Over the weekend I attended a talk by biologist David Hancock
https://hancockwildlife.org/ about eagles in South Surrey, the highest concentration of nesting bald eagles in the world, he says.
He attributed the density partly to the plainfin midshipman that breed in the intertidal zone of Boundary Bay. One, I had only heard of the midshipman in passing and two, I had no idea of the important role the fish played in the diets of eagles and their eaglets.
I learned about the midshipman during Mr Hancock's talk and then did some further digging...
* most of the year the midshipman live in the depths, up to several hundred metres deep, but they migrate to shore to spawn in the intertidal zone.
* I thought it was a sculpin but it's actually a species of toadfish
* the midshipman spawns in May June which coincides with the eagle's nesting season
* in the depths the midshipman is bioluminescent. It has rows of photopores along it's flank. These photopores look like buttons on the uniform of a naval midshipman, hence the name.
* The midshipman hides under rocks or buries itself in the sand/mud at low tide. It can breathe through it's skin when not in water
*the midshipman vocalizes during the breeding season. If you are on the beach at low tide, you can hear them grunt or hum
It's been interesting learning about midshipman and the significant role they play in the diet of seashore nesting eagles.