals except for Balaenoptera omurai which was only recently discovered and has no common name as yet. Classification The possession of whalebone is common to all of the suborderMysticeti, but their exact relationships to each other are not clear. They all evolved from toothed ancestors and were probably all fish-eaters in the past. The change of diet (of most of them) has put them very close to the start of the ocean food-chain, allowing them to harvest the enormous numbers of small planktonic organisms which feed directly on the microscopic phytoplankton. This abundant and nutritious diet has allowed some of them to become the largest animals on earth. Posted by John Blatchford Here is a list of my ‘Whale’ articles so far: Baleen Whales Right Whales – 4 species - My article about the Bowheads and Right Whales covers the whole family (Balaenidae) Rorquals – 8 species - Humpbacks are not, in many ways, typical of the family Balaenopteridae (the rorquals), and a better representative might well be the Blue Whale (an article is planned for very soon to present names at least, of all other rorquals). That will only leave 2 species; the Gray Whale and the Pygmy Right Whale, each in a family of their own. These two are neither Right Whales nor Rorquals, but they are certainly among the 14 species of Baleen Whales Toothed Whales Oceanic Dolphins – 40 species - Risso’s Dolphin and the Killer Whale are my two dolphin articles so far (the Killer Whale is a dolphin). I wrote about Risso’s Dolphin because I find the story of ‘Pelorus Jack’ very interesting, and then about Killer Whales because … well because they’re fantastic! I also wrote an earlier article about Dolphin Conservation where I looked at some of the problems whales face. There are about forty species of dolphin (although six of them are usually called whales). River Dolphins – 4 species. Porpoises – 6 species - Dawn Smith has written a nice article about the Vaquita (which is close to extinction). Family Monodontidae – 2 species – both the Beluga and the Narwhal are covered in my article ‘White Whales’. The Sperm Whale is in a family of his own, but there are also the closely related Pygmy Sperm Whale and Dwarf Sperm Whale. That only leaves the Beaked Whales – about 20 species – and very little is known about most of them! See also 'Marine Mammals'. Posted by John Blatchford ‘The Open Ocean’ suggests trying to grow plankton – here are a few further thoughts. Choice of Zooplankton Many copepod species could arrive accidentally with ‘live rock’, or they might be obtained from a fellow aquarist, but if you begin like this you will have no idea which species you are rearing (this might be fine for feeding the fish, but it will limit the scientific value of your observations). If you want to increase this scientific value then you will need to know which species you have. I would suggest trying a harpacticoid copepod, because they can graze phytoplankton or eat detritus, are very robust and many small fish like to eat them. You might have to splash out and buy a pure culture (maybe of Nitokra lacustris). Choice of Phytoplankton Again it is perfectly possible to ‘see what arrives’ in your tank, but as with the copepods (above) you will not know what you are feeding your copepods on and the scientific value will be limited. Once again you might decide to fork out for a pure culture (maybe of Thalassiosira weissflogii). Light Intensity N.lacustris has very small young which do not swim and will feed in the sediment at the bottom of the tank. When they grow into adults (life-cycle of 10/12 days) they will begin to swim weakly in the water and graze the T.weissflogii. The trick will be ensuring that their plant food grows at the correct rate, and experimenting with different light intensities and day-lengths could get you there! If you try this then please report your findings by contributing to the discussion. Posted by John Blatchford Marine Aquaria Ret Talbot has already written several articles about ‘Biotope Tanks’ (see Biotope-Based Marine Aquaria, Setting Up a Simple Refugium, Growing Mangroves for Aquarists, Marine Aquarium Biotoping, and The Display Refugium ), and he plans to write more. These are specific ‘how-to’ articles which suggest that hobbyists experiment with the ideas. Ecological Studies Each time a new refugium is set up something will be learnt. The experiment might succeed, or it might fail in some respect and lead to either a re-think or modification. This is all valuable information, and it would be good if these experiences could be shared. I have started a discussion forum to allow this sharing of ideas which follows on from the suggestion in my own article ‘Biotopes and Habitats’ that hobbyists can contribute significantly to our understanding of reef systems. Sharing Information There are thousands (maybe millions?) of people who keep marine aquaria around the world. If only a few of these experiment carefully with the idea of ‘biotope-based refugia’ much could be learnt. Hobbyists have great enthusiasm and persistence, (it is often said that people work harder at their hobby than their ‘day-job’!), and if only a few of those who experiment share their experiences we could get onto an exponential learning-curve. So – if you try something new tell the rest of us how it went by adding a comment in the discussion forum. Posted by John Blatchford Ret Talbot and I are continuing to write about the idea of trying to set up marine aquarium systems that are as natural as possible. Reef Aquarium introduces the hobby, and the two articles that follow (‘Biotopes and Habitats’ and ‘Marine Aquarium Biotoping’) go a little further to explore the idea of Biotoping. Specific biotopes are discussed in a bit more detail in ‘Mangroves and Seagrasses’ and ‘Growing Mangroves for Aquarists’ – with the first looking at their roles in nature and the second explaining how to build these biotopes into the tank system. The last article (so far!) goes much further by suggesting how the hobbyist might set up a series of tanks based on a very specific natural reef system (‘Replicating Habitat in the Tank’). When this is attempted we begin to move towards the situation where amateurs can really add to our understanding of natural reef ecosystems. - by working out how individual plants and animals contribute to maintaining water quality and keeping corals and reef fish happy we can help people who are trying to save what is left of the world’s coral reefs. As always we would encourage hobbyists who experiment with these systems to contribute to the discussion so that others can learn from successes and failures. Posted by John Blatchford History of Glass Aquaria In the mid nineteenth century people began to keep fish in glass tanks, but without electricity in the home it was difficult to control the temperature. Tropical freshwater tanks were possible as soon as electricity was installed (early twentieth century in many places), and the keeping of tropical marine specimens in the home took off in the 1960’s with the development of silicone sealants. This overcame the problem of metal frames and made it possible to build large all-glass tanks for the first time. Biotope Aquaria In the mid nineteenth century people were keeping freshwater aquaria stocked with an assortment of cold-water fish, plants and invertebrates - attempting to create stable aquatic environments. This approach is still found in many public aquaria, and practiced by many hobbyists, and it can lead to satisfying displays which look very much like the ‘real thing’ and are relatively stable. It is unfortunately rather difficult to set up this sort of ‘biotope aquarium’ with marine systems because the different organisms that need to work together are usually best kept separate from one-another. Biotope Tanks Recently people have begun to experiment with systems which involve a number of small tanks that are linked to the main display aquarium. These ‘biotope tanks’ house the more delicate (or unsightly!) organisms that are needed to help purify the water and cycle nutrients efficiently. Ret Talbot has a number of articles which go into the practical side of this technique, and I have written about some of the theoretical aspects (see ‘how to set up a display tank’ and ‘Biotopes and Habitats’ for examples). Discussion Both Ret and I would like people to let others know about their successes and failures through the discussion forum. Posted by John Blatchford In 2007 a swarm of jellyfish attacked an Irish salmon farm, and in 2006 over ten thousand people needed medical treatment after being stung while swimming off the Spanish coast. Global Warming Before 2007 Mauve Stingers had never caused problems in British waters, and it is thought that global warming might be responsible for this new phenomenon. Warmer water in general, or maybe effects on ocean currents might be bringing these jellyfish further north. Swansea University has received a grant of £50,000 to help specialists find out exactly what is happening. Ecological Data Pelagica noctiluca has never been studied in great detail, and it is only since the damage was caused to the salmon farm in Ireland that interest has been generated. There are insufficient past records to show whether the recent large swarms in the seas around Britain are normal for this species, or if this behaviour has started recently. The fear is that warmer water is bringing the jellyfish further north, and that Mauve Stingers will begin to appear regularly in the future. Before anything can be decided it will be necessary to collect some basic ecological data about this species, and this has been started by researchers counting the jellyfish they see from the deck of passenger ferries that regularly cross the Irish Sea. Source: ‘UK coasts on alert for return of killer jellyfish.’ by Science Editor Robin McKie – The Observer 13/01/08 Posted by John Blatchford Darwin and Fitzroy Darwin’s trip on the Beagle helped him establish himself as a reputable scientist, and my article ‘Darwin’s Studies’ describes how he developed from an amateur enthusiast. Although he is always associated with theories about evolution he also worked on many other biological and geological problems. His works on earthworms, coral reefs and barnacles are still held in high regard. But Darwin was not the sole example of a naturalist who profited from naval expeditions: Cook and Banks HMS Endeavour left Plymouth in 1768 to sail round Cape Horn and then on to Tahiti. She stayed three months to make astronomical observations (a transit of Venus) before continuing towards New Zealand charting the Southern Hemisphere. On April 29 1770 Cook made the first landing on the coast of Australia, and the botanist Joseph Banks went ashore. Cook originally named the place ‘Stingray Bay’, but later decided to call it ‘Botany Bay’ to acknowledge the many unique plant discoveries made by Banks. At a time when only the rich had the luxury of the time to study plants and animals it was often naval expeditions like these two that gave British naturalists the opportunity to carry their enthusiasms beyond the English countryside. They travelled the world and brought back new specimens which fuelled the academic development of the life sciences. |
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