By Paige Welsh
Oil tankers cross the open ocean. Photocredit: Pixabay
The high seas may appear uniform on the surface, but beneath the waves, currents are constantly moving nutrients, microscopic fish and invertebrate larvae, while larger species—like whales and sharks—migrate vast distances. The mobility of ocean species makes establishing a Marine Protected Area (MPA), a zone in the ocean with special legal protections for conservation, difficult in the open ocean.
Lisa Wedding, who was recently promoted to research associate in spatial ecology and analysis for the Center for Ocean Solutions, recognized the need to examine the state of open ocean management, and took the initiative to help organize and edit a Special Theme section of the journal Endangered Species Research. Entitled “Geospatial approaches to support pelagic conservation planning and adaptive management,” this special issue will feature research papers that apply a geospatial, (i.e., location oriented), approach to open ocean management. The research takes a hard look at how location, size and shape of an MPA affects its value for conservation and suggests the potential for MPAs that morph in space and shape over time. Collaborating with researchers in the field, including Dana Briscoe (Hopkins Marine Station, Stanford University) and Sara Maxwell (Old Dominion University, formerly a postdoc at Hopkins Marine Station), Wedding hopes to illuminate current challenges and solutions to mangeing an ocean on the move.
“The theme section of Endangered Species Research seeks to bridge the gap between geospatial science and marine conservation. We’ve focused on highlighting research that uses innovative approaches to support effective marine conservation planning strategies for pelagic ecosystems,” said Wedding.
One of the challenges the researchers seek to address is the struggle to survey such an enormous ecosystem. In small, relatively small shallow areas, scuba divers or ROVs can count species and measure ocean conditions. The vastness of the open ocean makes these methods infeasible. The Theme Section highlights how technology can bridge these data gaps. For example, authors Fujioka & Halpin demonstrate the potential for scientists to pool their data online with resources like OBIS Seamap to make models that will predict the presence of species.
Scientists can also use oceanographic features, such as sea-surface temperature and florescence, which is used to measure the presence of phytoplankton, to predict habitat. For example, Dransfield et al. demonstrate the use of oceanographic features to predict the migratory routes of humpback whales in order to prevent fatal collisions with container ships.
Oceanographic remote sensing and biological diversity estimates can be combined in Geographic Information Systems to model the pelagic environment. Photo Credit: Marine Geospatial Ecology Lab, Duke University
When the food chain goes with the flow, management should get dynamic
However, humpback whales and many top predators in the ocean do not stay in one place because their habitat and food sources are dynamic and constantly on the move. Briscoe’s research in the ESA Theme Section evaluates how traditional protection strategies, like creating protected zones with stationary borders, should become more dynamic, and flexible to changing ocean conditions.
“Because many threatened and exploited marine species move through an ever changing environment in the open ocean, there is a need to move beyond traditional, two-dimensional approaches to marine conservation, and into dynamic management approaches,” said Briscoe.
Designing open ocean MPAs to protect highly mobile top predators, like bluefin tuna, could mean creating protective zones that follow these species as they migrate, or that focus on conserving key bluefin habitat, such as spawning areas. Understanding food web connections, whom eats whom, is also critical because MPAs may need to protect prey species and their key habitats as well.
Managers in Hawaii are already demonstrating what dynamic ocean management may look like with sea turtles. Managers use regularly updated maps of ocean temperatures to predict where sea turtles will appear and ask fishermen to voluntarily avoid those areas to reduce by-catch.
To protect marine ecosystems, we need to understand humans
The authors of the the ESA Theme Section also call for greater consideration of the human dimensions of conservation. They stress the importance of social science research to better tailor spatial management policies while respecting unique cultures and economies. Maxwell et al., for example, codified the ways that the few existing large-scale MPAs have been managed in the past to create a framework for how to best manage future large-scale MPAs. In addition, they lay out initial steps to make management enforcement cost-effective and feasible. Maxwell believes the average person is also a stakeholder and has reason to think about open ocean protection.
“We as humans actively rely on the ocean - we eat fish, and we use items that have been shipped across the ocean. We have a responsibility to make sure these activites occur in a way that balances our needs with maintaining the ecosystems. MPAs have been shown in some instances to actually increase [fish] stocks by protecting marine wildlife, which can be critically important to many parts of the world’s population,” explained Maxwell.
“The next step should move beyond mapping human use, and integrate social values and, perceptions and culture at sea, which is more challenging, but important,” said Wedding.
The interaction between human systems and ecosystems can be as deep and complicated as the ocean itself, but Wedding, Briscoe, Maxwell and their colleagues are working to inform a new wave of management on the move.