Toxic Algal Blooms May Prove to be Fatal for Sharks!

Sharks have roamed the oceans of the earth far longer than most extant animal species. They have contributed much to myths, legends and folklore in the past and even Hollywood in recent times. Their evolutionary success can be attributed, at least partly, to their amazing skills as predators that have instilled overwhelming fear in humans. However, a recent study reveals how, relatively innocuous algae species can destroy shark brains and even kill them!

Algal blooms…

That result from multiple fish die-offs or agricultural run-off caused by humans, and which occasionally are referred to as ‘red tides’ due to their red color, have been shown to produce toxins that can significantly affect the brain physiology of many species of sharks.

Brain-changing compounds?

The toxins in question are called brevetoxins, since they are brain-changing compounds that bind to proteins that control sodium flow in the brains of sharks. This disturbs the sodium flow, causes nerve cells to over-fire and results in hyperexcitability of the shark brain that may occasionally even prove fatal!

The study was conducted…

Using 30 juvenile lemon sharks, and following exposure to the algal blooms, these animals demonstrated significantly high levels of the toxic compounds in their brain, liver and gills.

Out in the ocean, sharks ingest these toxins along with contaminated water and food. The long-term impact of this is yet unknown as shark embryos containing the toxic substance may even affect the reproductive success of sharks in the long-run.

Via: discovery