Iycee Charles de Gaulle Summary Species Conservation Report Of The Florida Manatee Biology Essay

Species Conservation Report Of The Florida Manatee Biology Essay

The Trichechus manatus latriostris ( T.m.latirostris ) is an aquatic mammal listed as endangered on the IUCN Red List. The Trichechus manatus is situated chiefly in the United States, and is peculiarly abundant around the seashore of Florida ( Figure 1 ) . The West Indian Trichechus manatus is divided into 2 sub-species ; the Florida Manatee ( T.m.latirostris ) and the Antillean Manatee ( T.m. manatus ) . The West Indian Manatee species as a whole is listed as vulnerable on the IUCN Red List. Ecological preservation is the effort to protect species on Earth from hazard and extinction ( Allendorf FW, 2007 ) . Most preservation attempts have focused on the Florida Manatee and they are intensely studied in the south-east provinces of America. The coinage ‘s chief menace is human activity, along with home ground alterations and low generative rates ( Deutsch CJ, 2008 ) .

The West Indian Manatee is one of the 4 staying species of the Sirenia, the others being the Dugong ( Dugong dugon ) , the West African Manatee ( Trichechus senegalensis ) and the Amazonian Manatee ( Trichechus inunguis ) ( Bossart GD, 1999 ) . These other species of Sirenia have similar menaces and preservation jobs to the Florida Manatee. The Sirenia are believed to hold evolved from four footed land mammals, with the elephant being their supposed ascendant. Fossil records found that both Manatees and Dugong dugons were present in the West Atlantic and Caribbean, but the Trichechus manatuss prevailed over the Dugong dugons in these countries due to better adaptative characteristics for eating the more scratchy flora ( Van Beter VB, 1989 ) .

T.m.latirostris are big aquatic mammals which can turn to 13 pess long and weigh up to 3000 lbs. They range from Grey to brown in coloring material and are sparsely covered by all right hairs, with thicker beards on their faces. Manatees are seal-like in description ; they are insulated by great sums of blubber with big level dress suits which they use to impel themselves through the H2O. T.m.latirostris have 2 fins used for balance, with 3 or 4 nails at the terminal of each one. Their tegument is finely wrinkly and cleaned by animals that eat algae and other growings off the tegument ‘s surface. T.m.latirostris is really heavy boned with no marrow pits in their ribs and limbs. It has a bulblike face with little broad eyes with an interior membrane for protection against foreign organic structures. It has a big neb like nose with little anterior nariss dwelling of valves which are tightly closed when underwater ( Van Beter VB, 1989 ) . The Florida Manatee is unusual in that its dentitions are continuously replaced throughout its life-time. New grinders grow at the dorsum of the jaw and are easy worn down as they move frontward to the forepart and autumn out. The Manatee ‘s encephalon is considered to be comparatively little in relation to its organic structure size ( Van Beter VB, 1989 ) .

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T.m.latirostris herbivorous diet consists of vascular aquatic flora from the shallow Waterss of their home ground. They are devouring feeders and devour about 15 % of their organic structure weight daily ( Van Beter VB, 1989 ) . T.m.latirostris are indiscriminate in their pick of workss, although they appear to prefer submersed workss, eating seagrass, Trichechus manatus grass and shoalgrass, merely fall backing to feeding on drifting flora and algae when these are non available ( Hartman DS, 1979 ) . The Manatees ability to replace its dentitions is thought to be an adaptation to their diet as sand from the sea floor is frequently assorted with the workss they eat doing them scratchy ( Van Beter VB, 1989 ) .

The Florida Manatee lives in a really specific home ground carry throughing certain standards. Surveies have shown that the temperature, deepness, flora, salt, tides, currents and weather all have to be within certain degrees for the Florida Manatee to shack at that place ( Hartman DS, 1979 ) . The temperature of the H2O is highly of import to Florida Manatees due to their low metabolic rates and high thermic conductance ( Marmontel M, 1997 ) . They are seasonal migratory animals ; when Waterss drop below 20 & A ; deg ; C they migrate south to of course warmer Waterss. They have besides been observed migrating to unnaturally warmer Waterss, peculiarly to H2O mercantile establishments near powerplants. The bulk of Manatees tend to return to the same warm H2O sanctuaries each twelvemonth ; the most popular around Florida are Crystal River and Blue Spring. When temperatures rise, most Trichechus manatuss disperse back to their usual homes ( Deutsch CJ 2008 ) . The deepness of the H2O is understood to be one of the most of import factors for the Trichechus manatus. T.m.latirostris prefer a deepness of 2 to 3 meters for both resting and for traveling, though they will venture into shallower Waterss to acquire to H2O of their preferred deepness if the distance is short. A Trichechus manatus will merely plunge into deep H2O to avoid danger ; the chief ground for their abomination of deep H2O is thought to be the higher force per unit area degree. Tides are hence an influence on the location of Trichechus manatuss ; low tides prevent them from accessing countries closer to the shore, but they take advantage of high tides to make workss which are usually unaccessible to them ( Hartman DS, 1979 ) . Manatees move between fresh and seawater, nevertheless, they are believed to prefer fresh H2O countries as they are most frequently seen in rivers and estuaries and are ne’er excessively far from a fresh water beginning. Manatees tend to avoid countries with fast currents, preferring to swim nearer the shore than against fast moving H2O, nevertheless they have been observed swimming easy against the current, taking their clip instead than using any more attempt than is necessary ( Hartman DS, 1979 ) .

Florida Manatees spend their clip feeding, resting and traveling and are really mellow, slow-moving mammals. Bing mammals, T.m.latirostris have to come up to take a breath air every 3 to 5 proceedingss, although when resting they can remain underwater for up to 20 proceedingss and when they expend tonss of energy they submerge around every 30 seconds ( Salvage the Manatee, 2010 ) . Manatees travel at velocities of 3 to 5 stat mis per hr, although they can make 20 stat mis per hr for short distances. They are really graceful, frequently executing athletic somersets, turns and bends underwater ( Taylor D, 2004 ) . Manatees on a regular basis travel entirely during summer, though it is non unusual to see larger groups, peculiarly in migration safeties ( Deutsch CJ, 2008 ) . Manatees have a specific niche within the aquatic community as they help to distribute workss and wildlife through consumption and elimination and they besides aid preservation of animals which depend on them for nutrient and protection ( Goedeke TL, 2004 ) .

Female Trichechus manatuss reach sexual adulthood at around 3 old ages old and can give birth at 4. However females at this age are frequently excessively inexperient to look after the calf and most Trichechus manatuss do non reproduce until they are 6 to 10 old ages old ( Van Beter VB, 1989 ) . Male Trichechus manatuss reach sexual adulthood earlier than females, between 3 and 4 old ages old. When the female ‘s oestrous rhythm begins, males form a coupling herd which can last for up to 4 hebdomads. Males articulation and leave the herd day-to-day and intense competition in undertaken to copulate with the female ( Deutsch CJ, 2008 ) . The female is persistently pursued and efforts to fly until she has selected a suited spouse. Consecutive sexual intercourse is understood to happen during this period, with the older and stronger Trichechus manatuss contending off the competition for their coupling rights. Manatees do non organize lasting bonds with spouses and sexual intercourse is undertaken merely briefly ( Van Beter VB, 1989 ) .

The Trichechus manatus gestation period is between 12 and 13 months. T.m.latirostris give birth to a individual calf, twins are highly rare but do on occasion happen. Manatees are non thought to hold a specific coupling period and hence calving occurs throughout the twelvemonth. They give birth at intervals of between 2 and 5 old ages ( Van Beter VB, 1989 ) . Calfs are born mensurating 4 to 4.5 pess in length and weighing approximately 66 lbs. The female Trichechus manatus has really rich milk incorporating tonss of proteins, fats and salts. The calves ab initio suckle milk from their female parent ‘s nipples, feeding underwater for up to 3 proceedingss at a clip. Calfs are born with grinders and get down feeding on workss a few hebdomads after birth when their dentitions begin to travel frontward at a rate of 0.03 inches per month. Florida Trichechus manatus calves are dependent on their female parents for up to two old ages, and tend to shack near to her throughout their life ; research suggests this propinquity allows the immature to larn migration paths and good winter safety countries. T.m.latirostris can populate for up to 50 old ages ( Van Beter VB, 1989 ) .

Populations of T.m.latirostris are non easy to gauge due to tracking troubles, but the figure of Florida Manatees in 2001 was estimated at around 3,300. Having less than 2,500 grownup persons in a population of a species is considered as endangered on the IUCN Red List. The Florida Manatee ‘s position changed from vulnerable to endangered in 2007. The population figure was estimated utilizing range-wide synoptic studies which have been carried out every twelvemonth since 1991. The copiousness information is collected during winter when Trichechus manatuss tend to garner in the same warm H2O locations ( Deutsch CJ, 2008 ) . The Numberss estimated merely includes Trichechus manatuss within the proving country therefore the copiousness informations can non be to the full relied on ( Craig BA, 1997 ) .

The Florida Manatee can be divided in 4 subpopulations, and the synoptic study of 2001 estimated the Numberss within these different populations.

Subpopulation

Location

Estimated Numberss 2001

Atlantic

East seashore of Florida

1,444

Upper St. Johns River

South of Palatka

112

Northwestern united states

Gulf seashore between Pasco-Hernando county line and Louisianna

377

Southwest

Between Pasco-Hernando county line and Whitewater Bay in Monroe

1,367

( Deutsch CJ, 2008 ) .

A Population Viability Analysis ( PVA ) Model, which is the most suited theoretical theoretical account in this case, was applied to the Florida Manatee population in 2006, which allows an estimate for future Numberss to be established. The statistical theoretical account indicated that there is a 55.5 % opportunity of a 20 % diminution in the following 2 coevalss ( a coevals equals around 20 old ages ) and a 12.1 % opportunity of a 50 % diminution within the following 3 coevalss ( Deutsch CJ, 2008 ) . Annual mortality of T.m.latirostris is highly high and although decease rates are thought to be diminishing, a record figure of Trichechus manatus deceases have already occurred in 2010. The figure of deceases recorded this twelvemonth in Florida by the 30/09/10 was 656, higher than the record of 429 deceases in 2009, which is an estimated loss of 13 % of the Florida Manatee ‘s minimal population ( Trip K, 2010 ) .

The chief menaces to T.m.latirostris are both natural and anthropogenetic. Human activity, habitat loss, clime alteration and slow reproduction rates are the biggest menaces presently confronting the Florida Manatees. The biggest menace from world is watercraft hits. Estimated figures for the sum of Trichechus manatus deceases that can be attributed to hits with boats are more than 30 % of one-year mortalities. Boats can do both blunt and crisp injury depending on which country of the boats the Trichechus manatus impacts on, but both can be fatal ( Nowacek SM, 2004 ) . Strict velocity limitations in Manatee abundant countries have reduced the sum of boat-related deceases as the Trichechus manatuss have more clip to travel out of the oncoming boat ‘s way and mulcts are issued to any vas interrupting the velocity bound. The Trichechus manatus safeties of Barge Canal and a 4.5km subdivision of Sykes Creek were observed before and after velocity limitations were put into topographic point. Merely one decease was recorded in the safeties during the 42 months following the velocity limitation, compared to 8 deceases in the old 42 months ( Laist D, 2006 ) . Other anthropogenetic menaces are entanglement in angling lines and cyberspaces, oppressing or asphyxiation by going trapped in inundation control measures such as inundation Gatess, H2O pollution and consumption of or web with cast-off litter ( Bossart GD, 1999 ) .

Climate alteration would hold a immense consequence on Florida Trichechus manatuss, peculiarly due to their temperature demands. Climate alteration is besides linked to the increasing badness of coastal storms. Hurricanes are already a regular happening on the south-eastern seashore of the U.S and do a big figure of manatee deceases each twelvemonth, straight every bit good as indirectly. Indirectly, the Trichechus manatus ‘s home grounds are frequently disrupted along with their nutrient beginnings ( Langtimm CA, 2003 ) , and general alterations in flora could do famishment or forced migration to more works abundant countries. The slow reproductive rates are another menace to the Florida Trichechus manatus Numberss, along with high mortality rates in calves. The decease of the female parent leaves the calf defenceless ensuing in malnutrition, boat hits or timeserving disease. Disease and cold related deceases besides contribute to one-year mortality ; ruddy tide events in peculiar have wiped out big proportions of the Florida Trichechus manatus population in the yesteryear ( Bossart GD, 1999 ) .

Social perceptual experience of Florida Manatees has significantly changed over the old ages. Historically, Trichechus manatuss were hunted and killed for athletics and meat until involvement in them grew and people began to contend for preservation. State Laws were passed protecting the Florida Manatees and the harvest home of Trichechus manatuss was banned in 1893, nevertheless this jurisprudence was virtually ignored and the killing continued. Historic myths about the animals were the cause for a batch of poaching ; for illustration, one myth claimed Trichechus manatuss ate big sums of fish, and hence fisherman thought they were plagues ( Goedeke TL, 2004 ) . More Torahs were passed and Florida Manatees became protected under the Marine Mammal Protection Act of 1972 and the Endangered Species Act of 1973. Unfortunately, these Torahs were besides uneffective. It was non until the 1970s when the Save the Manatee Club was founded and the Florida Manatee was named as the State Marine Animal by the FMSA ( Florida Manatee Sanctuary Act of 1978 ) that the Torahs became effectual. The chief precedence became to educate and increase public consciousness of the Florida Manatee ( Goedeke TL, 2004 ) . By the 1990s fundraising by trading Trichechus manatus merchandises was doing a important difference. The societal perceptual experience of T.m.latirostris changed from cryptic monster to being a soft challenging animal. Manatee ‘adoption ‘ plans were introduced and are really popular, with people patronizing and calling an single Trichechus manatus, raising financess for Trichechus manatuss in the procedure. Greater public consciousness led to the deceases of single Trichechus manatuss being extremely publicised and focused upon in newspapers and telecasting studies, foregrounding the high decease rate of Florida Trichechus manatuss ( Goedeke TL, 2004 ) .

Figure 2. Photograph of a Diver with a Young Florida Manatee ( sourced from Tampa Bay, 2009 )

The increasing popularity of wildlife touristry and ‘swimming with animate beings ‘ has besides helped to raise money and consciousness for Florida Manatees. Close to 100,000 tourers visit Crystal River in Florida every twelvemonth to swim and interact with the Trichechus manatuss. Florida Trichechus manatuss are really accessible and allow visitants to acquire up near and interact with them ( Figure 2 ) . Manatee brush boat Tourss have besides become really popular in the past few old ages ( Sorice MG, 2006 ) . Surveies have looked at both the positive and negative effects of this type of touristry. The primary concern was against alterations in the Trichechus manatus ‘s behavior and modus operandis. Human interaction was observed to excite the Trichechus manatuss and do exhilaration and playful behavior. This could hold a positive consequence as it could take to greater interactions within the species and hence increased reproduction. However excessively much energy outgo could hold negative impacts and impact the Trichechus manatus ‘s behavior. Surveies have besides discovered that Trichechus manatuss are more sociable in the forenoon and disfavor aqualung equipment due to the noise and bubbles. Therefore some direction has to be undertaken to make up one’s mind on appropriate sums of interaction between the Trichechus manatuss and people, every bit good as the times and ordinances about equipment that can be used ( Sorice MG, 2006 ) .

The preservation of Florida Trichechus manatuss has come to be of overriding importance. Manatee populations will go on to diminish if nil is done to protect them. MPPs ( Manatee Protection Programmes ) have been developed in 13 counties of Florida. These programmes include limitations and Torahs put into topographic point to protect Florida Trichechus manatuss. They province strict regulations on any farther break to manatee home grounds including the enlargement or development of boating installations. The programs include purposes to significantly diminish and finally halt the human deaths due to hits with watercrafts. Increasing public consciousness is another portion of the MPPs, originating the show of postings informing of the protection patterns of Florida Manatees. The program besides aims to finally diminish the sum of Trichechus manatus deceases in general and to conserve and protect these endangered animals ( Indian River County, 2004 ) . These programs are a starting block for the hereafter of Florida Manatees, and although protection has been put in topographic point, mortality rates of T.m.latirostris are still at a record high and more must be done to forestall their entire extinction