Parks that can move when the animals do
Climate change is pushing marine animals out of their protected areas. Ways must be found to ensure that their protection migrates with them, naturalists say.
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Greater extremes of wet, hot, and dry are “the dirty secret behind climate change,” says Pidgeon. El Niño, a periodic warming of surface waters in the eastern Pacific that scientists think will become more frequent in a warmer world, halts the upwelling that fuels many marine ecosystems. On the Atlantic side, Boersma has noted that heavier and more frequent rainfall, which can flood penguin nests, lowers their reproductive success.Skip to next paragraph
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What needs to be done?
Preparations for a changing marine environment include making reserves bigger in anticipation of a general shift toward the poles, say scientists. Better yet, design marine reserves as networks, like California’s, so critters can hop poleward on “what you might think of as steppingstones,” says Dennis Heinemann, a senior scientist with the Ocean Conservancy in Washington, D.C.
Protecting habitat critical to keystone species will also help. California kelp, for example, needs a hard substrate. To aid its migration, rocky areas along the way should be protected.
Another strategy: Protect places known to be important at crucial stages of critters’ life cycles. The ice’s edge in the Arctic, for example: Marine mammals use it as a staging area for hunting and foraging. The long-ranging bluefin tuna could be protected while it spawns in the Gulf of Mexico.
That might mean shutting down or restricting fishing in an area during a certain period of the year. Migrating species like whales and sea turtles ride currents. Removing shipping traffic and fishing from these sea highways during migration periods would lessen mortality.
There are some precedents for these approaches. Some migrating birds enjoy protected nesting grounds and wintering grounds, but nothing in between, and that suffices, says Pauly.
New technologies will play pivotal role
But as these protected areas will be pegged to ocean conditions rather than geographic locations, new technologies will necessarily play a pivotal role.
Satellites can see high concentrations of chlorophyll – blooms of algae – and help scientists infer where upwelling is occurring and where feeding grounds are likely to be.
Endeavors like the National Science Foundation’s Ocean Observatories Initiative, which scientists will soon begin putting in place, will increase the number of sensors at sea and vastly improve humans’ ability to see what’s happening where and adjust accordingly.
New smaller fish tags, meanwhile, have already revealed a lot about when, where, and why fish migrate.
“We’re sort of getting a fish’s eye view of the undersea world,” says Cornell’s Greene. “The biology gives us a really strong signal that enables us to look for things that sometimes slip past the physical oceanographers.”
GPS-enabled Vehicle Monitoring Systems, common on boats, will play an important role both in enforcement, and in helping boats navigate around MPAs of complex shape of shifting location. (They’ve historically been mostly square-shaped, though ecosystems typically aren’t, partly to make them easier to avoid.)
But the more difficult question is political. Where will plans for species that cross national borders be hammered out? How will nations manage the high seas where, currently, there’s little governance beyond a nation’s 200-mile wide exclusive economic zone?
One model: The 25-nation Commission for the Conservation of Antarctic Marine Living Resources governs fishing, especially that of krill, in the Southern Ocean. Another model: Colombia, Ecuador, Costa Rica, and Panama have agreed under the San José Declaration to manage jointly the marine species that migrate among the nations’ waters together.
“Those sorts of approaches are going to have to become more common,” says Pidgeon.