More Out-of-Town Visitors
This post was written by guest blogger Mike Bush, a grad student in FIU's aquatic ecology lab (http://faculty.fiu.edu/~trexlerj/).
|Boaters trying to push whales back to deep waters. Photo from CNN.com|
About a month ago, a pod of around 50 short-finned pilot whales beached themselves on a remote shore in the southwestern part of Everglades National Park. Normally these are deep-water beasts, but for whatever reason, this particular group of animals navigated several miles through shallow sandy shoals, only to end up stranded. Pilot whales are well-known for mass strandings, and the reasons for these strandings are unknown but are thought to be related to sick individuals trying to gain some respite. The tight-knit social structure of the animals then may lead to other animals following their sick brethren into shallow water. Another theory is that the animals may get move in to shallow areas inadvertently and are unable to successfully navigate back out using echolocation. Whatever the reason, this is actually just one of several strandings that have happened in Florida in the last few years. Through the efforts of some very hard working park service staff and volunteers, it is thought that upwards of half of the animals may have survived the rescue effort. Eleven whales were later found on a beach in the Lower Keys, thought to be from this group. They may have survived the rescue effort but may have been too weakened to survive for a trip back out to deeper waters. Before this post depresses you too much, remember that short-finned pilot whales are species of least concern for conservation efforts, meaning that they are an abundant animal and the loss of 20-30 animals shouldn’t be detrimental to the persistence of the species. Also, and perhaps more importantly, this was a natural event, and a couple dozen whale bodies (these guys can get to be almost 20 feet long!) will feed a lot of smaller animals out in the shallow sandbars. I heard several reports of small sharks feeding on the carcasses, and the whales will also provide food for countless crabs, fishes, and seabirds, thus providing an important nutrient subsidy for a large stretch of the food chain.
The recent stranding just goes to show that even though the Everglades is known for alligators, storks, and panthers, a massive swath of the park is marine, and sometimes we get visitors of a larger sort.
There’s a whole slew of articles out there on the strandings. Here’s a link to the most recent article, published by the Miami Herald: http://www.miamiherald.com/2013/12/09/3808627/eleven-pilot-whales-from-everglades.html.