Why is marine biodiversity footprinting behind?
As ocean conservation comes under renewed global focus — most recently with the UN Ocean Conference (UNOC) held in Nice — it's becoming increasingly clear that marine biodiversity remains a major blind spot in sustainability assessment and footprinting frameworks.
While terrestrial biodiversity measurement tools have made substantial progress in recent years, methods for evaluating impacts, dependencies and risks on ocean ecosystems are still in their infancy.
So why is that? And what can we do about it?
The global ocean context: ambition vs. reality
The ocean covers over 70% of the Earth’s surface and is home to more than 230,000 known marine species, with actual numbers likely in the millions. The importance of protecting this biome is clear and embedded in global commitments like the “30x30” goal set under the Kunming-Montreal Global Biodiversity Framework (GBF): protect 30% of marine areas by 2030.
But progress remains slow. At UNOC 2025 in Nice, many highlighted the gap between ambition and reality. A key milestone is the UN High Seas Treaty, adopted in 2023. It aims to create a legal framework for conserving biodiversity in areas beyond national jurisdiction, which make up nearly two-thirds of the ocean. However, the treaty still requires ratification by 60 countries to enter into force — as of mid-2025, only 50 have ratified, leaving a critical implementation gap.
What makes the marine biome unique — and threatened?
The ocean isn’t a single biome, but a complex, multilayered realm including shallow coastal zones, deep-sea floors, coral reefs, and open pelagic waters. Many of these ecosystems are still largely unexplored: over 80% of the seabed remains unmapped using modern techniques (Seabed 2030 initiative).
Marine ecosystems are not only rich in biodiversity but essential to planetary stability. They:
regulate climate through carbon storage - oceans absorb ~25% of CO₂ emissions annually (UNEP, 2021).
support food chains, from plankton to apex predators.
provide habitat for critical species, with coral reefs alone covering 0.1% of the ocean floor but support approx. 25% of all known marine species — including fish, mollusks, crustaceans, and sponges (WWF).
But they’re under growing pressure from human activity:
overexploitation of marine species: nearly 35% of global fish stocks are overfished (FAO, 2022), with some apex species like sharks seeing biomass declines of up to 70% in the last 50 years (Nature, 2021).
Pollution and acidification: marine plastic pollution is expected to triple by 2040 (Pew Charitable Trusts, 2020). Ocean acidification has risen by 30% since the industrial era, threatening shell-forming organisms.
Coastal habitat loss: mangroves, seagrasses, and salt marshes are disappearing due to coastal development, with an estimated 35% of global mangrove cover lost since 1980.
Shipping & underwater noise pollution: commercial shipping emits low-frequency noise that travels hundreds of kilometers underwater, interfering with species such as whales and dolphins, which rely on echolocation for navigation, feeding, and mating. Chronic noise has been shown to reduce reproductive success and cause chronic stress and disorientation in cetaceans (Science, 2021).
Why has marine biodiversity footprinting lagged?
Integrating marine ecosystems into biodiversity footprinting models is technically and scientifically complex. Some of the reasons include:
monitoring accessibility: deep and remote marine environments are extremely difficult to monitor. In situ surveys require costly submersibles, sonar mapping, or remote sensing, unlike terrestrial biodiversity which benefits from satellite imagery and ground-based observation.
3D ecosystems: oceans operate in a 3D space, complicating population tracking and ecosystem boundary definitions. Organisms are mobile across depth layers and currents, making modeling more complex than on land.
As a result of those factors, unlike forests or freshwater systems, marine habitats lack consistent, high-resolution biodiversity datasets, especially for invertebrates and deep-sea organisms.
For the same reason, there are fewer established pressure-impact models: terrestrial biodiversity footprinting often relies on pressure-impact relationships (e.g., land use → habitat loss). In marine contexts, those links are harder to quantify due to indirect impacts (e.g., ship noise → whale stress → population effects).
Where are we seeing progress?
Despite these challenges, innovation and research are moving things forward:
Technological advances:
eDNA (environmental DNA) now allows scientists to detect species presence by analyzing trace DNA in seawater samples, rather than relying on visual sightings or direct capture. This technique is especially powerful for cryptic or deep-sea species, and can drastically reduce field time and cost. For example, in 2022, researchers used eDNA to identify over 50 species of fish and invertebrates in the Mediterranean Sea in under 24 hours.
Soft robotics and AI-powered underwater drones are opening new frontiers in deep-sea exploration and species behavior mapping. For example, MIT’s soft robotic fish “SoFi” can swim in coral reefs and record video without disturbing marine life, helping researchers study natural behavior in situ (MIT CSAIL).
Proxy indicators are emerging as credible alternatives to direct impact data: overfishing or exposure to maritime transport are being used to assess footprint intensity.
New target-setting frameworks: the Science-Based Targets Network (SBTN) launched its Ocean Hub in 2024, setting global guidance on reducing marine pressures and enhancing protection. It focuses on 2 pillars:
Overexploitation – tracking fish stock health and reducing unsustainable harvests.
Marine habitat protection – particularly coral reefs, seagrass beds, and mangroves.
How we address marine biodiversity at Darwin
At Darwin, we take a biome-agnostic approach — helping companies assess impacts, dependencies, and risks across terrestrial, freshwater, and marine ecosystems alike.
We integrate marine considerations through:
LCA-based pressure indicators that include marine eutrophication, acidification, and plastic pollution pathways.
Spatial overlays that flag sensitive marine areas (e.g., Marine Protected Areas, Ramsar zones) and coastal impacts.
Proxies for pressure exposure, such as intensity of maritime shipping or overfishing hotspots, when species-level data is missing.
Support for emerging frameworks like SBTN’s Ocean Hub and TNFD's marine-specific metrics.
We recognise marine footprinting is still evolving, and we’re actively monitoring advances in ocean science and conservation metrics.
Let’s keep the conversation going
Understanding and managing ocean impacts is no longer optional. As regulatory frameworks like the High Seas Treaty and the EU Nature Restoration Law begin to take hold, companies will increasingly need to account for marine pressures — from shipping routes to supply chain fishing practices.
At Darwin, we’re committed to helping organisations stay ahead of the curve — even when it comes to the deepest, most complex ecosystems on Earth.
📩 Feel free to reach out if you’d like to explore how we can support your marine biodiversity assessment efforts.
