AIDScience
 MARIALUZ CALDERON | Change Password | Change User Info | CiteTrack Alerts | Subscription Help | Sign Out
dEbates: Submit a response to this
article
Related articles in Science
Similar articles found in:
SCIENCE Online
Search Medline for articles by:
Boesch, D. || Kidwell, S.
Alert me when:
new articles cite this article
Download to Citation Manager
Factors in the Decline of
Coastal Ecosystems
In their review "historical overfishing and the recent collapse of
coastal ecosystems," Jeremy B. C. Jackson and colleagues argue
for the "primacy" of overfishing in the collapse, in contrast to
pollution, species introductions, climate change, diseases, and
other human impacts (special issue on Ecology Through Time, 27
Jul., p. 629). They suggest that overfishing had the earliest
impacts and was a necessary precondition for the occurrence of
other maladies. Although we agree that fishing has contributed to major changes in coastal ecosystems,
we believe Jackson and co-authors overstate the case for its primacy. The overfishing and nutrient
pollution of coastal seas, for example, have frequently proceeded simultaneously and contributed to
degradation synergistically (1).
In Chesapeake Bay, as the authors point out, the process of eutrophication began with land clearing in
the 18th century, well before the mechanized harvest of oysters in the late 19th century. Although most
of the filtration capacity of oyster populations had been reduced by the 1930s, the dramatic
intensification of hypoxia and the extensive loss of seagrasses occurred later, during the last half of the
20th century, associated with a more than doubling of the already elevated nitrogen loading (2).
Recognizing that rebuilding oyster populations could help to mitigate planktonic overproduction due to
nutrient pollution (3), the multistate Chesapeake Bay Program has established the ambitious goal of a
10-fold increase in oyster biomass. But restoration of oysters even to precolonial abundances is unlikely
to eliminate algal blooms and hypoxia and recover seagrasses without also significantly reducing
nutrient loading. Decreasing bottom-up stimulation and increasing top-down controls will be required.
Although the degradation of oyster reefs by overfishing might have made oysters more susceptible to
endemic diseases, a particularly virulent pathogen (Haplosporidum nelsoni) was introduced from a
nonindigenous oyster host in the 1950s (4). This introduced disease now greatly limits the ability to
reestablish oyster populations.
Similarly, it is not likely that intact populations of large consumers, such as green turtles and sea cows,
would have prevented the deleterious consequences of nutrient pollution, sedimentation, and other
human-induced stresses on tropical seagrass ecosystems witnessed in the late 20th century in such
Science -- Boesch et al. 293 (5535): 1589c
file:///C|/Documents and Settings/Administrator/Des... 2001/Science -- Boesch et al_ 293 (5535) 1589c.htm (1 of 5) [1/23/2002 10:49:43 AM]
regions as Australia (5) and Florida Bay (6). And there were no similar large consumers of temperate
seagrasses, which have also undergone decline. Regardless of the historical sequence of human stresses,
amelioration of multiple stresses must take a multi-pronged approach to restore coastal ecosystems.
Donald Boesch,*
University of Maryland Center for Environmental Science,
Cambridge, MD 21401, USA.
Eugene Burreson,
Virginia Institute of Marine Science,
Gloucester Point, VA 23062, USA.
William Dennison,
Department of Botany,
University of Queensland,
Brisbane 4027, Australia
Edward Houde,
University of Maryland Center for Environmental Science,
Cambridge, MD 21401, USA.
Michael Kemp,
University of Maryland Center for Environmental Science,
Cambridge, MD 21401, USA.
Victor Kennedy,
University of Maryland Center for Environmental Science,
Cambridge, MD 21401, USA.
Roger Newell,
University of Maryland Center for Environmental Science,
Cambridge, MD 21401, USA.
Kennedy Paynter,
University of Maryland Center for Environmental Science,
Cambridge, MD 21401, USA.
Robert Orth,
Virginia Institute of Marine Science,
Gloucester Point, VA 23062, USA.
Robert Ulanowicz
University of Maryland Center for Environmental Science,
Cambridge, MD 21401, USA.
*To whom correspondence should be addressed. E-mail: boesch@ca.umces.edu
References and Notes
J. F. Caddy, ICES J. Mar. Sci. 57, 628 (2000); R. I. E. Newell, J. Ott, in Ecosystems at the
Land-Sea Margin: Drainage Basin to Coastal Sea, T. C. Malone et al., Eds. (American
1.  
Science -- Boesch et al. 293 (5535): 1589c
file:///C|/Documents and Settings/Administrator/Des... 2001/Science -- Boesch et al_ 293 (5535) 1589c.htm (2 of 5) [1/23/2002 10:49:43 AM]
Geophysical Union, Washington, DC, 1999), pp. 265-293.
A. R. Zimmerman, E. A. Canuel, Mar. Chem. 69,117 (2000); A. W. Karlsen et al., Estuaries 23,
488 (2000); R. J. Orth, K. A. Moore, Science 222, 51 (1983); W. M. Kemp et al., Mar. Technol.
Soc. J. 17, 78 (1983); G. S. Brush, W. B. Hilgartner, Ecol. Monogr. 70, 645 (2000).
2.  
R. Ulanowicz, J. Tuttle, Estuaries 15, 298 (1992).3.  
E. M. Burreson et al., J. Aquat. Anim. Health 12, 1 (2000).4.  
E. G. Abal, W. C. Dennison, Mar. Freshwater Res. 47, 763 (1996); A. R. Preen et al., Aquat. Bot.
52, 3 (1995)
5.  
J. W. Fourqurean, M. B. Roblee, Estuaries 22, 345 (1999).6.  
Response
Our review is indeed about the deep historical roots of human degradation of a diverse suite of coastal
marine ecosystems, caused by and preconditioned by fishing exploitation and attendant damage to
biogenic marine habitats. The novelty of our study lies in its use of multiple associated disciplines, such
as paleontology, archaeology, governmental record analysis, and maritime natural history, to provide
ecological baselines of the past that long predate the formal discipline of ecology, as it can be traced to
Elton, Lotka, Park, Birch, and other early 20th-century founders. Synthesis of such historical
information for a variety of coastal marine ecosystems revealed a large impact of fishing and sea
hunting that generally predated other human impacts, independent of the system.
If our review can be construed as arguing that restoring the overfished species and habitats degraded by
fishing would be sufficient in themselves to counteract the deterioration of coastal marine ecosystems,
we apologize. No amount of success in restoring the sharks and sea turtles to remote coral reef
ecosystems, for example, will counteract the growing impacts of coral bleaching induced by global
warming and other physical causes. Furthermore, we concur that reduction in nutrient loading to the
world's estuaries and coastal seas is a critical component of management strategies to restore lost
ecosystem services and reverse eutrophication.
Likewise, if our narrative implies that fishing acts independently of other stressors, we welcome this
opportunity to reject such an interpretation. The synergistic interaction among multiple factors is the
essence of our argument that impacts of historical fishing preconditioned many coastal ecosystems to
subsequent collapse when later stressors were applied. For example, the reduction in height of subtidal
oyster reefs through incremental mining of shell matrix by dredge fishing in Chesapeake Bay and
Pamlico Sound interacts with oxygen depletion of bottom waters (1) and exposure to oyster disease (2)
to influence oyster health. Additionally, restoring the extent and stature of oyster reefs in Chesapeake
Bay and other bays worldwide is likely to restore substantial levels of water filtration--even if oyster
life-spans are still shortened by disease--because these reefs provide the unique hard substratum not
only for the rapidly growing juvenile oysters, but also for other epibiotic filter feeders like tunicates (3).
Oyster reef restoration must be valued for ecosystem services to water quality and estuarine habitat,
even if restoration of traditional oyster fisheries is also a goal over a longer time frame (4).
We prepared our review not to deny the impacts of other human activities on marine ecosystems but
rather to document and emphasize the significance of fishing impacts upon apex consumers, critical
biogenic habitat engineers, and important grazers that occurred so far in the past as to be often forgotten
Science -- Boesch et al. 293 (5535): 1589c
file:///C|/Documents and Settings/Administrator/Des... 2001/Science -- Boesch et al_ 293 (5535) 1589c.htm (3 of 5) [1/23/2002 10:49:43 AM]
and ignored in restoration plans. Human-induced extinctions in the marine environment have lagged
behind those of terrestrial ecosystems, so there still exists the biological potential with which to rebuild
coastal marine ecosystems. We need to recognize these historical fishing impacts to appreciate the
importance of apex consumer and grazer restoration in our integrated plans.
Charles Peterson,*
University of North Carolina at Chapel Hill,
Institute of Marine Science,
Morehead City, NC 28557, USA.
Jeremy Jackson,
Scripps Institution of Oceanography,
University of California, San Diego,
La Jolla, CA 92093-0244, USA.
Center for Tropical Paleoecology and Archeology,
Smithsonian Tropical Research Institute,
Republic of Panama.
Michael Kirby,
Scripps Institution of Oceanography,
University of California,
San Diego, La Jolla, CA 92093-0244, USA.
Hunter Lenihan,
University of North Carolina at Chapel Hill,
Institute of Marine Science,
Morehead City, NC 28557, USA.
Bruce Bourque,
Department of Anthropology,
Bates College,
Lewiston, ME 14240, USA.
Roger Bradbury,
Centre for Resource and Environmental Studies,
Australian National University,
Canberra, ACT 0200, Australia.
Richard Cooke,
Center for Tropical Paleoecology and Archeology,
Smithsonian Tropical Research Institute,
Republic of Panama.
Susan Kidwell
Department of Geophysical Sciences,
University of Chicago,
Chicago, IL 60637, USA
*To whom correspondence should be addressed. E-mail: cpeters@email.unc.edu
Science -- Boesch et al. 293 (5535): 1589c
file:///C|/Documents and Settings/Administrator/Des... 2001/Science -- Boesch et al_ 293 (5535) 1589c.htm (4 of 5) [1/23/2002 10:49:43 AM]
References and Notes
H. S. Lenihan, C. H. Peterson, Ecol. Appl. 8, 128 (1998).1.  
H. S. Lenihan et al., Limnol. Oceanogr. 44, 910 (1999).2.  
R. Zimmerman et al., NOAA Tech. Memo. NMFS-SEFC-249 (1989).3.  
M. A. Luckenbach, R. Mann, J. E. Wesson, Eds., Oyster Reef Restoration: A Symposium and
Synthesis of Approaches (Virginia Institute of Marine Sciences Press, Gloucester Point, VA,
1998).
4.  
dEbates: Submit a response to this
article
Related articles in Science
Similar articles found in:
SCIENCE Online
Search Medline for articles by:
Boesch, D. || Kidwell, S.
Alert me when:
new articles cite this article
Download to Citation Manager
Related articles in Science:
Historical Overfishing and the Recent Collapse of Coastal Ecosystems.
Jeremy B. C. Jackson, Michael X. Kirby, Wolfgang H. Berger, Karen A. Bjorndal, Louis W.
Botsford, Bruce J. Bourque, Roger H. Bradbury, Richard Cooke, Jon Erlandson, James A. Estes,
Terence P. Hughes, Susan Kidwell, Carina B. Lange, Hunter S. Lenihan, John M. Pandolfi,
Charles H. Peterson, Robert S. Steneck, Mia J. Tegner, and Robert R. Warner
Science 2001 293: 629-637. (in Review) [Abstract] [Full Text]  
Volume 293, Number 5535, Issue of 31 Aug 2001, pp. 1589-1591.
Copyright ? 2001 by The American Association for the Advancement of Science. All rights reserved.
Sign up for Job Alerts! STKE
Science -- Boesch et al. 293 (5535): 1589c
file:///C|/Documents and Settings/Administrator/Des... 2001/Science -- Boesch et al_ 293 (5535) 1589c.htm (5 of 5) [1/23/2002 10:49:43 AM]