KELP! Christian Hubert, Nicholas Gervasi, James Swain

OCEAN OASIS

The goal of this project is to explore design strategies to mitigate ocean acidification and to build resiliency in marine ecosystems, by cultivating kelp in sensitive locations to provide local environmental benefits, habitat restoration, sources of food, and strategies for coastline protection.

Ocean acidification derives from the entry of human‐produced carbon dioxide (CO2) into the sea. When CO2 enters seawater, it increases dissolved CO2 concentrations and also combines with water to form carbonic acid (H2CO3). The acidity of the world’s oceans has increased by 30 percent and is expected to double over pre-industrial levels by the end of this century. While ocean acidification is just one dimension of the global climate emergency, its consequences are far-reaching for marine and human life.

Around half the organic matter in the oceans is comprised of kelp and phytoplankton. Through photosynthesis they produce at least half of the atmosphere’s oxygen, in the process sequestering gigatons of carbon deep into the ocean. What makes oceans productive are upwellings of cold, nutrient-rich water from deep in the sea. Upwellings occur around the world such as in the Grand Banks of Newfoundland—the richest fishing ground in the world—where the icy Labrador Current meets the warm Gulf Stream. This phenomenon is known as overturning circulation.

We often think of the ocean as a single fluid entity, but over 90 percent of the heat caused by global warming is absorbed by surface waters. As surface water temperature increases, overturning circulation is thwarted, and up­welling of nutrients decreases or stops altogether. Phytoplankton and seaweed production drops, leading to a decline in the aquatic food chain.

Most of the carbon emitted by human activity is contained within the top five hundred feet of the oceans, causing surface acidification. Reversing this trend is mostly an issue of moving carbon from the near-surface photic zone into the middle and deep ocean. Oceans naturally send carbon from surface water into the depths, a process known as the biological pump.

Unfortunately, today’s loss of overturning circulation and increased acidification is steadily erasing the marine food chain. Ninety-nine percent of the subtropical and tropical oceans are now largely devoid of marine life. Satellite imagery is detecting a 4 to 8 percent annual decline in biological activity in the Atlantic, a number that exceeds predictions from global warming models. The oceans’ plankton and kelp are estimated to be declining 1 percent annually.

Marine permaculture arrays (MPAs) are lightweight latticed structures made of interconnected tubing, to which kelp can attach. They can be tethered near land, or guide themselves autonomously on the open sea. Since they are submerged 25 meters below sea level even the largest cargo ships and oil tankers can pass right over them with no damage, save some shredded kelp. A 0.4 square mile unit would recreate an entire marine ecosystem, akin to reforesting a desert.

Marine permaculture recreates the biological pump, enabling oceans to do the job they always have. Buoys attached to the MPAs rise and fall with the waves, powering very simple pumps that bring up colder waters from hundreds or even thousands of feet below sea level. As the nutrient-laden waters come to the sunlit surface, phytoplankton and kelp soak up the nutrients and grow.

With phytoplankton come algae, more kelp, and sea grass. These feed populations of herbivorous forage fish, filter feeders, crustaceans, and sea urchins. Carnivorous fish feast on the smaller herbivores, and seals and sea lions and sea otters feed on them. On top of this are seabirds, sharks… and fisher folk. The phytoplankton and kelp that is not consumed dies off and the majority drops into the deep sea, sequestering carbon for centuries in the form of dissolved carbon and carbonates.

Kelp combats acidification by sequestering submerged carbon. (See Blue Carbon cycle). It provides a rich habitat for other species, and is a potentially important source for human nutrition. We will investigate the possibilities for sustainable underwater farms for fish and algae, as well as surface or land based designs, with emphasis on materials, techniques, and social impact.

OCEAN OASIS

 The Ocean Oasis project is for a floating science and wellness platform, whose goal is to remediate some of the negative impacts of surface warming and acidification of ocean areas as a result of climate change. The oasis consists of a floating platform at the surface, an underwater level approximately 25 meters below the surface that provides attachment points for a kelp forest, and an “underwater fountain” bringing colder, nutrient-rich water up to the kelp level from the deeper waters below. At a local scale, the combination of the kelp and the admixture of deepwater will attract marine life, oxygenate “dead zones” in the immediate vicinity, and add nutrients to the water. The oasis can drift or navigate under sail and is intended to be part of a larger system of remediation through kelp cultivation.

            The Ocean Oasis will function in part as a wellness retreat, in part as a scientific research platform, and as a test case for marine urbanism. It is also meant to function as an experimental cooking school. The upper platform, slightly elevated above water level, will accommodate restorative human activities such as yoga and meditation, food preparation and dining, and be sheltered by a combination of a light bamboo structure and acrylic domes. The platform floats on a trimaran structure, giving it stability and the capacity to navigate. The main hull of the trimaran includes cabins below water level with views of the kelp forest and sea life. The outrigger pieces function as greenhouses and laboratories. As much as possible, the Oasis is meant to be self-sufficient and positive in its environmental impact. Human waste is to be integrated into an ecological sanitation system. Power is to be produced by solar and wind generation, and fresh water by solar desalination plus reverse osmosis.

  Approximately 25 meters below the surface, a suspended platform supports the “holdfasts” for the kelp forest. The kelp grows up from this platform and is trimmed close to water level. Colder water is pumped up from greater depths, via wave action pumps, using a system developed by Dr. Brian Von Herzen and the Climate Foundation. The pumps are attached to floating buoys that function by wave action. An “underwater fountain” brings the water to the platform level, where it nourishes the kelp forest. The pumps themselves can be raised or lowered as required. The kelp is frequently trimmed to provide ingredients for the cooking school, or to be allowed to drift away. The partly submerged cabins will afford spectacular views of the congregations of marine life around the oasis.

RESEARCH AND DOCUMENTATION

Macrocystis pyrifera, Giant kelp

Understanding Kelp forests: Where do they grow? How will climate change affect them? What are potential target sites for Kelp farming?

life cycle of kelp plants: Diagrams of growth, sealife, food potential, harvesting

kelp harvesting techniques, role in human food system

VISUAL RESOURCES / MOOD BOARD

LINKS AND BIBLIOGRAPHIES

Mariculture of Seaweeds

Seakura

Floating Forests

regenerative farming: Greenwave

marine permaculture arrays: Climate foundation

South Pacific Marine Park (kelp + bamboo)

Wave driven ocean pumps can be deployed in a linear array upstream from the target area to upwell cooler water into the mixed layer and reduce peak temperatures of surface waters.  Wave pump technology uses kinetic wave energy to bring up higher-nutrient deep water. In the presence of sunlight, and assuming appropriate ocean environmental conditions, the enhanced nutrients generate blooms of phytoplankton, which absorb dissolved CO2 and generate oxygen through the process of photosynthesis.

RESEARCHERS

Dr. Charles Yarish, University of Connecticut

Dr. Brian von Herzen (ocean pumps)