By: Mark J. Spalding, President, The Ocean Foundation


In the early part of December, I spent two weeks in San Francisco for a pair of meetings on Marine Protected Areas (MPAs), which is a general term for many different ways to set aside parts of the ocean and coastal areas to support health of marine plants and animals.  Wild Aid hosted the first one, which was the Global MPA Enforcement Conference.  The second was an Aspen Institute Ocean Dialogue, which dialogue was prompted by asking all the invitees to think about the role of MPAs and other spatial management in addressing overfishing.  Obviously, marine conservation (including the use of MPAs) is NOT exclusively fisheries oriented; we must address all the stressors on ocean ecosystems – and yet, at the same time, overfishing is the second biggest threat to the ocean (after climate change).  While many marine protected areas can and should be designed for multiple objectives (e.g. spawning protection, eco-tourism, recreational use or artisanal fishing), let me explain why we look at MPAs as a tool for fisheries management as well.

Marine Protected Areas have geographic boundaries, are designed to manage human impact on marine ecosystems, and take a long-term approach.  This framework provides criteria that allow us to also manage fisheries.  In MPAs, as with fisheries, we manage human actions in relationship to ecosystems (and ecosystem services); we protect ecosystems (or not), we do NOT manage nature:

  • MPAs should not be about single (commercial) species
  • MPAs should not be solely about managing a single activity

MPAs were originally conceived as a way to set aside certain places and protect representative biodiversity in the ocean, with either permanent or seasonal, or a mix of other restrictions on human activities.  Our national marine sanctuary system permits some activities and prohibits others (particularly oil and gas extraction).  MPAs have also become a tool for those working to manage fisheries in a way that promotes healthy populations of targeted commercial fish species.  In dealing with fisheries, MPAs can be used to create no-take zones, recreational fishing only zones, or restrict the kinds of fishing gear that can be used.  They can also restrict when fishing takes place in specific areas—for example, closure during fish spawning aggregations, or perhaps to avoid sea turtle nesting seasons.  It can also be used to address some of the consequences of over fishing.

Consequences of Overfishing

Overfishing is not only bad, but it is worse than we thought.  Fishery is the term we use for the effort to fish a specific species.  Twenty percent of fisheries have been assessed—meaning they have been studied to determine whether they have robust populations with good reproduction rates and whether fishing pressure needs to be reduced to ensure rebuilding of populations.  Of the remaining fisheries, fish populations are declining at disturbing rates, both in the 80% of fisheries that are unassessed, and for half (10%) of assessed fisheries.  This leaves us with just 10% of fisheries that are not currently in decline—despite some very real improvements that have been made in the way we manage fisheries, especially in the U.S.   At the same time, fishing effort has substantially increased and continues to increase each year.

Destructive gear and bycatch harm habitats and wildlife across all fisheries.  Incidental catch or bycatch is the taking of non-target fish and other animals by accident as part of hauling out the nets—a particular problem with both driftnets (which can be up to 35 miles long) and lost gear such as lost nets and fish traps which keep working even if they are no longer being used by humans—and in longlining—a form of fishing that uses lines between a mile and 50 miles long to catch fish on a series of baited hooks strung on the line.  Bycatch can be as much as 9 pounds for every one pound of a target species, such as shrimp, that makes it to the table.  The loss of gear, the dragging of nets, and the destruction of juvenile fish, sea turtles and other non-target species are all ways in which there are consequences to large scale, industrial fishing that both affect future fish populations and existing efforts to manage them better.

About 1 billion people rely on fish for protein every day and the global demand for fish is growing. While a little over half of this demand is currently met by aquaculture, we are still taking about 80 million tons of fish from the ocean every year.  Population growth, combined with increasing affluence means that we can expect demand for fish to rise in the future.  We know what the harm from fisheries is, and we can expect this human population growth to continue to compound existing overfishing, habitat loss due to the destructive gear we often employ, as well as overall declines in commercial fish species biomass because we target bigger older reproductive age fish.  As we have written in previous blogs, industrial harvesting of wild fish for global scale commercial consumption is not sustainable environmentally, while small-scale, community-controlled fisheries can be sustainable.

Another cause of overfishing is we simply have too many boats, chasing an ever-declining number of fish.  There an estimated four million fishing vessels in the world—nearly five times what we need for sustainability by some estimates.  And these fishers receive government subsidies (about US$25 billion a year globally) to expand the fishing industry.  This must stop if we expect that smaller, isolated coastal and island communities will by necessity remain dependent on being able to catch fish. Political decisions to create jobs, promote international trade, or to obtain fish for consumption as well as corporate market decisions mean we have investing in creating many industrial fishing fleets. And it keeps on growing despite the overcapacity.  Shipyards are building bigger, faster fish killing machines, augmented by better and better fish radar and other technology.  In addition, we have community-based near-shore subsistence and artisanal fishing, that also requires monitoring for best practices and long-term thinking.

I also believe that we have to be clear that we are not seeking a rebound of global commercial scale fisheries to a level where all of the fish protein needs of a billion or more people can be met by wild caught fish—it’s just not likely.  Even if the fish stocks rebound, we have to be disciplined so that any renewed fisheries are sustainable and thus leave enough biodiversity in the sea, and that we promote local seafood security by favoring the individual angler and community-based fishers, rather than global industrial scale exploitation.  And, we need to keep in mind how many economic losses we currently suffer as the result of the fish already taken out of the ocean (biodiversity, tourism, ecosystem services, and other existence values), and how bad our return on investment is when we subsidize fishing fleets.  So, we need to focus on the role of fish as part of biodiversity, protecting high-end predators for balance and to prevent top down trophic cascades (i.e. we need to protect the food of all ocean animals).

So, a recap: to save the ocean’s biodiversity and thus its ecosystem functions as well as the services those functioning ecosystems can provide, we need to substantially reduce fishing, set catches at a sustainable level, and prevent destructive and dangerous fishing activities.  Those steps are a lot easier for me to write than they are to accomplish, and some very good efforts are under way locally, regionally, nationally, and internationally.  And, one tool was the focus of the San Francisco, Aspen Institute ocean dialogue:  managing the space as well as the species.

Using Marine Protected Areas to Address A Top Threat

Just as on land we have a system of private and public lands with varying degrees of protection from a wide array of human activities, so too, we can use such a system in the sea.  Some fisheries management actions also focus on spatial management that restricts fishing effort (MPAs).  In some MPAs the restrictions are limited to not fishing a single specific species.  We just need to ensure that we are not displacing effort to other locations/species; that we are limiting the fishing in the right places and the right times of year; and that we adjust the management regime in the event of a significant change in temperature, ocean bottom, or ocean chemistry.  And, we need to remember that MPAs offer limited help with mobile (pelagic) species (like tuna or sea turtles)—gear restrictions, temporal limitations, and catch limits in the case of tuna all work better.

Human well-being is also an important focus as we design MPAs.  Thus any viable plan needs to include ecological, socio-cultural, esthetic and economic factors.  We know that fishing communities have the greatest stake in sustainability, and often, the fewest economic and geographic alternatives to fishing.  But, there is a differential between the distribution of the costs and the benefits of MPAs.  Localized, short-term costs (fishing restrictions) to produce global long-term benefits (a rebound of biodiversity) is a hard sell.  And, local benefits (more fish and more income) can take a long time to materialize.  Thus, it is important to identify ways in which to provide short-term benefits that offset enough of the costs to engage local stakeholders.  Unfortunately, we know from our experiences to date that if there is no stakeholder buy-in, then there is almost universal failure of MPA efforts.

Our management of human actions should focus on protecting ecosystems as a whole, even if enforcement (for now) is limited to the MPA (as a subset of an ecosystem).  Lots of human activities (some far away from the MPAs) affect the ecological success of an MPA.  So if we do our design right,  our scope needs to be wide enough to ensure consideration of potential harm such as that from chemical fertilizers intended to provide nutrients to crops way upstream when they are washed off the land and down the river and into our ocean.

The good news is that MPAs work.  They do protect biodiversity and help keep the food web intact.  And, there is strong evidence that where fishing is halted, or limited in some fashion, the species of commercial interest rebound along with the other biodiversity.  And, additional research has also supported the common sense notion that fish stocks and biodiversity that rebound inside the MPA spills over its boundaries.  But too little of the ocean is protected, in fact only 1% of the 71% of our blue planet is under some form of protection, and many of those MPAs are paper parks, in that they only exist on paper and are not enforced.  Update: Huge accomplishments have been made in the past decade for ocean protection, yet with only 1.6 percent of the ocean “strongly protected,” land conservation policy is far ahead, earning formal protection for almost 15 percent of land.  The science of marine protected areas is now mature and extensive, and the multiple threats facing the Earth’s ocean from overfishing, climate change, loss of biodiversity, acidification and many other issues warrant more accelerated, science-driven action. So how do we implement what we know into formal, legislative protection?

MPAs alone will not succeed.  They must be combined with other tools.  We need to pay attention to pollution, sediment management and other factors.  We need to do a better job to make sure spatial marine management is well coordinated with other forms of management (marine conservation policies and species protection generally), and with the roles of multiple agencies.  In addition, we need to acknowledge that carbon emission-driven ocean acidification and ocean warming mean that we are facing landscape scale change.  Our community agrees that we need to create as many new MPAs as possible, even as we monitor the existing ones to improve their design and effectiveness.  Marine protection needs a much bigger political constituency.  Please join our community (by donating or signing up for our newsletter) and help make the constituency bigger and stronger so that we can make change happen.