Emergence of anoxia in the California current large marine ecosystem.

Eastern boundary current systems are among the world's most productive large marine ecosystems. Because upwelling currents transport nutrient-rich but oxygen-depleted water onto shallow seas, large expanses of productive continental shelves can be vulnerable to the risk of extreme low-oxygen events. Here, we report the novel rise of water-column shelf anoxia in the northern California Current system, a large marine ecosystem with no previous record of such extreme oxygen deficits. The expansion of anoxia highlights the potential for rapid and discontinuous ecosystem change in productive coastal systems that sustain a major portion of the world's fisheries.

Coastal oceanography sets the pace of rocky intertidal community dynamics.

The structure of ecological communities reflects a tension among forces that alter populations. Marine ecologists previously emphasized control by locally operating forces (predation, competition, and disturbance), but newer studies suggest that inputs from large-scale oceanographically modulated subsidies (nutrients, particulates, and propagules) can strongly influence community structure and dynamics. On New Zealand rocky shores, the magnitude of such subsidies differs profoundly between contrasting oceanographic regimes. Community structure, and particularly the pace of community dynamics, differ dramatically between intermittent upwelling regimes compared with relatively persistent down-welling regimes. We suggest that subsidy rates are a key determinant of the intensity of species interactions, and thus of structure in marine systems, and perhaps also nonmarine communities.

Ecology. The value of nature and the nature of value.

Ecosystems are capital assets: When properly managed, they yield a flow of vital goods and services. Relative to other forms of capital, however, ecosystems are poorly understood, scarcely monitored, and--in many important cases--undergoing rapid degradation. The process of economic valuation could greatly improve stewardship. This potential is now being realized with innovative financial instruments and institutional arrangements.

Effect of aquaculture on world fish supplies.

Global production of farmed fish and shellfish has more than doubled in the past 15 years. Many people believe that such growth relieves pressure on ocean fisheries, but the opposite is true for some types of aquaculture. Farming carnivorous species requires large inputs of wild fish for feed. Some aquaculture systems also reduce wild fish supplies through habitat modification, wild seedstock collection and other ecological impacts. On balance, global aquaculture production still adds to world fish supplies; however, if the growing aquaculture industry is to sustain its contribution to world fish supplies, it must reduce wild fish inputs in feed and adopt more ecologically sound management practices.

Fine-scale variability of lanosol and its disulfate ester in the temperate red algaNeorhodomela larix.

Aqueous extraction and HPLC separation techniques were used to quantify two major bromophenols naturally present in the red algaNeorhodomela larix: lanosol (2,3-dibromo-4,5-dihydroxybenzyl alcohol) and its 1,4-disulfate ester. Maximum concentrations of each compound were as high as 1.5% on a wet mass basis. The within-plant distributions of lanosol and its ester were highly variable on centimeter scales: adjacent portions often varied by an order of magnitude in bromophenol content. Some bromophenol variation was related to algal phase, location within the algal thallus, and reproductive status. Bromophenol concentrations were higher in exterior vegetative regions and some reproductive structures (cystocarps and tetrasporangial branchlets) than in interior vegetative regions or male reproductive structures (spermatangial stichidia). In contrast to results reported for harvestedN. larix, there was no evidence that the intactin situ algae released either compound into seawater.