Most environmentally minded folks agree that human impact on the environment is bad. We clear out land and wilderness areas for our homes and work places, pollute the air with our extensive burning of fossil fuels and generate huge amounts of waste that have to be dumped somewhere.
But how do we feel about human intervention when it is aimed at improving the survival rate of an endangered species?
I have been working at Cumberland Island National Seashore in Georgia monitoring sea turtle nesting
. So far, we have had 117 nests and relocated 68 of them (58.1 percent).
We will relocate nests if we think there is a threat of predation or there is a lot of vegetation and roots growing through the cavity. The main reason for relocating the nests is that the turtles don't make it up high enough in the dunes, so the nests are in danger of being washed over by high tides.
A stretch of beach here, instead of having nicely sloping dunes, has steep drop-offs which are the result of erosion from a storm system that hit early in the nesting season. When the nesting turtles hit this, they either lay their nests right there at the edge of the dune or they turn around and go back to the ocean.
If the eggs were left there, they would be washed over by the tide several times through out their incubation. Depending on the stage of development and how many times they are inundated, the change in temperatures and lack of oxygen can alter their development or suffocate the little turtles.
For whatever reason, on other stretches of the beach, the turtles just don't crawl very far up into the dunes before laying their eggs.
If these turtles are not genetically programmed correctly to lay nests in places that will be conducive to development and survival of their eggs, then this turtle's genes wouldn't be passed on to the next generation in as great of numbers as a turtle that could select better nesting locations.
So, are we messing with the process of natural selection?
Turtles don't learn from other turtles how to nest or where the best spots are. After the female lays her eggs, she goes back to the ocean, never to reunite with the little ones again. Therefore, turtles must rely on instinct.
Sea turtles are known to return to nest at the same beach from which they hatched. Cumberland Island is a good beach for turtles to return to because it is undeveloped, but what about other beaches?
On many developed beaches the dunes are in bad shape because of people walking through them, attempts to fight erosion and high rise hotels just on the other side of them. On beaches like this, there is also a lot of light pollution
and other disturbances at night.
Should we protect these nests so that the turtles can hatch out and return to the same beach with the same (or worse) problems to lay another generation of eggs in twenty years?
My guess is that humans won't be actively relocating sea turtle nests until the end of time. So, are we inadvertently setting up this species to fail?
Aside from screwing with natural selection, there may also be several developmental factors that are dictated by the characteristics of the nest site that we change when we move a nest. There is still a lot that is unknown about sea turtles, and it is possible that most of them know what they are doing when they lay a nest. I mean, the modern sea turtles go back at least 60 million years.
Since our activities are at least part of the cause for the decline in the species, are we obligated to intervene by moving their nests?
More research needs to be done, so that we can make sure we are employing the best management practices for endangered species like sea turtles because we don't want to accidentally alter the gene pool and other characteristics of the population.
While I agree that nest monitoring and protection in order to increase the number of hatchlings might help stabalize sea turtle populations, I think that more attention should be paid to other problems they face.
As juveniles and adults, they are vulnerable to commercial trawling nets. They often get caught and drown, or suffer irreversible shock after escaping from a net. Several dead turtles that wash up on Cumberland's beach each year exhibit propeller wounds as well.
We should focus more of our efforts on reducing our impact instead of intervening in additional ways.