SCIENCE
Collecting samples
GIANT FORESTS IN THE SEA Words Qamar Schulyer
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all stalks tower above you, rising over 30 metres from the ground. Light filters through the canopy, softly illuminating a diverse and complex understory. The leaves sway gently, providing cover for a huge variety of species. You sense movement from the corner of your eye, and suddenly come face to face with a giant cuttlefish! That’s because this forest you’re in is a giant kelp forest, home to abalone, cray, and weedy seadragons. You’re diving in one of the last remaining stands of giant kelp in Tasmania; indeed, in all of Australia. Giant kelp once blanketed nearly the entire east coast of Tasmania, as well as parts of Victoria and South Australia, but over the past 30 years nearly 95% of it has died off. Now only isolated patches of habitat survive.
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This die off is not only a problem for the kelp itself, but also for the ecosystem it supports. Like coral reefs, kelp provides structure, protection, and food for a huge number of species, including many that are commercially important for Tasmania’s economy. So…what happened to cause such a precipitous decline? To find out, I spoke with Dr. Cayne Layton, a postdoctoral fellow at UTAS’s Institute for Marine and Antarctic Studies (IMAS). Cayne, originally from New South Wales, moved to Hobart specifically to study kelp for his PhD. He told me that the problem began, unsurprisingly, with us humans. One of the lesser known effects of climate change is that it alters normal ocean circulation patterns. Here in Tasmania, the main impact is that the East Australian Current (EAC) has strengthened and extended southward, bringing warm, nutrient
