Baselines and degradation of coral reefs in the Northern Line Islands.
Effective conservation requires rigorous baselines of pristine conditions to assess the impacts of human activities and to evaluate the efficacy of management. Most coral reefs are moderately to severely degraded by local human activities such as fishing and pollution as well as global change, hence it is difficult to separate local from global effects. To this end, we surveyed coral reefs on uninhabited atolls in the northern Line Islands to provide a baseline of reef community structure, and on increasingly populated atolls to document changes associated with human activities. We found that top predators and reef-building organisms dominated unpopulated Kingman and Palmyra, while small planktivorous fishes and fleshy algae dominated the populated atolls of Tabuaeran and Kiritimati. Sharks and other top predators overwhelmed the fish assemblages on Kingman and Palmyra so that the biomass pyramid was inverted (top-heavy). In contrast, the biomass pyramid at Tabuaeran and Kiritimati exhibited the typical bottom-heavy pattern. Reefs without people exhibited less coral disease and greater coral recruitment relative to more inhabited reefs. Thus, protection from overfishing and pollution appears to increase the resilience of reef ecosystems to the effects of global warming.
Sandin
Stuart A
SA
Center for Marine Biodiversity and Conservation, Scripps Institution of Oceanography, La Jolla, California, USA.
Smith
Jennifer E
JE
Demartini
Edward E
EE
Dinsdale
Elizabeth A
EA
Donner
Simon D
SD
Friedlander
Alan M
AM
Konotchick
Talina
T
Malay
Machel
M
Maragos
James E
JE
Obura
David
D
Pantos
Olga
O
Paulay
Gustav
G
Richie
Morgan
M
Rohwer
Forest
F
Schroeder
Robert E
RE
Walsh
Sheila
S
Jackson
Jeremy B C
JB
Knowlton
Nancy
N
Sala
Enric
E
D000818:Animals; D037421:Anthozoa; D018533:Biomass; D003247:Conservation of Natural Resources; D017753:Ecosystem; D056890:Eukaryota; D005399:Fishes; D005843:Geography; D017752:Greenhouse Effect; D014873:Water Pollutants
D014873:Water Pollutants