Page 138 - Environment: The Science Behind the Stories

were sampled in 2007, and the results enhanced support for oyster aquacul-
were stunning. The reef complex ture in the bay region. 1000 Total
Adults
supported an estimated 185 million Schulte’s restoration project cost Spat
oysters, a number nearly as large as roughly $3 million and will require 800
the wild population of 200 million oys- substantial investments if it is to be 8
ters estimated to live on the remaining repeated elsewhere in the bay. This 6
degraded habitat in all of Maryland’s is particularly true in upper portions Mean density (oysters per m 2 ) 600 4
waters. of the bay, where oyster reproduction 2
Higher reefs supported an aver- levels are lower (requiring restored 400 0
age of over 1000 oysters per square reefs to be “seeded” with oysters),
meter—four times more than the lower water conditions are poorer, and 200
reefs and 170 times more than unre- oysters are less resistant to dis-
stored bottom (Figure 3). Like natural ease. Many scientists contend that
reefs, the constructed reefs began expanded reef restoration efforts are 0
to solidify, providing a firm founda- worth the cost because they enhance High-relief Low-relief Unrestored
tion for the settlement of new oysters. oyster populations and provide a
In 2009, Schulte’s research made vital service to the bay through water Reef type
a splash when his team published filtering.
its findings in the journal Science, These efforts are encouraged by Figure 3 reef height had a profound
bringing international attention to their the success of the project to date. By effect on the density of adult oys-
study. summer 2012, the majority of high- ters and spat (newly settled oysters).
After reviewing eight alternative relief reef acreage was thriving, despite Schulte’s work suggested that native
approaches to oyster restoration that pressures from poachers and severe oyster populations could rebound in
portions of Chesapeake Bay if they
involved one or more oyster species, anoxic conditions in several years. were provided elevated reefs and were
the Corps advocated an approach that Moreover, many of the low-relief reefs protected from harvest. Data from Schulte,
avoided the introduction of non-native had accumulated enough shell to now D.M., R.P. Burke, and R.N. Lipicus, 2009.
oysters. Instead it proposed a combi- be classified as high-relief reef. The Unprecedented restoration of a native oyster
nation of native oyster restoration, a oyster recruitment in 2012 was some meta population. Science 325: 1124–1128.
temporary moratorium on oyster har- of the best Schulte had seen during the
vests (accompanied by a compensation project, boding well for the continuance
program for the oyster industry), and of the reef complexes.
Some scientists also see value
in promoting oyster farming, in which
restoration efforts would be supported
by businesses instead of taxpayers.
Regardless of how they will be
funded, protected sites for oyster
restoration efforts are being estab- CHAPTER 5 • Envi R onm E n TA l S y STE m S A nd E C o S y STE m E C ology
lished. Maryland recently designated
3640 hectares (9000 acres) of new
oyster sanctuaries—25% of existing
oyster reefs in state waters—where
restoration projects like Schulte’s could
be replicated. This movement toward
increased protection for oyster popula-
tions, coupled with findings of growing
resistance to disease in bay oysters,
has given new hope that native oysters
Figure 2 a water cannon blows oyster shells off a barge and onto the river bottom may once again thrive in the bay that
to create an artificial oyster reef for the experiment. bears their name.

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