In ‘How Far the Light Reaches’ Ocean Science and Memoir Make Magic

In the fascinating 2021 study Below the Edge of Darkness: A Memoir of Exploring Light and Life in the Deep Sea, oceanographer Edith Widder uses her struggle with vision as a point of departure to explore the role of light and sensory perception in the deep seas. That excellent work is a reminder that the best science is often that to which we have some personal connection. The small but growing body of science literature by writers who aren’t afraid to locate themselves in their work helps deconstruct the tenacious, yet ultimately artificial, borders between the scientific and the personal.

Sabrina Imbler’s How Far the Light Reaches: A Life in Ten Sea Creatures is another monumental step in that direction, probing the space where the personal and the scientific intersect. In 2020 Imbler produced a fascinating chapbook titled Dyke (Geology), which is a poetic reflection on life, sexuality, and geology. In that short work, science takes a backseat to the artfulness of Imbler’s prose, and the result is a satisfying foray into language and identity, in which science is put in service to poetry.

In How Far the Light Reaches, the science is front and centre, although it shares the stage with a compelling and deeply personal memoir. Imbler offers a series of essay-length reflections, vignettes from their life juxtaposed against a backdrop of fascinating marine creatures. Imbler is a science journalist who’s worked in the field of oceanography, and their discussion of these often obscure and fascinating marine life forms – Yeti crabs, sand strikers, but also goldfish and sturgeons – is comprehensive, accessible and riveting.

What renders How Far the Light Reaches particularly interesting is how they weave together their struggles with identity – gender identity, sexuality, ethnicity, and body image – and use the immense diversity of marine life to reveal new ways of considering our lives as human beings. A discussion of hybridity and the history of taxonomy, for instance, is juxtaposed with reflections on Imbler’s own Asian-American identity to underscore how western science and politics privilege certain forms of life over others and how the priorities of white men in both science and politics have reinforced each other.

In the essay “We Swarm”, Imbler likens the periodic eruptions of salp blooms in the oceans to the takeover of entire streets and neighbourhoods by joyful queer mobs during Pride month. Thiunderscoring the everlasting and naturalized presence of diversity in our world, which only catches our attention when it erupts in unanticipated swarms.

Their discussion of a marine worm colloquially known as the ‘sand striker’ provides a perceptive opening to discuss predatory men and sexual assault. The author finds hopeful models in the oceans which echo and reveal much about our human behaviour; for instance, the way sea breams work together to identify, reveal and warn others about the presence of these predatory creatures. The worm is a deadly attacker, but the breams fight back by alerting their fellow fish to its presence.

“The scientists marveled at the breams’ collective action,” Imbler writes. “Approaching and mobbing a predator such as a sand striker invites real danger – losing a fin, a patch of scales, even dying. But the scientists never saw the worm fighting back against these mobs. They never saw a fish placed in danger by alerting others to a threat. The breams swim around the reef to forage but never veer far from their home range, refusing to be forced out. They will do what they can to make this dangerous place safe for one another.”

Considering the strange and – to our experience – bizarre behaviour of marine life helps to unsettle human norms, to force us to reflect on the way we have come to naturalize our experience of the world. We have a tendency, as human beings, to construct models of normative reality based on our narrow experience of life, but the reality of the world is far more complex, full of diversity, adaptation, and change. This process of unsettling, of accepting the unexpected for what it is and seeking to learn from it – instead of trying to fit it into our narrow, pre-conceived boxes – generates a lot of wise asides and reflections throughout How Far the Light Reaches.

“Why is prey in nature videos always ‘unsuspecting’?” Imbler asks, reflecting on the narration in documentaries like Blue Planet II. “Though prey can be caught off guard, can be surprised, can even be ambushed, prey is never truly unsuspecting. It has evolved the blueprint of its body in response to, or in anticipation of, trauma…These adaptations are remarkable and make these creatures exceptional in our eyes, and yet would not be necessary without the constant threat of the predator.”

Much of How Far the Light Reaches focuses on Imbler’s coming out and growing up as queer, and at a politically fraught moment for America, there’s a tremendous amount of joy and hope to be found in these pages. The diversity of life in the oceans underscores the diversity of life everywhere; the fact that there is no one trajectory to evolution and that every mode of life and having its particular strength and beauty.

For a long time, scientists believed – erroneously – that all life on Earth relied on photosynthesis (energy derived from the sun) for survival and that this meant those eking out a life on the ocean floor had to survive off the scraps of dead flesh that fell from above; a sort of trickle-down food chain. Not so, we know now: much of the life around hydrothermal deep-sea vents rely on chemosynthesis, deriving life directly from chemical energy. The science here is fascinating, but there’s a bigger-picture lesson about how living creatures find ways to nourish themselves and survive.

“Hydrothermal vents revolutionized many of science’s core ideas about life, how and where it could exist,” writes Imbler. “It is only logical that scientists assumed the strange creatures living on the seafloor would survive on the flecks of fish that died nearer the surface, the scraps of sun-touched society. But these animals eked out an alternative way of life. I prefer to think of it not as a last resort but as a radical act of choosing what nurtures you. As queer people, we get to choose our families. Vent bacteria, tube worms, and yeti crabs just take it one step further. They choose what nourishes them. They turn away from the sun and toward something more elemental, the inner heat and chemistry of Earth.”

Imbler’s How Far the Light Reaches is an engaging read, whether one reads it for ocean science or memoir. The most valuable insights will be gained by those who read it for both.