Quiet Waters, but Questions Surface

Thrilled to be back on the American Princess yesterday for another whale and dolphin cruise, and the afternoon was proof positive that it doesn't matter if nothing's jumping - it's simply fun to be on a boat on a lovely day!

With the exception of a brief sighting of a small dolphin pod, the day was quiet -- and most relaxing. Merryl, our on-board naturalist extraordinaire, kept us busy with her excellent cetacean presentation, along with a touch tank filled with aquatic beauties collected just minutes before leaving the dock. Two different types of seaweed (one with tiny anemones attached!), a sea sponge, pipefish, glass shrimp and a juvenile crab no bigger than a 1/2 centimeter -- what could be better!?

Rounding our the excursion, we were treated with regular, albeit distant, views of another Wilson's Storm-petrel. I've become rather intrigued by this pelagic species ... note to self: read up and write.

While the day may not have been filled with quantity, as I reviewed my photos of the day, I realized that having fewer dolphin images allowed me to concentrate more on details -- specifically a peculiar attachment to some of the dorsal fins, something we noticed on our earlier cruise.

Common Bottlenose Dolphin with Pseudostalked Barnacle

At first we figured it was seaweed caught on the fin, but it looked too large and dark. American White Pelicans develop a bulbous lump on the bill around mating season -- perhaps this was a similar accoutrement?

Wrong!

We're all familiar with images of barnacle clusters on whales but these tiny organisms also hitch a ride on dolphins. I'm hardly an expert on this (so please readers, let me know if you can provide guidance), but think I've identified this as Xenobalanus globicipitis, or Pseudostalked Barnacle. A crustacean, this species seems to attach itself to dorsal fins, flippers and tails but has been noted in other places. According to the study I found, published by the Southern California Academy of Sciences in 2010, unhealthy dolphins tend to host Xenobalanus. This concerns me and raises questions. Are our dolphins not well? Could geography play a role in species distribution (the study was conducted off the California coast)? What percentage of the Atlantic Common Bottlenose Dolphin population is affected?

I'll have to dive deeper and find out.

Common Bottlenose Dolphin with Pseudostalk Barnacle