The nutrient-rich cold waters of coastal California provided with its rocky seafloor afford a perfect environment for lush kelp forests, that extend up into British Columbia and Alaska. But as waters are warming, with astounding rapidity, we need to ensure kelp beds are mapped, although many are often off the map, and difficult to register, even as their size has come to be threatened by global warming and climate change, in ways that eerily parallel the loss or threats to irreplaceable forested environments. While the nature of the decline of seaweed is not linked to warming waters directly, the shifting ecosystems that climate change has created have caused a drastic and rapid decline of seaweed’s offshore presence that we have yet to fully map. For the passive registration of kelp beds, traced by GPS or captured through aerial photography, is far less hands-on than examination of their extent would warrant, and low-flying satellites of remote sensing offer few possibilities for accurate mapping of their extent. The rapidity of the disappearance to kelp–and beds whose boundaries are shifting in time with the rapidity of the advance of forest fires on the scale of their destruction–pose problems of global dimensions that are pointing for the immediacy of loss of kelp of over 13,000 species whose biodiversity and creation of oxygen by photosynthesis feeds much of the world drives our own ecosystem.
Even a map of globally threatened areas cannot emphasize properly the extent to which the Pacific coastline provides a site of cold waters, ocean upwelling that provides rich mineral nutrients, and sunlight that makes it an especially abundant site of kelp forests, in a true megaregion of coastal ecology whose catastrophic loss is impossible to imagine. Even a map of kelp’s local abundance fails to map its ecoystemic centrality in adequate ways–ways that the diversity of kelp speciation also fails to capture, despite its clear .scientific value to survey the ocean populations that are most risk.
Miller, Lafferty, Lamy, Kui, Rassweller and Reid (2018)/Royal Society Publishing,
The particular vulnerability of the kelp biomass seems to have grown in unexpected ways not only due to climate warming, but to its particular vulnerability to ocean floor sessile predators like purple sea urchins, who are more likely, it is now believed, to eat phytoplankton and microalgae in the kelp understory, rather than kelp itself: however, the role of urchins in diminishing kelp forests, which themselves feed exclusively on sunlight, the combination of how a lack of upwellings due to climate change diminished urchin food supply and the inhospitable nature of warming waters to kelp forests may increase the vulnerability of kelp in coastal oceans.
While these maps depend on and reflect data derived from remote sensing, the often undermanned undersea beds of seaweed are rarely registered in detail by passive mapping systems. This is partly because of the difficulty of adequately mapping undersea life from airplane surveys, and secriung adequate lighting, tides, and lack of cloud cover to tracking the volume and contours of kelp forests and beds, which are hardly regular in nature, let alone the ecoystemic centrality of kelp that was perceived immediately by Darwin, in 1835, on his initial visit to the Galapagos Islands, where the naturalist was hit by ecological awe as he appreciated the productivity of the dense kelp forests that surrounded the islands as more important to its ecological diversity than on land forests. Awed by the abundant growth around the Galapagos of giant kelp, as he bent over the bow of the SS Beagle, processing kelp’s centrality of Macrocystis pyrifera as a foundation species of local coastal ecology.
As Darwin took in the waters surrounding the islands as seats of a hugely dynamic environment, he marveled. “Amidst the leaves of this plant numerous species of fish live, which nowhere else could find food or shelter; with their destruction the many cormorants and other fishing birds, and otters, seals, and porpoises, would soon perish also …’
The problem of mapping kelp biomass, however, is not only rooted in its quantitative presence, or directly tied to its species richness, but its amazingly generative levels of self-productivity, and energy production, but the engineering influence of kelp on the coastal environment–influences present in the attraction of populations of Pacific pelagic to California’s shore, the variety of local coastal species it feeds and protects, and the oxygenated waters it has produced–and the sense of deep time that we are in danger of forgetting, as kelp forests are being rapidly reduced.
Is the centrality of kelp within coastal ecosystems endangered of being undermined by the pointillist bias of even the best of our ecological maps, preventing us from inferring the foundational role of kelp in oceanic health? Have the machines of mapping kelp, in other words, proved less conducive than one would wish to appreciating the threats ocean warming poses on marine life?
The challenging situation is seeking to be remedied by the NASA Earth Observatory project by Mike Taylor and others. But submerged aquatic vegetation is less clearly part of a set of conventions and symbols, and the coding of aquatic negation presents some steep challenges for programmers, or computers attempting to translate remotely observed data to a distinct or recognizable visual form, let alone to register their presence of algae in valuable ways, anchored as they are to an ocean floor by holdfasts, migrating slightly with the tides. But when I started to see a huge bed of seaweed on coastal beaches, as if severed from its holdfasts, as if the seaweed were a refugee from the ocean floor. Indeed, the appearance of what seem remnants or reminders of entire kelp forests suggest a climate emergency that we have not begun to calculate–and lack abilities to calculate or reckon with.
1. The shifting waters in the very near-tidal zones where seaweed is anchored on holdfasts or on coastal rocks, and where kelp forests multiply was only revealed by the expansion of urchin barrens in recent years, that have expanded globally, but threaten to redesign coastal ecologies in ways we have yet to register adequately in many of our coastal maps. The crisis of kelp in the relatively unknown offshore has provoked a new interest and demand for mapping the causes of its drastic reduction, as well as the drastic reduction of its once-ab undant expanse.