Global Change

Project Title: Extrinsic and Intrinsic Factors Affecting the Resilience of Corals to Climate Change, and Their Use in Designing Marine Reserves

Principal Investigator: Charles Birkeland, USGS Hawaii Cooperative Fishery Research Unit

Introduction

The management of marine biological resources differs from that of terrestrial biological resources in that the adults of coral-reef communities, including fishes, are relatively stationary, and the placement of populations is determined by the movement and selection of the larval stages in the life histories. In terrestrial systems, the adults usually have the capability of relocating and choosing the spot to deposit eggs or raise offspring. In the marine environment, the critical decision is to determine where to focus the effort to save the source populations. To do this, the managers need to know what local aspects of the physical environment ameliorate the effects of global climate change. To put realistic limits on the time frame and on the thresholds of abilities of the key organisms, it is necessary to determine the mechanisms of acclimatization and the capacity for adaptation of the organisms. We have made substantial progress towards these objectives.

The focus and the overall goals of this project were developed in conjunction with NPSA staff to address the National Park Service’s management needs in the face of sustained elevated seawater temperatures and high irradiance levels that are likely to occur due to global warming. The first two long-term goals of the USGS BRD Climate Change Science Program is to “determine the sensitivity and response of ecosystems and ecological processes to environmental factors, including existing impacts at the local, landscape and continental level” and “to assess and predict how future environmental conditions may affect structure, function and long-term viability of natural and human impacted ecosystems”.

• What are the pathways by which previous experience with sublethal stress allows corals to acclimatize and become better prepared physiologically for additional stress?
  
• Is selection strong enough that adaptation to local environmental stresses can occur under usual levels of connectivity?
  
• How does the physical environment (e.g., climate/ocean interactions, local water motion, shade) enhance the ability of corals to endure thermal stress in some localities more than others?
  
• How is the capacity of coral communities to recover affected by initial community composition (e.g., branching, massive or mixed species) and by morphological characteristics of the reef (e.g., topographic complexity and solidified substrata)?

Contact Information

Charles Birkeland
USGS Hawaii Cooperative Fishery Research Unit
Department of Zoology, University of Hawaii
Honolulu, Hawaii 96822
Phone: 808-956-8350
E-mail: charlesb@hawaii.edu