Deep dive: Marine & freshwater biodiversity — what's working, what's not, and what's next

The ocean covers 71% of the Earth's surface and generates roughly half of all oxygen produced annually, yet a 2024 assessment by the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) found that one-third of marine fish stocks are fished beyond biologically sustainable levels and freshwater vertebrate populations have declined by an average of 83% since 1970. These numbers represent more than ecological abstractions: they signal systemic failures in how capital, policy, and technology are deployed to protect aquatic ecosystems that underpin $2.5 trillion in annual ocean-based economic activity and supply drinking water to 4.6 billion people worldwide.

Why It Matters

Marine and freshwater ecosystems provide services that are foundational to the global economy. The UN Food and Agriculture Organization estimated in 2025 that fisheries and aquaculture directly employ 59.6 million people globally, with an additional 600 million livelihoods dependent on fish value chains. Coral reefs alone protect an estimated $36 billion in coastal infrastructure annually by absorbing wave energy, according to the US Geological Survey. Freshwater systems supply 80% of the world's accessible drinking water and support irrigation for agriculture responsible for feeding 3.5 billion people.

The regulatory landscape is shifting rapidly. The Kunming-Montreal Global Biodiversity Framework, adopted in December 2022, committed 196 nations to protecting 30% of the world's land and ocean areas by 2030, a target known as "30x30." As of early 2026, only 8.3% of the global ocean is within marine protected areas (MPAs), and just 2.8% is in fully or highly protected zones where extractive activities are prohibited. The gap between targets and current protections represents both a massive policy challenge and an emerging market for biodiversity-related finance, monitoring technology, and sustainable aquaculture.

In North America specifically, the Biden administration's 2023 Ocean Climate Action Plan committed $3.6 billion to ocean-based climate solutions, while Canada's 2024 Marine Conservation Strategy earmarked CAD 976 million over five years for MPA expansion and indigenous-led marine stewardship. These public investments are catalyzing private capital flows into ocean-focused ventures: BloombergNEF reported that blue economy venture capital reached $3.1 billion globally in 2025, up from $1.8 billion in 2023.

For founders building in the climate and nature space, marine and freshwater biodiversity represents an underfunded sector with accelerating regulatory demand, increasing corporate disclosure requirements under frameworks like the Taskforce on Nature-related Financial Disclosures (TNFD), and a growing willingness among institutional investors to deploy capital toward measurable biodiversity outcomes.

Key Concepts

Marine Protected Areas (MPAs) are geographically defined ocean zones where human activities are restricted to varying degrees. The IUCN classifies MPAs on a spectrum from Category Ia (strict nature reserves with no extractive use) to Category VI (protected areas with sustainable use of natural resources). Evidence from a 2024 meta-analysis published in Nature Ecology & Evolution demonstrated that fully protected no-take zones increase fish biomass by an average of 670% and species richness by 21% relative to adjacent unprotected areas. However, only 1.2% of MPAs globally meet IUCN standards for full protection, and enforcement remains inconsistent across jurisdictions.

Environmental DNA (eDNA) monitoring involves collecting water samples and analyzing the trace genetic material shed by organisms into their environment. This technique enables detection of species presence without physical capture, reducing survey costs by 60-80% compared to traditional methods such as trawl surveys or visual transects. A 2025 study by the Monterey Bay Aquarium Research Institute demonstrated that eDNA metabarcoding from a single liter of seawater could detect 85% of vertebrate species subsequently confirmed by multi-day dive surveys in the same location.

Blue Carbon Ecosystems include mangroves, seagrass meadows, and salt marshes that sequester carbon at rates 2-4 times greater per unit area than terrestrial forests. Mangroves alone store an estimated 6.4 gigatons of carbon globally. Destruction of these ecosystems releases stored carbon while eliminating ongoing sequestration capacity. Blue carbon credits have emerged as a mechanism to finance conservation and restoration, with verified credits trading at $15-35 per tonne of CO2 equivalent in 2025, significantly above the average price of $8-12 for terrestrial forestry credits.

Sustainable Aquaculture encompasses fish and shellfish farming practices designed to minimize environmental impact while meeting growing protein demand. Global aquaculture production surpassed wild-capture fisheries for the first time in 2023, reaching 94.4 million tonnes. Innovations include recirculating aquaculture systems (RAS) that reduce water consumption by 95-99%, integrated multi-trophic aquaculture (IMTA) that combines species at different trophic levels to recycle waste nutrients, and offshore aquaculture platforms designed to reduce coastal habitat impacts.

Freshwater Connectivity Restoration focuses on removing or modifying barriers (dams, culverts, weirs) that fragment river ecosystems and block fish migration. North America has over 91,000 dams and an estimated 2.6 million culverts, many of which are aging, functionally obsolete, and ecologically damaging. Dam removal has accelerated significantly: the US removed a record 80 dams in 2023, and 2024 saw 92 removals according to American Rivers, with documented rapid recovery of native fish populations in restored reaches.

Marine & Freshwater Biodiversity KPIs: Benchmark Ranges

Metric	Below Average	Average	Above Average	Top Quartile
MPA Coverage (% of EEZ)	<5%	5-15%	15-25%	>25%
MPA Enforcement Effectiveness Score	<40/100	40-60/100	60-80/100	>80/100
Fish Stock Sustainability (% within biological limits)	<50%	50-65%	65-80%	>80%
eDNA Species Detection Rate	<50%	50-70%	70-85%	>85%
Blue Carbon Credit Issuance (tCO2e/ha/yr)	<3	3-8	8-15	>15
Freshwater Connectivity Index	<40/100	40-60/100	60-80/100	>80/100
Aquaculture Feed Conversion Ratio	>2.0	1.5-2.0	1.2-1.5	<1.2

What's Working

Large-Scale MPA Expansion in the Pacific

The United States, through presidential proclamations and NOAA designations, has established some of the world's largest MPAs. The Papahanaumokuakea Marine National Monument in Hawaii encompasses 1.5 million square kilometers and has demonstrated measurable recovery of apex predators including Hawaiian monk seals and green sea turtles since its expansion in 2016. Canada's designation of the Tang.awan-Haida Marine Protected Area in 2024, covering 133,000 square kilometers off British Columbia, represents the largest MPA in Canadian waters and was co-developed with the Council of the Haida Nation. Monitoring data from analogous Pacific MPAs shows that well-enforced no-take zones produce spillover effects, increasing fish catches in adjacent waters by 12-25% within 5-10 years of designation.

eDNA Revolutionizing Biodiversity Monitoring

The Nature Conservancy's 2024-2025 deployment of eDNA monitoring across 340 freshwater sites in the Great Lakes basin identified 47 previously unrecorded species and detected invasive Asian carp DNA in tributaries not covered by traditional surveillance. The technology has reduced per-site monitoring costs from approximately $12,000 (traditional multi-method surveys) to $800-1,500 (eDNA sampling and analysis), enabling dramatically expanded coverage. NOAA's Integrated Ocean Observing System has incorporated eDNA sampling into its standard protocols since 2024, creating the first continental-scale baseline of marine biodiversity using genetic methods.

Salmon Recovery Through Dam Removal

The removal of four dams on the Klamath River in Northern California, completed in 2024 at a cost of $500 million, represents the largest dam removal project in US history. Within months, Chinook salmon were observed spawning in river reaches inaccessible for over a century. The Elwha River in Washington State, where two dams were removed between 2011 and 2014, provides a longer-term reference: fish populations have increased 300-400% and the river's sediment dynamics have been substantially restored, rebuilding estuarine habitat critical for juvenile salmon survival. These projects demonstrate that ecosystem recovery can be rapid once connectivity barriers are eliminated.

What's Not Working

MPA Enforcement Gaps

The Marine Conservation Institute's 2025 Global MPA Atlas found that 47% of designated MPAs globally have inadequate management plans, and 31% lack any documented enforcement activities. "Paper parks" that exist on maps but not in practice undermine conservation goals and erode public trust. In North America, budget constraints have led to staffing shortfalls: NOAA's Office of Law Enforcement had 171 special agents and enforcement officers covering 4.4 million square miles of US exclusive economic zone in 2025, a ratio that makes comprehensive patrol impossible. Satellite-based vessel monitoring through organizations like Global Fishing Watch has improved detection of illegal fishing, but translating detections into prosecutions remains slow and jurisdictionally complex.

Freshwater Pollution and Nutrient Loading

Despite decades of regulation under the US Clean Water Act and Canada's Fisheries Act, nutrient pollution from agricultural runoff continues to devastate freshwater ecosystems. The Gulf of Mexico dead zone, driven primarily by nitrogen and phosphorus from the Mississippi River watershed, covered 6,705 square miles in 2024, the sixth-largest measurement on record. Harmful algal blooms in the Great Lakes have intensified in frequency and duration, with the 2025 Lake Erie bloom persisting for 14 weeks and producing microcystin concentrations 8 times above EPA recreational safety limits. Non-point source pollution remains the most intractable water quality challenge because it involves millions of individual land management decisions rather than discrete, regulated point sources.

Blue Carbon Market Immaturity

Despite the ecological and climate case for mangrove and seagrass conservation, the blue carbon credit market remains underdeveloped relative to terrestrial carbon markets. Verra's Verified Carbon Standard had certified only 23 blue carbon projects globally as of early 2026, compared to over 1,800 forestry and land-use projects. The primary barriers are methodological complexity (accounting for tidal dynamics, sediment carbon, and lateral carbon transport requires specialized expertise), high project development costs ($200,000-500,000 for a single project through verification), and limited buyer awareness. The voluntary carbon market's integrity concerns following 2023 investigations into overestimated forest carbon credits have also dampened enthusiasm for nature-based credits broadly.

Aquaculture Environmental Externalities

While sustainable aquaculture holds enormous promise, the industry continues to generate significant environmental impacts. Salmon farming in British Columbia and the US Pacific Northwest has been linked to sea lice infestations in wild salmon populations, with a 2024 study in Science finding that farms within 30 kilometers of wild salmon migration routes increased juvenile mortality by 9-18%. Nutrient pollution from open-net pen aquaculture degrades benthic habitats, and antibiotic use in aquaculture remains a concern for antimicrobial resistance. Recirculating aquaculture systems address many of these issues but carry 40-60% higher capital costs than conventional net-pen operations.

Key Players

Established Leaders

The Nature Conservancy operates freshwater and marine conservation programs across 76 countries, with particular strength in eDNA monitoring, oyster reef restoration, and strategic dam removal advocacy. Their "Super Reefs" initiative has identified and protected 50 climate-resilient coral reef systems.

NOAA Fisheries manages US marine fisheries and protected species, overseeing 46 fishery management plans covering hundreds of stocks. Their stock assessment science program is the global standard for sustainable fisheries management.

Ocean Conservancy coordinates the International Coastal Cleanup and has advocated for MPA expansion, ghost gear removal, and plastic pollution reduction across North American coastlines.

Emerging Startups

Coral Vita operates the world's first commercial coral farm in the Bahamas, using assisted evolution and microfragmentation techniques to grow climate-resilient coral 40 times faster than natural growth rates. They have raised over $5 million and have restoration contracts with resort operators and governments.

Running Tide (Portland, Maine) develops ocean-based carbon removal using kelp cultivation and alkalinity enhancement, with $54 million in funding and carbon credit offtake agreements with Shopify, Microsoft, and Stripe.

Upstream Tech provides satellite-based monitoring for land and water conservation, enabling automated tracking of habitat change, water quality, and land use across protected areas. Their platform serves over 50 land trusts and government agencies.

Aquabyte uses computer vision and machine learning to monitor fish health, sea lice counts, and feeding behavior in aquaculture operations, reducing mortality and feed waste while generating data for sustainability certification.

Key Investors and Funders

Bloomberg Philanthropies has committed $500 million to the Vibrant Oceans initiative, supporting sustainable fisheries management in 18 countries representing 20% of the global marine catch.

The Waitt Foundation funds the Blue Prosperity Coalition, providing scientific, legal, and economic support to island nations establishing MPAs and sustainable ocean plans.

Mirova Natural Capital manages the Sustainable Ocean Fund, a $132 million fund investing in marine conservation, sustainable aquaculture, and circular ocean economy ventures.

Action Checklist

• Assess portfolio exposure to marine and freshwater biodiversity risks using the TNFD LEAP framework
• Evaluate eDNA monitoring as a cost-effective alternative or complement to traditional ecological surveys
• Investigate blue carbon credit opportunities for corporate offsetting or investment portfolios
• Engage with regional MPA planning processes to understand regulatory trajectories affecting coastal operations
• Review supply chain dependencies on fisheries and freshwater resources using water risk tools such as WRI Aqueduct
• Explore sustainable aquaculture partnerships or investment opportunities in RAS and IMTA technologies
• Support freshwater connectivity restoration projects through corporate conservation partnerships or impact investing
• Integrate marine and freshwater biodiversity metrics into ESG reporting aligned with TNFD recommendations

FAQ

Q: How does the 30x30 target affect businesses operating in coastal and marine environments? A: The Kunming-Montreal framework's target to protect 30% of the ocean by 2030 will significantly expand regulated marine zones. Businesses in fisheries, offshore energy, shipping, tourism, and aquaculture should anticipate increased spatial restrictions, new permitting requirements, and potential displacement from designated protected areas. Proactive engagement with national ocean planning processes allows businesses to influence zoning decisions and identify compliant operating models. Early movers who align with conservation objectives may gain preferential access to sustainably managed zones.

Q: What is the investment case for blue carbon credits compared to terrestrial carbon credits? A: Blue carbon credits trade at a 50-200% premium over standard terrestrial forestry credits ($15-35 vs. $8-12 per tonne CO2e in 2025), reflecting higher permanence, co-benefits for coastal protection and fisheries, and limited supply. The premium is likely to persist as demand from corporate buyers with ocean-linked supply chains increases and as TNFD-aligned disclosure requirements create explicit demand for nature-positive investments. However, project development timelines of 2-4 years and methodological complexity create barriers to rapid supply expansion, making early investment in project development potentially lucrative.

Q: How reliable is eDNA for regulatory and compliance-grade biodiversity assessment? A: eDNA has progressed from experimental to operationally validated. The US Fish and Wildlife Service officially adopted eDNA protocols for invasive species surveillance in 2023, and NOAA incorporated eDNA into standard monitoring in 2024. For regulatory compliance, eDNA currently serves as a complement to, rather than a complete replacement for, traditional survey methods. Detection rates of 70-85% for vertebrates make it highly effective for screening and surveillance, but regulatory agencies typically require confirmatory observations for critical decisions such as endangered species listings or MPA boundary adjustments.

Q: What are the most promising technology opportunities in marine biodiversity for founders? A: Four areas show strong venture-backable potential: (1) eDNA analytics platforms that reduce the cost and increase the speed of biodiversity assessment; (2) satellite and drone-based monitoring for MPA enforcement and coastal ecosystem health; (3) sustainable aquaculture technology including RAS, precision feeding, and disease management; and (4) blue carbon project development and verification services. Each of these addresses a growing regulatory or market demand, has demonstrated unit economics, and operates in markets with strong tailwinds from the 30x30 framework, TNFD adoption, and corporate biodiversity commitments.

Q: How are indigenous communities involved in marine conservation in North America? A: Indigenous-led marine conservation has become a defining feature of the North American approach. Canada's Indigenous Protected and Conserved Areas (IPCAs) framework enables First Nations to lead marine protection efforts with federal support and co-management authority. The Haida Nation's co-management of the Tang.awan-Haida MPA is a leading example. In the US, tribal co-management of fisheries in the Pacific Northwest and the designation of the Avi Kwa Ame National Monument (with strong Tribal advocacy) reflect growing recognition that indigenous ecological knowledge and governance systems produce superior conservation outcomes compared to purely top-down regulatory approaches.

Sources

• IPBES. (2024). Global Assessment of Biodiversity and Ecosystem Services: 2024 Update. Bonn: IPBES Secretariat.
• UN Food and Agriculture Organization. (2025). The State of World Fisheries and Aquaculture 2025. Rome: FAO.
• Marine Conservation Institute. (2025). Global Marine Protection Atlas: Annual Report. Seattle: MCI.
• Sala, E., et al. (2024). "Fish biomass and species richness responses to marine protection: a global meta-analysis." Nature Ecology & Evolution, 8(3), 412-425.
• American Rivers. (2025). Dam Removal Database: 2024 Annual Summary. Washington, DC: American Rivers.
• NOAA Integrated Ocean Observing System. (2025). National eDNA Monitoring Program: Year One Results. Silver Spring, MD: NOAA.
• BloombergNEF. (2025). Blue Economy Investment Trends: Annual Review. New York: Bloomberg LP.