Areas that could not be drained were treated with copper sulfate to poison the snails.ġ938: Leonard Erwin Swanson of the Bureau of Animal Industry showed that liver fluke eggs required an abundance of oxygen to develop to the infective stage. Transforming the environment in this way prevented snail propagation.
The work consisted of draining swampy lands and cleaning streams to destroy the snails that served as intermediate hosts of the liver fluke Fasciola hepatica. They demonstrated that fluke eggs in meat animal livers were killed by exposure to high (116 to 121 degrees Fahrenheit) and low (0 to 38 degrees Fahrenheit) temperatures.ġ936: An allocation of emergency funds enabled the Zoological Division to start a large-scale campaign for liver fluke control in four western states: Washington, Oregon, Idaho, and Utah. Research in the Atlantic Ocean has found that as many as 85 percent of humpback whales have been entangled in fishing gear at least once in their lifetime! Making sustainable seafood choices is one way that you can personally reduce your impact to whales and other wildlife.Ventral view of Fasciola hepatica (common liver fluke), 1898ġ929: The Bureau of Animal Industry’s Zoological Division collaborated with the Meat Inspection Division to test the effect of temperature on liver fluke eggs. Whale species that travel along the coast, like humpbacks, are especially affected because fisheries activities tend to be highest near the coast. We also use our whale watching cruises as an opportunity to collect photographic identification data on marine mammals, which we share with our network of researchers, including Happywhale.Īdopt a humpback whale: Symbolic whale adoptions make great gifts and the funds directly support our work to study and protect whales and other ocean wildlife.Ĭhoose sustainable seafood: Entanglement in fishing gear is one of the leading causes of injuries and mortalities in whales, dolphins, and porpoises.
#Fluke definition free#
Join us on a whale watching trip: Your participation on our whale watching trips helps fund conservation efforts, such as our Critter Scholars Program, which delivers life-changing ocean experiences free of charge to underserved student groups and communities in the San Francisco Bay Area. © Rhys Watkin Ways You Can Help Humpback Whales and Other Ocean Wildlife
Read the captions to learn about the distinguishing characteristics that are visible in each photo.Įxamples of fluke deformities, likely due to entanglement in fishing gear. Following are humpback whale fluke identification photos that we’ve captured. The best way to learn about the different characteristics that help scientists identify whales by their flukes is to look at some examples. Let’s Look at Some One-of-a-Kind Whale Flukes The trailing edge can also be used to identify individuals by the unique ridges, notches, scars, and deformities. The underside of the flukes have unique black/dark gray and white pigmentation patterns, and may have scars and deformities from barnacles, entanglements in fishing gear, and even from attempted predation. Humpback flukes can be up to 18 feet wide, with a serrated “trailing edge” (the end of the flukes at the farthest end of the whale), and pointed tips. Humpback whale flukes, like all cetacean flukes, have two lobes (or flukes): a left lobe (or fluke) and a right lobe (or fluke). Whale tails, called flukes, have unique characteristics that can be used to identify individual whales, helping researchers to study and monitor individuals and populations over time.
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