字幕表 動画を再生する 英語字幕をプリント ♪♪ This week on WATERWAYS: Wading Birds of the Everglades, and Benthic studies. There are over 360 species of birds that spend at least part of the year in Everglades National Park. Some are shorebirds. Some are raptors. And some are wading birds. Blue heron. Snowy egret. Roseate spoonbill. Everglades National Park is a part-time home to sixteen species of wading birds. There are some amazing views of wading birds in the Everglades. In Florida Bay, what I think is the most striking thing is this broad expansive, beautiful water, the most scenic natural conditions ever and just hundreds of wading birds. Everglades National Park - a World Heritage Site, an International Biosphere Reserve, and a Wetland of International Importance - protects the largest subtropical wilderness in the United States, and is considered to be the most significant breeding grounds for tropical wading birds in North America. Because Everglades National Park was established for its flora and fauna, its wildlife primarily, which was the first park that was established for that explicit purpose. I mean, you know, there's no grand vistas in Everglades National Park. You know, there's no mountains, no grand canyons, none of that. But what there was, was these huge numbers of flocks of wading birds. And so, I think the Service understood the need to monitor that, because the numbers had already started to decline and they knew that. The story of wading birds in the Everglades is a story of bounty, decimation and rebirth. It is a conservation success story with caveats, and a lesson in ecology and hydrology. While we don't know how many wading birds existed in the Everglades prior to the arrival of Europeans, some experts have estimated as many as 2.5 million. But, by the early 1900s, it was a different story. The once-abundant wading bird population was decimated by a feather fashion frenzy, as well as the encroachment into their habitat. So disturbing was the slaughter of these birds and the destruction of their habitat by plume hunters that the state of Florida instituted a ban on plume hunting in 1900. In 1902 the Audubon Society in Monroe County hired Guy Bradley to protect wading birds and to arrest violators of the ban. A mere three years later, he was shot and killed while attempting to arrest a well-known plume hunter for killing egrets on Cape Sable. Further protection came with the advent of wildlife refuges, such as Pelican Island and Key West National Wildlife Refuge, specifically set aside to protect a colony of nesting birds. By the time Everglades National Park was established in 1947, wading bird numbers were down to about three hundred and fifty thousand - by the 1980s, they numbered even less. But in more recent years, wading bird populations have begun to rebound. Wading birds are, have shown definite improvements in the number of birds in the system, utilizing the system, and the number of birds nesting in the system. So, that's a vast improvement over what it was ten years ago. Is it anything like what it was historically? No! Will it ever be like that? Probably not. But it's certainly an improvement over what it was when, you know, wading birds in the, within the confines of Everglades National Park were probably, you know, maybe 3 or 4 percent of what they were historically. Spend a few minutes in the Everglades really looking, watching the wading birds and their unique behavior. Each has their own dance, their own strut; each hunting method a little different. There are tactile feeding birds like the white ibis, wood storks and roseate spoonbills, and there are visual predators like egrets and herons. The reddish egret abandons the stately nature of most other egrets by clumsily running around in shallow water scaring its prey from hiding places; plucking them from the water; or the ibis that uses its long, curved bill to probe the mud to capture insects and small fish along shorelines and shallows; or the great egret that gracefully and patiently stalks its prey, and, like a bolt of lightning, pierces the water snaring its meal. Can't tell an egret from a heron? Or a heron from a, heron? The great egret and the snowy egret look similar. But, a great egret has a yellow-orange beak and the all black legs. The snowy egret has an all black beak and black legs with yellow feet. You may find another white wading bird, often mistakenly called a great white heron. This is actually the great blue heron in a "white morph". Through genetic work, ornithologists no longer consider the great white heron to be a distinct species. Another heron often seen in the Everglades is the tri-colored heron. A tri-colored heron has a white belly whereas a little blue heron does not. Probably the wading bird that people most often want to see in the Everglades is wood storks . And they're the only North American stork; they're big. They have these great big sort of ugly flinty heads and a very unique habit of foraging. Wood storks, they're once again a Florida specialty. They do occur in other areas and they are expanding up into the southeastern U.S. Georgia, even North and South Carolina they occur now. But, they are something that you are most likely to see still in the Everglades. They're striking, being a large, fairly large wading bird. The most notable thing about them is when you get up close, the first thing people usually say is: "Haaa, that's an ugly wading bird!" They do have a, I guess, an unpleasant look to their skin on their head usually a bare head and neck; it's sort of blackish and almost woody-looking color. But they also have a white body and the trailing edge of their wing is beautiful black iridescent feathers. Another must see, of course, is the Roseate Spoonbill because they are absolutely gorgeous and many times of the year they are in breeding plumage in the Everglades and they have this beautiful flame/orange colored feathers that's just unforgettable. Snowy egrets are very commonly looked-after just because they're active and they have beautiful plumes, little white bird and very pugnacious, as well. Visit Snake Bight in Everglades National Park and you just might get a chance to see some of these wading birds in action. You might even see a flamingo or two! During the 1800s, large flocks of flamingos could be found in the Snake Bight area of Florida Bay, but the birds were relentlessly hunted for their meat, and all but disappeared after 1902. Today, individual flamingos or small flocks, presumably from the Bahamas and Caribbean, are occasionally spotted in the area. The status of many of these wading bird species is precarious. Roseate spoonbills are listed as federally threatened; wood storks are listed as endangered. And, all other wading birds have protected status within the state of Florida.The health of wading bird populations in Everglades National Park reflects the health of the Everglades. To monitor the health of the ecosystem, park staff have been tracking wading bird nesting populations using fixed-wing aircraft. Lori Oberhofer is a biologist with Everglades National Park. Between February and May, for 3 to 4 days a month and for 6 to 8 hours a day, she crisscrosses the park taking photographs of any wading bird nesting colonies she sees. Covering almost one point five million acres, Lori's flights take her across vast sawgrass prairies, cypress strands, mangrove coastlines and muck-filled swamps. This monitoring project has been conducted every year since 1985. We have almost a pure record going back to the 1940s. And the longer we continue monitoring these colonies, the more important this data becomes. We can see long-term trends over time. We're seeing some interesting trends now with how the colonies are moving into areas where they historically nested. Lori and her team are primarily concerned with the locations of the colonies and the species identification; but data collected on estimated sizes of those colonies, as well as data collected from areas surrounding the park, is proving to be equally important. We have a comprehensive program that counts birds from the Florida Keys through the central Everglades and then into Lake Okeechobee. So we have a very good handle on where birds are at any time in the breeding season and how their numbers are comparing with any previous year. Plume hunters were not the only reason wading bird populations declined. Early flood control measures and ensuring south Florida had an adequate water supply for its growing population also played a hand. It's the goal of the Comprehensive Everglades Restoration Plan, or CERP, to mitigate some of the adverse effects of these past water management actions by capturing fresh water that flows to the Atlantic Ocean and the Gulf and re-establishing a more historic flow of fresh water into the Everglades. If you drain the land too much, you end up with, not being able to produce the young fishes that the birds are going to eat. If you put too much water in the land and hold it there, the young fishes are eaten by the larger fishes. So, either extreme is bad for wading birds. Now we have two extremes going on, one of which is: a largely over-drained Everglades, like Everglades National Park and we have very much wetter, deeper areas like the water conservation areas, which are really good for large fish, but not necessarily good for small fish. Now that restoration of the Everglades has begun, resource managers, armed with one of the longest records of wading bird population distributions in the world, can more accurately correlate whether water management decisions are beneficial by measuring the effects on the fauna. As biologists have long understood, the health of wading bird populations is tied to the health of the overall ecosystem, especially the distribution, timing and amount of water flowing through the system. The water levels in the summer are high. That means that wading birds which have, are limited by leg length for foraging, have to find some place else to forage; they need shallow water to forage in. So they have to move someplace else. Water, fish, birds. It really isn't rocket science! It really isn't. It's pretty straightforward. You need, wading birds have to have concentrations of food at the right times of the year to nest. If we can restore the Everglades, in a way that gives them the functional parts of the ecosystem that they need, I think there's a really good chance that we're going to see a very large increase in the wading birds in the Everglades. In general, I think we've actually seen a pretty large increase, especially in the last decade. We've seen an increase in great egrets, white ibises, wood storks, of three to five times their breeding population. That's a really big increase and that's something that I think is great news and something that most of the population really doesn't really know about. The best way to see wading birds in Everglades National Park is by canoe or kayak although a hike along the Anhinga trail is a hot spot for wading bird sightings. These amazing birds are also often seen in the sawgrass prairie just off the main park road or at one of many scenic viewing areas like Paurotis Pond, Mrazek Pond or Eco Pond. Bring some binoculars, bring a bird guide, or just bring a love for the outdoors and a curiosity for the strange behaviors and quirky characteristics of south Florida's wading birds. Seeing an enormous flock of 500 ibises get up out of the marsh at once, is something that really does take your breath away. You don't get many chances to get your breath taken away these days. ♪♪ When one thinks of the Florida Keys National Marine Sanctuary, they often envision magnificent coral reefs with vibrant colors and ornate tropical species. But these areas are only a fraction of the area within Florida Keys National Marine Sanctuary boundaries; less than one percent. The Sanctuary protects the entire seafloor of the Florida Keys, and all the habitat types found there, including sand flats, hard bottom communities, seagrass beds, and the coral reef. Studying the bottom or benthic community over time gives scientists and managers critical information on ecosystem condition and how living resources are changing, for better, or worse. The seafloor and the benthic community of animals and plants that it supports are the foundation of the coral reef ecosystem in the Florida Keys. A way of looking at the sea bed or the sea floor is it really is, it's kind of like a barometer of what's going on, especially in the water itself. So, that's kind of the easiest way to think about it, so it's kind of an indicator for what's going on with water quality, what's happening in terms of, for example, fishing, if organisms are being removed, that gets reflected in the benthos. So benthic organisms, the things that are on the seabed, kind of, they kind of integrate all that. Mark Chiappone and his team, led by Dr. Steven Miller, Senior Research Scientist, Nova Southeastern University Oceanographic Center, began sampling the benthic environment across the Florida Keys annually in 1998. NOAA has funded much of this work, through their Coral Reef Conservation Program. Logistical support has been provided by the Florida Keys National Marine Sanctuary and Biscayne National Park, as well as the Florida Fish and Wildlife Research Institute. We will mark it with a diver flag. And so we have these divers that descend down to the base of the diver flag and then, basically, 2 fifteen meter or 50 foot transect tapes are spooled out basically survey on each side of the transect tape. And then we're surveying numbers, we're identifying the organisms, how many of them there are, their sizes, and then, in the case of corals, also, what their condition is. It's kinda like a diagnosis, it's as if a patient went to a doctor's office, how are they feeling, you know, how they look, and so, that's basically the data grab. The survey measures abundance of species, sizes of species, condition of species, and location. These numbers combine to provide a snapshot picture of the community structure and health of the coral system in the Florida Keys. Our program looks at not just corals, but pretty much just about everything that's attached to the sea bed. So that includes, you know gorgonians and sponges; we look at certain types of mollusks, including queen conch; we look at the urchins and so a variety of different benthic invertebrates. The team also looks at seaweed cover. Almost like the U.S. Census Bureau covering rural areas, suburban areas, cities; some of Mark Chiappone's survey areas are seemingly empty, others are teeming with life. But the ecosystem Mark is monitoring is much different than the one of years past. The overall snapshot includes results that range from dramatic change and decline, to places that still look in relatively good condition. Many of the historically abundant species and biogenic habitats had already been severely altered or reduced when the Sanctuary was designated in 1990. Resource managers are working to conserve pieces of that former ecosystem so it can be restored to an improved state. This research will help us do that. What's changed the most are the offshore reefs, where we previously had amazing stands of elkhorn and staghorn coral, both of which are largely gone. One of the methods that has already proven successful in managing this precious resource is the establishment of marine zones. Like areas set aside on land for conservation and separation of uses, setting aside areas in the oceans for conservation and the separation of uses is working to protect habitats and marine life. For example, we have zones in the Sanctuary that allow diving and snorkeling, no consumption activities. And then other areas which we call general use areas are areas where people can go fish, they can spear fish, they can do a lot of things that you maybe you cannot do in the diving and snorkeling areas. Marine zoning is critical to achieving the sanctuary's primary goal of resource protection and ensures that areas of high ecological importance will evolve in a natural state, with minimal human influence. ♪♪ Every research program conducted within the Florida Keys National Marine Sanctuary is designed to answer an important question that helps ecosystem managers understand the system better. Until this monitoring program was implemented, there was no research that showed how the benthic community responds to the combined influence of environmental changes and management actions across all habitat types and how protection through marine zoning has affected the benthic community over time. It's important for managers to understand where things might occur; what density they occur in? Are they occurring inside or outside zones, for example. If we start seeing that there are a lot of recruits, little small corals, occuring inside or outside the marine zones we would like to know more about why. Why is that happening? This research is designed specifically to help us answer those questions. This research directly informs the Sanctuary's science-based management decisions. The Sanctuary's advisory council and public working groups have used information from this long-term study to help draft recommendations for the future of Sanctuary rules and marine zones. Every 5-10 years the Sanctuary is required to update its regulations, its management plan, and this science feeds right into that development process. We incorporate science-based decision making into the way we approach marine zoning and how we manage the human interaction with the ecosystem. Mark and his team have sampled roughly 1600 locations throughout the Florida Keys ecosystem from Miami to the Tortugas and two very different stories have emerged from their work. There's good news and there are some things that are not so positive. On the up side, you know, there are still lots of places both in the Sanctuary and in Biscayne National Park that are really spectacular, spectacular in the sense of you dive, you jump in and there's 30, 40, 50 percent of the bottom is covered with live coral and they're big and they're healthy and there's a lot of reef and there's lots of fishes swimming around and most of these places are not heavily visited. They don't have mooring buoys and they're not well known. So there's still a lot of spectacular places out there. One of the "downsides" that Mark and his team detected was the massive loss of staghorn and elkhorn corals. Since the 1970s, these two important reef-building corals have suffered an estimated 95% decline in the Florida Keys. Staghorn and elkhorn corals were not the only species that the surveys determined were in trouble. Long-spine sea urchins, also called by their genus name, Diadema, were decimated by a disease that wiped out populations Caribbean-wide in the mid 1980s. One day these urchins were there and the next day they were not. And, they exhibited these disease-like symptoms that were, and it was 100% mortality when an urchin got infected. Their spines literally started to fall off and then their "tests", which is their body, literally kinda peeled apart, almost like an onion or an orange. So, that happened here in the Florida Keys. The first report of that was back in July of 1983. Long-spine sea urchins were and still are important herbivores contributing essential grazing activities to the ecosystem The loss of urchins was significant for reefs because it meant that less grazing of algae on hard surfaces was taking place at the reef. And so, two kinda group of organisms that are, that really tend to battle it out are the corals and the algae. And so, and there's and the corals have kind of a losing proposition sometimes because they don't grow as fast as most of the seaweeds, but as long as they can maintain their live tissue, then they have a fighting chance. So the reason that these herbivores, such as Diadema and Parrot fishes are so important, is they help to keep basically, they help to keep the seaweeds in check. And that provides one more justification for the long-term studies that are conducted in the Florida Keys. With data that covers decades, trends can be detected and causal relationships proven. The loss of one species affects the health of the entire ecosystem; and the efforts of one person can affect the future of our entire environment. Sometimes we have to make, we have to make sacrifices and maybe not do everything that we wanna do whenever we wanna do it. And a good example of that is in this system. For example, I love to fish and I love to eat seafood, but I know the reality of what it takes to get certain products, not all but certain products, to the table. And I know the damage that it causes, and so, it's all about making informed choices. Valid and substantiated data allow resource managers and the public to make informed choices needed to protect the ecosystem. It takes time, effort and resources for scientists to collect these data, but the information gained from such field work is the cornerstone for developing plans to protect and conserve the natural world around us. ♪♪
B2 中上級 水路 第271話「エバーグレーズの渡り鳥と底生生物の研究 (Waterways Episode 271 - Everglades Wading Birds & Benthic Studies) 69 4 richardwang に公開 2021 年 01 月 14 日 シェア シェア 保存 報告 動画の中の単語