This is something of a murky and hard to research subject. However, you may have noticed that when you snorkel in the Western Pacific Ocean or in the Indian Ocean, the Green Sea Turtles you see are larger and have redder shells.
Meanwhile, when you snorkel in the Eastern Pacific Ocean around Hawaii, the Green Sea Turtles are more of a black color.
If you’ve been to other areas such as the Caribbean or South America, you may have seen Green Sea Turtles with different coloring as well, since NOAA identifies eleven “Distinct Population Segments.”
Note: They are not called “Green Sea Turtles” because of the shell color. Rather, they are named this way because they have green fat lining the insides of their bodies.
Their classification so far goes:
Species: Chelonia Mydas
Curently, the Distinct Population Segments are only classified as “intra-species variations.” Chelonia Mydras, (commonly known as the “Green Sea Turtle,”) is considered a single species. In other words, these turtles who all look very different and who likely don’t breed are classified as the same for now.
The species variations include many factors like shape, size, diet, and color.
It should be noted that the usual reason to single out a “subspecies” is if Distinct Population Segments cannot breed with each other. I would point out that there is no evidence that these DPS are breeding. And if they are, they is no evidence that they can produce viable offspring.
(Think of horses and donkeys. They can mate and make a mule, but mules are sterile. A horse and a donkey cannot produce viable offspring with the ability to procreate.)
So to recap: We don’t know if different Distinct Population Segments of Green Sea Turtle can (or do) breed with each other, as this behavior has not been observed. This means that we need to ask: Are these animals sufficiently distinctive enough to warrant separate classifications? (If they are, each DPS could be classified as a subspecies.)
I am arguing that they are definitely different enough.
Green sea turtles from the Western Pacific and India Oceans are much larger, and live on a diet of things like squid, jellyfish, mangrove fruit, and sea grass. Since they live in warmer water, different foods are available to them. The difference in diet may be what causes them to have different pigment and to grow larger. Whatever the reason, they are very easily distinguished from their fellows.
Green Sea Turtles from the Eastern Pacific (most notably from Hawaii) are sometimes called “Black Sea Turtles” due to their dark coloring. These turtles are smaller on average, and their shells are more rounded. They have no access to tropical foods like mangrove fruit or sea grass. Instead, they seem to eat mostly algae and fish. In addition to these differences, this (I’m calling it) subspecies likes to come out of the water and bask. As far as I can tell, no one has observed this behavior in Green Sea Turtles anywhere else in the world.
So between the two types of Green Sea Turtle I have observed closely, I see a huge difference.
Why does this matter?
Well, if these eleven Distinct Population Segments can be classified as subspecies and are deemed significantly different, then each subspecies gets to be listed separately on the endangered species list.
Right now, the DPS are listed separately on a tentative basis. However, Hawaiian and Chamorro cultural proponents are fighting that classification because they want to be able to hunt sea turtles again. If these populations were classified as subspecies, they would have a better chance of staying on the Endangered Species List separately and they would be eligible for more long-term protection.
Think about it: These two types of Green Sea Turtles likely can’t breed with each other. They’re extremely different. Having them considered one species means that the populations could be assessed together to determine numbers! They’re far less likely to qualify for ongoing protection that way.
I hope that we’ll be able to get all eleven Distinct Population Segments of Green Sea Turtle classified as subspecies so that they will be eligible for separate protections in spite of any legal challenges.
What about the cultural heritage of hunting of these turtles?
This will sound awful but here it is: I’m Portuguese. That means my cultural heritage is invading foreign lands and killing their inhabitants. And just because it’s my heritage, that doesn’t make it okay. I am allowed to be ashamed of that part of my heritage and to know that my ancestors were wrong when they did all that hunting of natives for sport.
So maybe, if I can give up the parts of my heritage that were wrong, then so can everyone else.
If the Native populations of Guam and Hawaii can’t admit that killing these magical creatures is a mistake, then we have to do what we can to make sure it’s illegal to kill them. That’s why I want to ask that you write to NOAA and request that Green Sea Turtles Distinct Population Segments be recognized as separate subspecies. Please ask that their protections as eleven different endangered subspecies will be kept in place to prevent hunting them in the Hawaiian islands or Guam.
It’s rare that you see a Honu (Hawaiian word for green sea turtle) or Haagan (Chamorro word for Green Sea Turtle) when swimming because there aren’t enough of them. Let’s make sure that future generations get to enjoy these amazing creatures and that the people of today are not allowed to hunt them to extinction.
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