Exploring Idaho Inlet & Cross Sound
Situated at the mouth of Idaho Inlet, we anchored the National Geographic Sea Bird at Fox Creek this morning. The forest of Fox Creek is a striking example of a temperate rainforest and the hike affords views of many different stages in forest succession. A keen eye will also notice ordered depressions near the trail, evidence of bears worn onto the soil itself in the form of perennial tracks. Walking in the realm of such a powerful creature is a gift we should not take lightly or for granted.
This morning, though, I would leave the world of terrestrial life and explore the marine ecosystem. With Expedition Leader David Cothran leading with his trusty HD video camera, we dove nearby Shaw Island in hopes of encountering life very different than our own.
Splashing down into the chilly Southeast Alaska water, we descended into a kelp forest nearing the end of its annual growth cycle. Visibility this morning would not be classified as great by any means, but diving in cold water is often about looking for small creatures rather than grand vistas, so it didn’t bother us. This green water is also welcome because it is a testament to the high productivity of the Inside Passage.
Weaving through a fin-snagging Alaria and bull kelp forest, I could not help thinking about the Steller sea lion we saw just prior to splashdown. ‘Hopefully David’s shiny camera is more interesting than me.’ Any apprehension about encountering Earth’s largest sea lion on its own turf was quieted by the sight of a few special invertebrates. Nearing 60 feet deep, we found not one, but two basket stars clinging to rocks along a slope. Rather than expend energy seeking out food the way many other stars do, basket stars live in areas with consistent currents and use their specialized arms as suspension feeding tools. All they have to do is unroll their arms and harvest the bounty drifting by. David would surely not pass this opportunity up and he spent several moments capturing this interesting creature on film.
Just a few kicks away, another prize was found. Related to snails and slugs, a nudibranch of the genus Dendronotus was cruising the red algae and rocks for its next meal. Light pink with white-tipped, tree-like protrusions along its back, this type of sea slug often feeds voraciously on anemones, sometimes taking just one tentacle at a time. Once again, David squared up and began shooting, but by this time the cold was really setting in and it was time to start thinking about surfacing.
We slowly began our ascent out of the stark, deeper zone without brown algae up into the 45 foot zone where algae start to cover nearly everything in sight. Under the watchful eyes of kelp greenlings and juvenile rockfish, we weaved around Laminaria sp. kelp and stopped to admire a rather large sunflower star. When muscles are exposed to cold temperatures for extended periods of time, the signals sent to and from them are much slower than at optimal temperatures. My fingers had lost most of their dexterity by this point, so I signaled to David the “I’m cold. I’m going up” gesture and started my safety stop. It was there, at 15 feet that I found my last prize.
With a purpose and direction we will never understand, a moon jelly pulsed overhead. If just one of my bubbles got trapped in the bell of this animal, would it ‘drown’? Each contraction moved the jelly forward just a few inches at a time. How many thousands of times does that have to happen to get to the feeding grounds? Most jellies don’t have to worry about that because they have solved that problem in a very efficient manner.
Just go with the flow, it’ll take you where you need to go.
