Trophic responses to nutrient enrichment in a temperate seagrass food chain

Bivalve production and food chain efficiency in an experimental nursery system

Journal of the Marine Biological Association of the United Kingdom ◽

10.1017/s0025315400046038 ◽

1981 ◽

Vol 61 (1) ◽

pp. 243-256 ◽

Cited By ~ 21

Author(s):

P. G. Rodhouse ◽

B. Ottway ◽

G. M. Burnell

Keyword(s):

Conversion Efficiency ◽

Food Chain ◽

Nutrient Enrichment ◽

Algal Blooms ◽

Grazing Pressure ◽

Nitrogen Conversion

An experiment was performed to assess the productivity, food chain efficiency and nitrogen conversion efficiency of a semi-closed nursery system for bivalve spat held in upwelling columns. Algal blooms were encouraged by nutrient enrichment of onshore tanks and maintained for short periods under grazing pressure from bivalves.

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The dynamics of food chains under climate change and nutrient enrichment

Philosophical Transactions of the Royal Society B Biological Sciences ◽

10.1098/rstb.2012.0230 ◽

2012 ◽

Vol 367 (1605) ◽

pp. 2935-2944 ◽

Cited By ~ 103

Author(s):

Amrei Binzer ◽

Christian Guill ◽

Ulrich Brose ◽

Björn C. Rall

Keyword(s):

Food Chain ◽

Nutrient Enrichment ◽

Biodiversity Loss ◽

Low Fertility ◽

Interactive Effects ◽

Large Species ◽

Negative Effects ◽

Food Web Structure ◽

Population Dynamic Model ◽

The Individual

Warming has profound effects on biological rates such as metabolism, growth, feeding and death of organisms, eventually affecting their ability to survive. Using a nonlinear bioenergetic population-dynamic model that accounts for temperature and body-mass dependencies of biological rates, we analysed the individual and interactive effects of increasing temperature and nutrient enrichment on the dynamics of a three-species food chain. At low temperatures, warming counteracts the destabilizing effects of enrichment by both bottom-up (via the carrying capacity) and top-down (via biological rates) mechanisms. Together with increasing consumer body masses, warming increases the system tolerance to fertilization. Simultaneously, warming increases the risk of starvation for large species in low-fertility systems. This effect can be counteracted by increased fertilization. In combination, therefore, two main drivers of global change and biodiversity loss can have positive and negative effects on food chain stability. Our model incorporates the most recent empirical data and may thus be used as the basis for more complex forecasting models incorporating food-web structure.

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