“Tall Trees in Cold Seas: Sampling Period 3”
And just like that, summer is over. High latitude season shifts are pronounced and fierce; southeast Alaska is no different. Photosynthetic organisms rely on the heavy summer sunlight period to maximize their growth potential, soaking up as much energy as possible while the opportunity lasts. From March to August, plant-like life in southeast Alaska’s nearshore shallow seas undergoes a shocking change.
To collect footage underwater in the Inian Islands, one must be well prepared to scuba dive in an incredibly remote area, not only outfitted with the proper skills and experience, but also equipment. During this summer’s collaboration between National Geographic storytelling grants and the Inian Islands Institute, a small but dependable dive platform was established in residence at the Hobbit Hole – the first of its kind in such a remote corner of southeast Alaska. This allowed myself and my team to work with the confidence that our safety was protected, our oxygen was clean and locally sourced, and our dive protocol sound.
Late in March, my team began monitoring kelp forest habitat in the Inian Islands’ Otter Cove, which is most readily accessible through the narrow “Mosquito Pass”, running north-south between two large, ripping seawater channels. This pass begins the summer season bare, devoid of the annual kelp species playing at the water’s surface. These three photos show the progression of kelp growth in Mosquito Pass, spanning from late March,
to early June…
and finally mid-August.
The product of this pronounced growth spurt is found throughout the Inians, nearly every shallow rocky cove supports an annual kelp forest community. The third photo, taken during the August sampling period, shows evidence of the transition from summer to fall. Nereocystis kelp forests in the Inian Islands did indeed die off between mid-June and early August, signifying these habitats and the ecosystem they support are inexorably tied to available sunlight hours and seasonal summer conditions.
Though the summer must end, work carries on. At the end of August’s sampling period, my team deployed an underwater temperature monitor to our main study site at Otter Cove. A Hoboware logger, set at 22’ depth, will read and record seawater temperature hourly for one year. By next summer, an entire dataset will be retrievable with information previously unknown. As our world changes, as our climate shifts and pristine remote areas become scarce, it is ever more important to take note of the environment around us – protect what we don’t know by deeply learning from sites yet unmarred, striving to understand irreproducible natural baselines.
Written by National Geographic Young Explorer Alyssa Adler, the Inian Islands Institute’s 2019 Scientist in Residence and National Geographic grant recipient for project Tall Trees in Cold Seas.