Dr. Healy Hamilton's interests range from researching the effects of climate change on biodiversity to the evolution and conservation of cetaceans and seahorses. Her next research expedition will be in May 2011, when she travels to the Philippines to find seahorses, pipehorses, and pipefish for genetic analysis.
When Healy Hamilton, the Head of the Center for Biodiversity Research and Information at the Academy, talks about biodiversity, she calls it the “magic carpet ride” of life. She's talking about all the strands of the natural world—the vast array of plant, animal, and microbial life, the food, medicines, pure air and clean water they provide, and the network of habitats such as forests, deserts, coral reefs and tundra, lakes, and oceans—woven together in a rich, diverse, and detailed tapestry of life.
Today, she's worried the magic carpet ride is unraveling before our eyes. She sees the effects of climate change in temperature and rainfall, causing shifts in the locations where species can survive. Plants are rooted and can only move as their seedlings track the right environmental conditions, while animals can often migrate across landscapes “as long as there isn't a shopping center or an interstate in their way.” Even plants and animals currently living within the boundaries of protected areas face local extinction if their habitat shifts right out from under them.
Current Snowshoe Hare Distribution
Snowshoe Hare Distribution with Climate Change
In order to support conservation planning on a climate-altered Earth, Hamilton turns to the specimen collections at the Academy to study the effects of climate change on biodiversity. The collections, dating back more than a hundred years, represent the most reliable records of biodiversity on Earth. They provide invaluable information about what species occur where as Hamilton and her team map historical habitat ranges, look at current distributions, and project where species might go as the climate of the Earth continues to warm up. One of the tools at her disposal is the modeling of species distributions. Using these modeling techniques, Hamilton's maps show species' habitats literally moving out from under them.
As a society, the U.S. has a 100-year-plus tradition of protecting certain wilderness areas such as the Everglades or Glacier National Park. But as a conservation strategy, borders around a protected landscape are now outdated. In this system, the national parks and wilderness preserves are islands with static boundaries. But as the climate changes, the habitat requirements of the species within them are not static. They need to migrate.
Thanks to Hamilton's maps, we can see at a glance how species ranges are projected to shift across both protected and unprotected landscapes. They also demonstrate the crucial need for connecting core wilderness areas through transition and key linkage zones. These maps are incredibly powerful communication tools, and are being used by collaborators such as the Wildlands Project, who are working to implement connectivity conservation strategies. The survival of many iconic species rests upon the creation of connectivity corridors—huge swaths of protected habitat that stretch across entire continents.
Humankind has already significantly reduced the historical ranges of animals like the grizzly, the lynx, or the snowshoe hare. Now these species distributions will need to change again, this time in response to climate change. The implementation of continental-scale corridors between protected areas is one of Earth's best chances to conserve the vast array of species in the face of rapid climate change.
Palmyra Atoll seems to lie a thousand miles from nowhere. In truth, it’s located south of Hawaii and north of the equator, comprising fifty small islets surrounded by thousands of square miles of Pacific Ocean. Aside from a brief period of human habitation during World War II, Palmyra has never been permanently occupied by humans nor commercially fished. That has left the coral reefs surrounding Palmyra in pristine condition. The atoll is home to more than 160 reef-building coral species, more than 300 species of coral reef fishes, 29 bird species, and some species that are endangered elsewhere, including green sea turtles and the amazing coconut crab, the world's largest land invertebrate.
Palmyra's location in the central Pacific is also a region where some of the planet's most significant weather patterns originate. This fact, added to the atoll's unique history and intact biodiversity, makes it an ideal setting for a broad range of studies relevant to the conservation of island and coastal ecosystems worldwide. Because Palmyra's reefs are still in a natural (or baseline) condition, scientists can ask basic questions such as “What is the complete diversity of species in an intact coral reef?” or “What is the role of top predators in marine food webs?” There are very few other places in the world where these questions can be answered with so little influence from changes wrought by humans.
The outlook for Palmyra's pristine coral reefs is very promising. The atoll is managed as a National Wildlife Refuge in a unique partnership among The Nature Conservancy, the U.S. Fish and Wildlife Service, and the Palmyra Atoll Research Consortium. The California Academy of Sciences is a founding member of the consortium, which includes Stanford University, Scripps Institution of Oceanography, the American Museum of Natural History, the University of California at Santa Barbara, University of California at Irvine, University of Hawaii, the U.S. Geological Survey, and Victoria University of Wellington, New Zealand.
Academy scientist Healy Hamilton is currently spearheading the overall science program for the Palmyra Atoll Research Consortium. Hamilton's own research efforts on Palmyra seek to deepen our understanding of the connectedness of Pacific Ocean coral reef systems to one another, which helps in the design of marine protected areas. Among the questions Hamilton asks is whether Palmyra Atoll's healthy reefs “seed” more degraded reefs in the Pacific, or if the atoll only receives larvae from other locations.
Recently Hamilton spent five weeks on the island atoll, diving among sharks and searching for various species of octopus. For each species found, she and her colleague Dr. Christine Huffard of the Monterey Bay Aquarium Research Institute collected tiny clippings of octopus arm tips for genetic analysis. DNA sequences from Palmyra octopuses will be compared to other populations of the same species across the Pacific. By comparing the DNA from an octopus species found in different locations, Hamilton and Huffard can reveal the pattern of genetic information across the ocean. “You begin to build an idea how coral reefs are connected across oceans. This helps us form strategies to protect marine biodiversity,” she explains.
“Seahorses are the most charismatic of fishes,” says Healy Hamilton, lead scientist for the Academy's Seahorse Research & Conservation Program. “They have a head like a horse, a tail like a monkey, eyes that revolve like lizards, and they change color like chameleons. They've done so much to change their body plan that many people don't even know they are fishes.”
They move through the ocean with the grace of a ballerina. Many species bond for life. The male gets pregnant while the female performs a daily dance of gratitude. Is it any wonder that the seahorse has been an object of fascination for ages?
Unfortunately for the seahorse, it is also highly prized as an ingredient in many traditional Chinese medicines. Seahorses are used to treat liver ailments, reverse old age, or increase male virility, leading to an estimated harvest of 24 million seahorses a year from the world's oceans.
That's simply an unsustainable number. Because seahorses invest so much time and energy in reproduction, they produce relatively few offspring, and simply do not have the reproductive capacity to withstand this amount of fishing. To support wise management of seahorse populations, Hamilton launched Seahorse Sleuth, a website that enables biologists and resource managers to identify seahorse species using DNA sequences. Seahorse Sleuth allows the user to input a standard piece of DNA, then compares the results to a vouchered sequence database of verified specimens. Seahorse Sleuth will help determine which species are being most heavily exploited, and in some cases, from which ocean basins they are being taken.
In 2002, the 161 signatory countries of the Convention on International Trades in Endangered Species (CITES) agreed to manage the international trade in seahorses to ensure the survival of wild seahorse populations. However, CITES can only help sustain seahorses if there is adequate information regarding harvested species. Armed with the information in Seahorse Sleuth, Hamilton hopes to support the enforcement of international trade regulations as one important aspect in the fight for the continued survival of the seahorse.
Have a Question?
Q: How would you define biodiversity in layman's terms?
A: Biodiversity is both life itself and life giving. It provides us with food, medicine, clothing, building materials, fertile land, clean water, pure air, a stable climate, and spiritual respite. It has served us for all of human consciousness.
More about Dr. Hamilton
Director of the Center for Applied Biodiversity Informatics; Research Associate, Dept. of Ornithology & Mammalogy
Expeditions, Total: 8
Current Expedition: the Philippines, May 2011