Tuesday, December 15, 2009
Tuesday, June 30, 2009
Contamination at Mapua
The area surrounding Mapua made for prime conditions for the cultivation of a variety of commercial fruits. In 1932, Mapua would have been a logical place for the Fruitgrowers Chemical Company (FCC) to build its plant for manufacturing pesticides. Thirteen years later, production of the powerful new organochlorine pesticides began. The FCC plant was established in a time of far less scientific understanding of chemical toxins, and consequently little appreciation of the need for protecting people or the environment from exposure to them. There was virtually no care taken in the disposal of the factory’s waste products. The FCC plant site was abandoned in 1988, yet the organochlorine pesticides it produced were particularly persistent. Furthermore, in a mismanaged, inefficient, and ultimately ineffective attempt by the New Zealand government to “clean up” the toxic site lead to a release of a variety of additional toxins to the air and water. Discharges to the air pose potential risk to human health, while the discharges to the water threaten the ecology of the Waimea Estuary.
Prior to the clean up attempts, several investigations into contamination on the site, surrounding marine sediments, and adjacent residential lots identified the presence of some of the substances known to have been stored or manufactured on-site, including:
· Extensive contamination with organochlorine pesticides, especially DDT and its breakdown products, aldrin, dieldrin, and lindane
· Occasionally elevated levels of heavy metals (including chromium, arsenic, lead, cadmium and mercury) and elemental sulfur.
· Occasionally elevated levels of petroleum hydrocarbons
· Traces of chlorophenoxyacetic acid herbicides, phenoxy herbicides, organophosphates, triazines and other related nitrogen containing pesticides
· Traces of polychlorinated biphenyls (PCBs)
Marine sediment samples from the Waimea Inlet revealed contamination mainly by organochlorine compounds, particularly DDT and its metabolites. Metal and organochlorine levels in the groundwater exceeded guidelines for the protection of aquatic ecosystems and recreational water quality.
This clean up effort was a high risk strategy, as it was the first commercial application of a new technology in the middle of a village and close to a sensitive estuary. Mechano-chemical dehalogenation (MCD) was the method of clean up. This used a heated tumbling drier with a proprietary mixture of reagents to enhance treatment in hopes of degrading the toxic chemicals to inert products. One of these reagents was copper sulfate. The site auditor and the Engineer to the Contract warned the company managing the cleanup that they had serious concerns over the use of copper sulfate; yet at least 13 tons of copper was added to the site soils in the treatment process. Copper is highly toxic to marine ecosystems so it poses a particular hazard on the coastal Mapua site. Although the amount of copper sulfate was gradually reduced by about a third during the works, a large amount of copper remained behind at the site. There may be significant risks to the estuarine environment and plant life on the site, but no site-specific assessment criteria have been set for these receptors, so these risks have not been formally evaluated. Diammonium phosphate (DAP) and urea were also used as additives. At least 730 tons of DAP and 36 tons of urea were added to the site soils in this way. This is of concern because these nutrients are readily leachable and could be discharged to the estuary in groundwater, causing weed growth and eutrophication. Groundwater monitoring results show that DDT, lindane, nitrate and ammoniachemical nitrogen frequently exceeded consent threshold concentrations throughout the works often by orders of magnitude. Concentrations of copper, increased erratically throughout the works. Nitrate and DDT still exceed limits in some areas.
Not only was the selected method of cleanup inadequate, the process itself was seriously mismanaged. According to the Official Report released by the Parliamentary Commissioner for the Environment in July 2008, dioxin was released from the drier, but it is impossible to know now much due to inadequate monitoring. Why? The conditions in the soil drier were right for creating dioxin. For the MCD process to function efficiently, the soil being decontaminated must be dry. However, if contaminated soil particles in the drier come in contact with air above 250°C, organochlorine compounds in the soil may be converted to form dioxin (which did happen in one of the proof of performance trials) so specific precautions were included to prevent this situation arising during normal operations. In essence, the condition required the hottest part of the drier (the inlet) to be fitted with a temperature cut off, which would shut the drier down if the temperature exceeded 120°C. This was to reduce the volatilization of OCPs and prevent the formations of dioxins.
Inspections of the clean up process showed the temperatures of the drier inlet ranged from 250-396°C (the temperature depends on the water content of the soil). The design of the drier was such that, had this resource consent condition regarding the temperature cutoff been implemented, the soil output would likely have been about 15 percent of what was actually processed. This means that the MCD plant installed was not capable of complying with the temperature consent condition and functioning at the output envisaged.
Unfortunately, the impact of pollution on the estuarine water has not been investigated. So what’s the big fuss? Humans and other organisms in this community seem to be going about their business as usual, largely unaffected by this pollution. Before such an assertion can be made with confidence, the nature of these man made toxins must be carefully considered. The most profound impacts of these toxins on a given organism would occur at the molecular level, and therefore the consequences may seem less obvious. Although every user of bleach and swimming pools is familiar with chlorine, the element rarely exists in free form in nature: It is man-made. Chlorine is also extremely unstable and volatile, easily recombining with other elements. When combined with hydrocarbons and other chemicals, chlorine produces a bewildering number of molecular compounds that are almost universally poisonous to invertebrates, plants, animals, and humans. Although most organochlorine compounds are produced intentionally, they can also be produced unintentionally. Dioxins, one of the most deadly family of compounds known to man, are created when chlorine bleaches are used to treat lumber or pulps, and also during incineration of other compounds as was observed at Mapua. The family of organochlorines includes many famous chemicals now banned or restricted, such as DDT, chlordane, Mirex, Dieldrin, Heptaclor, all the PCB’s and ozone-disrupting CFCs as well.
Organochlorines are remarkably persistent and cannot be incorporated into the metabolic process of any organism on earth. Because organochlorines do not break down in water, they accumulate in the fatty tissues of organisms. Species that are higher on the food chain, such as humans, accumulate organochlorines to a far greater degree than might be anticipated by their exposure. There is every reason to believe that concentrations of these compounds in wildlife and humans will continue to increase as they move up the food chain. The implication of recent studies on effects of these compounds on human development is that we have within the human race a biological ozone hole, a series of chemical compounds whose effect will expand throughout the entire world population for decades, even if all such compounds ceased being manufactured today. Tests show that these compounds have adverse effects in very low concentrations, and because their widespread use and persistence, we face continuous re-exposure over our lifetime. Currently, human exposure to such substances in the United States is well within the tolerances where hormonal disruption can occur. An accumulation of forty years’ worth of such substances in the environment may require only a few minutes in the body at a critical time to cause genetic changes that are permanent and irreversible. The most disturbing suggestion of the research in this area is that because organochlorines clearly react with and disrupt sexual hormones, both androgens and estrogens, they can alter the function of the brain, and thus affect behavior, thought, and intelligence. Biologically speaking, our metabolic processes have little or no effect in rendering these substances into more harmless ones because humans and other organisms have never in their evolutionary history encountered similar compounds. Because of the slow maturation of human beings, we have not had sufficient time since the introduction of such chemicals to understand the multigenerational health consequences of exposure to organochlorines. It is well known that these compounds do play havoc with human physiology, with effects that include cancer, infertility, immune suppression, birth defects, and still births. More disturbing, is the ability of several organochlorine compounds to disrupt the endocrine system. They are mistakenly “recognized” by the human body as hormone messengers, thereby signaling the wrong information to cells and bodily functions. Because the compounds in question mimic the actions of natural hormones, binding to receptor sites in the body, they can alter the embryonic development of the organism in ways that are irreversible, although the effects may not be experienced until maturity. In wildlife, these chemicals cause decreased fertility, behavioral abnormalities, compromised immune systems, and monstrous defects, such as fish born with both male and female sex organs but incapable of reproduction.
The contamination at Mapua showed just how difficult cleaning up a toxic site can be. Perhaps the real issue at hand is not improving waste disposal and clean up technology, but rethinking if we as a society should find the production of these compounds acceptable in the first place. To err on the side of caution and acknowledge the things we still do not understand would be wise. I strongly urge others to analyze issues such as these critically, and bear in mind that common practice does not infer safe or sustainable.
Prior to the clean up attempts, several investigations into contamination on the site, surrounding marine sediments, and adjacent residential lots identified the presence of some of the substances known to have been stored or manufactured on-site, including:
· Extensive contamination with organochlorine pesticides, especially DDT and its breakdown products, aldrin, dieldrin, and lindane
· Occasionally elevated levels of heavy metals (including chromium, arsenic, lead, cadmium and mercury) and elemental sulfur.
· Occasionally elevated levels of petroleum hydrocarbons
· Traces of chlorophenoxyacetic acid herbicides, phenoxy herbicides, organophosphates, triazines and other related nitrogen containing pesticides
· Traces of polychlorinated biphenyls (PCBs)
Marine sediment samples from the Waimea Inlet revealed contamination mainly by organochlorine compounds, particularly DDT and its metabolites. Metal and organochlorine levels in the groundwater exceeded guidelines for the protection of aquatic ecosystems and recreational water quality.
This clean up effort was a high risk strategy, as it was the first commercial application of a new technology in the middle of a village and close to a sensitive estuary. Mechano-chemical dehalogenation (MCD) was the method of clean up. This used a heated tumbling drier with a proprietary mixture of reagents to enhance treatment in hopes of degrading the toxic chemicals to inert products. One of these reagents was copper sulfate. The site auditor and the Engineer to the Contract warned the company managing the cleanup that they had serious concerns over the use of copper sulfate; yet at least 13 tons of copper was added to the site soils in the treatment process. Copper is highly toxic to marine ecosystems so it poses a particular hazard on the coastal Mapua site. Although the amount of copper sulfate was gradually reduced by about a third during the works, a large amount of copper remained behind at the site. There may be significant risks to the estuarine environment and plant life on the site, but no site-specific assessment criteria have been set for these receptors, so these risks have not been formally evaluated. Diammonium phosphate (DAP) and urea were also used as additives. At least 730 tons of DAP and 36 tons of urea were added to the site soils in this way. This is of concern because these nutrients are readily leachable and could be discharged to the estuary in groundwater, causing weed growth and eutrophication. Groundwater monitoring results show that DDT, lindane, nitrate and ammoniachemical nitrogen frequently exceeded consent threshold concentrations throughout the works often by orders of magnitude. Concentrations of copper, increased erratically throughout the works. Nitrate and DDT still exceed limits in some areas.
Not only was the selected method of cleanup inadequate, the process itself was seriously mismanaged. According to the Official Report released by the Parliamentary Commissioner for the Environment in July 2008, dioxin was released from the drier, but it is impossible to know now much due to inadequate monitoring. Why? The conditions in the soil drier were right for creating dioxin. For the MCD process to function efficiently, the soil being decontaminated must be dry. However, if contaminated soil particles in the drier come in contact with air above 250°C, organochlorine compounds in the soil may be converted to form dioxin (which did happen in one of the proof of performance trials) so specific precautions were included to prevent this situation arising during normal operations. In essence, the condition required the hottest part of the drier (the inlet) to be fitted with a temperature cut off, which would shut the drier down if the temperature exceeded 120°C. This was to reduce the volatilization of OCPs and prevent the formations of dioxins.
Inspections of the clean up process showed the temperatures of the drier inlet ranged from 250-396°C (the temperature depends on the water content of the soil). The design of the drier was such that, had this resource consent condition regarding the temperature cutoff been implemented, the soil output would likely have been about 15 percent of what was actually processed. This means that the MCD plant installed was not capable of complying with the temperature consent condition and functioning at the output envisaged.
Unfortunately, the impact of pollution on the estuarine water has not been investigated. So what’s the big fuss? Humans and other organisms in this community seem to be going about their business as usual, largely unaffected by this pollution. Before such an assertion can be made with confidence, the nature of these man made toxins must be carefully considered. The most profound impacts of these toxins on a given organism would occur at the molecular level, and therefore the consequences may seem less obvious. Although every user of bleach and swimming pools is familiar with chlorine, the element rarely exists in free form in nature: It is man-made. Chlorine is also extremely unstable and volatile, easily recombining with other elements. When combined with hydrocarbons and other chemicals, chlorine produces a bewildering number of molecular compounds that are almost universally poisonous to invertebrates, plants, animals, and humans. Although most organochlorine compounds are produced intentionally, they can also be produced unintentionally. Dioxins, one of the most deadly family of compounds known to man, are created when chlorine bleaches are used to treat lumber or pulps, and also during incineration of other compounds as was observed at Mapua. The family of organochlorines includes many famous chemicals now banned or restricted, such as DDT, chlordane, Mirex, Dieldrin, Heptaclor, all the PCB’s and ozone-disrupting CFCs as well.
Organochlorines are remarkably persistent and cannot be incorporated into the metabolic process of any organism on earth. Because organochlorines do not break down in water, they accumulate in the fatty tissues of organisms. Species that are higher on the food chain, such as humans, accumulate organochlorines to a far greater degree than might be anticipated by their exposure. There is every reason to believe that concentrations of these compounds in wildlife and humans will continue to increase as they move up the food chain. The implication of recent studies on effects of these compounds on human development is that we have within the human race a biological ozone hole, a series of chemical compounds whose effect will expand throughout the entire world population for decades, even if all such compounds ceased being manufactured today. Tests show that these compounds have adverse effects in very low concentrations, and because their widespread use and persistence, we face continuous re-exposure over our lifetime. Currently, human exposure to such substances in the United States is well within the tolerances where hormonal disruption can occur. An accumulation of forty years’ worth of such substances in the environment may require only a few minutes in the body at a critical time to cause genetic changes that are permanent and irreversible. The most disturbing suggestion of the research in this area is that because organochlorines clearly react with and disrupt sexual hormones, both androgens and estrogens, they can alter the function of the brain, and thus affect behavior, thought, and intelligence. Biologically speaking, our metabolic processes have little or no effect in rendering these substances into more harmless ones because humans and other organisms have never in their evolutionary history encountered similar compounds. Because of the slow maturation of human beings, we have not had sufficient time since the introduction of such chemicals to understand the multigenerational health consequences of exposure to organochlorines. It is well known that these compounds do play havoc with human physiology, with effects that include cancer, infertility, immune suppression, birth defects, and still births. More disturbing, is the ability of several organochlorine compounds to disrupt the endocrine system. They are mistakenly “recognized” by the human body as hormone messengers, thereby signaling the wrong information to cells and bodily functions. Because the compounds in question mimic the actions of natural hormones, binding to receptor sites in the body, they can alter the embryonic development of the organism in ways that are irreversible, although the effects may not be experienced until maturity. In wildlife, these chemicals cause decreased fertility, behavioral abnormalities, compromised immune systems, and monstrous defects, such as fish born with both male and female sex organs but incapable of reproduction.
The contamination at Mapua showed just how difficult cleaning up a toxic site can be. Perhaps the real issue at hand is not improving waste disposal and clean up technology, but rethinking if we as a society should find the production of these compounds acceptable in the first place. To err on the side of caution and acknowledge the things we still do not understand would be wise. I strongly urge others to analyze issues such as these critically, and bear in mind that common practice does not infer safe or sustainable.
Sunday, June 28, 2009
Lake Moeraki
Visit to lake Moeraki 6/2/09
Today our group visited with Gerry McSweeney and learned about the "green" practices they use for their wilderness lodge. This place was one of the most green that we have seen so far. They have a carbon neutral footprint and create all the needed electricity by using falling water of the Moeraki River. They do not add to the growing problem of green house gases. This place was unique in the thickness of vegetation and the tropical rainforest which has survived because of its location. The forest was surrounded on three sides by the lodges, highway, and lake so the deer were deterred from entry.
This location was originally going to be logged until biologists McSweeney and Anne Saunders decided to save the podocarp trees and use them for nature tourism and economic benefit. By working with the Department of Conservation (DOC) they helped to change the minds of those in the Haast community and to see the benefits in preserving nature while also creating more jobs and a stable economy. As McSweeney put it, "You need to change the hearts and minds of the people; the problem with governmental decisions is that they can easily be reversed by the next government or anyone that comes to power." He also stated, "It's hard to be green when you're in the red." These two statements were really what their business was all about.
One focus of this group has been to save the Fjordland Crested (Tawaki) penguin. This species has struggled due to fishermen's dogs going after the distinctive smell of the penguins and killing them. Fishing with dogs has been outlawed, yet it is still a problem because people are not prosecuted when they bring their dog along on a fishing trip. These penguins are one of the rarest in the world and spend six months nesting in the rainforest and the other six months at sea.
The deer, stoats, possums, and ferrets are among the other problems that ruin the forest and decrease the island's uniqueness. McSweeney thus agreed to the spraying of a chemical known as 1080 over the land. Birds have a low susceptibilityto the formula and it biodegrades into sodium fluoride, which is found in many items including household toothpaste. No better method has been found thus far as it's not plausible to cover such a large area any other way. This chemical is sprayed every 2-3 years because that is how long it takes for these pests to repopulate the area. The rainforest takes what McSweeney refers to as a "double-whammy" because the deer destroy the undergrowth and the possums destroy the tree tops and canopy. The spraying of 1080 has helped the rainforest survive by reducing the numbers of unwanted possums and deer.
Katie J. and Anna
Today our group visited with Gerry McSweeney and learned about the "green" practices they use for their wilderness lodge. This place was one of the most green that we have seen so far. They have a carbon neutral footprint and create all the needed electricity by using falling water of the Moeraki River. They do not add to the growing problem of green house gases. This place was unique in the thickness of vegetation and the tropical rainforest which has survived because of its location. The forest was surrounded on three sides by the lodges, highway, and lake so the deer were deterred from entry.
This location was originally going to be logged until biologists McSweeney and Anne Saunders decided to save the podocarp trees and use them for nature tourism and economic benefit. By working with the Department of Conservation (DOC) they helped to change the minds of those in the Haast community and to see the benefits in preserving nature while also creating more jobs and a stable economy. As McSweeney put it, "You need to change the hearts and minds of the people; the problem with governmental decisions is that they can easily be reversed by the next government or anyone that comes to power." He also stated, "It's hard to be green when you're in the red." These two statements were really what their business was all about.
One focus of this group has been to save the Fjordland Crested (Tawaki) penguin. This species has struggled due to fishermen's dogs going after the distinctive smell of the penguins and killing them. Fishing with dogs has been outlawed, yet it is still a problem because people are not prosecuted when they bring their dog along on a fishing trip. These penguins are one of the rarest in the world and spend six months nesting in the rainforest and the other six months at sea.
The deer, stoats, possums, and ferrets are among the other problems that ruin the forest and decrease the island's uniqueness. McSweeney thus agreed to the spraying of a chemical known as 1080 over the land. Birds have a low susceptibilityto the formula and it biodegrades into sodium fluoride, which is found in many items including household toothpaste. No better method has been found thus far as it's not plausible to cover such a large area any other way. This chemical is sprayed every 2-3 years because that is how long it takes for these pests to repopulate the area. The rainforest takes what McSweeney refers to as a "double-whammy" because the deer destroy the undergrowth and the possums destroy the tree tops and canopy. The spraying of 1080 has helped the rainforest survive by reducing the numbers of unwanted possums and deer.
Katie J. and Anna
Cushion Plant
The first time I encountered the cushion plant was not in the greatest of circumstances. Justin and I decided that we were going to hike up Mount Miserable or some silly name like that right behind the research station we were staying at in Cass, in the South Island of New Zealand and stay in a tent for the night. After hiking through all of the thorny, sharp plants, Justin and I starting looking for a place to set up camp. This was no ordinary mountain however, the whole side that we were climbing seemed to be harboring a stream of water. It was really interesting and wet at the same time. Although you could not physically see this stream, you could hear it underneath the dense soft ground. So despite not being able to set up a tent on this hike, I did discover what I had later learned to be a very interesting plant; the cushion plant
The cushion plant is a low growing, mat-like plant that can be found all over the world. There are approximately 338 species of Cushion Plant. The do not grow to be much higher than slightly rased above the ground, but the are very thick and dense. Not to mention very soft. Watch the video below. Cushion Plants thrive in alpine, arctic, and sub-alpine condions.
They are able to thrive in these conditions due to their compact, extremely dense growth. As you can see in the photograph on the left, the density of these stems is so thick that they almost seem as one. This allows the plant to keep in warmth, sustain periods of drought because they are excellent at maintaining water, and are not as vulnerable to sheer winds. They maintain water so well, due to their root systems and the densities of their structures.The cushion plants are very slow growing. Their average growth rate is .6mm per year. Considering, that many of them, including those of which we saw on our hike, grow to be 3 meters across,
cushion plants can live a very long time. The live an average lifespan of 350 years, and some subspecies live to be over 3,000 years old. Another really unique thing about cushion plants is they create miniature ecosystems that allow for new life to flourish in places that without the cushion plant would be impossible. In the photograph on the left you can see a little fungi growing right out of the cushion plant. I was unable to find mushrooms in any other location during that whole hike on Mount Miserable. I agree with the author of the wikipedia page on the cushion plant when he says that the cushion plant is an "ecosystem engineer." you can tell with every step you took on that hike, that these cushion plants are and have been modifying the mountainside. They have a nurse effect on their surrounding environment, allowing life to take place, and new ecosystems to develope.A Little From the Parliament of the Cook Islands
Since not many bio students went to Parliament in the Cook Islands, I thought I'd give you all a little info about what we covered on June 11th.
Although we discussed quite a bit of material, as far as I know, Joe made the appointment with Deputy Clerk Puna to discuss issues with the seabed mining bill that is being dicussed in their legislature. According to a report by SPC Coastline Fisheries the Cook Islands Exclusive Economic Zone covers 1.8 million square kilometers in which there is an estimated 7.5 trillion tons of mineral resources in manganese nodules. The nodules are formed by metallic elements that slowly precipitate out of the ocean water. The nodules grow at a rate of only 2 mm/million years. Deep currents flowing from the Antarctic region towards the equator influence the formation of nodules in Cook Island waters, which are rich in cobalt, nickel and copper. Of these metals, cobalt is the most valuable, and the nodules of the Cook Island waters are thought to have the highest cobalt content in all of the Pacific, estimated to be about 32 million tons. These 32 million tons are thought to be able to meet current world demands for more than 500 years. (cobalt is mostly used industrially, especially in the aircraft industry, rechargeable batteries, and laptops). The monetary value of these metals is estimated to be NZ$ 2 trillion for cobalt, NZ$ 380 billion for nickel, and over NZ$ 50 billion for copper. These nodules occur in waters around 5000 meters deep, which can be a real challenge for mining, and could cause a great deal of disruption to the seabed. Previously, most cobalt has come from Africa, but these supplies have not been consistent and thus other sources are significant. Environmentally the consequences of harvesting these nodules could be devistating, but they are honestly not known. Collecting the nodules could have a significant affect on the seafloor ecosystem especially by sediment plumes that will surely be generated. If the nodules are harvested and processed, more than 95% of the weight would be in unstable tailings because it is unlikely that the manganese and iron will be recoverable, which means disposal of these tailings.
As Puna indicated (this is pretty true in the states as well), the problem is that as long as revenue can be generated, the government will continue their actions.
MORE TO COME!!! I'm at work :-)
Although we discussed quite a bit of material, as far as I know, Joe made the appointment with Deputy Clerk Puna to discuss issues with the seabed mining bill that is being dicussed in their legislature. According to a report by SPC Coastline Fisheries the Cook Islands Exclusive Economic Zone covers 1.8 million square kilometers in which there is an estimated 7.5 trillion tons of mineral resources in manganese nodules. The nodules are formed by metallic elements that slowly precipitate out of the ocean water. The nodules grow at a rate of only 2 mm/million years. Deep currents flowing from the Antarctic region towards the equator influence the formation of nodules in Cook Island waters, which are rich in cobalt, nickel and copper. Of these metals, cobalt is the most valuable, and the nodules of the Cook Island waters are thought to have the highest cobalt content in all of the Pacific, estimated to be about 32 million tons. These 32 million tons are thought to be able to meet current world demands for more than 500 years. (cobalt is mostly used industrially, especially in the aircraft industry, rechargeable batteries, and laptops). The monetary value of these metals is estimated to be NZ$ 2 trillion for cobalt, NZ$ 380 billion for nickel, and over NZ$ 50 billion for copper. These nodules occur in waters around 5000 meters deep, which can be a real challenge for mining, and could cause a great deal of disruption to the seabed. Previously, most cobalt has come from Africa, but these supplies have not been consistent and thus other sources are significant. Environmentally the consequences of harvesting these nodules could be devistating, but they are honestly not known. Collecting the nodules could have a significant affect on the seafloor ecosystem especially by sediment plumes that will surely be generated. If the nodules are harvested and processed, more than 95% of the weight would be in unstable tailings because it is unlikely that the manganese and iron will be recoverable, which means disposal of these tailings.
As Puna indicated (this is pretty true in the states as well), the problem is that as long as revenue can be generated, the government will continue their actions.
MORE TO COME!!! I'm at work :-)
Wednesday, June 17, 2009
Mount Aspiring National Park Birds
On Friday , June 5, while hiking near Glenorchy in Mount Aspiring National Park, I got the opportunity to observe several birds, some of which are now rare in New Zealand compared to just a few hundred years ago. The first bird I got a glimpse of was the Yellowhead, as it foraged among the moss that all but completely covered the beech forest we walked through. The Yellowhead (Mohua ochrocephala) is now the most threatened species of its genus, though in the 1800’s it was apparently very common, inhabiting podocarp-hardwood forests (such as Rimu, Totara and Miro). The clearing of those forests as well as the introduction of new mammalian predators (rats, stoats, etc) led to its decline and now this insectivorous bird is found only in beech forests with fertile soils where it can find plenty of food. It is now estimated that 1000 to 2500 Yellowhead birds remain.
As we walked, flittering along close to the forest floor were Acanthisitta chloris chloris, the
As we were heading back, there was a great commotion of birds in a nearby tree that had produced fruit. Among those present were some of the aforementioned birds plus another type we had not seen yet: the kakariki, yellow-crowned parakeet. The yellow-crowned parakeet still inhabits parts of mainland
This however is just a small sampling of the diversity of
Glowworms
" I wish I was a glowworm, a glowworm is never glum. 'Cos how can you be grumpy when the Sunshine's from your bum"
Larson Burrows (1910-1994) was a local explorer who re-discovered the te-ana-au glowworm cave in 1948. Glowworms can reach up to 3 cm in length and have a life expectancy of about 11 months with different stages of life. The glowworm life starts as an egg and takes about 3 weeks to hatch. The eggs are clumped together by mucus like filaments, these eggs are small and dense. Once hatched they are small larva. The larva stage is where the glowworms builds a nest and begins to try to catch food by releasing lines down that reach anywhere from 1/2-7 inches long and up to 70 lines can be dropped from the nest. These lines are known as "fishing lines." The contain a paralyzing agent which kills the insect that fly into the lines. The insect is attracted to the bio luminescence of the glowworm. Then the glowworm pulls the line up in which the insect was caught on. Once the glowworm has enough energy it suspends itself on a long thread in its pupa stage. This lasts about 12 to 13 days to become the adult fly. to release itself from the cocoon like structure, the adult fly expands and contracts its body until the cocoon breaks open. The adult fly is only alive long enough to reproduce and for female lay eggs. The female usually dies after laying the eggs, males on the other hand can live up to 5 days. This is short because the adult fly in both male and female have no mouths nor do they have stomachs. The soul purpose it so reproduce. This overall life cycle of the glowworm. Interesting facts, the more hungry the glowworm is the brighter its bio luminescence is. Glowworms live in caves because it has low temperature and humidity fluctuations, glowworms are also found in dense forest floors where the living conditions are met.
** No pictures were allowed in the cave, this was taken from google image**
I actually posted this blog the night that we went, but when i went on here I noticed my blog wasnt on here but that I created my own blog about glowworms! haha WOOPS!
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