字幕列表 影片播放 列印英文字幕 In the Spring of 2008 an eighty-four foot pleasure boat departed from Ft. Lauderdale bound for the Caribbean. Thirty miles south of Miami, it strayed from marked navigation channels into the shallow waters of Biscayne National Park. Suddenly, running at full speed it collided with a coral reef near Elliot Key. Corals, sponges and sea fans were instantly obliterated as the boats twin propellers plowed through the reef. The engines were disabled and the powerless vessel drifted in the wind until grounding on a second reef. Here, the wind and waves rocked the boat on its hull, shattering the ancient coral mounds and pounding the reef into rubble. A coral reef that had taken centuries to grow was destroyed in just moments. Two and a half years later, coral researchers and resource managers are searching for solutions to help the oceans declining coral reefs. Can new technologies and naturally occurring biological mechanisms help restore the lost coral communities? And can ecological balance be returned to Floridas coral reefs? Major funding for this program was provided by The Batchelor Foundation, encouraging people to preserve and protect Americas underwater resources. Biscayne National Park is an undersea garden filled with multi-colored sponges, corals and sea fans. At the northern extent of the Florida Keys reef tract its sea grass beds, coral reefs and mangrove shorelines cover more than 170,000 acres a gem in the National Park system, but an area with a history of damaging boat groundings. Corals in Biscayne National Park and on a global scale are in a serious state of decline due to stresses like climate change, disease outbreaks and overfishing. Since the late 1970s close to ninety-eight per cent of staghorn and elkhorn corals have disappeared from the reefs in Florida and the Caribbean. Because corals are having such a difficult time persisting, resource managers want to restore boating impacts like the 2008 grounding site in the park. When the vessel grounded it crushed up the surface of the reef into a rubble field and were trying to use a combination of adhesives to stabilize that rubble. Were collecting the rubble into mounds like this and like this and well be using a combination of cement and natural sponges that are found right here on the reef to bind this rubble to stabilize it through time. Right now the rubble mounds are in the process of being put together. Were installing rebar stakes like this that will help us monitor them through time and well be looking at things such as coral recruitment, the stability of the mounds themselves, if they change in size and shape and height, and well probably monitor theses for a period of at least five years. Researchers at the University of Miami have developed one of the first underwater applications for mosaic imaging, a technique comparable to aerial photography on the land. This technology will create useful perspectives of the coral reef and grounding site in Biscayne National Park. The diver swims back and forth in a lawnmower-like pattern recording overlapping images of the underwater landscape. Later, at the university laboratory, a single seamless image of the reef is produced. This is basically an unprecedented baseline in terms of the amount of information you can get in a very short amount of time. Three-dimensional images can be created over time to show reef areas where corals grow best, the places where restoration is most likely to succeed. New growths of soft corals and sponges are returning to the grounding site, but the boats most damaging impacts are still evident. The damage extends several hundreds of square meters and really theres no easy way to document that. Here were able to use the video and the stills to really cover the entire area both the affected area and also the community around it so we know what this area should look like when its fully restored. Coral reef restoration gained traction in the Florida Keys National Marine Sanctuary with marine biologists like Harold Hudson, The Reef Doctor, and Ken Nedimeyer. Hudson, a restoration specialist for the sanctuary, perfected a design for reef modules that were used for the structural repair of a large vessel grounding site, the Wellwood, on Molasses Reef near Key Largo. Nedimeyer performed the biological restoration with transplanted corals grown in his undersea nursery. His restoration plan was validated when it was discovered that the transplants on the reef were spawning several years sooner than expected. I was real excited, I thought man, this is amazing because this is exactly what weve been trying to say that were going to do which is re-establish these spawning populations of corals. It brought a whole new life to the possibility of not just putting corals back on the reef but re-establishing breeding populations that could then re-populate other downstream areas. Nedimeyers coral nursery is the largest in the country and a model for many coral aquaculturists. Here you encounter a hundred rows of coral fragments mounted on concrete blocks. Each coral is attached to a disc with a label designating its origin and genotype, or genetic properties. More than a thousand staghorn cuttings are strung from six line nurseries suspended in the water column by floats and cross-tied with horizontal lines. On a line nursery they grow down, they grow to the side, they grow all different directions. And another thing thats nice about them, if a turtle or a shark or a fish bumps against them on the line they just bounce out of the way and they swing right back to where they were. If a turtle bumps against a coral thats firmly mounted on a disc itll break it off. Nedimyer cultivates staghorn coral, one of the principle reef building corals and one listed as threatened under the Endangered Species Act. He cultivates them in his nursery for a year then transplants them to the reef. One of the things we need to be doing is preserving the genetic diversity that we still have. And if we dont preserve as much of that as possible right now we wont have anything to work with in ten or fifteen years. Research Associate Tom Capo and colleagues at the University of Miamis experimental hatchery are preserving the genetic diversity of orphaned corals whose survival was threatened by storms, boat groundings and anchor pulls. Some were recovered from the grounding site in Biscayne National Park. Researchers are trying to answer questions about a destructive phenomenon known as coral bleaching. Whats going on? Is it disease? Is it some sort of water quality parameter? And many of these questions cannot be answered easily in the field. So the goal is to have a coral genetic bank, a coral resource that we can provide genetically maintained strains of coral to people, bona fide researchers around the world so that they can look at these problems, at these issues, and look at them in a scientific way. In a partnership between Biscayne National Park and the University of Miami, trained volunteers assist Capo with a labor-intensive process known as fragmentation to produce a large number of small coral specimens. You should have one ready for him now, I mean he should not stop. Travertine plates are marked, drilled and fitted with passive integrated transponders, or PIT tags, that will give each coral a unique identity. The large corals are cut into fragments, each about an inch-and-a-half in diameter. The bottom surface is shaped on a tile saw. The fragment is thoroughly dried, super-glued to a PIT tag plate and cataloged for future reference. Half of the fragments will be transplanted at the coral restoration site in Biscayne National Park, the other half will remain at the facility for monitoring and lab studies to help Capo and coral researchers answer another difficult question. How can we enhance all of this to make the only reef tract in the continental United States a viable place rather than seeing it deteriorate like its been doing over the past ten years? One of Capos research partners, Martin Moe, a marine biologist in the Florida Keys, believes he has an answer. In 1983, there was this tremendous plague and it hit only one organism. And that was the long-spined sea urchin, Diadema Antellerum that occupied all the reefs of the Caribbean, the Bahamas, Florida, they were all very densely occupied by diadema. And diadema peformed the essential task of cleaning the algae off the reefs and conditioning the substrate so that it would accept and encourage coral growth and the growth of many kinds of fish and invertebrates. Within one year 98% of all the diadema antellerum from the mouth of the Panama Canal all the way up to Bermuda were history, were toast. They all died quickly. At first, divers like Ken Nedimeyer were happy about the decline of the sharp-spined creatures. As much as I dont like getting stabbed by them, theyre important and I want to have them back. Like sheep grazing in a pasture, diadema sea urchins graze the macroalgae that grow on the reefs and inhibit coral reproduction. A lot of the problems are directly related to the sea urchins. If you fix all of the water quality issues and fix all of these other things but you dont fix the sea urchin problem youre not going to have a coral reef. Sea urchins play a really important role. Ken and I came to the point of view that the loss of the diadema was critical to the decline of the reefs. Now, our coral reef decline comes from many factors not just the loss of diadema. But that is certainly one of the most critical elements because its the diadema that maintain that balance between coral and algae growth. With support from the Florida Keys National Marine Sanctuary, Nedimeyer and Moe did two experimental reef studies where they re-introduced the diadema. A year later, the findings were remarkable. Juvenile corals increased by more than 150%, coralline algae, which encourages coral settlement and growth, was sharply higher, and macroalgae was reduced from 11% to less than 2%. I started with the Florida Board of Conservation Marine Laboratory back in 1962. Florida was a very different place back then. I worked with the Keys and the Keys were magical. I remember going out and diving around John Pennekamp area and there were huge stands of elkhorn coral, palmatta, beautiful. And it was such a tremendous environment. And when I came back in the late 90s the reef was so much different and it was so sad to see what was a glorious coral environment just become for the most part a lot of algae covered rocks. It seemed like the best thing that I could do was to work with the diadema because nobody else was doing it and it was something essential to do. Martin Moe is committed to perfecting the technology to reproduce, or culture diadema in the laboratory. Today he begins a new culture process, or run by selecting diadema that are ready to spawn. Immersing them in a tub of warm water stimulates the spawn. Oh yeah. Now thats a male. You can see the white sperm there. Yes sir, thats a female. Weve got spawning first three. How about that? OK, this is the product from the spawn. Apparently a male and a female both went which means that I should have eggs in here. Oh yes, that is nice. I can see fertilization membranes are present around every egg so we know weve had a good spawn. We know weve got good eggs. Out of, lets say, five million eggs that were spawned here, which is a pretty good estimate, and out of those five million youd probably be lucky if one, or two made it, in nature, all the way through the process and became a juvenile. And then youd be lucky if one of those survived into adulthood, very lucky actually. The following morning he counts the developing embryos. The eggs hatch in about 24 hours or so, 18-24 hours, they become blastulas, they become prisms which is the initial urchin shape. The embryos are transferred to three larvae culture tanks where they will eat and grow for the next thirty-five to forty-five days. But, unlike other types of invertebrates, diadema larvae will die if they settle on the bottom of the tanks. Finding a method to mimic the natural ocean current to keep the larvae in suspension had been Martins biggest trial during his early culture attempts. Maintaining a sterile environment had been another problem. Entire runs had failed in the culture tanks. The weeks ahead will again test his system and the diademas ability to survive. Meanwhile, the fragmented corals from the University of Miami have arrived at the grounding site in Biscayne National Park. Volunteers swim with buckets of cement and crates of tiles to the transplant areas. Another group has re-attached broken pieces and transplanted nursery-raised coral to the site. And resource managers are betting on the feasibility of a new restoration technique. Were going to be using sponges to bind the rubble that was created by this grounding incident and this is the first time weve tried this and to our knowledge the first time sponges have been used in an actual restoration project for this purpose. Sponges are known to play an ecological role in binding rubble in a natural reef setting. Theres also evidence that coral will settle and grow more favorably on an area thats been bound by sponges. Right here weve marked a sponge where we cut a fragment off yesterday. Weve tagged and marked the parent colony so that we can track it through time and see how that lesion heals just to make sure its doing OK. The sponge fragment we took from there weve attached over in our sponge nursery. Each tile has nine PVC trees. We attach one sponge fragment to each PVC tree. We cut these sponge fragments off the parent colonies that I showed you earlier. Were trying to get the cut surface in contact with the paver stone at least as closely as possible. Our colleagues have shown that those cut surfaces bind to whatever theyre in contact with, very quickly if all goes well. So we hope to come back and see these sponges growing down onto the tiles and also up starting to branch out. And the idea is that in time once the sponges grow and start getting larger that you can then cut fragments off of these and use them in restoration projects. We tried to get all of our fragments cut to approximately ten centimeters in size. We harvested these fragments yesterday and some of them are starting to show a slightly blackish color. Were not sure if thats a good thing or a bad thing. Were going to be watching these sponges carefully on a daily basis in the beginning and then probably every week or so to see how they survive and grow. When they started to turn black we started to get very concerned, not knowing if we had done something wrong, or not knowing if we had potentially killed all these sponge fragments we had harvested. However we were very relieved to see that even the next day the blackness goes away, the sponges are doing great, and they appear to be re-attaching very quickly to both the rubble pieces that theyve been attached to and also to the grow out structures. For forty days Martin Moe has been monitoring the survival and growth of the diadema larvae. A week ago, he hit a setback - all three cultures were struck by an infestation of Vorticella, an organism that causes competition for food and a decline in the larval development. But, one of the cultures showed a larger number of well-formed larvae than the other two. He made a decision to dedicate the remaining food supply to the survival of the well-formed culture and abandon the others. It might be the only chance for at least some of the larvae to reach the settlement phase. Now this one is ready to come out, and we can check for settlers on it. And they settle as larvae and then they go through metamorphosis in which all the spines and larval tissue all drop down into the rudiment and the rudiment becomes a little round juvenile. And you can pull it out of the settlement, like this, and the water stays in these little cubicles, then you put it right down into the settlement tray. The water in the settlement tray is all adjusted for temperature, ph, alkalinity, calcium, and its ready to support the process of metamorphosis and the early juvenile. After they go through metamorphosis theyre a soft little creature. And they cant survive as a soft little creature. They have to pull calcium carbonate, the same stuff your bones are made out of, out of the water, which is dissolved in the water, and they have to form their hard parts and their mouth parts so that they can actually scrape and feed and survive as a sea urchin rather than a pelagic floating larvae. And then it can be carried and placed down into this raceway kind of facility. I call it a raceway, theres a water current that moves through the whole tank like this, and as they are settling there it keeps the water fresh and clear around them. They grow and become little urchins on these plates. At some point it becomes optimum to pick the plate up and put it in a bucket, theyll stay stuck on the plate, then you can move them to any kind of a grow out area that you wish. After four years of developing the technology to raise lab cultured diadema, Martin Moe is nearing the end of his quest. When we get to the point where we can produce large numbers of juvenile diadema then we can begin to research on what is the best way to re-establish them on the reef. At that point, along with Kens work with the corals and what Ive been able to develop with the diadema, we can come together and we can achieve at least some semblance of ecological restoration on the reefs. At the grounding site the sponge transplants are healthy and growing. Amanda Bourque is watchful as the sponges replicate their natural behavior in a transformed environment. But, it will take several years of monitoring before the success of this project is fully known. Coral reef restoration is an emerging science built on innovative ideas, lessons learned and continual refinement of the human technologies that are helping nature restore its gardens of the sea. Major funding for this program was provided by The Batchelor Foundation, encouraging people to preserve and protect Americas underwater resources.
B2 中高級 美國腔 "礁石復興 "全集簡介 ("Reef Revival" Full-Length Episode) 316 25 realvip 發佈於 2021 年 01 月 14 日 更多分享 分享 收藏 回報 影片單字