Sea lice as a density-dependent constraint to salmonid farming.
Summary of "Sea lice as a density-dependent constraint to salmonid farming."
Fisheries catches worldwide have shown no increase over the last two decades, while aquaculture has been booming. To cover the demand for fish in the growing human population, continued high growth rates in aquaculture are needed. A potential constraint to such growth is infectious diseases, as disease transmission rates are expected to increase with increasing densities of farmed fish. Using an extensive dataset from all farms growing salmonids along the Norwegian coast, we document that densities of farmed salmonids surrounding individual farms have a strong effect on farm levels of parasitic sea lice and efforts to control sea lice infections. Furthermore, increased intervention efforts have been unsuccessful in controlling elevated infection levels in high salmonid density areas in 2009-2010. Our results emphasize host density effects of farmed salmonids on the population dynamics of sea lice and suggest that parasitic sea lice represent a potent negative feedback mechanism that may limit sustainable spatial densities of farmed salmonids.
Affiliation
Norwegian Veterinary Institute, PO Box 750 Sentrum, 0106 Oslo, Norway. peder.jansen@vetinst.no
Journal Details
This article was published in the following journal.
Name: Proceedings. Biological sciences / The Royal Society
ISSN: 1471-2954
Pages: 2330-8
Links
- PubMed Source: http://www.ncbi.nlm.nih.gov/pubmed/22319130
- DOI: http://dx.doi.org/10.1098/rspb.2012.0084
Medical and Biotech [MESH] Definitions
Lice
A general name for small, wingless, parasitic insects, previously of the order Phthiraptera. Though exact taxonomy is still controversial, they can be grouped in the orders ANOPLURA (sucking lice), MALLOPHAGA (biting lice), and Rhynchophthirina (elephant-lice).
Phthiraptera
An order of small, wingless parasitic insects, commonly known as lice. The suborders include ANOPLURA (sucking lice); AMBLYCERA; ISCHNOCERA; and Rhynchophthirina (elephant and warthog lice).
Piscirickettsiaceae Infections
Infections with bacteria of the family PISCIRICKETTSIACEAE, causing septicemic disease of salmonid fish (SALMONIDAE). Piscirickettsia-like bacteria are also associated with disease syndromes in non-salmonid fish.
Mallophaga
An order of insects comprising the chewing lice or biting lice, many of which are parasitic on wild birds and domestic fowl and on wild and domestic mammals. Suborders include Amblycera and Ischnocera.
Centrifugation, Density Gradient
Separation of particles according to density by employing a gradient of varying densities. At equilibrium each particle settles in the gradient at a point equal to its density. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
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