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50 Years of Science That’s Shaped Our Lives

A Bay Weekly Conversation with Anson ‘Tuck’ Hines, ­Smithsonian Environmental Research Center Director

In 1962, the Smithsonian Institution of Washington, D.C., found itself the beneficiary of farmer Robert Lee Forrest’s unanticipated bequest: a 368-acre dairy farm in Edgewater pushing up against the Rhode River — plus $1.7 million.
    Over half a century, that idyllic spot grew to the 2,650-acre Smithsonian Environmental Research Center, with hundreds of scientists working to figure out piece by piece the huge puzzle of coexistence on a small planet with limited resources. Director Tuck Hines told Bay Weekly editor Sandra Olivetti Martin what’s come of the inheritance.

Bay Weekly    Has your perch on the Rhode River above Chesapeake Bay shaped the Smithsonian Environmental Research Center’s take on what are important research questions?
Tuck Hines    We’ve focused on five big areas, all touching us right here: manifestations of global change; pollution; land use; coastal ecosystems and how fishing impacts the food web; and invasive species.

Bay Weekly    You’re a marine ecologist and a crab researcher. What have you learned about crabs that the rest of us don’t know?
Tuck Hines    A long time ago, we didn’t know much about the basic biology of blue crabs. We didn’t understand how long they lived, how many batches of eggs they would produce, how they move in the environment, how many times a day they need to eat.
    There are 14 of us in my lab this summer, but initially it was me alone. I spent a lot of time in the Bay catching crabs to learn where they migrate and how much they eat. I’ve put together a detailed understanding of feeding, fighting, mating, migration and how all that applies to understanding how crabs interact with the fishery. We’ve looked at virtually every aspect of blue crab biology. A lot of what we know about migration, we know from our research.

Bay Weekly    How often do crabs need to eat? And what?
Tuck Hines    Seven to nine times a day, especially small invertebrate clams.

Bay Weekly    Do they eat one another?
Tuck Hines    The impact of predators on blue crabs is very profound. Watermen say rockfish eat blue crabs, but the major source of mortality is not rockfish. It’s other blue crabs. It’s crab pots, seines and trawls: the fishery. Watermen exploit different stages of the life cycle. But crabs need their the whole complicated web of ecosytems in their migratory route, out into the Bay plume into the ocean and up into nurseries like the Rhode River.

Bay Weekly    How has all this knowledge shaped our blue crab fishery?
Tuck Hines    We were able to show, especially in 2010-2011, that population was limited by the number of babies coming into the system; reproduction wasn’t sufficient. It’s not much different from raising chickens; more babies in the nursery could increase the population. The University of Maryland has done that with its aquaculture system.

Bay Weekly    How has Maryland Department of Natural Resources used your discoveries?
Tuck Hines    We showed that blue crabs were being limited by predation — and not by rockfish. That led in 2008 to the moratorium on the winter dredge fishery in both Virginia and Maryland.

SERC intern Brooke Weigel holds up a blue catfish caught on a research cruise. Blue catfish are one of many invasive species in the Chesapeake.

Bay Weekly    What’s the bottom line?
Tuck Hines    We believed we could never overfish crabs; we believed they were infinite. We’ve learned that they are not. We’ve seen them overfished like all the other species. If we don’t protect female spawning stock in numbers and habitat, crabs will become in danger not of extinction but of not supporting the large fishery we expect of cheap blue crabs in great abundance.

Bay Weekly    What should we do now?
Tuck Hines    Reduce fishing pressure. A crab let go by a recreational crabber has a 75 percent chance of being caught in two weeks. We should restrict and set quotas. But it has to be balanced. Catch only males and there’d not be enough for reproduction. When you adjust regulations, blue crabs do come back.

Bay Weekly    When you talk about the food web, you suggest that what happens to crabs matters beyond crabs and crabbers, crab pickers and crab eaters.
Tuck Hines    The food web is an elaborate and intricate connection of organisms feeding off each other. Coastal systems have the top-down of influence of predation.
       Worldwide and in the Bay, fishing has drastically altered the food web in the size, structure, age and number of species. We’ve changed the whole biodiversity and therefore ecosystem processes.

Bay Weekly    So much of what’s happening in food webs leads back to people …
Tuck Hines    Yes, because another big influence in coastal systems is nutrients, with nitrogen and phosphorus running off the land and fueling plankton production, which then decays and consumes oxygen, leading to issues of nutrient use and management.

Bay Weekly    You’ve followed the flow from its source to what we can do about it …
Tuck Hines    A big source of nutrient pollution, nitrogen and phosphorus to some extent, is agriculture: overfertilizing, manure — here it’s chickens, in North Carolina hogs, in Pennsylvania cows. The trick is how to prevent it getting to streams and rivers. We’ve measured how land use mixes affect that and shown that critical area and riparian legislation have had a great result.

Eric Johnson and Rob Aguilar get a snapshot of life on Chesapeake Bay on a trawling cruise.

    That buffer of 100 feet on stream sides is really effective in taking up nutrients. Also important is how the land is used, not just percentages of this and that. Put forest closest to streams and not agriculture or development, and you’ll be a lot more effective in reducing nutrient loading. Also important is being effective in measuring how much nutrients crops need and not putting in more. Also winter cover crops.

Bay Weekly    What have you learned that should be known by people who live by the water?
Tuck Hines    In the past five years, we’ve done a very interesting program on shoreline development that’s part of our research into global change. The most effective way to protect your shoreline against rising seawater is — rather than rock walls — to create natural habitats and marshes to prevent erosion and create habitat.
    We’ve been researching how rising sea level will interact with marshes. Will they be able to keep up with sea level rise or will they be inundated and reduced? We’ve found that marsh plants keep up with water rise by putting roots into soil, creating a peat system. But with too much rise, we’ll lose this critical buffer for storm protection and habitat.

Bay Weekly    Are we on a path to being inundated and reduced?
Tuck Hines    We have a lot of problems. But in each of these areas, sound science can create solutions. It is not a hopeless task.
    But people really do have to take the rate of global change seriously. Environmental changes are accelerating and becoming more intense, and that will keep growing with human population growth coming up above nine billion by 2050. We’re leaving the flat stretch of the curve of change. Now we’re at the inflection point, where the curve goes steeply uphill — or down.
    That will force change on people.

50th Anniversary Open House Saturday, May 16

See science at work and get out in nature: Take a hayride; climb the weather tower where scientists track rain and the sun’s energy; search for crabs and oysters on the docks;
wade into the river with a seine net for fish; discover the past; and enjoy ecology-themed kids’ crafts, face painting and other activities at the Smithsonian Environmental Research Center, 647 Contees Wharf Rd., Edgewater, 10am-3pm. free but rsvp for free parking (otherwise $10) and river cruises (on the half hour 10:30an-1:30pm):