Document Type
Article
Department/Program
Virginia Institute of Marine Science
Publication Date
2004
Journal
MARINE ECOLOGY PROGRESS SERIES
Volume
269
First Page
49
Last Page
59
Abstract
The fitness or population growth rate of populations with Allee effects increases with increasing population size or density up to a certain threshold. Allee effects are possible in marine populations, as they are less open than has been assumed and may have a metapopulation structure. We modelled the population consequences of Allee effects and show that increases in mortality interact with critical Allee thresholds, such that an Allee effect with no population consequences at low mortality can drive a population to extinction when mortality is increased. In heavily fished species, populations with strong Allee effects go extinct at lower levels of fishing mortality, or conversely as fishing mortality increases, weaker Allee effects can drive population to extinction. We found little empirical evidence in the literature for widespread Allee effects in marine populations, although we found some suggestive observations, particularly for broadcast spawners and in exploited populations This might be due to methodological problems or long time lags. Many marine species have components of their life history or ecology which could in theory generate Allee effects; however the population level consequences of these potential mechanisms remains virtually unexplored. We suggest that including Allee effects in models of vulnerable populations may be critical for the precautionary management of exploited and threatened marine species.
DOI
10.3354/meps269049
Keywords
Allee effects; positive density dependence; inverse density dependence; depensation
Recommended Citation
Gascoigne, J and Lipcius, Rom, Allee effects in marine systems (2004). MARINE ECOLOGY PROGRESS SERIES, 269, 49-59.
10.3354/meps269049
