Science - USA (2020-10-02)

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tion of the planet to be conserved using a

combination of conventional protected ar-

eas and other effective area-based conserva-

tion measures ( 5 ). The formulation of these

targets may yet change, but the underlying

intent will likely remain: We need to pro-

tect more of our planet than we currently

do, and we need to use spatial planning to

guide that protection.

Historically, protected areas have been

designed and managed first for terrestrial

ecosystems and their species, with fresh-

water considered as an afterthought, if at

all. For example, at least 1249 large dams

are located in protected areas, with the pro-

cesses of “downgrading, downsizing, and

degazettement” having legalized dam con-

struction within many of these areas ( 6 ).

A study of continental Africa ( 7 ) showed

that the proportion of freshwater species

whose ranges are substantially covered by

protected areas and Ramsar sites (wetlands

designated to be of international impor-

tance under the Ramsar Convention) is

much smaller than for birds or mammals.

Globally, about 70% of river reaches (by

length) have no protected areas in their up-

stream catchments, rendering them partly

conserved at best ( 8 ). These and other

shortfalls can be traced back in part to a

lack of freshwater-focused conservation

planning and investment ( 1 ).

At the same time, as Leal et al. rightly

observe, conventional protected areas are

no silver bullet for conserving freshwater

biodiversity. Instead, they are part of a

toolbox of options that should also em-

brace a growing set of strategic adaptive

management approaches for freshwater

protection. Among these options is area-

based protection of systems beyond pro-

tected areas, including lands with collec-

tive tenure rights for indigenous peoples

and local communities.

Recommendations already exist for inte-

grating freshwater conservation priorities

into larger landscape strategies, in particu-

lar through entire watershed management

plans ( 9 , 10 ). The International Union for

Conservation of Nature’s approach for

identifying freshwater Key Biodiversity

Areas (KBAs), which then serve as spatial

conservation planning inputs to critical

site networks, is one applied example [e.g.,

Lake Victoria, East Africa ( 11 )]. These ho-

listic approaches consider not only aquatic

habitats of importance but also the land-

scapes in which these habitats are embed-

ded, which strongly regulate flow, sedi-

ment, and nutrient regimes in rivers, lakes,

and wetlands. Freshwater KBAs and simi-

lar efforts acknowledge the impossibility

of securing freshwater species and systems

without addressing the lands draining to

them. Leal et al.’s study shows not only

high reward for achieving freshwater con-

servation targets from such an integrated

approach but also low risk to achieving

paired terrestrial targets.

The good news from Leal et al.’s study—

namely that when we conserve freshwater

species and habitats, we receive multiple

biodiversity cobenefits—also applies to the

delivery of ecosystem services. Two-thirds

of today’s human population lives down-

stream from protected areas, and more

than one-quarter of water provisions sup-

plied by the world’s protected areas are

exposed to low levels of threat ( 12 ). There

is a win-win from protecting important

source water areas for human communi-

ties; an assessment of the likely source

catchments of 4000 cities supplying water

to up to 1.7 billion people showed that 85%

of the area of these catchments overlaps

with high biodiversity value freshwater

ecoregions ( 13 ).

Achieving this wealth of benefits will

require strong policy that recognizes the

connections between terrestrial and fresh-

water systems and that treats those systems

as equal in importance. And this strong

policy must be matched with the resources

to enact it. At present, freshwater systems

receive a tiny percentage of overall envi-

ronmental funding; for example, only 3.2%

of the environmental funding provided by

European foundations, and about 8% pro-

vided by North American foundations, goes

to freshwater conservation in those regions

or elsewhere ( 14 ). These funding challenges

are likely to get worse, in the face of new

economic crises and humanitarian needs

in a world shaped by coronavirus disease

2019 and other potential pandemics. There

are always trade-offs associated with any

prioritization—in spatial planning, policy,

and resource allocation—but the study by

Leal et al., combined with complementary

analyses of the multiple benefits of healthy

fresh waters and their watersheds, suggests

that those trade-offs may be more accept-

able than we think. j

REFERENCES AND NOTES

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10.1126/science.abe3887

The Amazonas Lowlands ecoregion contains a rich and diverse fauna. The main types of vegetation include seasonally flooded forests. There are strong ecological links

between the aquatic and terrestrial habitats. Rivers and forests supply multiple ecosystem services to the communities living in the region.

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