Background of the Study
Six of the seven species of sea polo-necks are listed as Endangered or Critically Endangered. In the Pacific part, leathery turtles polo-necks are heading for extinction and in the Mediterranean, green polo-neck Numberss have plummeted. Sea turtles appear to hold the possible to reproduce copiously by females can put 100s of eggs in one nesting season. But even under natural conditions, comparatively few immature polo-necks will last during their first twelvemonth of life.
The sea polo-neck hatchling stage is believed to be the life phase at highest rate of mortality, as scientists estimate that merely a few per 1000 hatchlings manage to last to make sexual adulthood ( Limpus, 1985 ) . In some utmost instances, the figure may be merely a few per 10s thousand ( Frazer, 1986 ) . Therefore, research on sea polo-neck hatchlings, peculiarly look intoing factors that may act upon their opportunities of endurance is important for sea polo-neck preservation.
Sea turtle hatchlings are peculiarly vulnerable to predation, both during the crawl ( from the nest to the sea ) and in the initial stage of their swim off from the beach when they cross shallow, marauder rich near-shore Waterss ( Salmon and Wyneken, 1987 ; Pilcher et al. , 2000 ; Gyuris, 2000 ) . The initial swimming stage lasts for about 24 hours ( Wyneken and Salmon, 1992 ) and it is characterized by about uninterrupted ‘frenzied ‘ swimming, which facilitates the rapid motion of hatchlings off from shallow near-shore countries ( Wyneken, 2000 ) . Factors which confound or delay the completion of this stage may significantly increase hatchling mortality ( Whelan and Wyneken, 2007 ) .
Hatchlings that do win in making the sea after enduring a drawn-out period in the nest or prolonged periods on the beach due to freak out hold been shown to compromise the manic swim offshore. Lorne and Salmon ( 2007 ) reported hatchlings that have completed offshore crawls were able to point off from shore in the absences of moving ridge cues ; whereas those placed in the sea after two hours of freak out were unable to make so. Furthermore, hatchling activities and swim velocity are known to diminish with increased keeping clip after outgrowth ( Pilcher and Enderby, 2001 ) .
During the first twelvemonth, many species of sea polo-necks are seldom seen. This first twelvemonth is termed as the “ lost twelvemonth ” to stress this spread in sea turtle life history information. From this minute on, observation becomes highly hard to the research workers. Carr ( 1952 ) claimed that the location of hatchling and post-hatchling polo-necks travel and what they do during their ‘lost ‘ old ages as critical for the Restoration of green polo-neck populations. Carr ( 1952 ) besides pointed out the hopelessness of preservation and Restoration of sea polo-necks until the basic biological science of the species is better known.
Taking all these fortunes into history, it is really importance to do every hatchling come ining the H2O column. These hatchlings have to be every bit healthy as possible and had higher opportunities to last the long swim in front. If hatchlings are compromised during this important phase they will hold a reduced opportunity of making maturity.
Throughout the universe, green polo-neck ( Chelonia mydas ) population have experienced important diminutions over the past 100 old ages, particularly due to habitat debasement ( change or devastation ) among other grounds as reviewed by Lutcavage et Al. ( 1997 ) . Hence, the green polo-neck is presently recognised internationally as species of preservation concern and in 2002 was placed in the IUCN ( World Conservation Union ) Red List of Threatened Animals. Therefore, there is active direction of sea polo-neck rookeries in many parts of the universe, including motion of whole clasps of eggs into hatcheries. However, the resettlement of clasps should be undertaken merely if by go forthing the clasps unmoved ( undisturbed ) , will ensuing their devastation ( Mortimer, 1999 ) .
1.2 Justification of the Study
There are two methods used to incubate eggs clasps of sea polo-neck in Malaysia which are the unmoved and ex-situ patterns. The first method, known as unmoved method, is a pattern where the nest is marked and left undisturbed to incubate of course after laid by females. Once hatched the hatchlings from unmoved nests crawl downhill towards the H2O line.
The 2nd method was the resettlement of egg clasp instantly after egg puting known as the ex-situ method. This method is normally applied to protect clasps from flood of sea H2O if the nest is located excessively close to the high tide grade, or from predation by worlds or other animate beings. Relocated eggs will be buried in a protected beach hatchery or in a Styrofoam boxes. Upon outgrowth, hatchlings will be collected and released at a certain point on the nesting beach.
Majority of the sea polo-neck preservation in Malaysia are rehearsing ex-situ egg incubation method. Sea turtle nests are transferred in a protected beach hatchery. In some instances, the nests will be incubated in Styrofoam boxes. Even though ex-situ is non recommended in sea polo-neck preservation, in certain instances this method is used when some fortunes occurred that do non let the usage of the hatchery. For illustration, Cherating Turtle Sanctuary in early 2009, the hatchery was still under redevelopment, ensuing in the usage of Styrofoam boxes. In the Geliga and Kemaman sanctuaries, they had to incubate eggs in Styrofoam boxes because deficient financess were available to pull off the hatchery.
In the interim, merely Redang Island sanctuaries keep rehearsing unmoved incubation method. Three nesting beaches in Redang Island are Mak Kepit and Mak Simpan managed by Department of Fisheries Terengganu and Chagar Hutang managed by the Sea Turtle Research Unit ( SEATRU ) of Universiti Malaysia Terengganu ( UMT ) . Most of the clip they are rehearsing unmoved method but during north-east monsoon season ( October and December ) they switch to the Styrofoam box incubation method.
Although different methods are used to incubate clasps of eggs in sanctuary direction, the quality of hatchlings ( in footings of locomotors public presentation and morphological feature ) produced by these different methods is unknown, and needs to be investigated. More than half a million green polo-neck hatchlings have been released to the sea yearly from whole sea polo-neck sanctuaries in Peninsular Malaysia ( east and west seashore ) over the last decennary as recorded by Department of Fisheries in 2009. However, we are disquieted if these sanctuaries are bring forthing hapless quality of hatchlings and ensuing to the comparatively little parts of sea turtle population in the hereafter.
In order to prove whether incubation method influences the quality of hatchlings, hatchling creep and initial swimming public presentation were measured as an index of hatchling quality. Both these public presentation steps are likely to impact the predation rate of hatchlings as they proceed down the beach and swim off into the comparative safety of deeper off-shore Waterss. As mentioned antecedently, hatchlings have to be every bit healthy as possible and this will give the best opportunity for them to last during swimming across the marauder rich near-shore Waterss.
Previous surveies in Malaysia merely address the hatched success of sea turtle hatchlings by comparing the use of different incubation methods. Hence, the inquiry appears here whether our hatchlings in world survive during early swimming or we are conveying them into high hazard of predation. Consequences from this survey will take to the reappraisal of the use of these three incubation methods from different position which is in term of hatchlings morphological characteristic and their locomotors public presentation. It is hope that, this survey will supply information to better our preservation attempts towards more quality hatchlings production.
The major purposes of this survey were:
To measure the temperature profiling of unmoved and ex-situ eggs incubation methods ;
To compare swimming public presentation and creeping velocity of green polo-neck hatchlings incubated in the unmoved and ex-situ ;
To find the relationship between eggs incubation temperature and morphological features of hatchlings with the hatchlings ‘ locomotors public presentation.