Sharks in the Bay???

Catchy title, huh?Sharks in the Bay?

In the past few months we have had a couple of readers submit “shark sightings” in Half Moon Bay. Our wonderful readers care about the facts, so they provided some photos for us to launch an investigation.  Are there sharks in the bay?

We put on our research hats and contacted the local dive and marine experts. After a short period of review, our qualified pros noticed a few key items in the photos. They then unanimously determined that the photos are not sharks but are in fact Spotted Eagle Rays. In order to arm you with knowledge, in the event you ever see something suspect in the bay, we are going to tell you how they came to this conclusion.

1) The submitted photos show a fin above the water. At first this can be mistaken as a dorsal fin, but if you look closely you will notice either a second fin alongside the first or a disturbance in the water alongside the other fin. The distance between these fins/disturbances is the same as the wingspan of a Ray.

Sharks in the Bay?

Credit Bites Animal Planet on
Credit Bites Animal Planet on

2) Notice the coloration on the fin facing us (which in the case of a ray reveals the bottom). You can see from the reader photo above and the ray picture to the right that the fin coloration is an almost exact match. There are no known shark dorsal fins (at least in our region of the world) that are white with a black outline. Thresher sharks would be the closest to this coloration, but the dorsal fin shape does not match and they prefer cooler waters.

NOAA has a great guide on shark identification here. They also have a separate guide here with closeup photos of dorsal fins from most of the sharks in our area.

3) Unlike dolphins, sharks do not live in groups. Sharks are typically loners. Unless the food supply is very short (or you just threw a bunch of chum into the water), it is uncommon to see them swimming in groups, let alone side by side in formation.

Do sharks occasionally come past the reef and into the bay, possibly. Do they ever come near the shore or in the shallows…none that we have observed.

Enjoy swimming in the bays and soaking up the wonderful Akumal sun!


1 Comment

  1. Except that that ´ray´ came into the bay from the reef, circled around parallel to shore and then left. Never seen an eagle ray do that!

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