Robert Blasiak
email: robert.blasiak@su.se

Jean-Baptiste Jouffray

Diva J Amon

Fredrik Moberg

Joachim Claudet

Peter Søgaard Jørgensen

Agnes Pranindita

Colette C C Wabnitz

Henrik Österblom

Peter Søgaard Jørgensen

A forgotten element of the blue economy: Marine biomimetics and inspiration from the deep sea

des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

Introduction

Nature has been a source of inspiration for humanity throughout history [START_REF] Moberg | Den uppfinningsrika planeten[END_REF][START_REF] Vincent | Biomimetics: its practice and theory[END_REF] . Its influence is evident in the first tools and cave paintings, is reflected in histories, mythologies and legends, and remains omnipresent today, inspiring everything from the design of airplanes and robots to computer algorithms, packaging and corporate management structures [START_REF] Gao | An overview of biomimetic robots with animal behaviors[END_REF][START_REF] Tian | Controlling Lipid Oxidation via a Biomimetic Iron Chelating Active Packaging Material[END_REF][START_REF] Halder | Biomimetic algorithms for coordinated motion: Theory and implementation[END_REF][START_REF] Guerrero | Biomimetic spiroid winglets for lift and drag control[END_REF][START_REF] Tazzi | Biomimicry in Organizations: Drawing inspiration from nature to find new efficient, effective and sustainable ways of managing business[END_REF] . This is the world of biomimicry and biomimetic approaches, which seek to solve conceptual and design problems by mimicking or emulating the structure or performance of organisms and ecosystems that shape the natural world [START_REF] Fish | Biomimetics and Marine Technology: An Introduction[END_REF][START_REF] Taubes | Biologists and Engineers Create a New Generation of Robots That Imitate Life[END_REF][START_REF] Scott | Polymers: Secrets from the deep sea[END_REF] .

The starting point for biomimetics is the observation of the natural world. Yet the planet's largest habitat -the ocean -has been mostly inaccessible for virtually the entirety of human history. For 3.7 billion years, life has existed in the ocean (three times as long as on land), and the tremendous variety of habitats in the ocean has resulted in comparably diverse morphologies, physiologies and behavioral mechanisms [START_REF] Fish | Biomimetics and Marine Technology: An Introduction[END_REF][START_REF] Blasiak | The ocean genome and future prospects for conservation and equity[END_REF] . While it covers 71% of the Earth's surface, the vast majority of the ocean remains infrequently visited [START_REF]Fisheries and Aquaculture -Fisheries and Aquaculture -Deep-sea ecosystems[END_REF] and largely unseen. Deep-sea habitats in particular are among the least known on Earth [START_REF] Levin | Global Observing Needs in the Deep Ocean[END_REF] . The deepest point in the ocean, the Challenger Deep in the Mariana Trench, was visited for the first time by humans in 1960 -for a total of 20 minutes -and was not visited again for over 50 years [START_REF]Fisheries and Aquaculture -Fisheries and Aquaculture -Deep-sea ecosystems[END_REF][START_REF] Greenaway | Revised depth of the Challenger Deep from submersible transects; including a general method for precise, pressure-derived depths in the ocean[END_REF][START_REF] Than | Cameron Completes Record-Breaking Mariana Trench Dive[END_REF] .

Ocean exploration in recent decades has resulted in the discovery of deep-sea ecosystems where species have adapted to thrive under extremes of salinity, pressure, light and temperature, including hydrothermal vents (1979) and brine pools (1983) [START_REF] Levin | Hydrothermal Vents and Methane Seeps: Rethinking the Sphere of Influence[END_REF][START_REF] Corliss | Submarine Thermal Springs on the Galápagos Rift[END_REF][START_REF] Paull | Biological Communities at the Florida Escarpment Resemble Hydrothermal Vent Taxa[END_REF][START_REF] Mora | How Many Species Are There on Earth and in the Ocean?[END_REF] . The potential for future discovery is vast: half of the ocean reaches depths of 4,000 meters or more, only 20% of the seabed has been mapped [START_REF] Gebco | Mapping progress[END_REF] , and 70-90% of marine species remain undescribed [START_REF] Mora | How Many Species Are There on Earth and in the Ocean?[END_REF][START_REF] Appeltans | The Magnitude of Global Marine Species Diversity[END_REF] . Real-time feeds from unmanned deep-sea submersibles outfitted with the latest camera equipment are now freely available [START_REF]Nautilus Live | Ocean Exploration Trust[END_REF][START_REF]NOAA Ocean Exploration Livestream: Camera 1[END_REF][START_REF]Live from R/V Falkor[END_REF] , with thousands of people around the world sharing the experience of seeing unmapped parts of the seafloor and seamounts and unknown species for the first time. Museums around the world are filled with specimens and collections of deep-sea life [START_REF] Collins | Strengthening the global network for sharing of marine biological collections: recommendations for a new agreement for biodiversity beyond national jurisdiction[END_REF] , and thousands of genetic sequences [START_REF] Blasiak | Corporate control and global governance of marine genetic resources[END_REF] , and even complete genomes [START_REF] Scott | The Genome of Deep-Sea Vent Chemolithoautotroph Thiomicrospira crunogena XCL-2[END_REF][START_REF] Nakagawa | Deep-sea vent ε-proteobacterial genomes provide insights into emergence of pathogens[END_REF][START_REF] Wang | Morphology and genome of a snailfish from the Mariana Trench provide insights into deep-sea adaptation[END_REF] , of deep-sea organisms are freely accessible in online databases [START_REF]Genome List -Genome -NCBI[END_REF][START_REF]Sequence Read Archive[END_REF] .

Recent advances in ocean science and exploration have occurred alongside a dramatic expansion in the scope and diversity of ocean-based activities and industries [START_REF] Jouffray | The Blue Acceleration: The Trajectory of Human Expansion into the Ocean[END_REF] . Today's ocean economy encompasses multiple industries that add up to over USD 1.9 trillion revenues annually [START_REF] Virdin | The Ocean 100: Transnational corporations in the ocean economy[END_REF] , including industries as diverse as aquaculture, fisheries, oil and gas, offshore wind, cruise tourism, and marine biotechnology [START_REF] Jouffray | The Blue Acceleration: The Trajectory of Human Expansion into the Ocean[END_REF] . As the ocean economy has grown, so too has attention to issues of equity and inclusivity, as just 100 companiesmostly headquartered in the Global North -accounted for nearly 60% of the ocean economy in 2018 [START_REF] Virdin | The Ocean 100: Transnational corporations in the ocean economy[END_REF][START_REF] Österblom | Towards ocean equity[END_REF] . In line with the UN Sustainable Development Goals and Agenda 2030, a variety of aspirational narratives have emerged of the ocean as a source of development that is not only sustainable but also equitable and inclusive. This type of ocean economy has been described by some as a "blue economy", a term that has become widely used in recent years, but which remains without a broadly agreed definition 1 35,43-47 . A complementary narrative of "exploration before exploitation" [START_REF] Cordes | Exploration before exploitation[END_REF] underscores the loss that could accrue from 3 embracing emerging extractive industries in the ocean, such as mining the seabed for metals and minerals, especially in the deep sea where recovery from impacts is extremely slow or impossible [START_REF] Amon | Assessment of scientific gaps related to the effective environmental management of deep-seabed mining[END_REF][START_REF] Smith | Deep-Sea Misconceptions Cause Underestimation of Seabed-Mining Impacts[END_REF][START_REF] Levin | Challenges to the sustainability of deep-seabed mining[END_REF] .

If mining and hydrocarbon extraction represent one approach to ocean resources, marine biomimetics represents a starkly different paradigm of resource use: innovation driven by exploration and understanding of the natural world and the life and processes that shape it. Yet in assessments of ocean uses and the blue economy, biomimetics is frequently excluded [START_REF] Virdin | The Ocean 100: Transnational corporations in the ocean economy[END_REF][START_REF] Jouffray | The Blue Acceleration: The Trajectory of Human Expansion into the Ocean[END_REF][START_REF] Crona | Sharing the seas: a review and analysis of ocean sector interactions[END_REF][53][54][START_REF] Dnv | Ocean's Future to 2050: A sectoral and regional forecast of the Blue Economy[END_REF] , or lumped together as a vaguely defined "emerging industry" [START_REF]The EU Blue Economy Report[END_REF][START_REF]The Ocean Economy in 2030[END_REF] . We contend that marine biomimetics is a unique element of the ocean economy: vastly diverse and with key benefits for the viability of multiple industries; well-established rather than emerging; and worthy of greater attention in the context of aspirational narratives of a sustainable, inclusive and equitable blue economy. The diversity of marine species that have spurred innovation also underscores the value of effective ocean conservation, as marine systems grow increasingly stressed by a changing climate and other anthropogenic pressures.

In the following, we first present a review of key focal areas for biomimetic design based on marine life, which then provides context for a closer look at the growing list of instances in which deep-sea life has inspired innovative design and technologies. We conclude by noting benefits that could arise from a more systematic articulation of marine biomimetics in the context of efforts to transform today's ocean economy into a sustainable, inclusive and equitable blue economy.

Biomimetic design inspired by marine life

The study of marine life has yielded insights into a range of specialized adaptations that allow species to thrive in a diverse range of environmental conditions, and which have been a source of inspiration [START_REF] Fish | Biomimetics and Marine Technology: An Introduction[END_REF][START_REF] Anderson | Ocean Innovation: Biomimetics Beneath the Waves[END_REF] . Categorizing the diversity of ways in which this inspiration translates into applications remains complex, with a wealth of associated terminology (Table 1), and often multiple non-exclusive terms used to describe a single innovation using a variety of available typologies [START_REF] Anderson | Ocean Innovation: Biomimetics Beneath the Waves[END_REF][START_REF] Vattam | A content account of creative analogies in biologically inspired design[END_REF][START_REF] Nagel | Establishing Analogy Categories for Bio-Inspired Design[END_REF][START_REF] Nagel | Fostering Diverse Analogical Transfer in Bio-Inspired Design[END_REF][START_REF] Perera | Re-designing materials for biomedical applications: from biomimicry to nature-inspired chemical engineering[END_REF] (e.g. by function, process, architecture, or material). For instance, the tubercles on humpback whale flippers (see Section 2.5) have inspired the development of wind turbine blades, which are simultaneously "bio-inspired" (i.e. they are inspired by the structure of a natural material), "biomorphic" (i.e. they resemble the shape of a living thing), "biomimetic" (i.e. they mimic the structure of the flipper), and are also an example of "biomimicry" (i.e. they did not directly inspire the wind turbine, but rather a more sustainable and optimized design of the blades) [START_REF] Fish | Biomimetics and Marine Technology: An Introduction[END_REF][START_REF] Fish | Biomimetics and the Application of the Leading-Edge Tubercles of the Humpback Whale Flipper[END_REF][START_REF] Shi | Learning from Humpback Whales for Improving the Energy Capturing Performance of Tidal Turbine Blades[END_REF] .

In this Review, we follow the spirit of Otto Schmitt, who is credited with coining the term "biomimetics" in the 1950s and argued that biomimetics was simply the "transfer of ideas and analogues from biology to technology" [START_REF] Vincent | Biomimetics: its practice and theory[END_REF][START_REF] Harkness | Appreciation ¶A Lifetime of Connections: Otto Herbert Schmitt, 1913 -1998[END_REF] . A similar instinct for simplification was articulated by Vincent and co-authors, who suggested that biomimetics could be used synonymously with "'biomimesis', 'biomimicry', 'bionics', 'biognosis', 'biologically inspired design' and similar words and phrases implying copying or adaptation or derivation from biology" 2 . While recognizing the potential for further disambiguation, we opt for this broader framing of biomimetics, and introduce seven broad groupings of marine biomimetic applications (Figure 1).

Adhesion

The survival of many marine organisms depends on their capacity to adhere to underwater surfaces. The biomineralized adhesives produced by barnacles and oysters as well as the adhesive "byssus threads" used by mussels allow for permanent adhesion, while viscous adhesive proteins secreted by echinoderms like sea stars, sea cucumbers and sea urchins allow for temporary adhesion, locomotion and handling of food. [START_REF] Scott | Polymers: Secrets from the deep sea[END_REF][START_REF] Ehrlich | Marine biological materials of invertebrate origin[END_REF][START_REF] Kamino | Barnacle Underwater Attachment[END_REF][START_REF] Smith | The Biochemistry and Mechanics of Gastropod Adhesive Gels[END_REF][START_REF] Flammang | Adhesive Secretions in Echinoderms: A Review[END_REF][START_REF] Silverman | Understanding Marine Mussel Adhesion[END_REF] The bioadhesive glue of limpets are up to 97% water, yet are comparable in strength to the cements of oysters and barnacles, and the diversity of marine invertebrate and diatom species that produce bioadhesive gels represent a vast research frontier [START_REF] Ehrlich | Marine biological materials of invertebrate origin[END_REF][START_REF] Smith | The Biochemistry and Mechanics of Gastropod Adhesive Gels[END_REF][START_REF] Molino | Diatom Adhesives: Molecular and Mechanical Properties[END_REF][START_REF] Aldred | Progress in the Study of Adhesion by Marine Invertebrate Larvae[END_REF] . The biomimetic potential associated with understanding the structure and chemistry of marine bioadhesives has applications across diverse medical fields focused on bone repair [START_REF] Scott | Polymers: Secrets from the deep sea[END_REF][START_REF] Lalzawmliana | Marine organisms as a source of natural matrix for bone tissue engineering[END_REF] , dentistry [START_REF] Green | Evolving Marine Biomimetics for Regenerative Dentistry[END_REF][START_REF] Şenel | Application of Chitosan Based Scaffolds for Drug Delivery and Tissue Engineering in Dentistry[END_REF] , tissue engineering [START_REF] Lalzawmliana | Clinical Application of Biomimetic Marine-Derived Materials for Tissue Engineering[END_REF] and as surgical sealants [START_REF] Heher | An overview of surgical sealant devices: current approaches and future trends[END_REF][START_REF] Gohar | Driving Medical Innovation Through Interdisciplinarity: Unique Opportunities and Challenges[END_REF][START_REF] Qiu | Bioadhesives in neurosurgery: a review[END_REF] , as well as in the construction of vessels and facilities in the marine environment, particularly when these require coatings and paints that need to adhere to water-facing surfaces [START_REF] Kamino | Underwater Adhesive of Marine Organisms as the Vital Link Between Biological Science and Material Science[END_REF][START_REF] Cholewinski | Algae-mussel-inspired hydrogel composite glue for underwater bonding[END_REF][START_REF] Zhao | Bio-inspired reversible underwater adhesive[END_REF][START_REF] Heinzmann | Supramolecular polymer adhesives: advanced materials inspired by nature[END_REF][START_REF] Shao | Biomimetic Underwater Adhesives with Environmentally Triggered Setting Mechanisms[END_REF] . Similarly, proteins in the byssus threads that mussels use to attach to surfaces have inspired the development of adhesives, which are infused with cerium-oxide nanoparticles [START_REF] Xu | Cerium oxide nanoparticle: a remarkably versatile rare earth nanomaterial for biological applications[END_REF] to provide anti-corrosion properties when applied to metal surfaces [START_REF] Zhang | Recent Development of Corrosion Protection Strategy Based on Mussel Adhesive Protein[END_REF][START_REF] Sababi | Corrosion Inhibiting Coating Based on Cerium Oxide and a Catecholic Polymer[END_REF] .

Antifouling

Wherever solid surfaces are found in the ocean, marine organisms begin to adhere to them, using the whole suite of chemical and structural adhesive capacities described in the previous section. This is a process called biofouling, namely the unwanted accumulation of such organisms to everything from submarine hulls to the cooling water intake pipes at nuclear power plants, and the implications for marine industries are severe. Biofouled ships, for instance, consume more fuel due to greater weight and increased friction, and potentially transfer invasive species across oceans [START_REF] Chen | Biomimetic surface coatings for marine antifouling: Natural antifoulants, synthetic polymers and surface microtopography[END_REF][START_REF] Hewitt | The Vessel as a Vector -Biofouling, Ballast Water and Sediments[END_REF] . The economic losses associated with marine biofouling currently cost marine industries over USD 150 billion annually [START_REF] Chen | Biomimetic surface coatings for marine antifouling: Natural antifoulants, synthetic polymers and surface microtopography[END_REF][START_REF] Manolakis | Recent Advances in Mussel-Inspired Synthetic Polymers as Marine Antifouling Coatings[END_REF][START_REF] Nurioglu | Non-toxic, non-biocide-release antifouling coatings based on molecular structure design for marine applications[END_REF] , with estimates of the global market for marine coatings predicted to top USD 15 billion by 2024 [START_REF] Chen | Biomimetic surface coatings for marine antifouling: Natural antifoulants, synthetic polymers and surface microtopography[END_REF] . Conventional biocides and antifouling paints used for antifouling carry a heavy environmental impact, including bioaccumulation of organotins and copper in marine mammals and other marine life [START_REF] Amara | Antifouling processes and toxicity effects of antifouling paints on marine environment. A review[END_REF][START_REF] Bergman | Environmental impacts of alternative antifouling methods and use patterns of leisure boat owners[END_REF] . Biomimetic approaches to address these issues have focused in particular on the natural coatings and compounds produced by marine organisms [START_REF] Chen | Biomimetic surface coatings for marine antifouling: Natural antifoulants, synthetic polymers and surface microtopography[END_REF][START_REF] Fusetani | Antifouling marine natural products[END_REF][START_REF] Ralston | Can Biomimicry and Bioinspiration Provide Solutions for Fouling Control?[END_REF] , including ascidians [START_REF] Levert | Antifouling Activity of Meroterpenes Isolated from the Ascidian Aplidium aff. densum[END_REF] , macroalgae, [START_REF] Salama | Antifouling activities of methanolic extracts of three macroalgal species from the Red Sea[END_REF] algal compounds [START_REF] Saha | Minireview: algal natural compounds and extracts as antifoulants[END_REF] , marine bacteria [START_REF] Dobretsov | Inhibition of marine biofouling by bacterial quorum sensing inhibitors[END_REF][START_REF] Aguila-Ramírez | Antifouling activity of symbiotic bacteria from sponge Aplysina gerardogreeni[END_REF] and sponges, presumably in an effort to avoid biofouling themselves 100 . Another rich source of inspiration has been the development of biomimetic surfaces based on the microtopography of marine organisms that function as natural antifoulants [START_REF] Ralston | Can Biomimicry and Bioinspiration Provide Solutions for Fouling Control?[END_REF] , including common marine shells, 101 crustaceans 102 , seaweed 103 , and sharkskin 104,105 .

Armor

The scales of fish have evolved to provide multiple benefits, most notably providing armoured protection without sacrificing flexibility. The scales of fish (and snakes) were likely already inspiring the development of armors in human antiquity, and Ehrlich notes historical examples extending back to the time of the Persian and Roman empires in which scale armor is referenced or depicted [START_REF] Ehrlich | Marine biological materials of invertebrate origin[END_REF]106 . The flexibility and protective properties of scales continue to inspire armor designs today 107,108 . The shells of mollusks have also inspired biomimetic designs (including military armor 109,110 ), with their nacreous layers outperforming conventional ceramics with regard to toughness and both tensile and compressive strength 111 . The biomineralization process through which shells form has been the subject of substantial research [112][113][114] , and multi-layered ceramics and composites inspired by seashell nacre are in development 111,115 . Mantis shrimps, a frequent source of inspiration (see also Section 2.6), possess a pair of appendages called dactyl clubs that they use to strike prey at speeds comparable to a fired bullet with a force of up to 153 kilograms (although mantis shrimps themselves only weigh 12-90 grams) 116 . The periodic helical structure of the layered fibers in mantis shrimp dactyl clubs and lobster claws have been studied and resulted in bioinspired fiber composite laminates with increased resistance to impact force, denting and cracking 117,118 .

Buoyancy

Neutral buoyancy can be an important asset for movement underwater [119][120][121] , and led to the evolution of swim bladders in fish some 400 million years ago [START_REF] Anderson | Ocean Innovation: Biomimetics Beneath the Waves[END_REF] . These gas-filled sacs are flexible and adjustable, with fish equilibrating them to provide neutral buoyancy at the topmost reaches of their respective habitats [START_REF] Anderson | Ocean Innovation: Biomimetics Beneath the Waves[END_REF]122 . Biomimetic design based on the swim bladder can be found during the Renaissance, with Giovanni Borelli publishing drawings of what could have been the world's first submarine in 1680 [START_REF] Fish | Biomimetics and Marine Technology: An Introduction[END_REF]123 (although no evidence exists that this project moved beyond conceptual drawings). Borelli's illustrated plate (Figure 2) includes not only biomimetic use of goatskin bags as a hydrostatic mechanism to submerge the submarine, but also a conceptualized diver who can move underwater using a large goatskin bag that was meant to double as a source of air and an adjustable buoyancy device 123 . The latter innovation foreshadowed a modern-day buoyancy compensation device, that itself mimics the fish's swim bladder, and enables divers to closely control their buoyancy [START_REF] Anderson | Ocean Innovation: Biomimetics Beneath the Waves[END_REF] . Buoyancy is a ubiquitous concern for operations at sea and underwater, and today there are a number of underwater robots, autonomous gliders and submersibles that have drawn inspiration not just from fish and their buoyancy-related movements 124 , but from marine species as diverse as whales 125,126 , dolphins 127,128 , jellyfish [129][130][131] , lobsters 129,132,133 , and copepods 134 .

Figure 2: Panel from "On the Motion of Animals" (De Motu Animalium) by Giovanni Alfonso Borelli (1680) illustrating the properties of fish swim bladders (upper left), and how they have inspired biomimetic design of a submarine using air-filled goatskin bags (lower right) as well as a diver's buoyancy device and tank of air (lower left). 123

Movement

The movement of life below water has been perhaps the richest -and one of the most varied -sources of inspiration for biomimetic design. During the Renaissance, Juliana Berners (15 th century) and Leonardo da Vinci (16 th century) were already remarking on the movement of water eddies, with the latter noting how the streamlined shape of fish could reduce drag [START_REF] Fish | Biomimetics and Marine Technology: An Introduction[END_REF]135,136 . The fusiform design of some fish, with rounded heads and bodies that gradually taper back to the tail, inspired (unsuccessful) biomimetic boat design efforts in the early 19 th century based on close studies of the movements of dolphins and trout, and, much later, (successful) design of nuclear submarines [START_REF] Fish | Biomimetics and Marine Technology: An Introduction[END_REF]137 . While the shape and movement of dolphins continue to be a source of inspiration 127,138 , finned fishes too have drawn intense interest [139][140][141] , as have sharks 142,143 and rays 144,145 . The fluid mechanics associated with rounded tubercles on the flippers of humpback whales have inspired design both below and above water, most notably in the shape of wind turbines, tidal turbines and even surfboards [START_REF] Fish | Biomimetics and the Application of the Leading-Edge Tubercles of the Humpback Whale Flipper[END_REF][START_REF] Shi | Learning from Humpback Whales for Improving the Energy Capturing Performance of Tidal Turbine Blades[END_REF]146,147 , while the flexible waving of macroalgae has led to the development of kelp-inspired wave energy generators 148 . The body design and propulsive systems of other marine life have inspired additional libraries of biomimetic design, including the jet propulsion and shape of squids [START_REF] Anderson | Ocean Innovation: Biomimetics Beneath the Waves[END_REF][149][150][151] and other mollusks 152 , the movement of siphonophores 153,154 , and the bell shape and contractions of jellyfish [START_REF] Anderson | Ocean Innovation: Biomimetics Beneath the Waves[END_REF]131,149,[155][156][157] . Applications extend from underwater vehicles all the way to the design of robots and spaceships specially adapted to explore other planets with starkly different atmospheric and gravitational conditions 158 . Recent advances in experimental modelling methods have even rendered the shape and movement of extinct marine animals such as plesiosaurs a source of rich biomimetic inspiration for the design of underwater robotics [159][160][161][162][163][164] .

Sensory

The sensory environment under water is distinctly different from above, with water rapidly absorbing light, and currents dispersing chemical trails [START_REF] Anderson | Ocean Innovation: Biomimetics Beneath the Waves[END_REF] . Consequently, marine life possesses sensory capacities particularly adapted to this environment. Elephant seals, for instance, vibrate their facial whiskers to help locate and pursue prey 165 , while dolphins and some whales are able to produce high-frequency sounds that enable them to echolocate prey [START_REF] Anderson | Ocean Innovation: Biomimetics Beneath the Waves[END_REF]166,167 . Dolphins and humpback whales also famously use bubble nets to gather their prey into confined spaces, and while traditional sonar fails in environments with heavy sedimentation or bubbles, they still find their prey [START_REF] Anderson | Ocean Innovation: Biomimetics Beneath the Waves[END_REF]168,169 . Biomimetic work on developing dolphin-inspired sonar and radar is ongoing, leading to the development of sonar movement tags for tracking animal movements 170 , with vast potential implications for maritime navigation 171 . Another novel sensory adaptation is found in sharks, which use their electrosensory system to detect the weak electric field generated by fish. Sharks also possess a "cerebellum chip" that identifies their own electric field and is able to account for this when processing external electromagnetic signals [START_REF] Anderson | Ocean Innovation: Biomimetics Beneath the Waves[END_REF] . Both the system of electroreceptors and the shark's ability to process this data have inspired the development of various innovations including sensors and artificial electroreceptors [START_REF] Anderson | Ocean Innovation: Biomimetics Beneath the Waves[END_REF]172,173 . A final sensory adaptation of note in the marine world is optical, as exemplified perhaps most spectacularly in the world's 450 species of mantis shrimp. Among other things, mantis shrimp eyes are compound, can move independently of one another, rotate up to 70 degrees in any direction, and see 16 channels of color (humans can process three) as well as ultraviolet and polarised light 174 . Associated biomimetic work has focused on adaptively enhancing contrast vision 175 , developing novel photodetectors 176 , and enhancing satellite imagery 177 .

Stealth

Marine life has evolved a diverse range of stealth adaptations, including passive camouflage that mimics background environment, and translucency that renders species almost invisible [START_REF] Anderson | Ocean Innovation: Biomimetics Beneath the Waves[END_REF] . Some species seek to mimic the appearance of other species that are poisonous, an approach also used in the design of banded surfboards and wetsuits meant to deter shark attacks by mimicking the patterns of banded seasnakes [START_REF] Anderson | Ocean Innovation: Biomimetics Beneath the Waves[END_REF]178 . The active camouflage used by cephalopods like octopi and cuttlefish to opportunistically mimic substrates has drawn intense interest 179 due among other things to its rapidity, with chromatophores that can flash different colors roughly five times every second [START_REF] Anderson | Ocean Innovation: Biomimetics Beneath the Waves[END_REF] . Cephalopod chromatophore cells have inspired the development of artificial skin 180,181 , paint-like coatings that can be triggered to change color 182,183 and artificial chromatophores 184,185 .

Other applications

While the previous sub-sections showcase some of the broader categories of marine biomimetics, they are pieces of a vibrant and rapidly expanding discipline. A comprehensive list would include the many biomimetic designs based on chitin [186][187][188][189] and collagen [190][191][192] , design and automation based on the schooling behavior of fish 193,194 , architecture inspired by marine species 195 , electrochemical batteries inspired by electric rays [START_REF] Anderson | Ocean Innovation: Biomimetics Beneath the Waves[END_REF]196 , use of coral skeletons as bone tissue scaffolds [197][198][199][200] , and many other innovations. In an even broader sense, groups of organisms and even entire ecosystems can be a source of inspiration, as in the case of coral reefs serving as an inspiration for industrial symbiosis 201 or nature-based solutions (Table 1) such as artificial reefs and coastal protection measures 202,203 .

Looking further to the periphery of marine biomimetics, two additional categories of innovation are of interest. The first of these, marine biodiscovery, often extends beyond biomimetics into the world of bioutilization, with marine natural products (secondary metabolites produced by marine organisms) being collected and subsequently used or modified to produce both medical and non-medical products. Some 700 new marine natural products are being discovered on an annual basis, and a total of nearly 40,000 have been identified to date 204,205 . In some cases, the proteins associated with marine natural products provide direct inspiration for the development of novel synthetic constructs. Iconic examples of commercial products originating from marine biodiscovery include a suite of marine drugs (20 or which are in clinical use today 206 , while at least 33 more are in clinical trials) [207][208][209] . The rates of successful drug discovery from marine natural products is up to four times higher than their terrestrial counterparts, suggesting rich further potential 210,211 . Looking beyond the specific instance of marine drugs, the study of marine life has been crucial for fundamental breakthroughs in medical science and beyond, including for instance the discovery of green fluorescent protein in the jellyfish Aequorea victoria (used for broad range of medical and biological applications) 212,213 , and understanding the cell cycle through experiments on sea urchins (and subsequent discovery of cyclins and associated drugs) 214 . Collectively, 13 Nobel Prizes in Chemistry and Medicine have been awarded for work on marine organisms 215 .

The second category of innovations located on the periphery of marine biomimetics does not look at individual organisms and ecological systems, but rather the conditions that create their environments, namely geomimetics (material design inspired by natural geological syntheses and natural materials formation) 216 . An extreme case under this umbrella is geomimetic design based on hydrothermal synthesis (i.e. methods for crystallization under conditions of high pressure and temperature), although analogue systems exist not only in the ocean (e.g. hydrothermal vent systems, which can be found in both the shallow and deep sea), but also hot acidic springs on land 216 . Hydrothermal synthesis has been used to generate both inorganic materials such as zeolite and synthetic gemstones, as well as organic "green" polymers 217 and polyimide-based covalent organic frameworks, which are promising materials for use as anodes in lithium-ion batteries 216,218 .

The deep sea as a source of inspiration

From an anthropocentric perspective, the deep sea is a place of extremes: the largest biome on Earth, where sunlight does not penetrate, where pressures force us into thick-walled submersibles, and with a diversity of environments characterized by extremes 219 . But what is extreme to us is attractive to others, with entire classes of organisms that thrive in extremes of temperature (thermophiles), acidity (acidophiles/alkaliphiles), salinity (halophiles), pressure (barophiles), and high metal concentrations (metalophiles) 216,220 . All such conditions are present in the deep sea, and often in combination, providing habitats for polyextremophiles (microorganisms that benefit from environments characterized by multiple of these "extreme" conditions) 216,221 .

Wherever we have looked for life in the deep ocean, we have found it, with over 25,000 deep-sea species already included in the World Register of Deep-Sea Species (WoRDSS), and likely orders of magnitude more yet to be described [START_REF] Blasiak | The ocean genome and future prospects for conservation and equity[END_REF][START_REF] Mora | How Many Species Are There on Earth and in the Ocean?[END_REF]222 . While various depths have been suggested as the starting point of the "deep ocean" 223 , here a 500 meter threshold is considered in line with the WoRDSS database 219,222 . In contrast to section 2, which provides a brief review of broad categories of marine biomimetics, the following sub-sections focus on individual deep-sea species and species groupings that have been a source of inspiration for diverse applications.

Deep-sea fishes

All the better to see you with -the Brownsnout spookfish and Glasshead barreleye fish

No light extends beyond 1,000 meters into the ocean, but some faint traces of residual daylight persist at depths from 500-1,000 meters, and a range of species in this zone produce bioluminescence 224 creating a unique sensory environment. A number of mesopelagic teleost fishes have evolved unique eyes that benefit from both sources of light (through a combination of reflective and refractive optics) (Figure 3A), with the two moststudied species being the brownsnout spookfish (Dolichopteryx longipes) and the glasshead barreleye fish (Rhynchohyalus natalensis) [224][225][226][227] . The reflective eyes of decapods like lobsters spurred advances in the field of astrophysics, namely the development of "lobster-eye" Xray telescopes 228,229 , and the biomimetic design potential of further telescope innovations focused on the unique tilting of mirror plates in D. longipes eyes has been suggested 230,231 . A recent study created advanced models to test the optical performance of D. longipes, paving the way to the development of optical systems that can function in harsh environments including the deep sea 232 . Other examples of biomimetic design are found in architecture, where the mirrored eyes of D. longipes inspired concepts of energy-saving roof designs by making optimal use of available daylight 233,234 , as well as in the design of a streamlined passenger car based on the body line of R. natalensis 235 .

All the better to eat you with -the Deep-sea dragonfish

While the structural properties of marine species have inspired the development of novel ceramics and related materials, such efforts have often focused on the nacreous layers of (coastal) mollusk shells. In the deep sea, the dragonfish (Aristostomias scintillans) initially attracted study due to its uniquely transparent teeth, which are thought to be an adaptation enabling further stealth, with the teeth becoming virtually invisible even in proximity to light produced by bioluminescent species (Figure 3B) 236 . A materials science approach to understanding A. scintillans teeth found that their transparency arises from a unique nanoscale structure, which also contributes to levels of hardness and sharpness comparable to the teeth of piranhas and great white sharks 236 and a source of inspiration for researchers looking to develop transparent ceramics 237 .

Moving under pressure -the Mariana snailfish

The morphology and movement of dolphins and trout have inspired vessel design in shallow waters. Likewise, the development of vessels that can move in the deep sea benefits from close study of deep-sea life. In 2017, scientists discovered a new hadal snailfish species (Pseudoliparis swirei) 238 in the Mariana Trench and collected specimens at depths of over 6,000 meters 29 (Figure 3C). A close study of its morphology in 2019 [START_REF] Wang | Morphology and genome of a snailfish from the Mariana Trench provide insights into deep-sea adaptation[END_REF] contributed to the spectacular development of an untethered soft robot with multiple points of inspiration from P. swirei, including the use of thin, flapping pectoral fins, and the distribution of comparatively heavier electronics within the robot's "head" similar to the distributed weight of the snailfish's skull 239 . The soft robot was successfully field-tested at a depth of 10,900 meters in the Mariana Trench, underscoring the potential of increased deep-ocean exploration through the development of additional soft robots that can function in conditions of extreme pressure 239 .

High-performance slime -the Atlantic Hagfish

The Atlantic hagfish (Myxine glutinosa) is an ancient species that is recognizable in fossils from 300 million years ago, and which is unique in the animal kingdom as having a skull but no spinal column 240 . The hagfish's defensive slime -which it produces in vast quantities within fractions of a second and is characterized by thousands of silklike protein threads 240has attracted curiosity for hundreds of years and transcended the scientific community to enter popular culture [241][242][243] . A search of the World Intellectual Property Organization (WIPO) Patentscope database 244 in July 2022 found 1,170 patents that reference the hagfish, with applications including use of slime threads for high-performance fibers, safety helmets, bulletproof vests, and even anti-shark sprays 241,242,245,246 .

Figure 3: Inspiration from deep-sea species. Life in the deep sea is specially adapted to thrive in areas characterized by high pressure, absence of sunlight and limited nutrients. Examples include (A) the mirrored eyes of mesopelagic teleost fish like the Glasshead barreleye fish; (B) the transparent teeth of the deep-sea dragonfish; (C) the morphology of the Mariana snailfish (note the CT scan revealing a small crustacean, the green shape, in the snailfish's stomach); (D) antifouling compounds extracted from deep-sea sponges; (E) the air-filled shell that provides buoyancy to the Ram's horn squid, and (F) the armored shell of the Scaly-foot snail. Photo credits: (A) and (B) MBARI; (C) Adam Summers/University of Washington; (D) CoralFISH/Havforskningsinstituttet ; (E) Schmidt Ocean Institute; (F) Chong

Chen.

Deep-sea sponges

Skeletons of the deep -deep-sea sponges

Deep-sea sponges have attracted intense interest, as they are known to form siliceous skeletons characterized by high levels of porosity that can act as natural tissue scaffolds 247- 250 . A challenge of treating bone defects in humans is the need for bone substitution materials, with the traditional sources being the patient themself (autogenous grafts), other individuals of the same species (allograft materials), or non-human species (xenografts) 251 . The former is frequently not available, and the latter two carry risk of disease transmission and host rejection, posing a major biomedical challenge. 251 Siliceous scaffolds provide an attractive source of either xenografts or biomimetic constructs inspired by their structure 248 . A recent study found diversity in porosity and pore size among representative deep-sea sponge species (Geodia barretti, Geodia atlantica, Stelletta normani, Phakellia ventilabrum, and Axinella infundibuliformis), suggesting varying inspirations for tissue engineering applications 248 .

High-definition flow simulations of the deep-sea sponge Euplectella aspergillum have shed light on the internal architecture of sponge skeletons and their capacity to reduce hydrodynamic stress 252 , while other simulations of its grid-like structure and bracings resulted in biomimetic lattice geometries with implications for the design and resilience of modern infrastructure, and minimizing the amount of material needed for construction 195,253,254 . One of the most iconic such examples is "The Gherkin" in London's financial district, which due to its design is claimed to function on half the energy of a similarly sized office building 195 . Similar structural analysis of the giant anchor spicules of Monorhaphis chuni have found optimized designs highly resistant to fractures and cracking, while simultaneously possessing optical properties enabling the transmissibility of visible light with potential fiber-optic applications 255,256 . The porous skeletons of deep-sea sponges have also inspired biomimetic design, with synthetic porous carbon fibers found to achieve high levels of absorption of oils and organic solvents, suggesting future use in bioremediation 257 . Likewise the stiffness and toughness of sponge skeletons has inspired the development of novel multi-layered pipewalls 258 . Patent filings associated with deep-sea sponges include the production of a novel antifouling compound from Geodia barretti (Figure 3D) 259 , and a composite material based on the silicated collagen matrix of the glass rope sponge, Hyalonema sieboldi 260 .

Other deep-sea fauna

Moving rapidly between depths -the Ram's horn squid While squids do not have internal buoyancy mechanisms comparable to the swim bladders of fish, an unusual variation is found in the Ram's horn squid (Spirula spirula), a deep-sea cephalopod mollusk that practices diel vertical migration, generally remaining at depths of 600-700 meters during the day to avoid predation, and rising at night to depths of 100-300 meters to feed [START_REF] Anderson | Ocean Innovation: Biomimetics Beneath the Waves[END_REF]261 . The "Ram's horn" of S. spirula comes from its capacity to manufacture a hollow gas-filled shell that remains almost entirely within its body, and which grows and adds chambers in an expanding spiral form throughout its life (Figure 3E) [START_REF] Anderson | Ocean Innovation: Biomimetics Beneath the Waves[END_REF] . While fish swim bladders can equilibrate somewhat to differing depths and pressures 122,262 , this process is slow. The much more rapid diel vertical migration of S. spirula is mediated by its rigid shell (although the shells implode at depths of 1,500 meters, marking a clear depth limit for the species) [START_REF] Anderson | Ocean Innovation: Biomimetics Beneath the Waves[END_REF]261 . Anderson and co-authors note that the biomimetic design of the Deepsea Challenger manned submersible, which descended to the ocean's deepest point (10,911 meters) in 2012, drew on both the shape and vertical orientation of S. spirula, as well as its shell, which it mimicked with a low-density foam of hollow microballoons [START_REF] Than | Cameron Completes Record-Breaking Mariana Trench Dive[END_REF][START_REF] Anderson | Ocean Innovation: Biomimetics Beneath the Waves[END_REF]263 .

The finest protection -the Scaly-foot snail

The scaly-foot snail (Chrysomallon squamiferum) is a gastropod mollusk species that was discovered in 1999 and has since been found on three hydrothermal vent systems at depths of over 2,400 meters 264 . Chrysomallon squamiferum is heavily armored, enabling it to survive the attacks of crabs that have been known to squeeze C. squamiferum in their claws for days (Figure 3F) 265,266 . Similar to other mollusks, C. squamiferum has a multilayered shell, but its iron-infused outer layer is unique (derived from the mineral-rich vent fluids) and followed by a thick organic layer and a third stiff mineralized layer, yielding remarkable protection that has attracted the attention of the US Department of Defense, which has funded research to explore its biomimetic potential for armor development 265,266 .

Non-toxic antifouling -Streptomyces albidoflavus strains

The bacterium Streptomyces albidoflavus is ubiquitous, with strains isolated from sources as diverse as a golf course in Korea 267 , a mangrove leaf in China 268 , soil in Poland 269 , and sediments collected at a depth of 5,100 meters in the Western Pacific Ocean 270 . Noting the many novel compounds that have been identified in marine Streptomyces, the latter strain (S. albidoflavus sp. UST040711-291) was cultured, and a set of five structurally similar compounds were isolated and studied 270,271 . Testing of the S. albidoflavus compounds identified functional properties, associated with the 2-furanone ring, that delivered powerful antifouling outcomes, leading the research group to file a corresponding patent on associated non-toxic antifouling derivatives 270,272 .

Revitalizing potentials -Cold-water corals

The cold-water coral Lophelia pertusa can be found at depths of up to 3,000 meters and is extremely slow growing, with radiocarbon dating suggesting it can live for up to 1,000 years, and form reefs that have been dated at over 40,000 years old 273 . It is highly vulnerable to deep-sea fishing gears 274 as well as oil exploration and extraction practices 275 . Such environmental concerns have led to experimentation with L. pertusa to understand the impacts of sedimentation and discard of drill cuttings 276 , as well as development of a biomimetic sensor that could monitor the deep-water sea-floor for impacts from drilling activities, using a system of cameras interspersed with nubbins and polyps of L. pertusa 277 . Likewise, while deep-sea sponge skeletons have drawn the most active interest in the development of biomimetic tissue scaffolds for biomedical applications, the structure of deep-sea bamboo corals (Isididae) has noted potential as a bone implant or substrate for bone revitalization [START_REF] Ehrlich | Marine biological materials of invertebrate origin[END_REF]250,278 .

A "Forgotten" Ocean Economy Sector: Current Challenges and Future Opportunities

As illustrated in this Review, the field of marine biomimetics is characterized by diversity: in the diversity of innovations it has generated, in the diversity of species that have provided inspiration (from megafauna to microorganisms) and in the diversity of ocean environments that sustain these species from the coastal zone to the deep sea. Furthermore, the economic value of innovations inspired by marine life is substantial (Box 1). Other key components of biomimetics -imagination, imitation, and inspiration -are universal elements of the human experience, suggesting the potential for marine biomimetics as a productive activity across geographies.

Where diversity is less evident, however, is in the beneficiaries of marine biomimetics. The majority of innovations identified in this Review are associated with industries disproportionately headquartered in the world's most highly industrialized countries: shipping, robotics, biomedical/biotechnology, wind energy, etc [START_REF] Virdin | The Ocean 100: Transnational corporations in the ocean economy[END_REF][START_REF] Jouffray | Blue Acceleration: An Ocean of Risks and Opportunities[END_REF] . Similarly, the capacity to cover costs of developing innovations and to subsequently access relevant industry counterparts may be a particular challenge to ensuring these activities are inclusive and the benefits are equitably shared (e.g. the timeline for bringing a new pharmaceutical to market can stretch across decades with costs of up to USD 1 billion [START_REF] Blasiak | Corporate control and global governance of marine genetic resources[END_REF]210 ). Although capacity building is a recognized priority of the UN Decade of Ocean Science for Sustainable Development 2021-2030 including for deep-sea research 279,280 , investments in marine science as well as contributions to the peer-reviewed literature remain highly skewed towards the world's most highly industrialized countries 281 . Marine biomimetics has also been largely neglected in blue economy strategies and framings [START_REF] Virdin | The Ocean 100: Transnational corporations in the ocean economy[END_REF][START_REF] Jouffray | The Blue Acceleration: The Trajectory of Human Expansion into the Ocean[END_REF][START_REF]The EU Blue Economy Report[END_REF][START_REF] Crona | Sharing the seas: a review and analysis of ocean sector interactions[END_REF][53][54][START_REF] Dnv | Ocean's Future to 2050: A sectoral and regional forecast of the Blue Economy[END_REF][START_REF]The Ocean Economy in 2030[END_REF] , and we suggest this may be related to the complexity and diversity of marine biomimetic applications as well as challenges in credibly valuing its economic benefits. While the economic value of innovations inspired by marine life can be estimated in some cases (Box 1), relying solely on monetary valuations would be a missed opportunity for articulating the unique position marine biomimetics could play in the blue economy, and for understanding the full value of nature [START_REF] Claudet | Transformational opportunities for an equitable ocean commons[END_REF]282 . Marine biomimetics does not depend on continuous marine resource use or extraction, and often results in innovations that reduce pollution, energy loss, or emissions, giving it a vanishingly light footprint alongside the stomping footprints of conventional ocean industries like cruise tourism or offshore oil and gas extraction. This will position marine biomimetics as a useful illustration of a blue economy sector if it can ensure that it not only drives sustainability, but also equity and inclusivity, while also spurring greater support for funding basic research on the ocean and the life it contains.

Marine biomimetics is particularly reliant on access to well-functioning marine ecosystems and the capacity to study these. The degradation of marine ecosystems has been widelydocumented and reported 53,283 . Iconic marine ecosystems like tropical reefs, for instance, face an existential threat from climate change and increasingly frequent marine heatwaves 284 , which are also a risk to deep-sea ecosystems 285 . Similarly, some of the most remote and least-studied deep-sea environments on Earth have an uncertain future as proponents of mining the international seabed push towards commercial operations, as hydrocarbon extraction moves into deeper and riskier waters, and with continuing use of destructive fishing gears that persist even in purportedly protected areas [START_REF] Jouffray | Blue Acceleration: An Ocean of Risks and Opportunities[END_REF][START_REF] Amon | Assessment of scientific gaps related to the effective environmental management of deep-seabed mining[END_REF]286,287 .

Can articulating the role and potential of marine biomimetics in the ocean economy prompt greater awareness of the benefits derived from the ocean? Can marine biomimetics be a sustainable ocean sector at the very heart of the blue economy, sparking inclusive and equitable collaborations across geographies, cultures and disciplines? Can marine biomimetics become a clear illustration of the importance of non-monetary valuation, spurring the protection of marine ecosystems as permanent repositories of inspiration? Can it inspire care, and ultimately a sense of stewardship? In this manuscript, we have illustrated the diverse scope and scale of marine biomimetics, and propose that working to address the challenges and questions in this section represents a rich research agenda and action space for scientists and policymakers alike.

Box 1: Examples of revenues and costs associated with key areas of marine biomimetics.

For comparison, estimated annual revenues of key ocean economy sectors include the offshore wind industry (USD 37 billion), cruise tourism (USD 47 billion), container shipping (USD 156 billion), seafood (276 billion), offshore oil and gas (USD 830 billion) [START_REF] Virdin | The Ocean 100: Transnational corporations in the ocean economy[END_REF] • Rust. According to estimates, in Sweden alone, the annual costs associated with corrosion total approximately SEK 90 billion (USD 9.5 billion) 288 . The development of biomimetic adhesive coatings, for instance with ceria nanoparticles inspired by mussel byssus threads, aim to cut corrosion rates (see section 2.1 on marine adhesives) [START_REF] Zhang | Recent Development of Corrosion Protection Strategy Based on Mussel Adhesive Protein[END_REF] .

• Biofouling. The global market for marine coatings is predicted to top USD 15 billion by 2024, and the economic losses associated with marine biofouling currently cost marine industries over USD 150 billion annually [START_REF] Chen | Biomimetic surface coatings for marine antifouling: Natural antifoulants, synthetic polymers and surface microtopography[END_REF][START_REF] Manolakis | Recent Advances in Mussel-Inspired Synthetic Polymers as Marine Antifouling Coatings[END_REF][START_REF] Nurioglu | Non-toxic, non-biocide-release antifouling coatings based on molecular structure design for marine applications[END_REF] (see section 2.2 on marine antifoulants).

• Tissue scaffolds. In the United States alone, over 49 tissue-engineering companies have been established (including 21 companies in the commercial phase of development and generating sales of an estimated USD 9 billion annually in 2017 289 (see sections 2.8 and 3.2 on tissue scaffolds).

• Robotics. The global underwater robotics market size is expected to reach USD 6.74 billion by 2025 290 , benefiting heavily from biomimetic design focused on the morphology and physiology of marine species (see sections 2.3-2.5, 3.1 and 3.3 on movement, armor and buoyancy).

• Pharmaceuticals. Revenues from five "marine drugs" (FDA-approved pharmaceuticals with compounds derived, synthesized or inspired by naturallyoccurring marine natural products -Adcetris, Halaven, Lovaza, Prialt and Yondelis) totalled over USD 12.1 billion from 2011-2020 (see section 2.8 and supplementary materials). Janine Benyus, 1997 293

Biomimetics

The process of mimicking the formation, structure or function of a biologically produced substance or material in order to produce or synthesize an artificial product. Derived from the Greek words bios, meaning "life", and mimesis, meaning "to imitate", biomimetics was coined by inventor Otto Schmitt

Figure 1 :

 1 Figure 1: Marine biomimetics. The diverse morphological, physiological and behavioral characteristics of marine species have inspired innovations that extend across diverse industries. Photo credits from left to right, first row: NOAA; Christian Gloor; CC0 Public Domain ; Luc Viatour; CC0 Public Domain ; Cédric Péneau; Christian Gloor. Second row: CC0 Public Domain; CC0 Public Domain; CC0 Public Domain; Jennifer Frame/JenniFish Ocean Test; CC0 Public Domain; NASA; SAMS.

Table 1 :

 1 Key concepts associated with nature-inspired activities

	Concept	Description	Sustainability	Main sectors/disciplines	Examples [inspired	Key reference(s)/origin
					by]
	Biomimicry	Learning from and then	Main focus	Ecologists, architects, city	Shinkansen 500 series
		emulating nature's forms, processes, and ecosystems to		planners	bullet trains in Japan [kingfisher] 291 ,
		create more sustainable			ventilation in Eastgate
		designs			Centre, Harare [termite nest] 292

  [START_REF] Harkness | Appreciation ¶A Lifetime of Connections: Otto Herbert Schmitt, 1913 -1998[END_REF]294 .

					swimming in fish	305
	Bio-utilisation	The direct use of nature for	Occasionally	Medicine, renewable	Gathering medicinal	Youyou Tu, 2011.	306
		ecological benefits		energy sector	plants; growing algae
					to make biofuels;
					cultivation of
					Artemisia annua to
	Bioremediation	or microbial or plant enzymes, to detoxify contaminants in Use of microorganisms, plants,	Frequently Main focus	Material engineering, industrial design Environmental engineering, Using bacteria to Velcro [burdock] 295 , gecko tape [gecko] produce malaria drug 306 artemisinin 296 , [sharks] 297 oilspills 307,308 , or break down sharkskin swimsuit	Otto Schmitt, 1969 294 Vidali, 2001 311
		soil or other environments			plants to bind,
					extract, and clean up heavy metals 309,310
	Biomorphic	Resembling or suggesting the	Rarely	Design, art, architecture	The Sagrada Família	Geoffrey Grigson, 1935 313
		forms of living organisms, often			church by Antoni
		in design and art			Gaudí in Barcelona
	Bionic Bio-affiliation Biophilia / biophilic design Biomechanics Bioinspired	The creation of modern engineering systems or a set of functions, based on biological systems and methods found in nature (or using artificial The idea that humans feels better and is healthier when in materials and methods to contact and connected with produce activity or movement nature in a person or animal) Human tendency to interact or be closely associated with other forms of life in nature: a desire or tendency to commune with nature; biophilic design is an extension of biophilia Study of the mechanical physics of biological processes or structures copying nature innovation is not about simply that the resulting idea or but also a way to emphasise General description of several of the concepts in this table,	Rarely Social sustainability Important Occasionally Context dependent	Engineering, medicine (electromechanical implants) Medicine, geriatrics Architects, construction Engineering, medicine Many	Self-healing concrete [seashells, trees]; the citrus press "Juicy [multiple organisms] 298,299 , Salif" by Philippe 312 Starck [squid] implants in humans [axolotl] 300 Therapeutic gardens for the elderly; parks in the urban environment Green or living walls promoting physical activity [groves, inside offices; natural meadows, streams] patterns, like curves and fractals, used in Studying the aerodynamics of bird 303 and insect 304 waterfalls] [forests, meadows, interior design See all above [multiple]	Jack Steele, 1960 301 Roy Remme and others, 314 2021. Wilson, E.O. 1986 302 1680 Giovanni Alfonso Borelli, Julian Vincent and others, 2006 315
					flight and the
					hydrodynamics of

We define the ocean economy to be the sum of economic activities related to the ocean and its coasts. Some consider the blue economy to be largely synonymous with the ocean economy[START_REF]The EU Blue Economy Report[END_REF] , while others consider it to implicitly encompass additional dimensions such as sustainability[START_REF]PROBLUE: The World Bank's Blue Economy Program[END_REF] and stewardship 38 . In this paper, we use this term to describe an aspirational vision of an ocean economy that is equitable, sustainable and inclusive, in line with articulations introduced around the

UN Convention on Sustainable Development (Rio+20) emphasizing more equitable sharing of benefits[START_REF] Silver | Blue Economy and Competing Discourses in International Oceans Governance[END_REF][START_REF]Blue Economy Concept Paper[END_REF][START_REF] Aisi | the Pacific Small Island Developing States[END_REF] and the Sustainable Blue Economy Finance Principles, which define a sustainable blue economy as one that "provides social and economic benefits for current and future generations; restores, protects and maintains diverse, productive and resilient ecosystems; and is based on clean technologies, renewable energy and circular material flows"[START_REF]Turning the tide: How to finance a sustainable ocean recovery[END_REF] .

Acknowledgements:

RB and AP are funded by FORMAS, project number 2020-01048. AP is funded by FORMAS, project number 2019-01220.

Nature-based solutions

Actions that are inspired and supported by nature, and which seek to build resilience while providing environmental, social and economic benefits.

Main focus

Conservation, spatial management