Abstract

Although numerous studies have reported the negative effects of shrimp aquaculture on water quality, little is known about the ecological effects of these practices in coastal lagoons and near-shore marine habitats. The impact of shrimp-farm effluents on the food webs of an impacted subtropical coastal lagoon in the Gulf of California was evaluated through measurements of isotopic (delta C-13, delta N-15) signatures in sediments, plants and animals, and compared with the results of a near-pristine reference site. Degradation was manifested in a strong reduction on fish diversity at the perturbed site. delta C-13 signatures provided ambiguous evidence of degradation while delta N-15 was a better descriptor of shrimp-farm effluent impact on coastal lagoon food webs. The site receiving nutrient-rich discharges showed significant enrichment of delta N-15 (approximate to 5 parts per thousand) in sediments, macroalgae, benthic algae, filterfeeders and omnivorous feeders, resulting in qualitative differences in foodweb structure between both lagoons. The food web in the perturbed site was sustained by sediment detritus and dominated by opportunistic species. The lowest influence on delta N-15 signatures by aquaculture discharges recorded in the upper trophic levels could be explained by the shift in the composition of biotic communities, and associated feeding strategies. While alterations in resource availability do not affect directly food chain length, trophic linkages between food web compartments can be reduced as a result of shrimp farm impacts. Our study demonstrates that nutrient-enriched discharges from shrimp-farm aquaculture generate changes in the availability of food sources, which reduce biodiversity and alter structural and functional food web characteristics. (C) 2011 Elsevier B.V. All rights reserved.

Keywords

Anthropogenic stress; Coastal lagoons; Ecosystem ecology; Gulf of California; Stable isotopes; Trophic relationships

Published in

Journal of Experimental Marine Biology and Ecology
2011, Volume: 402, number: 1-2, pages: 65-74
Publisher: ELSEVIER SCIENCE BV

SLU Authors

• Angeler, David

  • Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences
    

Sustainable Development Goals

SDG6 Ensure availability and sustainable management of water and sanitation for all
SDG15 Protect, restore and promote sustainable use of terrestrial ecosystems, sustainably manage forests, combat desertification, and halt and reverse land degradation and halt biodiversity loss
SDG14 Conserve and sustainably use the oceans, seas and marine resources for sustainable development


UKÄ Subject classification

Fish and Aquacultural Science


Publication identifier

DOI: https://doi.org/10.1016/j.jembe.2011.03.019

Permanent link to this page (URI)

https://res.slu.se/id/publ/59211