Placeholder Image

字幕列表 影片播放

  • 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.

In the Spring of 2008 an eighty-four foot pleasure boat departed from Ft. Lauderdale

字幕與單字

單字即點即查 點擊單字可以查詢單字解釋

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
影片單字