Florida manatee (Threats – conservation)- Part three/three

Video courtesy: the State Archives of Florida, USA

The title of this video: “Florida Silent Sirens: Manatees in Peril” and was filmed during 1980s

The caption of the video states: “This is an excellent film about the plight of the endangered manatee. It is narrated by Leonard Nimoy and is full of beautiful underwater photography. It shows tracking by radio collar, injured manatees and manatee interaction with people”.

Florida Manatee (Part 03)
 
The following review is the responsibility of Dr. Abdel Rahman El Gamal, Founder of the video channel/website
Threats: Human-related activities represent the main threat for manatees. These mainly include hunting, habitat destruction, adverse environmental conditions, ship strikes and others.
Hunting: Manatees were extensively hunted by indigenous people in the 18th and 19th centuries. Manatees were hunted for their meat, fat, and tough hides, Native Americans made shields, canoes, and shoes. Afterwards, manatees were hunted for their bones by Native Americans who used the ground bones to treat asthma and earache. 
Although there is no precise census of Florida manatees, some estimates of less than 2,000 manatees remaining in the United States, while other optimistic views estimate today’s population of Florida manatee at approximately 6,000 individuals.
 Habitat loss and destruction: As the human population increases along with the overall development in Florida (the home of this species) continues, manatee habitats were gradually lost especially when the damage reached the seagrasses (manatees’ main food source).
A key disturbance in water quality may be represented in the less availability of warm water from natural springs that provide manatees with a shelter during cold weather bearing in mind the sensitivity of manatees to cold water which may become fatal or even dangerous at temperatures below 20 degrees Celsius. In that regard, natural warm springs were used to keep manatees warm during winter and along with the reduced number of these springs, most manatees rely on the warm water outfall that power plants produce. However, if plants are shut down for whatever reason, manatees would be left and impacted by the cold.
Ship strikes: The threat of this issue is based on the slow-moving and near-surface swimming nature of the manatees that were involved in many reported violent collisions with propeller-driven boats and ships, leading frequently to maiming, disfigurement, and even death. This type of threat is typically identified by spiral cutting propeller scars on their backs. In severe collisions, manatees have been cut in half by large vessels like ships and tug boats. For survivors, the cuts due to ship strikes lead to infections, which can prove fatal. Studies show that a manatee may not be able to hear the approaching boats when they are performing day-to-day activities or distractions. It may worth noting that the threat from watercraft strikes accounts for about a quarter of Florida manatee deaths. In 2009, of the 429 Florida manatees recorded dead, 97 were killed by commercial and recreational vessels. It seems that number of collisions with motorboats continues to increase at an alarming rate. According to the Florida Fish and Wildlife Conservation Commission, 218 dead manatees were counted over the first six months of 2014. Of the 218 killed specimens, 18% died from encounters with boaters.
Red tide: Red tide which is a bloom of dinoflagellate producing toxins was responsible for incidences of manatee deaths. There are reports on 151 manatee deaths due to red tide in 1996.
Miscellaneous threats: these include variety of threats including occasional ingesting fishing gear (hooks, metal weights, etc.) while feeding. In some situations, ingesting some foreign materials such as monofilament line or string can block a manatee’s digestive system and may slowly kill it. Manatees are occasionally killed by entanglement in fishing gear, primarily crab pot float lines. Moreover, harassing and disturbing the manatees by human has been reported. According to the United States Fish and Wildlife Service, approximately 99 manatee deaths each year are related to human activities. In January 2016, there were 43 manatee deaths in Florida alone.
According to IUCN documents, the Florida manatee subspecies is listed as Endangered in 2008 on the basis of a population size of less than 2,500 mature individuals and the population is estimated to decline by at least 20% over the next two generations (estimated at ~40 years) due to anticipated future changes in warm-water habitat and threats from increasing watercraft traffic over the next several decades.
Conservation measures
Legal protection: According to Florida as well as the federal government, Manatees are classified endangered and hence it is illegal to injure or harm a manatee.
Protected Areas: Manatees have been protected for an unusually long time. The English declared Florida a manatee sanctuary in the 1700s and hunting manatees was prohibited. Establishment of more protected areas for manatees especially in the natural warm springs would serve an ideal warm shelter that the animals warm during winter. Under the Endangered Species Act, the protection of manatee’s critical habitats should be ensured.
Speed boats: Setting speed limits in waterways can help manatees by giving them enough time to avoid collisions and reducing the severity of collisions when they do occur. In particular centers, ships used are propelled only by water jets to protect manatee populations that occur in such regions.
Tourism: Manatee-watching tourism provides local people with financial incentive that encourage them to preserve the manatees and so tourists who are fond of this beautiful animals continue to visit and watch their grazing in their natural habitats. In fact, manatee-watching tourism has been found a very successful conservation action. In that regard, precautions should be in place to assure that boats carrying manatee watchers do not turn into additional threat to the animal populations.
Research: More scientific research is needed to understand manatees and their needs especially on priority topic such as their calving and feeding behaviors.
Citizen Involvement: Citizens are helping to preserve manatees through various initiatives which often vary from the formal approaches. Local people may act effectively in creating awareness regarding the conservation of manatees as well as contacting concerned agencies and in some situations they have created manatee’s defenders. The involvement of citizens proved to helpful to scientists, governmental agencies and utility companies providing them with their opinions to ensure that development plans need to consider the manatee populations and ensure that such plans don’t endanger these marine mammals.
Care facilities: There are a number of manatee rehabilitation centers and critical care facilities in the United States along with zoos and aquariums. Through these centers and facilities, a decent number of manatees have been helped and released.

Note: If you interested to know more on this interesting animal, you are welcome to visit the first part (video) and the second part of the same title on behavior and reproduction.

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