Hawksbill Turtle
- Class: Reptiles
- Order: Cheloniidae
- Latin name: Eretmochelys imbricata
- Range: Atlantic, Pacific and Indian Oceans ; Shallow tropical/subtropical seas, coral reefs, mangrove bays and estuaries
- IUCN Status: CR (Critically Endangered) / Cites: Appendix I
(2009 situation).
All from the living Sea turtles are counted among the oldest of currently existing animals, since earliest known ancestors for them are believed to have distinct from other turtles at least 110 Million years before our times. Likewise comparable to length of that evolutionary history is the species relatively long life-ages; an individual sea turtle can live up to 80 years, in natural circumstances.
Hawksbills 'justified' 'qualify' among the most threatened of sea animals and the level of endangerment isn't much differing in case of the other existing marine turtles. In fact all are threatened from their main surviving family Cheloniidae - that means; Green turtle (Chelonia mydas, EN), Loggerhead sea turtle (Caretta caretta, EN), Kemp's Ridley (Lepidochelys kempii, CR), Olive Ridley (Lepidochelys olivacea, VU) – the Flatback Turtle (Natator depressus), endemic for 'seas closer Australian continental shelf'' is listed as DD (data deficient). Another family of sea turtles, more evolutionary distant Dermochelyidae, includes as its sole surviving member only (equally Critically Endangered) Leatherback turtle (Dermochelys coriacea) - The largest from sea turtles, as individual specimen are known to have weighed from 250 kg to almost 1000 kg. (But smaller sea turtle species regularly weight under about 50 kg. To the comparison one can see the estimated size of turtles from Leatherback's extinct co-family, Protostegidae, which included fx Achelon, largest marine turtle and only found from fossil remains – although according to current knowledge they (perhaps) existed in the period of sea turtles early evolutionary beginnings, closely 100 Million years in the past.)
Since historical times, sea turtle shells have been collected by humans for decorative purposes, like jewelery, ornaments, glasses frames (and in our more luxurious days this has led even for such products as guitars made from turtle shell, like explained on this WWF-page briefly). Although the turtle trade nowadays is prohibited, the illegal market still flourishes. As well, turtles meat (and their eggs) are still preferred food sources in some countries. Also, many of the fishing nets still are 'non-turtle safe' where they get trapped (safer ones are fx those equipped with TEDs - so called turtle excluder devices). A sea turtle has to breath on the surface, otherways it drowns, and although they can sometimes remain hours under surface when sleeping/in rest, if in movement this time gap shortens a lot, for only some minutes.
And, other threats include fx also the marine pollution (marine debris, environmental contamination, etc), erosion of sea-side lands, non-native vegetation, and the destruction of coral reefs from silting and human building purposes, artificial lighting (last mentioned is threat since new-born hatchlings by instinct go towards the brightest source of light, and very often human lights on beaches etc leads them for the opposite direction ie they don't head for the sea) - and, as well diseases like FP (fibropapillomatosis), whose formation is not completely understood (/or: here in MSW a search from its causes fx from Wikipedia didn't return much information/researches post 1995), but likely the main reason is related to human caused pollution on coastal areas. (For more information see fx Aguirre-Lutz(2004)Note 1., and the other articles found we listed in the end of this, though due the aforementioned reasons we can in this case only advice to check for more recent information as well...) Anyway, in the 1990s the disease was even feared to ultimately cause sea turtles complete extinction, but nowadays is believed that in favorable conditions they (marine turtles) can recover from the disease in question. And...(the list continues) oil spillages for the sea waters of course, which in some parts of the world (middle-East, fx) is major problem. One enlargening harmful co-factor in the recent times has been the increase of tourism, since turtle breeding sites, sandy beaches have often been taken for the use in human purposes (most recently in the tropical coastlines of Asia). Mechanical beach vehicles, even walking can trouble turtles breeding and destroy the eggs/hatchlings. As peaceful beaches have continuously become rarer, also sea turtles nesting sites have declined (in during 20th century).
The effects of global warming on them are not yet known very adequately, but coral bleaching is one consequence believed to lead for losses in their natural habitat, coral reefs. Another, supposable consequence, although yet far less known with certainty is the possible effects from the warming of sea temperatures. For the migrating species, such as the Leatherback turtles, this can possibly cause changes for their usually preferred sea and terrestrial sites. Because the sea water temperature affect for the migratory routes turtles take, it is fx feared to also complicate already difficult conservation efforts - But since that's only researched nowadays, see (fx) "As the Seas Warm" from selected texts below. Also Hawksbills are migratory and one individual turtle can make rather complex journeys during its life-span.
Also, (many) sea turtles are dependant on the seagrass mats, growing close to reefs. Seagrasses are often considered having an important role as 'ecotone' in between the reefs and mangroves growing closer the coastlines, not the least because they have potential to adapt relatively easy for impacts of climate change and offer some protection from other factors, like fx the soil erosion of coasts. However, seagrasses also face several environmental problems, ao in form of declining water quality and chemical pollution, usually caused by herbicides and pesticides originating from coastal agricultural uses.Note 2(p. 35-6) (Question also has some considerable economic importance for humans since fx WWF 'The Coral Triangle"-Report notices the Climate Changes destructive impacts on coral reefs affecting some 150 Million people living in the region of Coral Triangle, about two thirds of them dependent for income coming from the biodiversity of the reefs, commercial fisheries by largest part but also some directly from fishing and from tourism as well. Also, importance of reef as biodiversity rich area is no less remarkable; the fishes, corals, etc., are mentioned appear there with greatest numbers of species worldwide.)Note 3(p. 36-43) Especially concerning the particular one species here, Hawksbill turtle, sea turtles are noticed also having important part in the reefs ecosystems, since their diet often contains various small invertebrates (that somewhat varying between the different species, but includes sponges and mollusks, snails, jellyfish, crabs and seaweed, and also algae). Therefore they have their part to do in the maintenance of healthy coral reefs – fx Hawksbills in various sea areas by controlling the spread of sponges which otherwise can out-compete reef-building corals for space Note 4.
Human caused pressures for sea turtles probably originate from rather long time, but especially they have been noticed in the recent 50 years time. As result, the Hawksbills are calculated as Critically endangered, mainly because in most of their populations there likely was/is noticed 80 per cent reduction during the past three generations – earlier, until about 1970s species was listed as Endangered. (To the comparison: Supposing turtle average life span about 40 years that would mean about 120 years period. For some other threatened species like fx Cheetahs [Acononyx jubatus, EN] period for the same three generations time is a lot shorter, about 42 years. Often, the time needed for the succesfull recovery may take even more time than that and species with longer time for maturity age naturally take more time to recover from continued overhunting, etc. Of course, doesn't prevent us to mention the Cheetahs being almost as much endangered, and some subspecies are also counted as CR.)
According to estimates in during that about 100 years, some millions of individual Hawksbill turtles were slaughtered for uses of the Europe, United States and Asian markets. Nowadays, as the declining trend has been noticed for some time, the conservation actions include fx establishment of protected areas for the nesting. Also, sea turtle trade was prohibited and species listed in 1970s with Cites appendice I (from the earlier appendice II; however, a largest buyer of tortoise-shell market, Japan didn't ban the shell imports until 1993). Since the international ruling is not always considered as binding agreement in all coutnries, the illegal trade still continues in some parts of the world. And the regular fishing too, which causes large number of turtle deaths, yearly. Juvenile Hawksbill turtles have also been noticed probably more vulnerable to be harmed by fishing nets than some other sea turtles.
All these things considered it appears by no means surprising that they're endangered by most populations. The changes on human use of the seasides would greatly benefit their chances for recovery, fx reduction in the building of new beach sites and/or coastal residents. Since no-one believes that to happen, and can't expect the marine pollution to lessen either, supposedly the protected marine areas and decline in the illegal trade are their best hopes. Not until recent times there probably hasn't been much such conservation areas, similar to those on land (But because we don't claim to hold any uttermost knowledge from the subject/marine conservation, etc, reader is also adviced to view further readings from fx the links/texts selected below.)
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Notes/further reading:
Coral reefs:
[Notes 2 and 3] The Coral Triangle and Climate Change: Ecosystems, people and societies at risk. WWF. (pdf) available fx here.
Fibropapillomatosis(FP):
[Note 1] Aguirre, A. ; Lutz, P., “Marine Turtles as Sentinels of Ecosystem Health: Is Fibropapillomatosis an Indicator?” EcoHealth 1, 275–283 (2004), doi: 10.1007/s10393-004-0097-3
(summary – obtaining complete text requires payment.)
Mascarenhas, R ; Iverson, P., "Fibropapillomatosis in Stranded Green Turtles (Chelonia mydas) in Paraiba State, Northeastern Brazil: Evidence of a Brazilian Epizootic?", Marine Turtle Newsletter 120:3-6, [2008?]
Marine Turtles:
[Note 4.] Mortimer, J.A. ; Donnelly, M. 2008, Eretmochelys imbricata. IUCN. IUCN Red List of Threatened Species. 2009.1. www.iucnredlist.org
Stiles, D., “The Marine Turtle Product Trade in Viet Nam”. Marine Turtle Newsletter 124:6-9, [2009?]
(Also one can check Seaturtle.org for Marine Turtle Newsletters overall and other related information.)
From http://www.swan.ac.uk/bs/turtle/hays_publications2.htm :
(fx:)
"As the Seas Warm". Science 313/2006.(August) [Pdf]
Hays GC, Broderick AC, Glen F, Godley BJ (2003). Climate change and sea turtles: a 150-year reconstruction of incubation temperatures at a major marine turtle rookery. Global Change Biology 9, 642-646. [Pdf]
Aiken JJ, Godley BJ, Broderick AC, Austin T, Ebanks-Petrie G, Hays GC (2001). Two hundred years after a commercial marine turtle fishery: the current status of marine turtles nesting in the Cayman Islands. Oryx 35, 145-151. [Pdf]
...And as additional mention, there's probably a lot from marine turtles at the Mongabay (fx), from where we find fx this article from plastic garbage on seas and it's words of wisdom (by Dr James, some kind of authority on this field apparently): "...hopeful aspect is that humans can easily begin addressing the solution, without major lifestyle changes...it's as simple as reducing packaging and moving towards alternative, biodegradable materials and recycling."
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