Goals & Mission

The INTERNATIONAL CONSORTIUM FOR RESEARCH ON UPWELLING MARINE BIOGEOGRAPHIC AREAS:
Integration of science, training and outreach missions

The International Consortium for Research on Upwelling Marine Biogeographic Areas is a group of research teams in marine ecology at five universities located on three continents and one large island in both the northern and southern hemispheres. The unifying theme of the Consortium is the integrative study of the functioning of coastal ecosystems in rocky intertidal and shallow subtidal communities and the waters bathing them out to about 10 km offshore. In particular, each group studies multiple local communities that span a range of oceanographic conditions across stretches of coastline ranging to several hundred km in length.

Individual groups within the Consortium have developed comparable lines of research that deal with the links between benthic and pelagic ecosystems. Comprehensive datasets now exist for a host of processes and conditions along all these coasts, and thanks to previous exchanges and workshops, the general methods utilized to gather data in each region are closely similar. The ICORUMBA is a unique organization in marine ecosystem science; we know of no other comparable international organization focused on ecology and oceanography that covers such an extensive geographic scope. Since climate change is a global phenomenon, a global strategy of scientific study of the ecological consequences of such change seems essential.

Coastal Ecosystems: “Canaries in the coal mine” for global marine ecosystems?

Coastal marine ecosystems are the most productive areas of the world’s oceans, and in part because of this and their proximity to the densest human populations, they are also the most heavily impacted by human activity. Because coastal ecosystems are highly dynamic, discerning whether or not changes have occurred or are occurring and predicting their trajectories can be problematic. Studies of the ICORUMBA (and PISCO) have been focused on alleviating the relatively poor understanding of how coastal ecosystems are affected by oceanographic-climatic processes. A particularly important “black box” of marine ecology worldwide has been the magnitude and importance of the exchange of organic and inorganic materials between ecological intertidal and subtidal communities onshore and the adjacent oceanic waters.

With efforts from other researchers, ICORUMBA research suggests that three kinds of linkage are critical:

• nutrients for growth of macrophytes and phytoplankton,
• particulate food for filter-feeding invertebrates (phytoplankton and detritus)
• propagules for replenishment of populations of marine organisms.

These factors are crucially dependent on the nature of coastal alongshore and cross-shelf currents and other transport processes, and the extent to which they carry water and particles to and from the shore (e.g., “downwelling” and “upwelling,” “tidal bores,” “eddys”). Studies in South Africa, for example, have shown that over continental scales (1000’s of km), that nutrients, macrophyte and phytoplankton productivity, and average biomass of filter feeders and grazers all decline along a gradient of high to low upwelling from west to south to east along the coast (Bustamante et al. 1995). Similarly, studies along the Oregon coast suggest that among sites, predation, grazing, growth of filter-feeders, prey recruitment, and phytoplankton concentration are all positively correlated and that high values of each are associated with high rates of retention of upwelled water near the coast (Menge et al. 1997, Menge 2000, Menge et al. 2004). Comparable results with some variation in specific details have been documented in Chile (Navarrete et al. 2004), New Zealand (Menge et al. 1999, Menge et al. 2003), and southern California (Blanchette et al. 2004, Menge et al. 2004). Clearly, coastal pelagic and benthic systems can be closely coupled, but because of variation in specific details we do not yet have a clear understanding of which ocean-benthic links are universal and which vary among sites, regions and hemispheres as a consequence of different spatial/temporal scales or specific characteristics of each system. This is the integrative goal of the ICORUMBA.

The urgency of gaining such understanding is suggested by recent unprecedented changes along the Oregon coast. In summer 2002, a “hypoxic” event, or period of oxygen levels so low as to generate mass die-offs of marine organisms such as fish, crabs and other invertebrates, occurred over an 820 km2 sector of the central Oregon coast (Grantham et al. 2004). While hypoxic events in coastal ecosystems are known from other regions (e.g., natural events are a characteristic feature off South Africa-Namibia and Chile; human-caused events have occurred in the Gulf of Mexico near the mouth of the Mississippi River)(Rabalais 2002, Rabalais et al. 2002, Bakun and Weeks 2004), to our knowledge they have never been recorded along the US west coast. Putting ICORUMBA/PISCO efforts together with those of oceanographers studying the US west coast, the OSU group realized that the changes observed were actually a relatively local expression of a much larger-scale phenomenon involving a massive southward intrusion of exceptionally cold, salty, and low O2 sub-Arctic water from the north Pacific. The edges of this mass of water were moved onto the continental shelf along the Oregon coast by an unusually long upwelling event, and its naturally low O2 concentrations were driven into hypoxia by bacterial decomposition of dead sinking cells, a process that uses oxygen. The source of the dead cells is the unusually dense phytoplankton blooms generated by the nutrient inputs from the strong upwelling. Hypoxia has returned each of the last two summers (2003, 2004) suggesting the possibility of a major and persistent shift in oceanographic conditions in the north Pacific. Another hint of change in such events is that in South Africa, hypoxic events may be increasing in frequency (Pitcher and Calder 2000).

We believe that the occurrence of large-scale events, such as the hypoxic events off Oregon, or El Niño events along the eastern Pacific, as well as the inevitability of climate change over the next decades, argue strongly for redoubled efforts to understand coastal ecosystem dynamics. We also believe that we, the ICORUMBA (and PISCO) already have developed important insights into how these systems work, at least at the scale of each region (US west coast, Chile, New Zealand, South Africa). Our current focus is on integrating and synthesizing our understanding so that we can provide a platform for future, more coordinated advances in studying pattern, process and change in these ecosystems.

Literature Cited

Bakun, A. and S. J. Weeks. 2004. Greenhouse gas buildup, sardines, submarine eruptions and the possibility of abrupt degradation of intense marine upwelling ecosystems. Ecology Letters 7:1015-1023.

Blanchette, C. A., S. D. Gaines, and B. S. T. Helmuth. 2004. Extreme spatial variation in the distribution, abundance and growth of the intertidal dominant, Mytilus californianus, around Point Conception CA. (unpublished MS).

Bustamante, R. H., G. M. Branch, S. Eekhout, B. Robertson, P. Zoutendyk, M. Schleyer, A. Dye, N. Hanekom, D. Keats, M. Jurd, and C. McQuaid. 1995. Gradients of intertidal primary productivity around the coast of South Africa and their relationships with consumer biomass. Oecologia 102:189-201.

Grantham, B. A., F. Chan, K. J. Nielsen, D. S. Fox, J. A. Barth, A. Huyer, J. Lubchenco, and B. A. Menge. 2004. Upwelling-driven nearshore hypoxia signals ecosystem and oceanographic changes in the Northeast Pacific. Nature 429:749-754.

Menge, B. A. 2000. Top-down and bottom-up community regulation in marine rocky intertidal habitats. Journal of Experimental Marine Biology and Ecology 250:257-289.

Menge, B. A., C. A. Blanchette, P. Raimondi, T. L. Freidenburg, S. D. Gaines, J. Lubchenco, D. Lohse, G. Hudson, M. M. Foley, and J. Pamplin. 2004. Species interaction strength: testing model predictions along an upwelling gradient. Ecological Monographs 74:(in press).

Menge, B. A., B. A. Daley, J. Lubchenco, E. Sanford, E. Dahlhoff, P. M. Halpin, G. Hudson, and J. L. Burnaford. 1999. Top-down and bottom-up regulation of New Zealand rocky intertidal communities. Ecological Monographs 69:297-330.

Menge, B. A., B. A. Daley, P. A. Wheeler, E. Dahlhoff, E. Sanford, and P. T. Strub. 1997. Benthic-pelagic links and rocky intertidal communities: bottom-up effects on top-down control? Proceedings of the National Academy of Sciences, USA 94:14530-14535.

Menge, B. A., J. Lubchenco, M. E. S. Bracken, F. Chan, M. M. Foley, T. L. Freidenburg, S. D. Gaines, G. Hudson, C. Krenz, H. Leslie, D. N. L. Menge, R. Russell, and M. S. Webster. 2003. Coastal oceanography set the pace of rocky intertidal community dynamics. Proceedings of the National Academy of Science, USA 100:12229-12234.

Navarrete, S. A., B. R. Broitman, and E. A. Wieters. 2004. Oceanographic control of species interactions over regional scales: setting the limits to ecological generalization. unpublished manuscript.

Pitcher, G. C., and D. Calder. 2000. Harmful algal blooms of the southern Benguela Current: a review and appraisal of monitoring from 1989 to 1997. South African Journal of Marine Science-Suid-Afrikaanse Tydskrif Vir Seewetenskap 22:255-271.

Rabalais, N. N., R.E. Turner, Q. Dortch, D. Justic, V.J. Bierman Jr. and W.J. Wiseman Jr. 2002. Nutrient-enhanced productivity in the northern Gulf of Mexico: past, present and future. Hydrobiologia 475/476:39-63.

Rabalais, N. N., R. E. Turner, and W. J. Wiseman, Jr. 2002. Hypoxia in the Gulf of Mexico, a.k.a. "The Dead Zone." Annual Review of Ecology and Systematics 33:235-263.